The DAP produces a number of quality assessment plots, ranging from those specific to the results of a given analysis module for a single observation to plots of global properties for all observations analyzed for a given MPL/DR. The QA plots are limited in many ways, but the following is a description of the current QA plots produced.
Warning
The file location and description below is specific to the MaNGA data. However, similar QA plots can be made for non-MaNGA data; see execution
.
Script: $MANGADAP_DIR/bin/spotcheck_dap_maps
Output root: $MANGA_SPECTRO_ANALYSIS/$MANGADRP_VER/$MANGADAP_VER/[DAPTYPE]/[PLATE]/[IFU]/qa
Output file: manga-[PLATE]-[IFUDESIGN]-MAPS-[DAPTYPE]-spotcheck.png
MAPS
file for quick assessment of the quality of the analysis. The PLATEIFU
and MaNGA ID are given at the top of the figure. The panels show from top-to-bottom and left-to-right: g-band-weighted mean flux (SPX_MFLUX
), g-band-weighted spaxel S/N (SPX_SNR
), bin ID number (BINID
), g-band-weighted bin S/N (BIN_SNR
), 68% growth of the fractional residual of the stellar-continuum (kinematics) fit (STELLAR_FOM
; channel 68th perc frac resid
), χν2 of the stellar-continuum (kinematics) fit (STELLAR_FOM
; channel rchi2
), stellar velocity (STELLAR_VEL
), (uncorrected) stellar velocity dispersion (STELLAR_SIGMA
), non-parametric ${\rm H}\alpha$ flux (EMLINE_SFLUX
; channel Ha-6564
), Gaussian-fit ${\rm H}\alpha$ flux (EMLINE_GFLUX
; channel Ha-6564
), ionized-gas velocity (EMLINE_GVEL
; channel Ha-6564
), (uncorrected) ${\rm
H}\alpha$ emission-line velocity dispersion (EMLINE_GSIGMA
; channel Ha-6564
), non-parametric ${\rm H}\beta$ flux (EMLINE_SFLUX
; channel Hb-4862
), Gaussian-fit ${\rm
H}\beta$ flux (EMLINE_GFLUX
; channel Hb-4862
), D4000 index (SPECINDEX
; channel D4000
), and the Dn4000 index (SPECINDEX
; channel Dn4000
).
Script: $MANGADAP_DIR/bin/dap_ppxffit_qa
Output root: $MANGA_SPECTRO_ANALYSIS/$MANGADRP_VER/$MANGADAP_VER/[DAPTYPE]/[PLATE]/[IFU]/qa
Output file: manga-[PLATE]-[IFUDESIGN]-MAPS-[DAPTYPE]-ppxffit.png
stellar-kinematics
). The plot includes a few non-trivial metrics: A is the sum of the absolute value of the additive polynomial coefficients, An is similarly computed as A except that the coefficients have been normalized by the mean g-band weighted flux, and δAn is the RMS of the polynomial coefficients with respect to their median. The metrics denoted as T, Tn, and δTn are similarly computed but using the template coefficients. These sets of metrics are meant to provide a sense of how strongly the additive polynomial coefficients and template mix vary across the galaxy. Strong variations likely indicate artifacts in the spectra that are throwing off the fit. The example shown here is typical. In detail, the panels show from top-to-bottom and left-to-right: The g-band-weighted spaxel S/N, the 68% and 95% growth of the fractional residuals, the reduced χν2, the g-band-weighted mean flux, A, An, δAn, the g − r color derived from the MaNGA datacube (see the GIMG
and RIMG
extensions in the DRP datacube), T, Tn, δTn, the stellar velocity field, the "observed" (i.e., uncorrected) stellar velocity dispersion field, the correction to apply to the stellar velocity dispersion to account for the resolution difference between the templates and the MaNGA spectra, and the corrected (astrophysical) stellar velocity dispersion.
Script: $MANGADAP_DIR/bin/dap_fit_residuals
Output root: $MANGA_SPECTRO_ANALYSIS/$MANGADRP_VER/$MANGADAP_VER/[DAPTYPE]/[PLATE]/[IFU]/qa
Output files:
Maps used to assess the quality of the stellar continuum fits (left) and the emission-line model fits (right). Left: The maps in the first two rows, top-to-bottom and left-to-right, are: the SDSS gri image with a purple hexagon outlining the approximate size of the MaNGA IFU, the g-band-weighted spaxel S/N, the g − r color derived from the MaNGA datacube (see the
manga-[PLATE]-[IFUDESIGN]-LOGCUBE-[DAPTYPE]-sc-fitqa-maps.png
(left)manga-[PLATE]-[IFUDESIGN]-LOGCUBE-[DAPTYPE]-el-fitqa-maps.png
(right)
GIMG
and RIMG
extensions in the DRP datacube), the RMS of the fit residuals, the RMS of the model-normalized residuals (i.e., the "fractional" RMS), and χν2. The bottom row shows, from left-to-right the 68% and 99% growth of the error-normalized residuals and their ratio with respect to the expectation of a Gaussian. If the distribution of the error-normalized residuals strictly follow a Gaussian distribution, the spaxesl in the left, middle, and right maps should be 1, 2.6, and 1, respectively. Specifically for the right-most image in the bottom row, spaxels below 1 have a distribution of the fit residuals the falls more steeply than a Gaussian, whereas values larger than 1 imply a more peaked distribution (or at least one that has strong outliers). A more direct view of the distributions relative to a Gaussian are shown in the fitqa-growth
plots below. Right: The maps in the bottom two rows are the same as shown for the stellar-continuum modeling. The middle and right-most plots in the top row, however, are the amplitude-to-noise ratio of the ${\rm H}\alpha$ line and the ratio of the ${\rm H}\alpha$ and ${\rm
H}\beta$ fluxes.
Output files:
The left and right panel groups are identical; the left panels are for the stellar-continuum-fitting module and the right panels are for the emission-line-fitting module. Top: The top group panels show, from top-to-bottom, the flux and S/N (gray) averaged over all fitted spectra, the residuals averaged over all spectra, the model-normalized residuals averaged over all spectra, and the error-normalized residuals over all spectra. These plots aim to highlight any spectral regions that are poorly fit for all spectra, on average. Bottom: Two-dimensional maps of the residuals where wavelengths are ordered along the abscissa and the fitted spectra are organized along the ordinate; the value along the ordinate is the bin ID number. The residuals are shown twice, the top rows shows them at their native values (within the limits of the plot resolution) and the bottom smooths the data spectrally by 100 pixels. Masked regions are shown in white (e.g., emission-line regions in stellar-continuum fits in the left group). From left-to-right, the 2d images show the absolute value of the residuals (|Δ|), the model-normalized residuals, and the error-normalized residuals.
manga-[PLATE]-[IFUDESIGN]-LOGCUBE-[DAPTYPE]-sc-fitqa-lambda.png
(left)manga-[PLATE]-[IFUDESIGN]-LOGCUBE-[DAPTYPE]-el-fitqa-lambda.png
(right)
Output files:
The left and right panel groups are identical; the left panels are for the stellar-continuum-fitting module and the right panels are for the emission-line-fitting module. Top: The top row of panels shows the growth curves (or actually 1 − g(x)) for the absolute value of the residuals, the model-normalized residuals, and the error-normalized residuals. One line is shown for each fitted spectrum; the lines are plotted from lowest to highest ${\rm S/N}_g$. In the right-most panel, the black line shows the expectation for a Gaussian error distribution. Bottom: From left to-right, the RMS of the absolute value of the residuals, the RMS of the model-normalized residuals, and χν2.
manga-[PLATE]-[IFUDESIGN]-LOGCUBE-[DAPTYPE]-sc-fitqa-growth.png
(left)manga-[PLATE]-[IFUDESIGN]-LOGCUBE-[DAPTYPE]-el-fitqa-growth.png
(right)
Script: $MANGADAP_DIR/bin/dap_plate_fit_qa
Output root: $MANGA_SPECTRO_ANALYSIS/$MANGADRP_VER/$MANGADAP_VER/[DAPTYPE]/[PLATE]/qa
Output file: [PLATE]-fitqa.png
PLATEIFU
) numbers in red have been flagged by the DRP as having critical data-reduction issues (CRITICAL
). Each panel shows a fit metric against the g-band S/N of the spectrum. The top row shows the reduced chi-square and the bottom row show the RMS of the model-normalized residuals. Compare to Figure 27 from Westfall et al. (2019, AJ, 158, 231).
Script: $MANGADAP_DIR/bin/dapall_qa
Output root: $MANGA_SPECTRO_ANALYSIS/$MANGADRP_VER/$MANGADAP_VER/[DAPTYPE]/qa
Output file: dapall_radialcoverage.png
Output file: dapall_redshift_dist.png
metadatamodel-dapall
, where z* is from the STELLAR_Z
column and $z_{\rm gas}$ is from HA_Z
. The bottom-left panel shows the scatter plot (one point per observations) with observations flagged as CRITICAL
by the DRP in red. The gray histograms only use data from datacubes that are not flagged as CRITICAL
.
Output file: dapall_mass_vel.png
Output file: dapall_mass_sigma.png
Output file: dapall_ew_d4000.png
Output file: dapall_mgfe_hbeta.png
Output file: dapall_mass_lha.png