- 5 minute overview/background of our science
- 5 minutes on our specific research
- 5 minutes on our general computation need
- 5 minutes on our specific analysis in relation to computation and what is our specific needs for computers
- 5 minutes for results and greater impacts
- 5 minutes for questions
- title slide: First Look at Protostars: High Fidelity Modeling and the Youngest of Stars with OSCER
- collaboration: VANDAM, HOPS, misc
- motivation
- questions we try to answer are generally: where did we come from, what else is out there, and where are we going to end up?
- questions we (specifically) answer: Where did we come from, how did we get here, what else is out there, and are we unique
(not everyone is an astronomer much less expert of star/planet formation)
- background on star formation
- evolution of stars: MC -> Protostar -> Main Sequence (star) -> Giants -> WD/NS/BH -> MC ...
- What determines the specific track: to first order mass
- whats interesting is once you hit MS, the only thing that matters (to first order) is mass
- what determines MS and single/multiple star.
- what about planets? Gas is gone so gas giant formation not possible at MS
- Look at Cloud -> Class III
- evolution
- when does gas leave?
- pictures of orion/perseus HST
- these are optically thick....big problem
- interesting, opacity is related to frequency so just go to longer wavelengths: IR/RADIO
- evolution of stars: MC -> Protostar -> Main Sequence (star) -> Giants -> WD/NS/BH -> MC ...
- Instruments
- problem, resolution is also frequency dependent theta = lambda/size
- so now we need large telescopes. We want <10AU scales and stuff is away so we need 0.1'' resolution
- similar to saying 1/1000 of your fingernail width at arms length away from your eye.
- which means we need telescopes on order of the size of km at least...
- not doable
- interferometry
- lots of smaller telescopes across several miles acts like 1 big telescope(with limitations)
- fixed our problems
- alma, vla, noema, carma
- so what kind of data do we get?
- photometry
- just like a camera from your cellphone we can get an image
- if we do this a lot we get the energy distribution of objet
- spectroscopy
- this gives us color, not just 3 color but thousands. Gives us information of atoms, molecules
- we get both simultaneously
- photometry
- so to summarize we went from HST -> ALMA
- now we can look at the systems themselves and not just the environment or nulk properties
- from these we can get stellar mass, disk mass, size, speeds, molecular abundance, temperatures, geometries, multiplicities, etc
- problem, resolution is also frequency dependent theta = lambda/size
- Computation
- parameters
- we now have 20-40 parameters to fit with a lot of degeneracy
- turning into a computation problem
- we want to make a model, fit this model to the data, and then get the model parameters
- sounds like a great problem for parallelization and MCMC
- so now our problem is one of scalability
- we want to reach numerical convergence of the models and statistical convergence of the model parameter sets
- insert EMCEE,openmpi, pdspy
- insert slide about scalability
- computation requirements
- generally models take 60k core-hours for a single system
- we have a few hundred of these
- our systems
- 2x 28 physical core
- so while good not enough (months of convergence)
- into oscer
- generally we ask for 5-15 nodes x 20 core x 48 hours x 15-5 separate runs x systems
- some take more and some take less depending on complexity, how quickly they converge, etc
- currently not GPU ready so we just want max CPU core hours
- generally models take 60k core-hours for a single system
- we are requesting a lot but why again?
- parameters
- impacts and fundamentals
- we are trying to understand our universse and namely understand how did we form and what other things form in the universe
- are we unique?
- where/when/how do planets form and same for stars.
- how do we get the tichness of chemicals
- we want to answer these in a statistically significant way too so that means large observational surveys, lots of models
- our group at OU + collaborations around the world are the forerunners of this field
- thanks
- none of this would happen without OSCER, OU, NSF, and the collaborators
- special thanks to Henry, Horst, Oscer IT, and CAS IT