Increased Burstiness at High Redshift in Multi-Physics Models Combining Supernova Feedback, Radiative Transfer and Cosmic Rays

Kavli Affiliate: Debora Sijacki

| First 5 Authors: Tibor Dome, Sergio Martin-Alvarez, Sandro Tacchella, Yuxuan Yuan, Debora Sijacki

| Summary:

We study star formation variability, or burstiness, as a method to constrain
and compare different galaxy formation models at high redshift using the Azahar
simulation suite. The models range from magneto-hydrodynamics with a
magneto-thermo-turbulent prescription for star formation (iMHD) to more
sophisticated setups incorporating radiative transfer (RTiMHD) and cosmic ray
physics (RTnsCRiMHD). Analysing a sample of galaxies at redshifts $z=4-10$, we
find that the RTnsCRiMHD model exhibits more regular star formation periodicity
compared to iMHD and RTiMHD, as revealed by the Lomb-Scargle periodogram. While
the RTiMHD model captures a notable degree of stochasticity in star formation
without cosmic rays, RTnsCRiMHD galaxies display even greater scatter in the
burst intensity and in the scatter around the star-forming main sequence. To
evaluate the burstiness in RTnsCRiMHD against observations, we generate a mock
spectrum during a mini-quenching event at $z=7.5$. This spectrum aligns well
with the low-mass quiescent galaxy JADES-GS-z7-01-QU observed at $z=7.3$,
though some discrepancies attributed to stellar metallicity hint at a composite
spectrum. Our findings highlight the importance of including complex physical
processes like cosmic rays and radiative transfer in simulations to accurately
capture the bursty nature of star formation in high-redshift galaxies. Future
JWST observations, particularly regarding the scatter around the star-forming
main sequence, have the potential to refine and guide the next generation of
galaxy formation models.

| Search Query: ArXiv Query: search_query=au:”Debora Sijacki”&id_list=&start=0&max_results=3

Read More