Cold Gas in a Post-starburst Pair in the z ∼ 1.4 HeavyMetal Survey: Major Mergers as a Pathway to Retain Gas in Quenched Galaxies
Recent observations at low redshift have revealed that some post-starburst galaxies retain significant molecular gas reservoirs despite low ongoing star formation rates, challenging most theoretical predictions that rely on heating or expelling gas reservoirs to shut down star formation. To test whe...
| Published in: | The Astrophysical Journal |
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| Main Authors: | , , , , , , , , , , , , , , |
| Format: | Article |
| Language: | English |
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IOP Publishing
2025-01-01
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| Online Access: | https://doi.org/10.3847/1538-4357/ae0933 |
| _version_ | 1848664310189916160 |
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| author | Katherine A. Suess Aliza G. Beverage Mariska Kriek Justin S. Spilker Rachel Bezanson Vincenzo R. D’Onofrio Jenny E. Greene Jamie Lin Yuanze Luo Desika Narayanan Imad Pasha Sedona H. Price David J. Setton Margaret E. Verrico Yunchong Zhang |
| author_facet | Katherine A. Suess Aliza G. Beverage Mariska Kriek Justin S. Spilker Rachel Bezanson Vincenzo R. D’Onofrio Jenny E. Greene Jamie Lin Yuanze Luo Desika Narayanan Imad Pasha Sedona H. Price David J. Setton Margaret E. Verrico Yunchong Zhang |
| author_sort | Katherine A. Suess |
| collection | DOAJ |
| container_title | The Astrophysical Journal |
| description | Recent observations at low redshift have revealed that some post-starburst galaxies retain significant molecular gas reservoirs despite low ongoing star formation rates, challenging most theoretical predictions that rely on heating or expelling gas reservoirs to shut down star formation. To test whether this finding holds during the peak epoch of quenching, here we present Atacama Large Millimeter/submillimeter Array CO(2–1) observations of five spectroscopically confirmed massive post-starburst galaxies at z ∼ 1.4 from the HeavyMetal survey. While four galaxies are undetected in CO emission, we detect ${M}_{{{\rm{H}}}_{2}}\sim 1{0}^{9.7}\,{M}_{\odot }$ of molecular gas in one system. The detected system is a close pair of two massive ( M _* = 10 ^11.1−11.2 M _⊙ ) post-starburst galaxies with no clear tidal features, likely caught in the early stages of a major merger. These results suggest that mergers may be a key factor in retaining molecular gas while simultaneously suppressing star formation in quenched galaxies at high redshift, possibly by driving increased turbulence that decreases star formation efficiency. Our nondetected galaxies have postburst ages >200 Myr, consistent with results at z < 1; however, our gas-rich post-starburst pair is significantly older than typical gas-rich quenched systems at low redshift. Our results highlight the importance of major mergers in shaping the cold gas content of quiescent galaxies during the peak epoch of quenching. |
| format | Article |
| id | doaj-art-285dc9998dfd4b89a92cce3bf9f9fc9c |
| institution | Directory of Open Access Journals |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| spelling | doaj-art-285dc9998dfd4b89a92cce3bf9f9fc9c2025-10-31T06:23:39ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01993215810.3847/1538-4357/ae0933Cold Gas in a Post-starburst Pair in the z ∼ 1.4 HeavyMetal Survey: Major Mergers as a Pathway to Retain Gas in Quenched GalaxiesKatherine A. Suess0https://orcid.org/0000-0002-1714-1905Aliza G. Beverage1https://orcid.org/0000-0002-9861-4515Mariska Kriek2https://orcid.org/0000-0002-7613-9872Justin S. Spilker3https://orcid.org/0000-0003-3256-5615Rachel Bezanson4https://orcid.org/0000-0001-5063-8254Vincenzo R. D’Onofrio5https://orcid.org/0000-0002-1759-6205Jenny E. Greene6https://orcid.org/0000-0002-5612-3427Jamie Lin7https://orcid.org/0000-0002-3101-8348Yuanze Luo8https://orcid.org/0000-0002-0696-6952Desika Narayanan9https://orcid.org/0000-0002-7064-4309Imad Pasha10https://orcid.org/0000-0002-7075-9931Sedona H. Price11https://orcid.org/0000-0002-0108-4176David J. Setton12https://orcid.org/0000-0003-4075-7393Margaret E. Verrico13https://orcid.org/0000-0003-1535-4277Yunchong Zhang14https://orcid.org/0000-0001-6454-1699Department for Astrophysical & Planetary Science, University of Colorado , Boulder, CO 80309, USA ; suess@colorado.eduObservatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USA; Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USALeiden Observatory, Leiden University , P.O. Box 9513, 2300 RA Leiden, The NetherlandsDepartment of Physics and Astronomy and George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , 4242 TAMU, College Station, TX 77843-4242, USADepartment of Physics and Astronomy and PITT PACC, University of Pittsburgh , Pittsburgh, PA 15260, USADepartment of Physics and Astronomy and George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , 4242 TAMU, College Station, TX 77843-4242, USADepartment of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USADepartment of Physics and Astronomy, Tufts University , Medford, MA 02155, USADepartment of Physics and Astronomy and George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , 4242 TAMU, College Station, TX 77843-4242, USADepartment of Astronomy, University of Florida , 211 Bryant Space Sciences Center, Gainesville, FL 32611, USA; Cosmic Dawn Center at the Niels Bohr Institute, University of Copenhagen and DTU-Space , Technical University of Denmark, DenmarkDragonfly Focused Research Organization , 150 Washington Avenue, Santa Fe, NM 87501, USA; Department of Astronomy , Yale University, 219 Prospect Street, New Haven, CT 06511, USASpace Telescope Science Institute (STScI) , 3700 San Martin Drive, Baltimore, MD 21218, USADepartment of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USAUniversity of Illinois Urbana-Champaign Department of Astronomy, University of Illinois, 1002 W. Green St., Urbana, IL 61801, USA; Center for AstroPhysical Surveys , National Center for Supercomputing Applications, 1205 West Clark Street, Urbana, IL 61801, USADepartment of Physics and Astronomy and PITT PACC, University of Pittsburgh , Pittsburgh, PA 15260, USARecent observations at low redshift have revealed that some post-starburst galaxies retain significant molecular gas reservoirs despite low ongoing star formation rates, challenging most theoretical predictions that rely on heating or expelling gas reservoirs to shut down star formation. To test whether this finding holds during the peak epoch of quenching, here we present Atacama Large Millimeter/submillimeter Array CO(2–1) observations of five spectroscopically confirmed massive post-starburst galaxies at z ∼ 1.4 from the HeavyMetal survey. While four galaxies are undetected in CO emission, we detect ${M}_{{{\rm{H}}}_{2}}\sim 1{0}^{9.7}\,{M}_{\odot }$ of molecular gas in one system. The detected system is a close pair of two massive ( M _* = 10 ^11.1−11.2 M _⊙ ) post-starburst galaxies with no clear tidal features, likely caught in the early stages of a major merger. These results suggest that mergers may be a key factor in retaining molecular gas while simultaneously suppressing star formation in quenched galaxies at high redshift, possibly by driving increased turbulence that decreases star formation efficiency. Our nondetected galaxies have postburst ages >200 Myr, consistent with results at z < 1; however, our gas-rich post-starburst pair is significantly older than typical gas-rich quenched systems at low redshift. Our results highlight the importance of major mergers in shaping the cold gas content of quiescent galaxies during the peak epoch of quenching.https://doi.org/10.3847/1538-4357/ae0933Galaxy evolutionGalaxy quenchingGalaxy formationPost-starburst galaxiesQuenched galaxies |
| spellingShingle | Katherine A. Suess Aliza G. Beverage Mariska Kriek Justin S. Spilker Rachel Bezanson Vincenzo R. D’Onofrio Jenny E. Greene Jamie Lin Yuanze Luo Desika Narayanan Imad Pasha Sedona H. Price David J. Setton Margaret E. Verrico Yunchong Zhang Cold Gas in a Post-starburst Pair in the z ∼ 1.4 HeavyMetal Survey: Major Mergers as a Pathway to Retain Gas in Quenched Galaxies Galaxy evolution Galaxy quenching Galaxy formation Post-starburst galaxies Quenched galaxies |
| title | Cold Gas in a Post-starburst Pair in the z ∼ 1.4 HeavyMetal Survey: Major Mergers as a Pathway to Retain Gas in Quenched Galaxies |
| title_full | Cold Gas in a Post-starburst Pair in the z ∼ 1.4 HeavyMetal Survey: Major Mergers as a Pathway to Retain Gas in Quenched Galaxies |
| title_fullStr | Cold Gas in a Post-starburst Pair in the z ∼ 1.4 HeavyMetal Survey: Major Mergers as a Pathway to Retain Gas in Quenched Galaxies |
| title_full_unstemmed | Cold Gas in a Post-starburst Pair in the z ∼ 1.4 HeavyMetal Survey: Major Mergers as a Pathway to Retain Gas in Quenched Galaxies |
| title_short | Cold Gas in a Post-starburst Pair in the z ∼ 1.4 HeavyMetal Survey: Major Mergers as a Pathway to Retain Gas in Quenched Galaxies |
| title_sort | cold gas in a post starburst pair in the z ∼ 1 4 heavymetal survey major mergers as a pathway to retain gas in quenched galaxies |
| topic | Galaxy evolution Galaxy quenching Galaxy formation Post-starburst galaxies Quenched galaxies |
| url | https://doi.org/10.3847/1538-4357/ae0933 |
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