From f2dd33afad979c4b4cc316f7a74ab81e33d51af0 Mon Sep 17 00:00:00 2001 From: Dan Foreman-Mackey Date: Wed, 25 Jan 2023 11:11:41 -0500 Subject: [PATCH] Removing abstracts from .bib Ref: https://github.com/openjournals/joss-reviews/issues/4475 --- paper/paper.bib | 53 ------------------------------------------------- 1 file changed, 53 deletions(-) diff --git a/paper/paper.bib b/paper/paper.bib index e660618d0..a52b89344 100644 --- a/paper/paper.bib +++ b/paper/paper.bib @@ -31,7 +31,6 @@ @article{astropy2 Year = 2018, Bdsk-Url-1 = {https://doi.org/10.3847/1538-3881/aabc4f}} @article{PyLops, -abstract = {Linear operators and optimisation are at the core of many algorithms used in signal and image processing, remote sensing, and inverse problems. For small to medium-scale problems, existing software packages (e.g., MATLAB, Python numpy and scipy) allow for explicitly building dense (or sparse) matrices and performing algebraic operations (e.g., computation of matrix-vector products and manipulation of matrices) with syntax that closely represents their corresponding analytical forms. However, many real application, large-scale operators do not lend themselves to explicit matrix representations, usually forcing practitioners to forego of the convenient linear-algebra syntax available for their explicit-matrix counterparts. PyLops is an open-source Python library providing a flexible and scalable framework for the creation and combination of so-called linear operators, class-based entities that represent matrices and inherit their associated syntax convenience, but do not rely on the creation of explicit matrices. We show that PyLops operators can dramatically reduce the memory load and CPU computations compared to explicit-matrix calculations, while still allowing users to seamlessly use their existing knowledge of compact matrix-based syntax that scales to any problem size because no explicit matrices are required.}, archivePrefix = {arXiv}, arxivId = {1907.12349}, author = {Ravasi, Matteo and Vasconcelos, Ivan}, @@ -42,7 +41,6 @@ @article{PyLops year = {2019} } @article{colossus, -abstract = {This paper introduces Colossus, a public, open-source python package for calculations related to cosmology, the large-scale structure (LSS) of matter in the universe, and the properties of dark matter halos. The code is designed to be fast and easy to use, with a coherent, well-documented user interface. The cosmology module implements Friedman-Lemaitre-Robertson-Walker cosmologies including curvature, relativistic species, and different dark energy equations of state, and provides fast computations of the linear matter power spectrum, variance, and correlation function. The LSS module is concerned with the properties of peaks in Gaussian random fields and halos in a statistical sense, including their peak height, peak curvature, halo bias, and mass function. The halo module deals with spherical overdensity radii and masses, density profiles, concentration, and the splashback radius. To facilitate the rapid exploration of these quantities, Colossus implements more than 40 different fitting functions from the literature. I discuss the core routines in detail, with particular emphasis on their accuracy. Colossus is available at bitbucket.org/bdiemer/colossus.}, archivePrefix = {arXiv}, arxivId = {1712.04512}, author = {Diemer, Benedikt}, @@ -74,7 +72,6 @@ @article{corner journal = {The Journal of Open Source Software} } @article{dynesty, -abstract = {We present dynesty, a public, open-source, python package to estimate Bayesian posteriors and evidences (marginal likelihoods) using the dynamic nested sampling methods developed by Higson et al. By adaptively allocating samples based on posterior structure, dynamic nested sampling has the benefits of Markov chain Monte Carlo (MCMC) algorithms that focus exclusively on posterior estimation while retaining nested sampling's ability to estimate evidences and sample from complex, multimodal distributions. We provide an overview of nested sampling, its extension to dynamic nested sampling, the algorithmic challenges involved, and the various approaches taken to solve them in this and previous work. We then examine dynesty's performance on a variety of toy problems along with several astronomical applications. We find in particular problems dynesty can provide substantial improvements in sampling efficiency compared to popular MCMC approaches in the astronomical literature. More detailed statistical results related to nested sampling are also included in the appendix.}, archivePrefix = {arXiv}, arxivId = {1904.02180}, author = {Speagle, Joshua S}, @@ -91,7 +88,6 @@ @article{dynesty year = {2020} } @article{emcee, -abstract = {We introduce a stable, well tested Python implementation of the affine-invariant ensemble sampler for Markov chain Monte Carlo (MCMC) proposed by Goodman {\&} Weare (2010). The code is open source and has already been used in several published projects in the astrophysics literature. The algorithm behind emcee has several advantages over traditional MCMC sampling methods and it has excellent performance as measured by the autocorrelation time (or function calls per independent sample). One major advantage of the algorithm is that it requires hand-tuning of only 1 or 2 parameters compared to {\$}\backslashsim N{\^{}}2{\$} for a traditional algorithm in an N-dimensional parameter space. In this document, we describe the algorithm and the details of our implementation and API. Exploiting the parallelism of the ensemble method, emcee permits any user to take advantage of multiple CPU cores without extra effort. The code is available online at http://dan.iel.fm/emcee under the MIT License.}, archivePrefix = {arXiv}, arxivId = {1202.3665}, author = {Foreman-Mackey, Daniel and Hogg, David W. and Lang, Dustin and Goodman, Jonathan}, @@ -113,15 +109,11 @@ @article{matplotlib Volume = {9}, Number = {3}, Pages = {90--95}, - abstract = {Matplotlib is a 2D graphics package used for Python for - application development, interactive scripting, and publication-quality - image generation across user interfaces and operating systems.}, publisher = {IEEE COMPUTER SOC}, doi = {10.1109/MCSE.2007.55}, year = 2007 } @article{numba, -abstract = {Dynamic, interpreted languages, like Python, are attractive for domain-experts and scientists experimenting with new ideas. However, the performance of the interpreter is of-ten a barrier when scaling to larger data sets. This paper presents a just-in-time compiler for Python that focuses in scientific and array-oriented computing. Starting with the simple syntax of Python, Numba compiles a subset of the language into efficient machine code that is comparable in performance to a traditional compiled language. In addi-tion, we share our experience in building a JIT compiler using LLVM[1].}, author = {Lam, Siu Kwan and Pitrou, Antoine and Seibert, Stanley}, doi = {10.1145/2833157.2833162}, file = {:home/jammy/Documents/Papers/Software/numba{\_}sc15.pdf:pdf}, @@ -155,7 +147,6 @@ @article{pyautofit journal = {Journal of Open Source Software} } @article{multinest, -abstract = {We present further development and the first public release of our multimodal nested sampling algorithm, called MultiNest. This Bayesian inference tool calculates the evidence, with an associated error estimate, and produces posterior samples from distributions that may contain multiple modes and pronounced (curving) degeneracies in high dimensions. The developments presented here lead to further substantial improvements in sampling efficiency and robustness, as compared to the original algorithm presented in Feroz and Hobson, which itself significantly outperformed existing Markov chain Monte Carlo techniques in a wide range of astrophysical inference problems. The accuracy and economy of the MultiNest algorithm are demonstrated by application to two toy problems and to a cosmological inference problem focusing on the extension of the vanilla $\Lambda$ cold dark matter model to include spatial curvature and a varying equation of state for dark energy. The MultiNest software, which is fully parallelized using MPI and includes an interface to CosmoMC, is available at http://www.mrao.cam.ac.uk/software/multinest/. It will also be released as part of the SuperBayeS package, for the analysis of supersymmetric theories of particle physics, at http://www.superbayes.org. {\textcopyright} 2009 RAS.}, archivePrefix = {arXiv}, arxivId = {0809.3437}, author = {Feroz, F. and Hobson, M. P. and Bridges, M.}, @@ -172,7 +163,6 @@ @article{multinest year = {2009} } @article{pymultinest, -abstract = {Context. Aims. Active galactic nuclei are known to have complex X-ray spectra that depend on both the properties of the accreting super-massive black hole (e.g. mass, accretion rate) and the distribution of obscuring material in its vicinity (i.e. the "torus"). Often however, simple and even unphysical models are adopted to represent the X-ray spectra of AGN, which do not capture the complexity and diversity of the observations. In the case of blank field surveys in particular, this should have an impact on e.g. the determination of the AGN luminosity function, the inferred accretion history of the Universe and also on our understanding of the relation between AGN and their host galaxies. Methods. We develop a Bayesian framework for model comparison and parameter estimation of X-ray spectra. We take into account uncertainties associated with both the Poisson nature of X-ray data and the determination of source redshift using photometric methods. We also demonstrate how Bayesian model comparison can be used to select among ten different physically motivated X-ray spectral models the one that provides a better representation of the observations. This methodology is applied to X-ray AGN in the 4 Ms Chandra Deep Field South. Results. For the {\~{}}350 AGN in that field, our analysis identifies four components needed to represent the diversity of the observed X-ray spectra: (1) an intrinsic power law; (2) a cold obscurer which reprocesses the radiation due to photo-electric absorption, Compton scattering and Fe-K fluorescence; (3) an unabsorbed power law associated with Thomson scattering off ionised clouds; and (4) Compton reflection, most noticeable from a stronger-than-expected Fe-K line. Simpler models, such as a photo-electrically absorbed power law with a Thomson scattering component, are ruled out with decisive evidence (B {\textgreater} 100). We also find that ignoring the Thomson scattering component results in underestimation of the inferred column density, NH, of the obscurer. Regarding the geometry of the obscurer, there is strong evidence against both a completely closed (e.g. sphere), or entirely open (e.g. blob of material along the line of sight), toroidal geometry in favour of an intermediate case. Conclusions. Despite the use of low-count spectra, our methodology is able to draw strong inferences on the geometry of the torus. Simpler models are ruled out in favour of a geometrically extended structure with significant Compton scattering. We confirm the presence of a soft component, possibly associated with Thomson scattering off ionised clouds in the opening angle of the torus. The additional Compton reflection required by data over that predicted by toroidal geometry models, may be a sign of a density gradient in the torus or reflection off the accretion disk. Finally, we release a catalogue of AGN in the CDFS with estimated parameters such as the accretion luminosity in the 2-10 keV band and the column density, NH, of the obscurer. {\textcopyright} ESO, 2014.}, archivePrefix = {arXiv}, arxivId = {1402.0004}, author = {Buchner, J. and Georgakakis, A. and Nandra, K. and Hsu, L. and Rangel, C. and Brightman, M. and Merloni, A. and Salvato, M. and Donley, J. and Kocevski, D.}, @@ -188,7 +178,6 @@ @article{pymultinest year = {2014} } @article{pynufft, -abstract = {A Python non-uniform fast Fourier transform (PyNUFFT) package has been developed to accelerate multidimensional non-Cartesian image reconstruction on heterogeneous platforms. Since scientific computing with Python encompasses a mature and integrated environment, the time efficiency of the NUFFT algorithm has been a major obstacle to real-time non-Cartesian image reconstruction with Python. The current PyNUFFT software enables multi-dimensional NUFFT accelerated on a heterogeneous platform, which yields an efficient solution to many non-Cartesian imaging problems. The PyNUFFT also provides several solvers, including the conjugate gradient method, 1 total variation regularized ordinary least square (L1TV-OLS), and 1 total variation regularized least absolute deviation (L1TV-LAD). Metaprogramming libraries have been employed to accelerate PyNUFFT. The PyNUFFT package has been tested on multi-core central processing units (CPUs) and graphic processing units (GPUs), with acceleration factors of 6.3–9.5× on a 32-thread CPU platform and 5.4–13× on a GPU.}, author = {Lin, Jyh Miin}, doi = {10.3390/jimaging4030051}, file = {:home/jammy/Documents/Papers/Software/jimaging-04-00051-v2.pdf:pdf}, @@ -265,7 +254,6 @@ @article{scipy doi = {10.1038/s41592-019-0686-2}, } @article{Alexander2019, -abstract = {Dark matter substructure has the potential to discriminate between broad classes of dark matter models. With this in mind, we construct novel solutions to the equations of motion governing condensate dark matter candidates, namely axion Bose-Einstein condensates and superfluids. These solutions are highly compressed along one axis and thus have a disk-like geometry. We discuss linear stability of these solutions, consider the astrophysical implications as a large-scale dark disk or as small scale substructure, and find a characteristic signal in strong gravitational lensing. This adds to the growing body of work that indicates that the morphology of dark matter substructure is a powerful probe of the nature of dark matter.}, archivePrefix = {arXiv}, arxivId = {1901.03694}, author = {Alexander, Stephon and Bramburger, Jason J. and McDonough, Evan}, @@ -281,7 +269,6 @@ @article{Alexander2019 year = {2019} } @article{Bolton2012, -abstract = {We present an analysis of the evolution of the central mass-density profile of massive elliptical galaxies from the SLACS and BELLS strong gravitational lens samples over the redshift interval z ≈ 0.1-0.6, based on the combination of strong-lensing aperture mass and stellar velocity-dispersion constraints. We find a significant trend toward steeper mass profiles (parameterized by the power-law density model with $\rho$ ∝ r-$\gamma$) at later cosmic times, with magnitude d 〈$\gamma$〉/dz = -0.60 ± 0.15. We show that the combined lens-galaxy sample is consistent with a non-evolving distribution of stellar velocity dispersions. Considering possible additional dependence of 〈$\gamma$〉 on lens-galaxy stellar mass, effective radius, and S{\'{e}}rsic index, we find marginal evidence for shallower mass profiles at higher masses and larger sizes, but with a significance that is subdominant to the redshift dependence. Using the results of published Monte Carlo simulations of spectroscopic lens surveys, we verify that our mass-profile evolution result cannot be explained by lensing selection biases as a function of redshift. Interpreted as a true evolutionary signal, our result suggests that major dry mergers involving off-axis trajectories play a significant role in the evolution of the average mass-density structure of massive early-type galaxies over the past 6Gyr. We also consider an alternative non-evolutionary hypothesis based on variations in the strong-lensing measurement aperture with redshift, which would imply the detection of an "inflection zone" marking the transition between the baryon-dominated and dark-matter halo-dominated regions of the lens galaxies. Further observations of the combined SLACS+BELLS sample can constrain this picture more precisely, and enable a more detailed investigation of the multivariate dependences of galaxy mass structure across cosmic time. {\textcopyright} 2012. The American Astronomical Society. All rights reserved.}, archivePrefix = {arXiv}, arxivId = {1201.2988}, author = {Bolton, Adam S. and Brownstein, Joel R. and Kochanek, Christopher S. and Shu, Yiping and Schlegel, David J. and Eisenstein, Daniel J. and Wake, David A. and Connolly, Natalia and Maraston, Claudia and Arneson, Ryan A. and Weaver, Benjamin A.}, @@ -298,7 +285,6 @@ @article{Bolton2012 year = {2012} } @article{Collett2015, -abstract = {Ongoing and future imaging surveys represent significant improvements in depth, area, and seeing compared to current data sets. These improvements offer the opportunity to discover up to three orders of magnitude more galaxy-galaxy strong lenses than are currently known. In this work we forecast the number of lenses that will be discoverable in forthcoming surveys and simulate their properties. We generate a population of statistically realistic strong lenses and simulate observations of this population for the Dark Energy Survey (DES), the Large Synoptic Survey Telescope (LSST), and Euclid surveys. We verify our model against the galaxy-scale lens search of the Canada-France-Hawaii Telescope Legacy Survey, predicting 250 discoverable lenses compared to 220 found by Gavazzi et al. The predicted Einstein radius distribution is also remarkably similar to that found by Sonnenfeld et al. For future surveys we find that, assuming Poisson limited lens galaxy subtraction, searches of the DES, LSST, and Euclid data sets should discover 2400, 120000, and 170000 galaxy-galaxy strong lenses, respectively. Finders using blue-minus-red (g - i) difference imaging for lens subtraction can discover 1300 and 62000 lenses in DES and LSST. The uncertainties on the model are dominated by the high-redshift source population, which typically gives fractional errors on the discoverable lens number at the level of tens of percent. We find that doubling the signal-to-noise ratio required for a lens to be detectable approximately halves the number of detectable lenses in each survey, indicating the importance of understanding the selection function and the sensitivity of future lens finders in interpreting strong lens statistics. We make our population forecasting and simulated observation codes publicly available so that the selection function of strong lens finders can easily be calibrated.}, archivePrefix = {arXiv}, arxivId = {1507.02657}, author = {Collett, Thomas E.}, @@ -315,7 +301,6 @@ @article{Collett2015 year = {2015} } @article{Czoske2012, -abstract = {This paper presents the full Very Large Telescope (VLT)/VIMOS-IFU data set and related data products from an ESO Large Programme with the observational goal of obtaining two-dimensional kinematic data of early-type lens galaxies, out to one effective radius. The sample consists of 17 early-type galaxies (ETGs) selected from the SLACS gravitational-lens survey. The galaxies cover the redshift range from 0.08 to 0.35 and have stellar velocity dispersions between 200 and 350 kms-1. This programme is complemented by a similar observational programme on Keck, using long-slit spectroscopy. In combination with multi-band imaging data, the kinematic data provide stringent constraints on the inner mass profiles of ETGs beyond the local Universe. Our Large Programme thus extends studies of nearby ETGs (e.g. SAURON/ATLAS3D) by an order of magnitude in distance and towards higher masses. We provide an overview of our observational strategy, the data products (luminosity-weighted spectra andHubble Space Telescopeimages) and derived products (i.e. two-dimensional fields of velocity dispersions and streaming motions) that have been used in a number of published and forthcoming lensing, kinematic and stellar-population studies. These studies also pave the way for future studies of ETGs atz≈ 1 with the upcoming extremely large telescopes. {\textcopyright} 2011 The Authors MNRAS {\textcopyright} 2011 RAS.}, archivePrefix = {arXiv}, arxivId = {1108.0577}, author = {Czoske, Oliver and Barnab{\`{e}}, Matteo and Koopmans, L{\'{e}}on V.E. and Treu, Tommaso and Bolton, Adam S.}, @@ -331,7 +316,6 @@ @article{Czoske2012 year = {2012} } @article{Dye2014, -abstract = {We have determined the mass density radial profiles of the first five strong gravitational lens systems discovered by the Herschel Astrophysical Terahertz Large Area Survey. We present an enhancement of the semilinear lens inversion method of Warren {\&} Dye which allows simultaneous reconstruction of several different wavebands and apply this to dual-band imaging of the lenses acquired with the Hubble Space Telescope. The five systems analysed here have lens redshifts which span a range 0.22 ≤ z ≤ 0.94. Our findings are consistent with other studies by concluding that: (1) the logarithmic slope of the total mass density profile steepens with decreasing redshift; (2) the slope is positively correlated with the average total projected mass density of the lens contained within half the effective radius and negatively correlated with the effective radius; (3) the fraction of dark matter contained within half the effective radius increases with increasing effective radius and increases with redshift. {\textcopyright} 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.}, archivePrefix = {arXiv}, arxivId = {1311.5893}, author = {Dye, S. and Negrello, M. and Hopwood, R. and Nightingale, J. W. and Bussmann, R. S. and Amber, S. and Bourne, N. and Cooray, A. and Dariush, A. and Dunne, L. and Eales, S. A. and Gonzalez-Nuevo, J. and Ibar, E. and Ivison, R. J. and Maddox, S. and Valiante, E. and Smith, M.}, @@ -347,7 +331,6 @@ @article{Dye2014 year = {2014} } @article{Enia2018, -abstract = {We perform lens modelling and source reconstruction of Sub-millimetre Array2D (SMA) data for a sample of 12 strongly lensed galaxies selected at 500$\mu$m in the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). A previous analysis of the same data set used a single S{\'{e}}rsic profile to model the light distribution of each background galaxy. Here we model the source brightness distribution with an adaptive pixel scale scheme, extended to work in the Fourier visibility space of interferometry. We also present new SMA observations for seven other candidate lensed galaxies from theH-ATLAS sample. Our derived lens model parameters are in general consistent with previous findings. However, our estimated magnification factors, ranging from 3 to 10, are lower. The discrepancies are observed in particular where the reconstructed source hints at the presence of multiple knots of emission.We define an effective radius of the reconstructed sources based on the area in the source plane where emission is detected above 5s. We also fit the reconstructed source surface brightness with an elliptical Gaussian model. We derive a median value reff {\~{}} 1.77 kpc and a median Gaussian full width at half-maximum {\~{}}1.47 kpc. After correction for magnification, our sources have intrinsic star formation rates (SFR) {\~{}} 900-3500M⊙ yr-1, resulting in a median SFR surface density $\Sigma$SFR {\~{}} 132M⊙ yr-1 kpc-2 (or {\~{}}218M⊙ yr-1 kpc-2 for the Gaussian fit). This is consistent with that observed for other star-forming galaxies at similar redshifts, and is significantly below the Eddington limit for a radiation pressure regulated starburst.}, archivePrefix = {arXiv}, arxivId = {1801.01831}, author = {Enia, A. and Negrello, M. and Gurwell, M. and Dye, S. and Rodighiero, G. and Massardi, M. and {De Zotti}, G. and Franceschini, A. and Cooray, A. and van der Werf, P. and Birkinshaw, M. and Michalowski, M. J. and Oteo, I.}, @@ -365,7 +348,6 @@ @article{Enia2018 year = {2018} } @article{Hermans2019, -abstract = {Posterior inference with an intractable likelihood is becoming an increasingly common task in scientific domains which rely on sophisticated computer simulations. Typically, these mechanistic models do not admit tractable densities forcing practitioners to rely on approximations during inference. This work proposes a novel approach to address the intractability of the likelihood and the marginal model. We achieve this by learning a flexible estimator which approximates the likelihood-to-evidence ratio. The resulting amortized ratio estimator is embedded in MCMC samplers such as Metropolis-Hastings and Hamiltonian Monte Carlo to approximate the likelihood-ratio between consecutive states in the Markov chain, allowing us to draw samples from the intractable posterior. Techniques are presented to improve the numerical stability. We demonstrate our approach on a variety of benchmarks and compare against well-established approximate inference techniques. Scientific applications in high energy and astrophysics with high-dimensional observations show its applicability.}, archivePrefix = {arXiv}, arxivId = {1903.04057}, author = {Hermans, Joeri and Begy, Volodimir and Louppe, Gilles}, @@ -377,7 +359,6 @@ @article{Hermans2019 year = {2019} } @article{Koopmans2009, -abstract = {Based on 58 SLACS strong-lens early-type galaxies (ETGs) with direct total-mass and stellar-velocity dispersion measurements, we find that inside one effective radius massive elliptical galaxies with M eff ≳ 3 × 1010 M⊙ are well approximated by a power-law ellipsoid, with an average logarithmic density slope of 〈$\gamma$′ LD〉 ≡ -dlog($\rho$tot)/dlog(r) = 2.085 +0.025-0.018 (random error on mean) for isotropic orbits with $\beta$r = 0, 0.1 (syst.) and intrinsic scatter (all errors indicate the 68{\%} CL). We find no correlation of $\gamma$′LD with galaxy mass (M eff), rescaled radius (i.e., R einst/R eff) or redshift, despite intrinsic differences in density-slope between galaxies. Based on scaling relations, the average logarithmic density slope can be derived in an alternative manner, fully independent from dynamics, yielding 〈$\gamma$′SR〉 = 1.959 0.077. Agreement between the two values is reached for 〈$\beta$r〉 = 0.45 0.25, consistent with mild radial anisotropy. This agreement supports the robustness of our results, despite the increase in mass-to-light ratio with total galaxy mass: M eff L 1.3630.056V,eff. We conclude that massive ETGs are structurally close to homologous with close to isothermal total density profiles (≲10{\%} intrinsic scatter) and have at most some mild radial anisotropy. Our results provide new observational limits on galaxy formation and evolution scenarios, covering 4 Gyr look-back time. {\textcopyright} 2009. The American Astronomical Society.}, archivePrefix = {arXiv}, arxivId = {0906.1349}, author = {Koopmans, L. V.E. and Bolton, A. and Treu, T. and Czoske, O. and Auger, M. W. and Barnab{\`{e}}, M. and Vegetti, S. and Gavazzi, R. and Moustakas, L. A. and Burles, S.}, @@ -395,7 +376,6 @@ @article{Koopmans2009 year = {2009} } @article{McCully2014, -abstract = {In strong gravitational lens systems, the light bending is usually dominated by one main galaxy, but may be affected by other mass along the line of sight (LOS). Shear and convergence can be used to approximate the contributions from less significant perturbers (e.g. those that are projected far from the lens or have a small mass), but higher order effects need to be included for objects that are closer or more massive. We develop a framework for multiplane lensing that can handle an arbitrary combination of tidal planes treated with shear and convergence and planes treated exactly (i.e. including higher order terms). This framework addresses all of the traditional lensing observables including image positions, fluxes, and time delays to facilitate lens modelling that includes the non-linear effects due to mass along the LOS. It balances accuracy (accounting for higher order terms when necessary) with efficiency (compressing all other LOS effects into a set of matrices that can be calculated up front and cached for lens modelling). We identify a generalized multiplane mass sheet degeneracy, in which the effective shear and convergence are sums over the lensing planes with specific, redshift-dependent weighting factors. {\textcopyright} 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.}, archivePrefix = {arXiv}, arxivId = {1401.0197}, author = {McCully, Curtis and Keeton, Charles R. and Wong, Kenneth C. and Zabludoff, Ann I.}, @@ -412,7 +392,6 @@ @article{McCully2014 year = {2014} } @article{Negrello2014, -abstract = {We report on deep near-infrared observations obtained with the Wide Field Camera-3 (WFC3) onboard the Hubble Space Telescope (HST) of the first five confirmed gravitational lensing events discovered by the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). We succeed in disentangling the background galaxy from the lens to gain separate photometry of the two components. The HST data allow us to significantly improve on previous constraints of the mass in stars of the lensed galaxy and to perform accurate lens modelling of these systems, as described in the accompanying paper by Dye et al. We fit the spectral energy distributions of the background sources from near-IR to millimetre wavelengths and use the magnification factors estimated by Dye et al. to derive the intrinsic properties of the lensed galaxies. We find these galaxies to have star-formations rates (SFR) {\~{}} 400-2000 M⊙ yr-1, with {\~{}}(6-25) × 1010 M⊙ of their baryonic mass already turned into stars. At these rates of star formation, all remaining molecular gas will be exhausted in less than {\~{}}100 Myr, reaching a final mass in stars of a few 1011 M⊙. These galaxies are thus proto-ellipticals caught during their major episode of star formation, and observed at the peak epoch (z {\~{}} 1.5-3) of the cosmic star formation history of the Universe.}, archivePrefix = {arXiv}, arxivId = {1311.5898}, author = {Negrello, M. and Hopwood, R. and Dye, S. and da Cunha, E. and Serjeant, S. and Fritz, J. and Rowlands, K. and Fleuren, S. and Bussmann, R. S. and Cooray, A. and Dannerbauer, H. and Gonzalez-Nuevo, J. and Lapi, A. and Omont, A. and Amber, S. and Auld, R. and Baes, M. and Buttiglione, S. and Cava, A. and Danese, L. and Dariush, A. and {De Zotti}, G. and Dunne, L. and Eales, S. and Ibar, E. and Ivison, R. J. and Kim, S. and Leeuw, L. and Maddox, S. and Michalowski, M. J. and Massardi, M. and Pascale, E. and Pohlen, M. and Rigby, E. and Smith, D. J.B. and Sutherland, W. and Temi, P. and Wardlow, J.}, @@ -429,7 +408,6 @@ @article{Negrello2014 year = {2014} } @article{Nightingale2015, -abstract = {We present a new pixelized method for the inversion of gravitationally lensed extended source images which we term adaptive semi-linear inversion (SLI). At the heart of the method is an h-means clustering algorithm which is used to derive a source plane pixelization that adapts to the lens model magnification. The distinguishing feature of adaptive SLI is that every pixelization is derived from a random initialization, ensuring that data discretization is performed in a completely different and unique way for every lens model parameter set. We compare standard SLI on a fixed source pixel grid with the new method and demonstrate the shortcomings of the former when modelling singular power-law ellipsoid (SPLE) lens profiles. In particular, we demonstrate the superior reliability and efficiency of adaptive SLI which, by design, fixes the number of degrees of freedom (NDOF) of the optimization and thereby removes biases present with other methods that allow the NDOF to vary. In addition, we highlight the importance of data discretization in pixel-based inversion methods, showing that adaptive SLI averages over significant systematics that are present when a fixed source pixel grid is used. In the case of the SPLE lens profile, we show how the method successfully samples its highly degenerate posterior probability distribution function with a single nonlinear search. The robustness of adaptive SLI provides a firm foundation for the development of a strong lens modelling pipeline, which will become necessary in the short-term future to cope with the increasing rate of discovery of new strong lens systems.}, archivePrefix = {arXiv}, arxivId = {1412.7436}, author = {Nightingale, J. W. and Dye, S.}, @@ -446,7 +424,6 @@ @article{Nightingale2015 year = {2015} } @article{Nightingale2018, -abstract = {This work presents AutoLens, the first entirely automated modeling suite for the analysis of galaxy-scale strong gravitational lenses. AutoLens simultaneously models the lens galaxy's light and mass whilst reconstructing the extended source galaxy on an adaptive pixel-grid. The method's approach to source-plane discretization is amorphous, adapting its clustering and regularization to the intrinsic properties of the lensed source. The lens's light is fitted using a superposition of Sersic functions, allowing AutoLens to cleanly deblend its light from the source. Single-component mass models representing the lens's total mass density profile are demonstrated, which in conjunction with light modeling can detect central images using a centrally cored profile. Decomposed mass modeling is also shown, which can fully decouple a lens's light and dark matter and determine whether the two components are geometrically aligned. The complexity of the light and mass models is automatically chosen via Bayesian model comparison. These steps form AutoLens's automated analysis pipeline, such that all results in this work are generated without any user intervention. This is rigorously tested on a large suite of simulated images, assessing its performance on a broad range of lens profiles, source morphologies, and lensing geometries. The method's performance is excellent, with accurate light, mass, and source profiles inferred for data sets representative of both existing Hubble imaging and future Euclid wide-field observations.}, archivePrefix = {arXiv}, arxivId = {1708.07377}, author = {Nightingale, J. W. and Dye, S. and Massey, Richard J.}, @@ -464,7 +441,6 @@ @article{Nightingale2018 year = {2018} } @article{Nightingale2019, -abstract = {We investigate how strong gravitational lensing can test contemporary models of massive elliptical (ME) galaxy formation, by combining a traditional decomposition of their visible stellar distribution with a lensing analysis of their mass distribution. As a proof of concept, we study a sample of three ME lenses, observing that all are composed of two distinct baryonic structures, a 'red' central bulge surrounded by an extended envelope of stellar material. Whilst these two components look photometrically similar, their distinct lensing effects permit a clean decomposition of their mass structure. This allows us to infer two key pieces of information about each lens galaxy: (i) the stellar mass distribution (without invoking stellar populations models) and (ii) the inner dark matter halo mass. We argue that these two measurements are crucial to testing models of ME formation, as the stellar mass profile provides a diagnostic of baryonic accretion and feedback whilst the dark matter mass places each galaxy in the context of LCDM large-scale structure formation. We also detect large rotational offsets between the two stellar components and a lopsidedness in their outer mass distributions, which hold further information on the evolution of each ME. Finally, we discuss how this approach can be extended to galaxies of all Hubble types and what implication our results have for studies of strong gravitational lensing.}, archivePrefix = {arXiv}, arxivId = {1901.07801}, author = {Nightingale, J. W. and Massey, Richard J. and Harvey, David R. and Cooper, Andrew P. and Etherington, Amy and Tam, Sut Ieng and Hayes, Richard G.}, @@ -482,7 +458,6 @@ @article{Nightingale2019 year = {2019} } @article{Sonnenfeld2015, -abstract = {We investigate the cosmic evolution of the internal structure of massive early-type galaxies over half of the age of the universe. We perform a joint lensing and stellar dynamics analysis of a sample of 81 strong lenses from the Strong Lensing Legacy Survey and Sloan ACS Lens Survey and combine the results with a hierarchical Bayesian inference method to measure the distribution of dark matter mass and stellar initial mass function (IMF) across the population of massive early-type galaxies. Lensing selection effects are taken into account. We find that the dark matter mass projected within the inner 5 kpc increases for increasing redshift, decreases for increasing stellar mass density, but is roughly constant along the evolutionary tracks of early-type galaxies. The average dark matter slope is consistent with that of a Navarro-Frenk-White profile, but is not well constrained. The stellar IMF normalization is close to a Salpeter IMF at log M ∗ = 11.5 and scales strongly with increasing stellar mass. No dependence of the IMF on redshift or stellar mass density is detected. The anti-correlation between dark matter mass and stellar mass density supports the idea of mergers being more frequent in more massive dark matter halos.}, archivePrefix = {arXiv}, arxivId = {1410.1881}, author = {Sonnenfeld, Alessandro and Treu, Tommaso and Marshall, Philip J. and Suyu, Sherry H. and Gavazzi, Rapha{\"{e}}l and Auger, Matthew W. and Nipoti, Carlo}, @@ -499,7 +474,6 @@ @article{Sonnenfeld2015 year = {2015} } @article{Suyu2016, -abstract = {Strong gravitational lens systems with time delays between the multiple images allow measurements of time-delay distances, which are primarily sensitive to the Hubble constant that is key to probing dark energy, neutrino physics and the spatial curvature of the Universe, as well as discovering new physics. We present H0LiCOW (H0 Lenses in COSMOGRAIL's Wellspring), a program that aims to measure H0 with {\textless} 3.5 per cent uncertainty from five lens systems (B1608+656, RXJ1131-1231, HE 0435-1223, WFI2033-4723 and HE 1104-1805). We have been acquiring (1) time delays through COSMOGRAIL and Very Large Array2D monitoring, (2) high-resolution Hubble Space Telescope imaging for the lens mass modelling, (3) wide-field imaging and spectroscopy to characterize the lens environment and (4) moderate-resolution spectroscopy to obtain the stellar velocity dispersion of the lenses for mass modelling. In cosmological models with one-parameter extension to flat $\Lambda$ cold dark matter, we expect to measure H0 to {\textless} 3.5 per cent in most models, spatial curvature $\Omega$k to 0.004, w to 0.14 and the effective number of neutrino species to 0.2 (1$\sigma$ uncertainties) when combined with current cosmic microwave background (CMB) experiments. These are, respectively, a factor of {\~{}}15, {\~{}}2 and {\~{}}1.5 tighter than CMB alone. Our data set will further enable us to study the stellar initial mass function of the lens galaxies, and the co-evolution of supermassive black holes and their host galaxies. This program will provide a foundation for extracting cosmological distances from the hundreds of time-delay lenses that are expected to be discovered in current and future surveys.}, archivePrefix = {arXiv}, arxivId = {1607.00017}, author = {Suyu, S. H. and Bonvin, V. and Courbin, F. and Fassnacht, C. D. and Rusu, C. E. and Sluse, D. and Treu, T. and Wong, K. C. and Auger, M. W. and Ding, X. and Hilbert, S. and Marshall, P. J. and Rumbaugh, N. and Sonnenfeld, A. and Tewes, M. and Tihhonova, O. and Agnello, A. and Blandford, R. D. and Chen, G. C.F. and Collett, T. and Koopmans, L. V.E. and Liao, K. and Meylan, G. and Spiniello, C.}, @@ -517,7 +491,6 @@ @article{Suyu2016 year = {2017} } @article{Treu2009, -abstract = {We study the relation between the internal structure of early-type galaxies and their environment using 70 strong gravitational lenses from the SLACS Survey. The Sloan Digital Sky Survey (SDSS) database is used to determine two measures of overdensity of galaxies around each lens - the projected number density of galaxies inside the tenth nearest neighbor ($\Sigma$10) and within a cone of radius one h -1 Mpc (D 1). Our main results are as follows. (1) The average overdensity is somewhat larger than unity, consistent with lenses preferring overdense environments as expected for massive early-type galaxies (12/70 lenses are in known groups/clusters). (2) The distribution of overdensities is indistinguishable from that of "twin" nonlens galaxies selected from SDSS to have the same redshift and stellar velocity dispersion $\sigma$*. Thus, within our errors, lens galaxies are an unbiased population, and the SLACS results can be generalized to the overall population of early-type galaxies. (3) Typical contributions from external mass distribution are no more than a few percent in local mass density, reaching 10-20{\%} (0.05-0.10 external convergence) only in the most extreme overdensities. (4) No significant correlation between overdensity and slope of the mass-density profile of the lens galaxies is found. (5) Satellite galaxies (those with a more luminous companion) have marginally steeper mass-density profiles (as quantified by f SIE = $\sigma$*/$\sigma$SIE = 1.12 ± 0.05 versus 1.01 ± 0.01) and smaller dynamically normalized mass enclosed within the Einstein radius ($\Delta$log M Ein/M dim differs by -0.09 ± 0.03 dex) than central galaxies (those without). This result suggests that tidal stripping may affect the mass structure of early-type galaxies down to kpc scales probed by strong lensing, when they fall into larger structures. {\textcopyright} 2009. The American Astronomical Society. All rights reserved.}, archivePrefix = {arXiv}, arxivId = {0806.1056}, author = {Treu, Tommaso and Gavazzi, Rapha{\"{e}}l and Gorecki, Alexia and Marshall, Philip J. and Koopmans, L{\'{e}}on V.E. and Bolton, Adam S. and Moustakas, Leonidas A. and Burles, Scott}, @@ -534,7 +507,6 @@ @article{Treu2009 year = {2009} } @article{Vegetti2009, -abstract = {We introduce a new adaptive and fully Bayesian grid-based method to model strong gravitational lenses with extended images. The primary goal of this method is to quantify the level of luminous and dark mass substructure in massive galaxies, through their effect on highly magnified arcs and Einstein rings. The method is adaptive on the source plane, where a Delaunay tessellation is defined according to the lens mapping of a regular grid on to the source plane. The Bayesian penalty function allows us to recover the best non-linear potential-model parameters and/or a grid-based potential correction and to objectively quantify the level of regularization for both the source and potential. In addition, we implement a Nested-Sampling technique to quantify the errors on all non-linear mass model parameters - marginalized over all source and regularization parameters - and allow an objective ranking of different potential models in terms of the marginalized evidence. In particular, we are interested in comparing very smooth lens mass models with ones that contain mass substructures. The algorithm has been tested on a range of simulated data sets, created from a model of a realistic lens system. One of the lens systems is characterized by a smooth potential with a power-law density profile, 12 include a Navarro, Frenk and White (NFW) dark matter substructure of different masses and at different positions and one contains two NFW dark substructures with the same mass but with different positions. Reconstruction of the source and lens potential for all of these systems shows the method is able, in a realistic scenario, to identify perturbations with masses ≳107 M ⊙ when located on the Einstein ring. For positions both inside and outside of the ring, masses of at least 109 M⊙ are required (i.e. roughly the Einstein ring of the perturber needs to overlap with that of the main lens). Our method provides a fully novel and objective test of mass substructure in massive galaxies. {\textcopyright} 2008 RAS.}, archivePrefix = {arXiv}, arxivId = {0805.0201}, author = {Vegetti, S. and Koopmans, L. V.E.}, @@ -552,7 +524,6 @@ @article{Vegetti2009 year = {2009} } @article{Vegetti2014, -abstract = {We present the results of a search for galaxy substructures in a sample of 11 gravitational lens galaxies from the Sloan Lens ACS Survey by Bolton et al. We find no significant detection of mass clumps, except for a luminous satellite in the system SDSS J0956+5110. We use these non-detections, in combination with a previous detection in the system SDSS J0946+1006, to derive constraints on the substructure mass function in massive early-type host galaxies with an average redshift zlens {\~{}}0.2 and an average velocity dispersion seff {\~{}}270 km s-1. We perform a Bayesian inference on the substructure mass function, within a median region of about 32 kpc2 around the Einstein radius (Rein {\~{}}4.2 kpc). We infer a mean projected substructure mass fraction f = 0.0076+0.0208-0.0052 at the 68 per cent confidence level and a substructure mass function slopea {\textless} 2.93 at the 95 per cent confidence level for a uniform prior probability density on a. For a Gaussian prior based on cold dark matter (CDM) simulations, we infer f = 0.0064+0.0080-0.0042 and a slope of a =1.90+0.098-0.098 at the 68 per cent confidence level. Since only one substructure was detected in the full sample, we have little information on the mass function slope, which is therefore poorly constrained (i.e. the Bayes factor shows no positive preference for any of the two models). The inferred fraction is consistent with the expectations from CDM simulations and with inference from flux ratio anomalies at the 68 per cent confidence level. {\textcopyright} 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.}, archivePrefix = {arXiv}, arxivId = {1405.3666}, author = {Vegetti, S. and Koopmans, L. V.E. and Auger, M. W. and Treu, T. and Bolton, A. S.}, @@ -569,7 +540,6 @@ @article{Vegetti2014 year = {2014} } @article{Atek2015, -abstract = {Exploiting the power of gravitational lensing, the Hubble Frontier Fields (HFF) program aims at observing six massive galaxy clusters to explore the distant universe far beyond the limits of blank field surveys. Using the complete Hubble Space Telescope observations of the first HFF cluster A2744, we report the detection of 50 galaxy candidates at z ∼ 7 and eight candidates at z ∼ 8 in a total survey area of 0.96 arcmin2 in the source plane. Three of these galaxies are multiply imaged by the lensing cluster. Using an updated model of the mass distribution in the cluster we were able to calculate the magnification factor and the effective survey volume for each galaxy in order to compute the ultraviolet galaxy luminosity function (LF) at both redshifts 7 and 8. Our new measurements reliably extend the z ∼ 7 UV LF down to an absolute magnitude of MUV ∼ -15.5. We find a characteristic magnitude of M∗UV = -20.90-0.73+0.90 mag and a faint-end slope $\alpha$ = -2.01-0.28+0.20,close to previous determinations in blank fields. We show here for the first time that this slope remains steep down to very faint luminosities of 0.01 L∗. Although prone to large uncertainties, our results at z ∼ 8 also seem to confirm a steep faint-end slope below 0.1 L∗. The HFF program is therefore providing an extremely efficient way to study the faintest galaxy populations at z {\textgreater} 7 that would otherwise be inaccessible with current instrumentation. The full sample of six galaxy clusters will provide even better constraints on the buildup of galaxies at early epochs and their contribution to cosmic reionization.}, archivePrefix = {arXiv}, arxivId = {1409.0512}, author = {Atek, Hakim and Richard, Johan and Kneib, Jean Paul and Jauzac, Mathilde and Schaerer, Daniel and Clement, Benjamin and Limousin, Marceau and Jullo, Eric and Natarajan, Priyamvada and Egami, Eiichi and Ebeling, Harald}, @@ -585,7 +555,6 @@ @article{Atek2015 year = {2015} } @article{Jullo2010, -abstract = {Current efforts in observational cosmology are focused on characterizing the mass-energy content of the universe. We present results from a geometric test based on strong lensing in galaxy clusters. Based on Hubble Space Telescope images and extensive ground-based spectroscopic follow-up of the massive galaxy cluster Abell 1689, we used a parametric model to simultaneously constrain the cluster mass distribution and dark energy equation of state. Combining our cosmological constraints with those from x-ray clusters and the Wilkinson Microwave Anisotropy Probe 5-year data gives $\Omega$m = 0.25 ±0.05 and Wx = -0.97 ±0.07, which are consistent with results from other methods. Inclusion of our method with all other available techniques brings down the current 2$\sigma$ contours on the dark energy equation-of-state parameter wx by ∼30{\%}.}, archivePrefix = {arXiv}, arxivId = {1008.4802}, author = {Jullo, Eric and Natarajan, Priyamvada and Kneib, Jean Paul and D'Aloisio, Anson and Limousin, Marceau and Richard, Johan and Schimd, Carlo}, @@ -601,7 +570,6 @@ @article{Jullo2010 year = {2010} } @article{Richard2014, -abstract = {Extending over three Hubble Space Telescope (HST) cycles, the Hubble Frontier Fields (HFF) initiative constitutes the largest commitment ever of HST time to the exploration of the distant Universe via gravitational lensing by massive galaxy clusters. Here, we present models of the mass distribution in the six HFF cluster lenses, derived from a joint strong- and weak-lensing analysis anchored by a total of 88 multiple-image systems identified in existing HST data. The resulting maps of the projected mass distribution and of the gravitational magnification effectively calibrate the HFF clusters as gravitational telescopes. Allowing the computation of search areas in the source plane, these maps are provided to the community to facilitate the exploitation of forthcoming HFF data for quantitative studies of the gravitationally lensed population of background galaxies. Our models of the gravitational magnification afforded by the HFF clusters allow us to quantify the lensing-induced boost in sensitivity over blank-field observations and predict that galaxies at z {\textgreater} 10 and as faint as m(AB) = 32 will be detectable, up to 2 mag fainter than the limit of the Hubble Ultra Deep Field.}, author = {Richard, Johan and Jauzac, Mathilde and Limousin, Marceau and Jullo, Eric and Cl{\'{e}}ment, Benjamin and Ebeling, Harald and Kneib, Jean Paul and Atek, Hakim and Natarajan, Priya and Egami, Eiichi and Livermore, Rachael and Bower, Richard}, doi = {10.1093/mnras/stu1395}, file = {:home/jammy/Documents/Papers/StrongLensCluster/Richard2017HFFModels.pdf:pdf}, @@ -623,14 +591,12 @@ @article{Powell2020 pages = {515-530}, year = {2020}, month = {09}, - abstract = "{We present a new gravitational lens modelling technique designed to model high-resolution interferometric observations with large numbers of visibilities without the need to pre-average the data in time or frequency. We demonstrate the accuracy of the method using validation tests on mock observations. Using small data sets with ∼103 visibilities, we first compare our approach with the more traditional direct Fourier transform (DFT) implementation and direct linear solver. Our tests indicate that our source inversion is indistinguishable from that of the DFT. Our method also infers lens parameters to within 1 to 2 per cent of both the ground truth and DFT, given sufficiently high signal-to-noise ratio (SNR). When the SNR is as low as 5, both approaches lead to errors of several tens of per cent in the lens parameters and a severely disrupted source structure, indicating that this is related to the SNR and choice of priors rather than the modelling technique itself. We then analyse a large data set with ∼108 visibilities and a SNR matching real global Very Long Baseline Interferometry observations of the gravitational lens system MG J0751+2716. The size of the data is such that it cannot be modelled with traditional implementations. Using our novel technique, we find that we can infer the lens parameters and the source brightness distribution, respectively, with an RMS error of 0.25 and 0.97 per cent relative to the ground truth.}", issn = {0035-8711}, doi = {10.1093/mnras/staa2740}, url = {https://doi.org/10.1093/mnras/staa2740}, eprint = {https://academic.oup.com/mnras/article-pdf/501/1/515/35069118/staa2740.pdf}, } @article{Birrer2018a, -abstract = {We present lenstronomy, a multi-purpose open-source gravitational lens modelling pythonpackage. lenstronomy is able to reconstruct the lens mass and surface brightness distributions of strong lensing systems using forward modelling. lenstronomy supports a wide range of analytic lens and light models in arbitrary combination. The software is also able to reconstruct complex extended sources (Birrer et. al 2015) as well as being able to model point sources. We designed lenstronomy to be stable, flexible and numerically accurate, with a clear user interface that could be deployed across different platforms. Throughout its development, we have actively used lenstronomy to make several measurements including deriving constraints on dark matter properties in strong lenses, measuring the expansion history of the universe with time-delay cosmography, measuring cosmic shear with Einstein rings and decomposing quasar and host galaxy light. The software is distributed under the MIT license. The documentation, starter guide, example notebooks, source code and installation guidelines can be found at https://lenstronomy.readthedocs.io.}, archivePrefix = {arXiv}, arxivId = {1803.09746}, author = {Birrer, Simon and Amara, Adam}, @@ -668,7 +634,6 @@ @ARTICLE{spilker16a adsnote = {Provided by the SAO/NASA Astrophysics Data System} } @article{Haussler2013, -abstract = {In this paper, we demonstrate a new method for fitting galaxy profiles which makes use of the full multiwavelength data provided by modern large optical-near-infrared imaging surveys. We present a new version of GALAPAGOS, which utilizes a recently developed multiwavelength version of GALFIT, and enables the automated measurement of wavelength-dependent S{\'{e}}rsic profile parameters for very large samples of galaxies. Our newtechnique is extensively tested to assess the reliability of both pieces of software, GALFIT and GALAPAGOS on both real ugrizY JHK imaging data from the Galaxy And Mass Assembly survey and simulated data made to the same specifications. We find that fitting galaxy light profiles with multiwavelength data increases the stability and accuracy of the measured parameters, and hence produces more complete and meaningful multiwavelength photometry than has been available previously. The improvement is particularly significant for magnitudes in low-S/N bands and for structural parameters like half-light radius re and S{\'{e}}rsic index n for which a prior is used by constraining these parameters to a polynomial as a function of wavelength. This allows the fitting routines to push the magnitude of galaxies for which sensible values can be derived to fainter limits. The technique utilizes a smooth transition of galaxy parameters with wavelength, creating more physically meaningful transitions than single-band fitting and allows accurate interpolation between passbands, perfect for derivation of rest-frame values. {\textcopyright} 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.}, archivePrefix = {arXiv}, arxivId = {1212.3332}, author = {H{\"{a}}u{\ss}ler, Boris and Bamford, Steven P. and Vika, Marina and Rojas, Alex L. and Barden, Marco and Kelvin, Lee S. and Alpaslan, Mehmet and Robotham, Aaron S.G. and Driver, Simon P. and Baldry, I. K. and Brough, Sarah and Hopkins, Andrew M. and Liske, Jochen and Nichol, Robert C. and Popescu, Cristina C. and Tuffs, Richard J.}, @@ -685,7 +650,6 @@ @article{Haussler2013 year = {2013} } @article{Ding2021, -abstract = {Galight is a Python-based open-source package that can be used to perform two-dimensional model fitting of optical and near-infrared images to characterize the light distribution of galaxies with components including a disk, bulge, bar, and quasar. The decomposition of stellar components has been demonstrated in published studies of inactive galaxies and quasar host galaxies observed by the Hubble Space Telescope and Subaru's Hyper Suprime-Cam. Galight utilizes the image modeling capabilities of lenstronomy while redesigning the user interface for the analysis of large samples of extragalactic sources. The package is user-friendly with some automatic features such as determining the cutout size of the modeling frame, searching for PSF-stars in field-of-view, estimating the noise map of the data, identifying all the objects to set the initial model, and associated parameters to fit them simultaneously. These features minimize the manpower and allow the automatic fitting tasks. The software is distributed under the MIT license. The source code, installation guidelines, and example notebooks code can be found at https://galight.readthedocs.io/en/latest/}, archivePrefix = {arXiv}, arxivId = {2111.08721}, author = {Ding, Xuheng and Birrer, Simon and Treu, Tommaso and Silverman, John D.}, @@ -698,7 +662,6 @@ @article{Ding2021 year = {2021} } @article{Peng2002, -abstract = {We present a two-dimensional (2-D) fitting algorithm (GALFIT) designed to extract structural components from galaxy images, with emphasis on closely modeling light profiles of spatially well-resolved, nearby galaxies observed with the Hubble Space Telescope. Our algorithm improves on previous techniques in two areas, by being able to simultaneously fit a galaxy with an arbitrary number of components, and with optimization in computation speed, suited for working on large galaxy images. We use 2-D models such as the ``Nuker'' law, the Sersic (de Vaucouleurs) profile, an exponential disk, and Gaussian or Moffat functions. The azimuthal shapes are generalized ellipses that can fit disky and boxy components. Many galaxies with complex isophotes, ellipticity changes, and position-angle twists can be modeled accurately in 2-D. When examined in detail, we find that even simple-looking galaxies generally require at least three components to be modeled accurately, rather than the one or two components more often employed. We illustrate this by way of 7 case studies, which include regular and barred spiral galaxies, highly disky lenticular galaxies, and elliptical galaxies displaying various levels of complexities. A useful extension of this algorithm is to accurately extract nuclear point sources in galaxies. We compare 2-D and 1-D extraction techniques on simulated images of galaxies having nuclear slopes with different degrees of cuspiness, and we then illustrate the application of the program to several examples of nearby galaxies with weak nuclei.}, archivePrefix = {arXiv}, arxivId = {astro-ph/0204182}, author = {Peng, Chien Y. and Ho, Luis C. and Impey, Chris D. and Rix, Hans-Walter}, @@ -716,7 +679,6 @@ @article{Peng2002 year = {2002} } @article{Robotham2017, -abstract = {We present PROFIT, a new code for Bayesian two-dimensional photometric galaxy profile modelling. PROFIT consists of a low-level C++ library (libprofit), accessible via a command-line interface and documented API, along with high-level R (PROFIT) and PYTHON (PyProFit) interfaces (available at github.com/ICRAR/libprofit, github.com/ICRAR/ProFit, and github.com/ICRAR/pyprofit, respectively). R PROFIT is also available pre-built from CRAN; however, this version will be slightly behind the latest GitHub version. libprofit offers fast and accurate two-dimensional integration for a useful number of profiles, including S{\'{e}}rsic, Core-S{\'{e}}rsic, broken-exponential, Ferrer, Moffat, empirical King, point-source, and sky, with a simple mechanism for adding new profiles. We show detailed comparisons between libprofit and GALFIT. libprofit is both faster and more accurate than GALFIT at integrating the ubiquitous S{\'{e}}rsic profile for the most common values of the S{\'{e}}rsic index n (0.5 < n < 8). The high-level fitting code PROFIT is tested on a sample of galaxies with both SDSS and deeper KiDS imaging. We find good agreement in the fit parameters, with larger scatter in best-fitting parameters from fitting images from different sources (SDSS versus KiDS) than from using different codes (PROFIT versus GALFIT). A large suite of Monte Carlo-simulated images are used to assess prospects for automated bulge-disc decomposition with PROFIT on SDSS, KiDS, and future LSST imaging. We find that the biggest increases in fit quality come from moving from SDSS- to KiDS-quality data, with less significant gains moving from KiDS to LSST.}, archivePrefix = {arXiv}, arxivId = {1611.08586}, author = {Robotham, A. S.G. and Taranu, D. S. and Tobar, R. and Moffett, A. and Driver, S. P.}, @@ -733,7 +695,6 @@ @article{Robotham2017 year = {2017} } @article{Erwin2015, -abstract = {I describe a new, open-source astronomical image-fitting program called imfit, specialized for galaxies but potentially useful for other sources, which is fast, flexible, and highly extensible. A key characteristic of the program is an object-oriented design that allows new types of image components (two-dimensional surfacebrightness functions) to be easily written and added to the program. Image functions provided with imfit include the usual suspects for galaxy decompositions (S{\'{e}}rsic, exponential, Gaussian), along with Core-S{\'{e}}rsic and brokenexponential profiles, elliptical rings, and three components that perform line-of-sight integration through threedimensional luminosity-density models of disks and rings seen at arbitrary inclinations. Available minimization algorithms include Levenberg-Marquardt, Nelder-Mead simplex, and Differential Evolution, allowing trade-offs between speed and decreased sensitivity to local minima in the fit landscape. Minimization can be done using the standard $\chi$2 statistic (using either data or model values to estimate per-pixel Gaussian errors, or else user-supplied error images) or Poisson-based maximum-likelihood statistics; the latter approach is particularly appropriate for cases of Poisson data in the low-count regime. I show that fitting low-signal-to-noise ratio galaxy images using $\chi$2 minimization and individual-pixel Gaussian uncertainties can lead to significant biases in fitted parameter values, which are avoided if a Poisson-based statistic is used; this is true even when Gaussian read noise is present.}, archivePrefix = {arXiv}, arxivId = {1408.1097}, author = {Erwin, Peter}, @@ -749,7 +710,6 @@ @article{Erwin2015 year = {2015} } @article{Vehtari2020, -abstract = {A common divide-and-conquer approach for Bayesian computation with big data is to partition the data, perform local inference for each piece separately, and combine the results to obtain a global posterior approximation. While being conceptually and computationally appealing, this method involves the problematic need to also split the prior for the local inferences; these weakened priors may not provide enough regularization for each separate computation, thus eliminating one of the key advantages of Bayesian methods. To resolve this dilemma while still retaining the generalizability of the underlying local inference method, we apply the idea of expectation propagation (EP) as a framework for distributed Bayesian inference. The central idea is to iteratively update approximations to the local likelihoods given the state of the other approximations and the prior. The present paper has two roles: we review the steps that are needed to keep EP algorithms numerically stable, and we suggest a general approach, inspired by EP, for approaching data partitioning problems in a way that achieves the computational benefits of parallelism while allowing each local update to make use of relevant information from the other sites. In addition, we demonstrate how the method can be applied in a hierarchical context to make use of partitioning of both data and parameters. The paper describes a general algorithmic framework, rather than a specific algorithm, and presents an example implementation for it.}, archivePrefix = {arXiv}, arxivId = {1412.4869}, author = {Vehtari, Aki and Gelman, Andrew and Sivula, Tuomas and Jyl{\"{a}}nki, Pasi and Tran, Dustin and Sahai, Swupnil and Blomstedt, Paul and Cunningham, John P. and Schiminovich, David and Robert, Christian P.}, @@ -764,7 +724,6 @@ @article{Vehtari2020 year = {2020} } @article{VanDerWel2012, -abstract = {We present global structural parameter measurements of 109,533 unique, H{\_}F160W-selected objects from the CANDELS multi-cycle treasury program. Sersic model fits for these objects are produced with GALFIT in all available near-infrared filters (H{\_}F160W, J{\_}F125W and, for a subset, Y{\_}F105W). The parameters of the best-fitting Sersic models (total magnitude, half-light radius, Sersic index, axis ratio, and position angle) are made public, along with newly constructed point spread functions for each field and filter. Random uncertainties in the measured parameters are estimated for each individual object based on a comparison between multiple, independent measurements of the same set of objects. To quantify systematic uncertainties we create a mosaic with simulated galaxy images with a realistic distribution of input parameters and then process and analyze the mosaic in an identical manner as the real data. We find that accurate and precise measurements -- to 10{\%} or better -- of all structural parameters can typically be obtained for galaxies with H{\_}F160W {\textless} 23, with comparable fidelity for basic size and shape measurements for galaxies to H{\_}F160W {\$\sim${}} 24.5.}, archivePrefix = {arXiv}, arxivId = {1211.6954}, author = {{Van Der Wel}, A and Bell, E F and H{\"{a}}ussler, B and McGrath, E J and Chang, Yu Yen and Guo, Yicheng and McIntosh, D H and Rix, H W and Barden, M and Cheung, E and Faber, S M and Ferguson, H C and Galametz, A and Grogin, N A and Hartley, W and Kartaltepe, J S and Kocevski, D D and Koekemoer, A M and Lotz, J and Mozena, M and Peth, M A and Peng, Chien Y}, @@ -779,7 +738,6 @@ @article{VanDerWel2012 year = {2012} } @article{Vulcani2014, -abstract = {We investigate the relationship between colour and structure within galaxies using a large, volume-limited sample of bright, low-redshift galaxies with optical-near-infrared imaging from the Galaxy AndMass Assembly survey.We fit single-component,wavelength-dependent, elliptical S{\'{e}}rsic models to all passbands simultaneously, using software developed by the MegaMorph project. Dividing our sample by n and colour, the recovered wavelength variations in effective radius (Re) and S{\'{e}}rsic index (n) reveal the internal structure, and hence formation history, of different types of galaxies. All these trends depend on n; some have an additional dependence on galaxy colour. Late-type galaxies (nr < 2.5) show a dramatic increase in S{\'{e}}rsic index with wavelength. This might be a result of their two-component (bulge-disc) nature, though stellar population gradients within each component and dust attenuation are likely to play a role. All galaxies show a substantial decrease in Re with wavelength. This is strongest for early types (nr > 2.5), even though they maintain constant n with wavelength, revealing that ellipticals are a superimposition of different stellar populations associated with multiple collapse and merging events. Processes leading to structures with larger Re must be associated with lower metallicity or younger stellar populations. This appears to rule out the formation of young cores through dissipative gas accretion as an important mechanism in the recent lives of luminous elliptical galaxies. {\textcopyright} 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.}, archivePrefix = {arXiv}, arxivId = {1404.0377}, author = {Vulcani, Benedetta and Bamford, Steven P. and H{\"{a}}u{\ss}ler, Boris and Vika, Marina and Rojas, Alex and Agius, Nicola K. and Baldry, Ivan and Bauer, Amanda E. and Brown, Michael J.I. and Driver, Simon and Graham, Alister W. and Kelvin, Lee S. and Liske, Jochen and Loveday, Jon and Popescu, Cristina C. and Robotham, Aaron S.G. and Tuffs, Richard J.}, @@ -796,7 +754,6 @@ @article{Vulcani2014 year = {2014} } @book{Sersic1968, -abstract = {Not Available}, author = {Sersic, J L}, booktitle = {Cordoba}, keywords = {GALAXIES,GROUPS OF GALAXIES,atlases}, @@ -805,7 +762,6 @@ @book{Sersic1968 year = {1968} } @article{Kormendy2015a, -abstract = {Bulge components of disc galaxies are the high-density centers interior to their outer discs. Once thought to be equivalent to elliptical galaxies, their observed properties and formation histories turn out to be richer and more varied than those of ellipticals. This book reviews progress in many areas of bulge studies. Two advances deserve emphasis: (1) Observations divide bulges into "classical bulges" that look indistinguishable from ellipticals and "pseudobulges" that are discier and (except in S0s) more actively star-forming than are ellipticals. Classical bulges and ellipticals are thought to form by major galaxy mergers. Discy pseudobulges are a product of the slow ("secular") evolution of galaxy discs. Nonaxisymmetries such as bars and oval distortions transport some disc gas toward the center, where it starbursts and builds a dense central component that is discier in structure than are classical bulges. Secular evolution explains many regular structures (e.g., rings) seen in galaxy discs. It is a new area of galaxy evolution work that complements hierarchical clustering. (2) Studies of high-redshift galaxies reveal that their discs are so gas-rich that they are violently unstable to the formation of mass clumps that sink to the center and merge. This is an alternative channel for the formation of classical bulges. This chapter summarizes big-picture successes and unsolved problems in the formation of bulges and ellipticals and their coevolution (or not) with supermassive black holes. I present an observer's perspective on simulations of cold dark matter galaxy formation including baryonic physics. Our picture of the quenching of star formation is becoming general and secure at redshifts z < 1. I conclude with a list of major uncertainties and problems. The biggest challenge is to produce realistic bulgesCellipticals and realistic discs that overlap over a factor of >1000 in mass but that differ from each other as we observe over that whole range. A related difficulty is how hierarchical clustering makes so many giant, bulgeless galaxies in field but not cluster environments. I present arguments that we rely too much on star-formation feedback and AGN feedback to solve these challenges.}, archivePrefix = {arXiv}, arxivId = {1504.03330}, author = {Kormendy, John}, @@ -819,7 +775,6 @@ @article{Kormendy2015a year = {2015} } @article{Oh2017, -abstract = {We investigate two-dimensional image decomposition of nearby, morphologically selected early-type galaxies (ETGs). We are motivated by recent observational evidence of significant size growth of quiescent galaxies and theoretical development advocating a two-phase formation scenario for ETGs. We find that a significant fraction of nearby ETGs show changes in isophotal shape that require multi-component models. The characteristic sizes of the inner and outer component are $\sim 3$ and $\sim 15$ kpc. The inner component lies on the mass-size relation of ETGs at $z \sim 0.25-0.75$, while the outer component tends to be more elliptical and hints at a stochastic buildup process. We find real physical differences between the single- and double-component ETGs, with the double-component galaxies being younger and more metal-rich. The fraction of double component ETGs increases with increasing $\sigma$ and decreases in denser environments. We hypothesize that double-component systems were able to accrete gas and small galaxies until later times, boosting their central densities, building up their outer parts, and lowering their typical central ages. In contrast, the oldest galaxies, perhaps due to residing in richer environments, have no remaining hints of their last accretion episode.}, archivePrefix = {arXiv}, arxivId = {1612.06495}, author = {Oh, Semyeong and Greene, Jenny E. and Lackner, Claire N.}, @@ -836,7 +791,6 @@ @article{Oh2017 year = {2017} } @article{Lackner2012, -abstract = {We present a set of bulge-disc decompositions for a sample of 71825 Sloan Digital Sky Survey (SDSS) main-sample galaxies in the redshift range 0.003 {\textless} z {\textless} 0.05. We have fitted each galaxy with either a de Vaucouleurs ('classical') or an exponential ('pseudo-') bulge and an exponential disc. Two-dimensional S{\'{e}}rsic fits are performed when the two-component fits are not statistically significant or when the fits are poor, even in the presence of high signal-to-noise ratio (S/N). We study the robustness of our two-component fits by studying a bright subsample of galaxies and we study the systematics of these fits with decreasing resolution and S/N. Only 30 percent of our sample have been fitted with two-component fits in which both components are non-zero. The g-r and g-i colours of each component for the two-component models are determined using linear templates derived from the r-band model. We attempt a physical classification of types of fits into disc galaxies, pseudo-bulges, classical bulges and ellipticals. Our classification of galaxies agrees well with previous large bulge plus disc (B+D) decomposed samples. Using our galaxy classifications, we find that Petrosian concentration is a good indicator of bulge-to-total ratio, while overall S{\'{e}}rsic index is not. Additionally, we find that the majority of green valley galaxies are bulge+disc galaxies. Furthermore, in the transition from green to red B+D galaxies, the total galaxy colour is most strongly correlated with the disc colour. {\textcopyright}2012 The Authors Monthly Notices of the Royal Astronomical Society {\textcopyright}2012 RAS.}, archivePrefix = {arXiv}, arxivId = {1201.0763}, author = {Lackner, C N and Gunn, J E}, @@ -853,7 +807,6 @@ @article{Lackner2012 year = {2012} } @book{Graham2013, -abstract = {A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in “nebulae.”� This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, disks, and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus, briefly, the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disk ratios, bulgeless galaxies, bars, and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses, and stellar concentrations are presented, many of which are shown to be curved. These “redshift zero” relations not only quantify the behavior and nature of galaxies in the Universe today but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body simulations, or semi-analytical modeling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1. 5 < z < 2. 5 may be the bulges of modern disk galaxies.}, archivePrefix = {arXiv}, arxivId = {1108.0997}, author = {Graham, Alister W.}, @@ -869,7 +822,6 @@ @book{Graham2013 year = {2013} } @article{Coenda2017, -abstract = {We present a comparative analysis of the properties of passive, star-forming and transition (green valley) galaxies in four discrete environments: field, groups, the outskirts and the core of X-ray clusters. We construct samples of galaxies from the Sloan Digital Sky Survey in these environments so that they are bound to have similar redshift distributions. The classification of galaxies into the three sequences is based on theUV-optical colourNUV-r. We study a number of galaxy properties: stellar mass, morphology, specific star formation rate and the history of star formation. The analysis of green valley (GV) galaxies reveals that the physical mechanisms responsible for external quenching become more efficient moving from the field to denser environments. We confirm previous findings thatGVgalaxies have intermediate morphologies; moreover, we find that this appears to be independent of the environment. Regarding the stellar mass of GV galaxies, we find that they tend to be more massive in the field than in denser environments. On average, GV galaxies account for $\sim$20 per cent of all galaxies in groups and X-ray clusters. We find evidence that the field environment is inefficient in transforming lowmass galaxies. GV galaxies have average star formation histories intermediate between passive and star-forming galaxies, and have a clear and consistent dependence on the environment: both, the quenching time and the amplitude of the star formation rate, decrease towards higher density environments.}, archivePrefix = {arXiv}, arxivId = {1710.05928}, author = {Coenda, Valeria and Mart{\'{i}}nez, H{\'{e}}ctor J. and Muriel, Hern{\'{a}}n}, @@ -887,7 +839,6 @@ @article{Coenda2017 year = {2018} } @article{Buitrago2008, -abstract = {We measure the sizes of 82 massive (M{\textgreater}10{\^{}}11 M{\_}sun) galaxies at 1.7{\textless}z{\textless}3 utilizing deep HST NICMOS data taken in the GOODS North and South fields. Our sample is almost an order of magnitude larger than previous studies at these redshifts, providing the first statistical study of massive galaxy sizes at z{\textgreater}2, confirming the extreme compactness of these galaxies. We split our sample into disk-like (n{\textless}2) and spheroid-like (n{\textgreater}2) galaxies based on their Sersic indices, and find that at a given stellar mass disk-like galaxies at z{\$\sim${}}2.3 are a factor of 2.6+/-0.3 smaller than present day equal mass systems, and spheroid-like galaxies at the same redshifts are 4.3+/-0.7 smaller than comparatively massive elliptical galaxies today. At z{\textgreater}2 our results are compatible with both a leveling off, or a mild evolution in size. Furthermore, the high density ({\$\sim${}}2x10{\^{}}10 M{\_}sun kpc{\^{}}-3) of massive galaxies at these redshifts, which are similar to present day globular clusters, possibly makes any further evolution in sizes beyond z=3 unlikely.}, archivePrefix = {arXiv}, arxivId = {0807.4141}, author = {Buitrago, Fernando and Trujillo, Ignacio and Conselice, Christopher J and Bouwens, Rychard J and Dickinson, Mark and Yan, Haojing}, @@ -903,7 +854,6 @@ @article{Buitrago2008 year = {2008} } @article{Blain2002, -abstract = {A cosmologically significant population of very luminous high-redshift galaxies has recently been discovered at submillimeter (submm) wavelengths. Advances in submm detector technologies have opened this new window on the distant Universe. Here we discuss the properties of the high-redshift submm galaxies, their significance for our understanding of the process of galaxy formation, and the selection effects that apply to deep submm surveys. The submm galaxies generate a significant fraction of the energy output of all the galaxies in the early Universe. We emphasize the importance of studying a complete sample of submm galaxies, and stress that because they are typically very faint in other wavebands, these follow-up observations are very challenging. Finally, we discuss the surveys that will be made using the next generation of submm-wave instruments under development. {\textcopyright} 2002 Elsevier Science B.V. All rights reserved.}, archivePrefix = {arXiv}, arxivId = {astro-ph/0202228}, author = {Blain, Andrew W. and Smail, Ian and Ivison, R. J. and Kneib, J. P. and Frayer, David T.}, @@ -921,7 +871,6 @@ @article{Blain2002 year = {2002} } @article{Hodge2019, -abstract = {We present sub-kpc-scale mapping of the 870 $\mu$m ALMA continuum emission in six luminous ($L_{\rm IR}\sim\sim\sim5\sim\times10^{12}$ L$_{\odot}$) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. Our high-fidelity 0.07$''$-resolution imaging ($\sim$500 pc) reveals robust evidence for structures with deconvolved sizes of $\lesssim$0.5-1 kpc embedded within (dominant) exponential dust disks. The large-scale morphologies of the structures within some of the galaxies show clear curvature and/or clump-like structures bracketing elongated nuclear emission, suggestive of bars, star-forming rings, and spiral arms. In this interpretation, the ratio of the `ring' and `bar' radii (1.9$\pm$0.3) agrees with that measured for such features in local galaxies. These potential spiral/ring/bar structures would be consistent with the idea of tidal disturbances, with their detailed properties implying flat inner rotation curves and Toomre-unstable disks (Q<1). The inferred one-dimensional velocity dispersions ($\sigma_{\rm r}\lesssim$ 70-160 km s$^{-1}$) are marginally consistent with the limits implied if the sizes of the largest structures are comparable to the Jeans length. We create maps of the star formation rate density ($\Sigma_{\rm SFR}$) on $\sim$500 pc scales and show that the SMGs are able to sustain a given (galaxy-averaged) $\Sigma_{\rm SFR}$ over much larger physical scales than local (ultra-)luminous infrared galaxies. However, on 500 pc scales, they do not exceed the Eddington limit set by radiation pressure on dust. If confirmed by kinematics, the potential presence of non-axisymmetric structures would provide a means for net angular momentum loss and efficient star formation, helping to explain the very high star formation rates measured in SMGs.}, archivePrefix = {arXiv}, arxivId = {1810.12307}, author = {Hodge, J. A. and Smail, I. and Walter, F. and da Cunha, E. and Swinbank, A. M. and Rybak, M. and Venemans, B. and Brandt, W. N. and Rivera, G. Calistro and Chapman, S. C. and Chen, Chian-Chou and Cox, P. and Dannerbauer, H. and Decarli, R. and Greve, T. R. and Knudsen, K. K. and Menten, K. M. and Schinnerer, E. and Simpson, J. M. and van der Werf, P. and Wardlow, J. L. and Weiss, A.}, @@ -940,7 +889,6 @@ @article{Hodge2019 year = {2019} } @article{Casey2014, -abstract = {Far-infrared and submillimeter wavelength surveys have now established the important role of dusty, star-forming galaxies (DSFGs) in the assembly of stellar mass and the evolution of massive galaxies in the Universe. The brightest of these galaxies have infrared luminosities in excess of 1013L⊙ with implied star-formation rates of thousands of solar masses per year. They represent the most intense starbursts in the Universe, yet many are completely optically obscured. Their easy detection at submm wavelengths is due to dust heated by ultraviolet radiation of newly forming stars. When summed up, all of the dusty, star-forming galaxies in the Universe produce an infrared radiation field that has an equal energy density as the direct starlight emission from all galaxies visible at ultraviolet and optical wavelengths. The bulk of this infrared extragalactic background light emanates from galaxies as diverse as gas-rich disks to mergers of intense starbursting galaxies. Major advances in far-infrared instrumentation in recent years, both space-based and ground-based, has led to the detection of nearly a million DSFGs, yet our understanding of the underlying astrophysics that govern the start and end of the dusty starburst phase is still in nascent stage. This review is aimed at summarizing the current status of DSFG studies, focusing especially on the detailed characterization of the best-understood subset (submillimeter galaxies, who were summarized in the last review of this field over a decade ago, Blain et al., 2002), but also the selection and characterization of more recently discovered DSFG populations. We review DSFG population statistics, their physical properties including dust, gas and stellar contents, their environments, and current theoretical models related to the formation and evolution of these galaxies. {\textcopyright} 2014 Elsevier B.V.}, archivePrefix = {arXiv}, arxivId = {astro-ph/9806317}, author = {Casey, Caitlin M. and Narayanan, Desika and Cooray, Asantha}, @@ -958,7 +906,6 @@ @article{Casey2014 year = {2014} } @article{Hubble1926, -abstract = {This contribution gives the results of a statistical investigation of 400 extragalactic nebulae for which Holetschek has determined total visual magnitudes. The list is complete for the brighter nebulae in the northern sky and is representative to 12.5 mag. or fainter. The classification employed is based on the forms of the photographic images. About 3 per cent are irregular, but the remaining nebulae fall into a sequence of type forms characterized by rotational symmetry about dominating nuclei. The sequence is composed of two sections, the elliptical nebulae and the spirals, which merge into each other. Luminosity relations. - The distribution of magnitudes appears to be uniform throughout the sequence. For each type or stage in the sequence, the total magnitudes are related to the logarithms of the maximum diameters by the formula, mT = C - 5 log d, where C varies progressively from type to type, indicating a variation in diameter for a given magnitude or vice versa. By applying corrections to C, the nebulae can be reduced to a standard type and then a single formula expresses the relation for all nebulae from the Magellanic Clouds to the faintest that can be classified. When the minor diameter is used, the value of C is approximately constant throughout the entire sequence. The coefficient of log d corresponds with the inverse-square law, which suggests that the nebulae are all of the same order of absolute luminosity and that apparent magnitudes are measures of distance. This hypothesis is supported by similar results for the nuclear magnitudes and the magnitudes of the brightest stars involved, and by the small range in luminosities among nebulae whose distances are already known. Distances and absolute dimensions. - The mean absolute visual magnitude, as derived from the nebulae whose distances are known, is -15.2. The statistical expression for the distance in parsecs is then log D = 4.04 + 0.2 mT. where mT is the total apparent magnitude. This leads to mean values for absolute dimensions at various stages in the sequence of types. Masses appear to be of the order of 2.6x108 Msun. Distribution and density of space. - To apparent magnitude about 16.7, corresponding to an exposure of one hour on fast plates with the 60-inch reflector, the numbers of nebulae to various limits of total magnitude vary directly with the volumes of space represented by the limits. This indicates an approximately uniform density of space, of the order of one nebula per 1017 cubic parsecs or 1.5x10-31 in C.G.S. units. The corresponding radius of curvature of the finite universe of general relativity is of the order of 2.7x1010 parsecs, or about 600 times the distance at which normal nebulae can be detected with the 100-inch reflector.}, author = {Hubble, E. P.}, doi = {10.1086/143018}, issn = {0004-637X},