Dwarf–Dwarf Interactions Can Both Trigger and Quench Star Formation
It is exceedingly rare to find quiescent low-mass galaxies in the field at low redshift. UGC 5205 is an example of such a quenched field dwarf ( M _⋆ ∼ 3 × 10 ^8 M _⊙ ). Despite a wealth of cold gas ( M _HI ∼ 3.5 × 10 ^8 M _⊙ ) and UV emission that indicates significant star formation in the past fe...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad18cb |
| _version_ | 1797293817921011712 |
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| author | Erin Kado-Fong Azia Robinson Kristina Nyland Jenny E. Greene Katherine A. Suess Sabrina Stierwalt Rachael Beaton |
| author_facet | Erin Kado-Fong Azia Robinson Kristina Nyland Jenny E. Greene Katherine A. Suess Sabrina Stierwalt Rachael Beaton |
| author_sort | Erin Kado-Fong |
| collection | DOAJ |
| description | It is exceedingly rare to find quiescent low-mass galaxies in the field at low redshift. UGC 5205 is an example of such a quenched field dwarf ( M _⋆ ∼ 3 × 10 ^8 M _⊙ ). Despite a wealth of cold gas ( M _HI ∼ 3.5 × 10 ^8 M _⊙ ) and UV emission that indicates significant star formation in the past few hundred megayears, there is no detection of H α emission—star formation in the last ∼10 Myr—across the face of the galaxy. Meanwhile, the near equal-mass companion of UGC 5205, PGC 027864, is starbursting (which has an H α equivalent width > 1000 Å). In this work, we present new Karl G. Jansky Very Large Array 21 cm line observations of UGC 5205, showing that the lack of star formation is caused by an absence of H i in the main body of the galaxy. The H i of UGC 5205 is highly disturbed; the bulk of the H i resides in several-kiloparsec–long tails, while the H i of PGC 027864 is dominated by ordered rotation. We model the stellar populations of UGC 5205 to show that, as indicated by the UV and H α emission, the galaxy underwent a coordinated quenching event ∼100–300 Myr ago. The asymmetry of outcomes for UGC 5205 and PGC 027864 demonstrate that major mergers can both quench and trigger star formation in dwarfs. However, because the gas remains bound to the system, we suggest that such mergers only temporarily quench star formation. We estimate a total quenched time of ∼560 Myr for UGC 5205, consistent with established upper limits on the quenched fraction of a few percent for dwarfs in the field. |
| first_indexed | 2024-03-07T21:21:20Z |
| format | Article |
| id | doaj.art-d0c0dc74a5b043a39ac40314892937a9 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-07T21:21:20Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-d0c0dc74a5b043a39ac40314892937a92024-02-27T13:26:19ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-0196313710.3847/1538-4357/ad18cbDwarf–Dwarf Interactions Can Both Trigger and Quench Star FormationErin Kado-Fong0https://orcid.org/0000-0002-0332-177XAzia Robinson1Kristina Nyland2https://orcid.org/0000-0003-1991-370XJenny E. Greene3https://orcid.org/0000-0002-5612-3427Katherine A. Suess4https://orcid.org/0000-0002-1714-1905Sabrina Stierwalt5https://orcid.org/0000-0002-2596-8531Rachael Beaton6https://orcid.org/0000-0002-1691-8217Physics 4 Department, Yale Center for Astronomy & Astrophysics , P.O. Box 208120, New Haven, CT 06520, USA ; erin.kado-fong@yale.eduDepartment of Astrophysical Sciences, Princeton University , Princeton, NJ 08540, USAU.S. Naval Research Laboratory , 4555 Overlook Ave SW, Washington, DC 20375, USADepartment of Astrophysical Sciences, Princeton University , Princeton, NJ 08540, USAKavli Institute for Particle Astrophysics and Cosmology and Department of Physics, Stanford University , Stanford, CA 94305, USAPhysics Department, 1600 Campus Road, Occidental College , Los Angeles, CA 90041, USASpace Telescope Science Institute , Baltimore, MD 21218, USA; Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USAIt is exceedingly rare to find quiescent low-mass galaxies in the field at low redshift. UGC 5205 is an example of such a quenched field dwarf ( M _⋆ ∼ 3 × 10 ^8 M _⊙ ). Despite a wealth of cold gas ( M _HI ∼ 3.5 × 10 ^8 M _⊙ ) and UV emission that indicates significant star formation in the past few hundred megayears, there is no detection of H α emission—star formation in the last ∼10 Myr—across the face of the galaxy. Meanwhile, the near equal-mass companion of UGC 5205, PGC 027864, is starbursting (which has an H α equivalent width > 1000 Å). In this work, we present new Karl G. Jansky Very Large Array 21 cm line observations of UGC 5205, showing that the lack of star formation is caused by an absence of H i in the main body of the galaxy. The H i of UGC 5205 is highly disturbed; the bulk of the H i resides in several-kiloparsec–long tails, while the H i of PGC 027864 is dominated by ordered rotation. We model the stellar populations of UGC 5205 to show that, as indicated by the UV and H α emission, the galaxy underwent a coordinated quenching event ∼100–300 Myr ago. The asymmetry of outcomes for UGC 5205 and PGC 027864 demonstrate that major mergers can both quench and trigger star formation in dwarfs. However, because the gas remains bound to the system, we suggest that such mergers only temporarily quench star formation. We estimate a total quenched time of ∼560 Myr for UGC 5205, consistent with established upper limits on the quenched fraction of a few percent for dwarfs in the field.https://doi.org/10.3847/1538-4357/ad18cbGalaxy interactionsStar formationTidal tailsGalaxy quenchingInterstellar atomic gas |
| spellingShingle | Erin Kado-Fong Azia Robinson Kristina Nyland Jenny E. Greene Katherine A. Suess Sabrina Stierwalt Rachael Beaton Dwarf–Dwarf Interactions Can Both Trigger and Quench Star Formation The Astrophysical Journal Galaxy interactions Star formation Tidal tails Galaxy quenching Interstellar atomic gas |
| title | Dwarf–Dwarf Interactions Can Both Trigger and Quench Star Formation |
| title_full | Dwarf–Dwarf Interactions Can Both Trigger and Quench Star Formation |
| title_fullStr | Dwarf–Dwarf Interactions Can Both Trigger and Quench Star Formation |
| title_full_unstemmed | Dwarf–Dwarf Interactions Can Both Trigger and Quench Star Formation |
| title_short | Dwarf–Dwarf Interactions Can Both Trigger and Quench Star Formation |
| title_sort | dwarf dwarf interactions can both trigger and quench star formation |
| topic | Galaxy interactions Star formation Tidal tails Galaxy quenching Interstellar atomic gas |
| url | https://doi.org/10.3847/1538-4357/ad18cb |
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