The Astrophysical Journal (Jan 2025)
CEERS: Increasing Scatter along the Star-forming Main Sequence Indicates Early Galaxies Form in Bursts
- Justin W. Cole,
- Casey Papovich,
- Steven L. Finkelstein,
- Micaela B. Bagley,
- Mark Dickinson,
- Kartheik G. Iyer,
- L. Y. Aaron Yung,
- Laure Ciesla,
- Ricardo O. Amorín,
- Pablo Arrabal Haro,
- Rachana Bhatawdekar,
- Antonello Calabrò,
- Nikko J. Cleri,
- Alexander de la Vega,
- Avishai Dekel,
- Ryan Endsley,
- Eric Gawiser,
- Mauro Giavalisco,
- Nimish P. Hathi,
- Michaela Hirschmann,
- Benne W. Holwerda,
- Jeyhan S. Kartaltepe,
- Anton M. Koekemoer,
- Ray A. Lucas,
- Sara Mascia,
- Bahram Mobasher,
- Pablo G. Pérez-González,
- Giulia Rodighiero,
- Kaila Ronayne,
- Sandro Tacchella,
- Benjamin J. Weiner,
- Stephen M. Wilkins
Affiliations
- Justin W. Cole
- ORCiD
- Department of Physics and Astronomy, Texas A&M University , College Station, TX, 77843-4242, USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242, USA
- Casey Papovich
- ORCiD
- Department of Physics and Astronomy, Texas A&M University , College Station, TX, 77843-4242, USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242, USA
- Steven L. Finkelstein
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712-1205, USA
- Micaela B. Bagley
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712-1205, USA
- Mark Dickinson
- ORCiD
- NSF’s National Optical-Infrared Astronomy Research Laboratory , 950 N. Cherry Ave., Tucson, AZ 85719, USA
- Kartheik G. Iyer
- ORCiD
- Dunlap Institute for Astronomy & Astrophysics, University of Toronto , Toronto, ON M5S 3H4, Canada
- L. Y. Aaron Yung
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center , 8800 Greenbelt Rd, Greenbelt, MD 20771, USA; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Laure Ciesla
- ORCiD
- Aix Marseille Univ , CNRS, CNES, LAM, Marseille, France
- Ricardo O. Amorín
- ORCiD
- ARAID Foundation, Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Unidad Asociada al CSIC , Plaza San Juan 1, E–44001 Teruel, Spain; Departamento de Astronomía, Universidad de La Serena , Av. Juan Cisternas 1200 Norte, La Serena 1720236, Chile
- Pablo Arrabal Haro
- ORCiD
- NSF’s National Optical-Infrared Astronomy Research Laboratory , 950 N. Cherry Ave., Tucson, AZ 85719, USA
- Rachana Bhatawdekar
- ORCiD
- European Space Agency (ESA) , European Space Astronomy Centre (ESAC), Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Madrid, Spain
- Antonello Calabrò
- ORCiD
- INAF Osservatorio Astronomico di Roma , Via Frascati 33, 00078 Monteporzio Catone, Rome, Italy
- Nikko J. Cleri
- ORCiD
- Department of Physics and Astronomy, Texas A&M University , College Station, TX, 77843-4242, USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242, USA
- Alexander de la Vega
- ORCiD
- Department of Physics and Astronomy, University of California , 900 University Ave, Riverside, CA 92521, USA
- Avishai Dekel
- ORCiD
- Racah Institute of Physics, The Hebrew University of Jerusalem , Jerusalem 91904, Israel
- Ryan Endsley
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712-1205, USA
- Eric Gawiser
- ORCiD
- Department of Physics and Astronomy, Rutgers, the State University of New Jersey , Piscataway, NJ 08854, USA
- Mauro Giavalisco
- ORCiD
- University of Massachusetts Amherst , 710 North Pleasant Street, Amherst, MA 01003-9305, USA
- Nimish P. Hathi
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Michaela Hirschmann
- ORCiD
- Institute of Physics, Laboratory for galaxy evolution, EPFL , Observatory of Sauverny, Chemin Pegasi 51, 1290 Versoix, Switzerland; INAF, Astronomical Observatory of Trieste , Via G.P. Tiepolo 11, 34134 Trieste, Italy
- Benne W. Holwerda
- ORCiD
- Physics & Astronomy Department, University of Louisville , Louisville, KY 40292, USA
- Jeyhan S. Kartaltepe
- ORCiD
- Laboratory for Multiwavelength Astrophysics, School of Physics and Astronomy, Rochester Institute of Technology , 84 Lomb Memorial Drive, Rochester, NY 14623, USA
- Anton M. Koekemoer
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Ray A. Lucas
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Sara Mascia
- ORCiD
- INAF Osservatorio Astronomico di Roma , Via Frascati 33, 00078 Monteporzio Catone, Rome, Italy
- Bahram Mobasher
- ORCiD
- Department of Physics and Astronomy, University of California , 900 University Ave, Riverside, CA 92521, USA
- Pablo G. Pérez-González
- ORCiD
- Centro de Astrobiología (CAB), CSIC-INTA , Ctra. de Ajalvir km 4, Torrejón de Ardoz, E-28850, Madrid, Spain
- Giulia Rodighiero
- ORCiD
- Department of Physics and Astronomy, Università degli Studi di Padova , Vicolo dell’Osservatorio 3, I-35122, Padova, Italy; INAF - Osservatorio Astronomico di Padova , Vicolo dell’Osservatorio 5, I-35122, Padova, Italy
- Kaila Ronayne
- ORCiD
- Department of Physics and Astronomy, Texas A&M University , College Station, TX, 77843-4242, USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242, USA
- Sandro Tacchella
- ORCiD
- Kavli Institute for Cosmology, University of Cambridge , Madingley Road, Cambridge, CB3 0HA, UK; Cavendish Laboratory, University of Cambridge , 19 JJ Thomson Avenue, Cambridge, CB3 0HE, UK
- Benjamin J. Weiner
- ORCiD
- MMT/Steward Observatory, University of Arizona , 933 N. Cherry St, Tucson, AZ 85721, USA
- Stephen M. Wilkins
- ORCiD
- Astronomy Centre, University of Sussex , Falmer, Brighton, BN1 9QH, UK; Institute of Space Sciences and Astronomy, University of Malta , Msida MSD 2080, Malta
- DOI
- https://doi.org/10.3847/1538-4357/ad9a6a
- Journal volume & issue
-
Vol. 979,
no. 2
p. 193
Abstract
We present the star formation rate–stellar mass (SFR– M _* ) relation for galaxies in the Cosmic Evolution Early Release Science survey at 4.5 ≤ z ≤ 12. We model the JWST and Hubble Space Telescope rest-UV and rest-optical photometry of galaxies with flexible star formation histories (SFHs) using BAGPIPES. We consider SFRs averaged from the SFHs over 10 Myr (SFR _10 ) and 100 Myr (SFR _100 ), where the photometry probes SFRs on these timescales, effectively tracing nebular emission lines in the rest-optical (on ~10 Myr timescales) and the UV/optical continuum (on ~100 Myr timescales). We measure the slope, normalization and intrinsic scatter of the SFR– M _* relation, taking into account the uncertainty and the covariance of galaxy SFRs and M _* . From z ~ 5 to 9 there is larger scatter in the SFR _10 – M _* relation, with $\sigma (\mathrm{log}{\rm{S}}{\rm{F}}{{\rm{R}}}_{100})=0.4$ dex, compared to the SFR _100 – M _* relation, with $\sigma (\mathrm{log}SF{R}_{10})=0.1$ dex. This scatter increases with redshift and increasing stellar mass, at least out to z ~ 7. These results can be explained if galaxies at higher redshift experience an increase in star formation variability and form primarily in short, active periods, followed by a lull in star formation (i.e., “napping” phases). We see a significant trend in the ratio R _SFR = SFR _10 /SFR _100 in which, on average, R _SFR decreases with increasing stellar mass and increasing redshift. This yields a star formation “duty cycle” of ~40% for galaxies with $\mathrm{log}{M}_{* }/{M}_{\odot }\geqslant 9.3$ at z ~ 5, declining to ~20% at z ~ 9. Galaxies also experience longer lulls in star formation at higher redshift and at higher stellar mass, such that galaxies transition from periods of higher SFR variability at z ≳ 6 to smoother SFR evolution at z ≲ 4.5.
Keywords
