Sergio Martin-Alvarez
Gather.town id
CSF16
Poster Title
Dwarf galaxy formation beyond supernovae: magnetism, radiation and cosmic rays
Institution
University of Cambridge
Abstract (short summary)
Understanding star formation in dwarf galaxies has proven a persistent challenge for galaxy formation numerical simulations. In order for these simulations to produce results that better match observed galaxies, accounting for additional baryonic physics (e.g. stellar radiation, magnetic fields, and cosmic rays) has been frequently advocated. Nonetheless, in their absence, methods such as calibrating stellar feedback have allowed simulations to more effectively reproduce e.g. expected stellar masses. However, doing so has the detrimental effect of disrupting the match attained for other observables.
Investigating our simulations devised to explore the role played by these additional physics, I present here our first results from radiative transfer, cosmic rays, magnetohydrodynamical (RTCRMHD) simulations of a dwarf galaxy formation in a cosmological context. I compare our simulations with observational measures of stellar mass, morphology, kinematics, and metal enrichment. Our suite of simulations provides encouraging prospects suggesting RTCRMHD physics may contribute to overcome various ongoing dwarf galaxy formation problems, and in particular, to resolve or alleviate our necessity for stellar feedback calibration.
Investigating our simulations devised to explore the role played by these additional physics, I present here our first results from radiative transfer, cosmic rays, magnetohydrodynamical (RTCRMHD) simulations of a dwarf galaxy formation in a cosmological context. I compare our simulations with observational measures of stellar mass, morphology, kinematics, and metal enrichment. Our suite of simulations provides encouraging prospects suggesting RTCRMHD physics may contribute to overcome various ongoing dwarf galaxy formation problems, and in particular, to resolve or alleviate our necessity for stellar feedback calibration.
Plain text (extended) Summary
We briefly present a teaser of some of our findings running the first cosmological zoom-in simulations of dwarf galaxy formation featuring magnetohydrodynamics (MHD), radiative transfer (RT) and cosmic rays (CRs). We produce a suite of simulations of an isolated dwarf galaxy with stellar mass ~10^7 Msolar, departing from the basic star formation + stellar feedback up to a full-physics simulation with RTCRMHD. We evolve all these runs at least down to z~3.5. Accordingly, we have selected a system presenting no significant evolution between z ~ 4 and z = 0.
In this poster we focus on a subset of our simulations (6 out of 18). These runs are: no feedback, stellar feedback, MHD, RT, RT+MHD and RTCRMHD. Slide 2 displays how the studied dwarf galaxy evolves within the stellar mass - halo mass relation when featuring different physics. When RT and stellar feedback are combined, the former provides positive feedback, albeit this is delayed to z < 6. We find stellar radiation and cosmic rays to delay the growth of stellar mass. When reviewing mass-size relations in slide 3, we find once again stellar radiation and cosmic rays to be the most important additions to our simulations, both driving larger galaxy sizes. All runs appear to provide a good match to observations, but RTCRMHD and RT+MHD fare particularly well when compared with similar galaxies (WLM, Leo A, SagDIG). We finally showcase in slide 4 how synthetic observations of our galaxy also display notable changes attending to the physics employed by the simulation.
The pre-print of this work will soon appear on the arXiv. In the publication we review the aspects presented here in more detail, but also explore other components, additional galaxy relations, metal enrichment, or galactic outflows amongst others. We encourage the interested reader to keep an eye out. Equally, feel free to contact us with any doubts or questions (Sergio Martin-Alvarez; mailto: smartin@ast.cam.ac.uk).
In this poster we focus on a subset of our simulations (6 out of 18). These runs are: no feedback, stellar feedback, MHD, RT, RT+MHD and RTCRMHD. Slide 2 displays how the studied dwarf galaxy evolves within the stellar mass - halo mass relation when featuring different physics. When RT and stellar feedback are combined, the former provides positive feedback, albeit this is delayed to z < 6. We find stellar radiation and cosmic rays to delay the growth of stellar mass. When reviewing mass-size relations in slide 3, we find once again stellar radiation and cosmic rays to be the most important additions to our simulations, both driving larger galaxy sizes. All runs appear to provide a good match to observations, but RTCRMHD and RT+MHD fare particularly well when compared with similar galaxies (WLM, Leo A, SagDIG). We finally showcase in slide 4 how synthetic observations of our galaxy also display notable changes attending to the physics employed by the simulation.
The pre-print of this work will soon appear on the arXiv. In the publication we review the aspects presented here in more detail, but also explore other components, additional galaxy relations, metal enrichment, or galactic outflows amongst others. We encourage the interested reader to keep an eye out. Equally, feel free to contact us with any doubts or questions (Sergio Martin-Alvarez; mailto: smartin@ast.cam.ac.uk).
URL
Feel free to contact us with any doubts or questions (Sergio Martin-Alvarez; mailto: smartin@ast.cam.ac.uk). Also www.martin-alvarez.com
Poster file