Discovery and Characterization of Two Ultrafaint Dwarfs outside the Halo of the Milky Way: Leo M and Leo K
We report the discovery of two ultrafaint dwarf galaxies, Leo M and Leo K, that lie outside the halo of the Milky Way (MW). Using Hubble Space Telescope imaging of the resolved stars, we create color–magnitude diagrams reaching the oldest main-sequence turnoff of each system and (i) fit for structur...
Gespeichert in:
Veröffentlicht in: | The Astrophysical journal 2024-06, Vol.967 (2), p.161 |
---|---|
Hauptverfasser: | , , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
container_end_page | |
---|---|
container_issue | 2 |
container_start_page | 161 |
container_title | The Astrophysical journal |
container_volume | 967 |
creator | McQuinn, Kristen. B. W. Mao, Yao-Yuan Tollerud, Erik J. Cohen, Roger E. Shih, David Buckley, Matthew R. Dolphin, Andrew E. |
description | We report the discovery of two ultrafaint dwarf galaxies, Leo M and Leo K, that lie outside the halo of the Milky Way (MW). Using Hubble Space Telescope imaging of the resolved stars, we create color–magnitude diagrams reaching the oldest main-sequence turnoff of each system and (i) fit for structural parameters of the galaxies; (ii) measure their distances using the luminosity of the horizontal branch stars; (iii) estimate integrated magnitudes and stellar masses; and (iv) reconstruct the star formation histories. Based on their location in the Local Group, neither galaxy is currently within the halo of the MW although Leo K is located ∼26 kpc from the low-mass galaxy Leo T and these two systems may have had a past interaction. Leo M and Leo K have stellar masses of 1.8 − 0.2 + 0.3 × 10 4 M ⊙ and 1.2 ± 0.2 × 10 4 M ⊙ , and were quenched 10.6 − 1.1 + 2.2 Gyr and 12.8 − 4.2 + 0.1 Gyr ago, respectively. Given that the galaxies are at farther distances from the MW, it is unlikely that they were quenched by environmental processing. Instead, given their low stellar masses, their early quenching timescales are consistent with the scenario that a combination of reionization and stellar feedback shut down star formation at early cosmic times. |
doi_str_mv | 10.3847/1538-4357/ad429b |
format | Article |
fullrecord | <record><control><sourceid>proquest_cross</sourceid><recordid>TN_cdi_proquest_journals_3062694969</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><doaj_id>oai_doaj_org_article_a04c740a116f4155900c8eb8fa213cc7</doaj_id><sourcerecordid>3062694969</sourcerecordid><originalsourceid>FETCH-LOGICAL-c299t-e9d64ae5a16a14a7fad37a91094f605cf64b6f95ca43604900a10f93a939639d3</originalsourceid><addsrcrecordid>eNp1kc1PAjEQxRujiYjePTbx6mpLu13qzeAXEeIFordm6LZSXCm2RYJ_vbus0ZOnmXl585tJHkKnlFywPi8uac76GWd5cQkl78nZHur8SvuoQwjhmWDFyyE6inHRjD0pO2hx46L2nyZsMSxLPJhDAJ1McF-QnF9ib_Fk4_G0SgEsuGXCNxsINmK_TtGVBqe5wQ9Q-cbZ9GNXvW3xM2yv8Mh4PN5hm-7xGB1YqKI5-aldNL27nQwestHT_XBwPcp0_VHKjCwFB5MDFUA5FBZKVoCkRHIrSK6t4DNhZa6BM0G4JAQosZKBZFIwWbIuGrbc0sNCrYJ7h7BVHpzaCT68KgjJ6cooIFwXvAZQYTnN8xqm-2bWt9CjTOuiZp21rFXwH2sTk1r4dVjW7ytGRE9ILoWsXaR16eBjDMb-XqVENemoJgrVRKHadOqV83bF-dUf81_7NwwOjow</addsrcrecordid><sourcetype>Open Website</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>3062694969</pqid></control><display><type>article</type><title>Discovery and Characterization of Two Ultrafaint Dwarfs outside the Halo of the Milky Way: Leo M and Leo K</title><source>DOAJ Directory of Open Access Journals</source><source>Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals</source><source>Institute of Physics Open Access Journal Titles</source><source>Alma/SFX Local Collection</source><creator>McQuinn, Kristen. B. W. ; Mao, Yao-Yuan ; Tollerud, Erik J. ; Cohen, Roger E. ; Shih, David ; Buckley, Matthew R. ; Dolphin, Andrew E.</creator><creatorcontrib>McQuinn, Kristen. B. W. ; Mao, Yao-Yuan ; Tollerud, Erik J. ; Cohen, Roger E. ; Shih, David ; Buckley, Matthew R. ; Dolphin, Andrew E.</creatorcontrib><description>We report the discovery of two ultrafaint dwarf galaxies, Leo M and Leo K, that lie outside the halo of the Milky Way (MW). Using Hubble Space Telescope imaging of the resolved stars, we create color–magnitude diagrams reaching the oldest main-sequence turnoff of each system and (i) fit for structural parameters of the galaxies; (ii) measure their distances using the luminosity of the horizontal branch stars; (iii) estimate integrated magnitudes and stellar masses; and (iv) reconstruct the star formation histories. Based on their location in the Local Group, neither galaxy is currently within the halo of the MW although Leo K is located ∼26 kpc from the low-mass galaxy Leo T and these two systems may have had a past interaction. Leo M and Leo K have stellar masses of 1.8 − 0.2 + 0.3 × 10 4 M ⊙ and 1.2 ± 0.2 × 10 4 M ⊙ , and were quenched 10.6 − 1.1 + 2.2 Gyr and 12.8 − 4.2 + 0.1 Gyr ago, respectively. Given that the galaxies are at farther distances from the MW, it is unlikely that they were quenched by environmental processing. Instead, given their low stellar masses, their early quenching timescales are consistent with the scenario that a combination of reionization and stellar feedback shut down star formation at early cosmic times.</description><identifier>ISSN: 0004-637X</identifier><identifier>EISSN: 1538-4357</identifier><identifier>DOI: 10.3847/1538-4357/ad429b</identifier><language>eng</language><publisher>Philadelphia: The American Astronomical Society</publisher><subject>Dwarf galaxies ; Galaxies ; Galaxy quenching ; Hertzsprung Russell diagram ; Horizontal branch stars ; Hubble Space Telescope ; Ionization ; Local Group ; Local group (astronomy) ; Luminosity ; Milky Way ; Quenching ; Reionization ; Space telescopes ; Star & galaxy formation ; Star formation ; Stars ; Stars & galaxies ; Stellar populations</subject><ispartof>The Astrophysical journal, 2024-06, Vol.967 (2), p.161</ispartof><rights>2024. The Author(s). Published by the American Astronomical Society.</rights><rights>2024. The Author(s). Published by the American Astronomical Society. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><cites>FETCH-LOGICAL-c299t-e9d64ae5a16a14a7fad37a91094f605cf64b6f95ca43604900a10f93a939639d3</cites><orcidid>0000-0002-1200-0820 ; 0000-0001-8416-4093 ; 0000-0003-3408-3871 ; 0000-0001-5538-2614 ; 0000-0002-9599-310X ; 0000-0002-2970-7435 ; 0000-0003-1109-3460</orcidid></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktopdf>$$Uhttps://iopscience.iop.org/article/10.3847/1538-4357/ad429b/pdf$$EPDF$$P50$$Giop$$Hfree_for_read</linktopdf><link.rule.ids>314,780,784,864,2102,27924,27925,38890,53867</link.rule.ids></links><search><creatorcontrib>McQuinn, Kristen. B. W.</creatorcontrib><creatorcontrib>Mao, Yao-Yuan</creatorcontrib><creatorcontrib>Tollerud, Erik J.</creatorcontrib><creatorcontrib>Cohen, Roger E.</creatorcontrib><creatorcontrib>Shih, David</creatorcontrib><creatorcontrib>Buckley, Matthew R.</creatorcontrib><creatorcontrib>Dolphin, Andrew E.</creatorcontrib><title>Discovery and Characterization of Two Ultrafaint Dwarfs outside the Halo of the Milky Way: Leo M and Leo K</title><title>The Astrophysical journal</title><addtitle>APJ</addtitle><addtitle>Astrophys. J</addtitle><description>We report the discovery of two ultrafaint dwarf galaxies, Leo M and Leo K, that lie outside the halo of the Milky Way (MW). Using Hubble Space Telescope imaging of the resolved stars, we create color–magnitude diagrams reaching the oldest main-sequence turnoff of each system and (i) fit for structural parameters of the galaxies; (ii) measure their distances using the luminosity of the horizontal branch stars; (iii) estimate integrated magnitudes and stellar masses; and (iv) reconstruct the star formation histories. Based on their location in the Local Group, neither galaxy is currently within the halo of the MW although Leo K is located ∼26 kpc from the low-mass galaxy Leo T and these two systems may have had a past interaction. Leo M and Leo K have stellar masses of 1.8 − 0.2 + 0.3 × 10 4 M ⊙ and 1.2 ± 0.2 × 10 4 M ⊙ , and were quenched 10.6 − 1.1 + 2.2 Gyr and 12.8 − 4.2 + 0.1 Gyr ago, respectively. Given that the galaxies are at farther distances from the MW, it is unlikely that they were quenched by environmental processing. Instead, given their low stellar masses, their early quenching timescales are consistent with the scenario that a combination of reionization and stellar feedback shut down star formation at early cosmic times.</description><subject>Dwarf galaxies</subject><subject>Galaxies</subject><subject>Galaxy quenching</subject><subject>Hertzsprung Russell diagram</subject><subject>Horizontal branch stars</subject><subject>Hubble Space Telescope</subject><subject>Ionization</subject><subject>Local Group</subject><subject>Local group (astronomy)</subject><subject>Luminosity</subject><subject>Milky Way</subject><subject>Quenching</subject><subject>Reionization</subject><subject>Space telescopes</subject><subject>Star & galaxy formation</subject><subject>Star formation</subject><subject>Stars</subject><subject>Stars & galaxies</subject><subject>Stellar populations</subject><issn>0004-637X</issn><issn>1538-4357</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2024</creationdate><recordtype>article</recordtype><sourceid>O3W</sourceid><sourceid>DOA</sourceid><recordid>eNp1kc1PAjEQxRujiYjePTbx6mpLu13qzeAXEeIFordm6LZSXCm2RYJ_vbus0ZOnmXl585tJHkKnlFywPi8uac76GWd5cQkl78nZHur8SvuoQwjhmWDFyyE6inHRjD0pO2hx46L2nyZsMSxLPJhDAJ1McF-QnF9ib_Fk4_G0SgEsuGXCNxsINmK_TtGVBqe5wQ9Q-cbZ9GNXvW3xM2yv8Mh4PN5hm-7xGB1YqKI5-aldNL27nQwestHT_XBwPcp0_VHKjCwFB5MDFUA5FBZKVoCkRHIrSK6t4DNhZa6BM0G4JAQosZKBZFIwWbIuGrbc0sNCrYJ7h7BVHpzaCT68KgjJ6cooIFwXvAZQYTnN8xqm-2bWt9CjTOuiZp21rFXwH2sTk1r4dVjW7ytGRE9ILoWsXaR16eBjDMb-XqVENemoJgrVRKHadOqV83bF-dUf81_7NwwOjow</recordid><startdate>20240601</startdate><enddate>20240601</enddate><creator>McQuinn, Kristen. B. W.</creator><creator>Mao, Yao-Yuan</creator><creator>Tollerud, Erik J.</creator><creator>Cohen, Roger E.</creator><creator>Shih, David</creator><creator>Buckley, Matthew R.</creator><creator>Dolphin, Andrew E.</creator><general>The American Astronomical Society</general><general>IOP Publishing</general><scope>O3W</scope><scope>TSCCA</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7TG</scope><scope>8FD</scope><scope>H8D</scope><scope>KL.</scope><scope>L7M</scope><scope>DOA</scope><orcidid>https://orcid.org/0000-0002-1200-0820</orcidid><orcidid>https://orcid.org/0000-0001-8416-4093</orcidid><orcidid>https://orcid.org/0000-0003-3408-3871</orcidid><orcidid>https://orcid.org/0000-0001-5538-2614</orcidid><orcidid>https://orcid.org/0000-0002-9599-310X</orcidid><orcidid>https://orcid.org/0000-0002-2970-7435</orcidid><orcidid>https://orcid.org/0000-0003-1109-3460</orcidid></search><sort><creationdate>20240601</creationdate><title>Discovery and Characterization of Two Ultrafaint Dwarfs outside the Halo of the Milky Way: Leo M and Leo K</title><author>McQuinn, Kristen. B. W. ; Mao, Yao-Yuan ; Tollerud, Erik J. ; Cohen, Roger E. ; Shih, David ; Buckley, Matthew R. ; Dolphin, Andrew E.</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c299t-e9d64ae5a16a14a7fad37a91094f605cf64b6f95ca43604900a10f93a939639d3</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2024</creationdate><topic>Dwarf galaxies</topic><topic>Galaxies</topic><topic>Galaxy quenching</topic><topic>Hertzsprung Russell diagram</topic><topic>Horizontal branch stars</topic><topic>Hubble Space Telescope</topic><topic>Ionization</topic><topic>Local Group</topic><topic>Local group (astronomy)</topic><topic>Luminosity</topic><topic>Milky Way</topic><topic>Quenching</topic><topic>Reionization</topic><topic>Space telescopes</topic><topic>Star & galaxy formation</topic><topic>Star formation</topic><topic>Stars</topic><topic>Stars & galaxies</topic><topic>Stellar populations</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>McQuinn, Kristen. B. W.</creatorcontrib><creatorcontrib>Mao, Yao-Yuan</creatorcontrib><creatorcontrib>Tollerud, Erik J.</creatorcontrib><creatorcontrib>Cohen, Roger E.</creatorcontrib><creatorcontrib>Shih, David</creatorcontrib><creatorcontrib>Buckley, Matthew R.</creatorcontrib><creatorcontrib>Dolphin, Andrew E.</creatorcontrib><collection>Institute of Physics Open Access Journal Titles</collection><collection>IOPscience (Open Access)</collection><collection>CrossRef</collection><collection>Meteorological & Geoastrophysical Abstracts</collection><collection>Technology Research Database</collection><collection>Aerospace Database</collection><collection>Meteorological & Geoastrophysical Abstracts - Academic</collection><collection>Advanced Technologies Database with Aerospace</collection><collection>DOAJ Directory of Open Access Journals</collection><jtitle>The Astrophysical journal</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>McQuinn, Kristen. B. W.</au><au>Mao, Yao-Yuan</au><au>Tollerud, Erik J.</au><au>Cohen, Roger E.</au><au>Shih, David</au><au>Buckley, Matthew R.</au><au>Dolphin, Andrew E.</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Discovery and Characterization of Two Ultrafaint Dwarfs outside the Halo of the Milky Way: Leo M and Leo K</atitle><jtitle>The Astrophysical journal</jtitle><stitle>APJ</stitle><addtitle>Astrophys. J</addtitle><date>2024-06-01</date><risdate>2024</risdate><volume>967</volume><issue>2</issue><spage>161</spage><pages>161-</pages><issn>0004-637X</issn><eissn>1538-4357</eissn><abstract>We report the discovery of two ultrafaint dwarf galaxies, Leo M and Leo K, that lie outside the halo of the Milky Way (MW). Using Hubble Space Telescope imaging of the resolved stars, we create color–magnitude diagrams reaching the oldest main-sequence turnoff of each system and (i) fit for structural parameters of the galaxies; (ii) measure their distances using the luminosity of the horizontal branch stars; (iii) estimate integrated magnitudes and stellar masses; and (iv) reconstruct the star formation histories. Based on their location in the Local Group, neither galaxy is currently within the halo of the MW although Leo K is located ∼26 kpc from the low-mass galaxy Leo T and these two systems may have had a past interaction. Leo M and Leo K have stellar masses of 1.8 − 0.2 + 0.3 × 10 4 M ⊙ and 1.2 ± 0.2 × 10 4 M ⊙ , and were quenched 10.6 − 1.1 + 2.2 Gyr and 12.8 − 4.2 + 0.1 Gyr ago, respectively. Given that the galaxies are at farther distances from the MW, it is unlikely that they were quenched by environmental processing. Instead, given their low stellar masses, their early quenching timescales are consistent with the scenario that a combination of reionization and stellar feedback shut down star formation at early cosmic times.</abstract><cop>Philadelphia</cop><pub>The American Astronomical Society</pub><doi>10.3847/1538-4357/ad429b</doi><tpages>11</tpages><orcidid>https://orcid.org/0000-0002-1200-0820</orcidid><orcidid>https://orcid.org/0000-0001-8416-4093</orcidid><orcidid>https://orcid.org/0000-0003-3408-3871</orcidid><orcidid>https://orcid.org/0000-0001-5538-2614</orcidid><orcidid>https://orcid.org/0000-0002-9599-310X</orcidid><orcidid>https://orcid.org/0000-0002-2970-7435</orcidid><orcidid>https://orcid.org/0000-0003-1109-3460</orcidid><oa>free_for_read</oa></addata></record> |
fulltext | fulltext |
identifier | ISSN: 0004-637X |
ispartof | The Astrophysical journal, 2024-06, Vol.967 (2), p.161 |
issn | 0004-637X 1538-4357 |
language | eng |
recordid | cdi_proquest_journals_3062694969 |
source | DOAJ Directory of Open Access Journals; Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals; Institute of Physics Open Access Journal Titles; Alma/SFX Local Collection |
subjects | Dwarf galaxies Galaxies Galaxy quenching Hertzsprung Russell diagram Horizontal branch stars Hubble Space Telescope Ionization Local Group Local group (astronomy) Luminosity Milky Way Quenching Reionization Space telescopes Star & galaxy formation Star formation Stars Stars & galaxies Stellar populations |
title | Discovery and Characterization of Two Ultrafaint Dwarfs outside the Halo of the Milky Way: Leo M and Leo K |
url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-23T03%3A42%3A48IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_cross&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Discovery%20and%20Characterization%20of%20Two%20Ultrafaint%20Dwarfs%20outside%20the%20Halo%20of%20the%20Milky%20Way:%20Leo%20M%20and%20Leo%20K&rft.jtitle=The%20Astrophysical%20journal&rft.au=McQuinn,%20Kristen.%20B.%20W.&rft.date=2024-06-01&rft.volume=967&rft.issue=2&rft.spage=161&rft.pages=161-&rft.issn=0004-637X&rft.eissn=1538-4357&rft_id=info:doi/10.3847/1538-4357/ad429b&rft_dat=%3Cproquest_cross%3E3062694969%3C/proquest_cross%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=3062694969&rft_id=info:pmid/&rft_doaj_id=oai_doaj_org_article_a04c740a116f4155900c8eb8fa213cc7&rfr_iscdi=true |