Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Nick Scoville
Andreas Faisst
John Weaver
Sune Toft
Henry McCracken
Olivier Ilbert
Tanio Diaz-Santos
Johannes Staguhn
Jin Koda
Caitlin Casey
David Sanders
Bahram Mobasher
Nima Chartab
Zahra Sattari
Peter Capak
Paul Vanden Bout
Angela Bongiorno
Catherine Vlahakis
Kartik Sheth
Min Yun
Abstract： ALMA observations of the long wavelength dust continuum are used to estimate the gas masses in a sample of 708 star-forming (SF) galaxies at z = 0.3 to 4.5. We determine the dependence of gas masses and star formation efficiencies (SFE=SFR per unit gass mass). We find that 70 percent of the increase in SFRs of the MS is due to the increased gas masses at earlier epochs while 30 percent is due to increased efficiency of SF. For galaxies above the MS this is reversed with 70 percent of the increased SFR relative to the MS being due to elevated SFEs. Thus, the major evolution of star formation activity at early epochs is driven by increased gas masses, while the starburst activity taking galaxies above the MS is due to enhanced triggering of star formation (likely due to galactic merging). The interstellar gas peaks at z = 2 and dominates the stellar mass down to z = 1.2. Accretion rates needed to maintain continuity of the MS evolution exceed 100 Msun per yr at z > 2. The galactic gas contents are likely the driving determinant for both the rise in SF and AGN activity from z = 5 to their peak at z = 2 and subsequent fall to lower z. We suggest that for self-gravitating clouds with supersonic turbulence, cloud collisions and the filamentary structure of the clouds regulate the star formation activity.
Peer Review Status:
Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Yun Wang
Lee Armus
Andrew Benson
Emanuele Daddi
Andreas Faisst
Anthony Gonzalez
Casey Papovich
Zoran Ninkov
Massimo Robberto
Randall J. Rose
Thomas
Rose
Claudia Scarlata
S. A. Stanford
Todd Veach
Zhongxu Zhai
Bradford Benson
L. E. Bleem
Michael W. Davis
George Helou
Abstract： ISCEA (Infrared Satellite for Cosmic Evolution Astrophysics) is a small
astrophysics mission whose Science Goal is to discover how galaxies evolved in
the cosmic web of dark matter at cosmic noon. Its Science Objective is to
determine the history of star formation and its quenching in galaxies as a
function of local density and stellar mass when the Universe was 3-5 Gyrs old
(1.2
Peer Review Status:Awaiting Review
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