Duty Cycle and the Increasing Star Formation History of z>=6 Galaxies
Jason Jaacks (1), Kentaro Nagamine (1), Jun-Hwan Choi (2) ((1) UNLV,, (2) Kentucky)

TL;DR
This study uses cosmological simulations to analyze the star formation history and duty cycle of high-redshift galaxies, revealing mass-dependent observable fractions and implications for galaxy surveys.
Contribution
It provides the first detailed characterization of the duty cycle and star formation history of z>=6 galaxies, with analytic fits to observational completeness corrections.
Findings
Star formation history can be modeled as exponential or power-law with mass-dependent timescales.
Duty cycle sharply transitions from zero to one around stellar mass of 10^7 to 10^9 Msun.
Duty cycle corrections significantly impact the inferred galaxy stellar mass functions and star formation rate density.
Abstract
We examine the duty cycle and the history of star formation (SFH) for high-redshift galaxies at z>=6 using cosmological hydrodynamic simulations. We find that, even though individual galaxies have bursty SFH, the averaged SFH between z~15 to z=6 can be characterized well by either an exponentially increasing functional form with characteristic time-scales of 70 Myr to 200 Myr for galaxies with stellar masses Ms~10^6 Msun to >10^10 Msun respectively, or by a simple power-law form which exhibits a similar mass dependent time-scales. Using the SFH of individual galaxies, we measure the duty cycle of star formation (DC_SFH); i.e., the fraction of time a galaxy of a particular mass spends above a star formation rate (SFR) threshold which would make it observable to the Hubble Space Telescope (HST) during a given epoch. We also examine the fraction of galaxies at a given redshift that are…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
