Merger Signatures are Common, but not Universal, in Massive, Recently Quenched Galaxies at z ~ 0.7

Journal Article · Thu May 18 00:00:00 EDT 2023 · The Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/acc38b· OSTI ID:2425230

Verrico, Margaret E. ^[1]; Setton, David J. ^[2]; Bezanson, Rachel ^[2]; Greene, Jenny E. ^[3]; Suess, Katherine A. ^[4]; Goulding, Andy D. ^[3]; Spilker, Justin S. ^[5]; Kriek, Mariska ^[6]; Feldmann, Robert ^[7]; Narayanan, Desika ^[8]; Donofrio, Vincenzo ^[5]; Khullar, Gourav ^[2]

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1. Univ. of Pittsburgh, PA (United States); Univ. of Illinois at Urbana-Champaign, IL (United States)
2. Univ. of Pittsburgh, PA (United States)
3. Princeton Univ., NJ (United States)
4. Univ. of California, Berkeley, CA (United States); Univ. of California, Santa Cruz, CA (United States); Stanford Univ., CA (United States)
5. Texas A & M Univ., College Station, TX (United States)
6. Leiden Univ. (Netherlands)
7. Univ. of Zurich (Switzerland)
8. Univ. of Florida, Gainesville, FL (United States); University of Florida Informatics Institute, Gainesville, FL (United States); Univ. of Copenhagen (Denmark). The Niels Bohr Inst.; Technical Univ. of Denmark, Lyngby (Denmark)

We present visual classifications of merger-induced tidal disturbances in 143 M* ~ 10¹¹M_⊙ post-starburst galaxies at z ~ 0.7 identified in the $$SQuIGG\vec{L}E$$ Sample. This sample spectroscopically selects galaxies from the Sloan Digital Sky Survey that have stopped their primary epoch of star formation within the past ~500 Myr. Visual classifications are performed on Hyper Suprime-Cam imaging. We compare to a control sample of mass- and redshift-matched star-forming and quiescent galaxies from the Large Early Galaxy Census and find that post-starburst galaxies are more likely to be classified as disturbed than either category. This corresponds to a factor of $3.6$$$$^{+2.9}_{-1.3}$$ times the disturbance rate of older quiescent galaxies and $2.1$$$$^{+1.9}_{-.73}$$ times the disturbance rate of star-forming galaxies. Assuming tidal features persist for ≲500 Myr, this suggests merging is coincident with quenching in a significant fraction of these post-starbursts. Galaxies with tidal disturbances are younger on average than undisturbed post-starburst galaxies in our sample, suggesting tidal features from a major merger may have faded over time. This may be exacerbated by the fact that, on average, the undisturbed subset is fainter, rendering low-surface-brightness tidal features harder to identify. However, the presence of 10 young (≲150 Myr since quenching) undisturbed galaxies suggests that major mergers are not the only fast physical mechanism that shut down the primary epoch of star formation in massive galaxies at intermediate redshift.

• Research Organization: US Department of Energy (USDOE), Washington, DC (United States). Office of Science, Sloan Digital Sky Survey (SDSS)
• Sponsoring Organization: National Science Foundation (NSF); Swiss National Science Foundation (SNSF); USDOE Office of Science (SC)
• OSTI ID: 2425230
• Journal Information: The Astrophysical Journal, Journal Name: The Astrophysical Journal Journal Issue: 1 Vol. 949; ISSN 0004-637X
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS