Age dating the Galactic bar with the nuclear stellar disc

ABSTRACT From the decades of the theoretical studies, it is well known that the formation of the bar triggers the gas funnelling into the central sub-kpc region and leads to the formation of a kinematically cold nuclear stellar disc (NSD). We demonstrate that this mechanism can be used to identify t...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Monthly notices of the Royal Astronomical Society 2020-03, Vol.492 (3), p.4500-4511
Hauptverfasser: Baba, Junichi, Kawata, Daisuke
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
container_end_page 4511
container_issue 3
container_start_page 4500
container_title Monthly notices of the Royal Astronomical Society
container_volume 492
creator Baba, Junichi
Kawata, Daisuke
description ABSTRACT From the decades of the theoretical studies, it is well known that the formation of the bar triggers the gas funnelling into the central sub-kpc region and leads to the formation of a kinematically cold nuclear stellar disc (NSD). We demonstrate that this mechanism can be used to identify the formation epoch of the Galactic bar, using an N-body/hydrodynamics simulation of an isolated Milky Way–like galaxy. As shown in many previous literature, our simulation shows that the bar formation triggers an intense star formation for ∼1 Gyr in the central region and forms an NSD. As a result, the oldest age limit of the NSD is relatively sharp, and the oldest population becomes similar to the age of the bar. Therefore, the age distribution of the NSD tells us the formation epoch of the bar. We discuss that a major challenge in measuring the age distribution of the NSD in the Milky Way is contamination from other non-negligible stellar components in the central region, such as a classical bulge component. We demonstrate that because the NSD is kinematically colder than the other stellar populations in the Galactic central region, the NSD population can be kinematically distinguished from the other stellar populations, if the 3D velocity of tracer stars is accurately measured. Hence, in addition to the line-of-sight velocities from spectroscopic surveys, the accurate measurements of the transverse velocities of stars are necessary, and hence the near-infrared space astrometry mission, JASMINE, would play a crucial role to identify the formation epoch of the Galactic bar. We also discuss that the accuracy of stellar age estimation is also crucial to measure the oldest limit of the NSD stellar population.
doi_str_mv 10.1093/mnras/staa140
format Article
fullrecord <record><control><sourceid>oup_cross</sourceid><recordid>TN_cdi_crossref_primary_10_1093_mnras_staa140</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><oup_id>10.1093/mnras/staa140</oup_id><sourcerecordid>10.1093/mnras/staa140</sourcerecordid><originalsourceid>FETCH-LOGICAL-c270t-f42f2cc92a1676c9aa76cca08009a17bcc2415bfd6fef31ea1d1b19fcdb0bf973</originalsourceid><addsrcrecordid>eNqFj0FLw0AQhRdRMFaP3nP0snZmN9l0j6VoKxS86DlMJrttJE3L7hbx3xvb3r28B4-PB58QjwjPCFZPd0OgOI2JCAu4EhlqU0pljbkWGYAu5axCvBV3MX4BQKGVyYSdb1zeUuqGTZ62Ll9ST5w6zhsK-XeXtqd1OHLvxiEm1_djt13ke3HjqY_u4dIT8fn68rFYyfX78m0xX0tWFSTpC-UVs1WEpjJsicZkghmAJawaZlVg2fjWeOc1OsIWG7Se2wYabys9EfL8y2EfY3C-PoRuR-GnRqj_vOuTd33xHvmnM78_Hv5BfwGyTlwQ</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype></control><display><type>article</type><title>Age dating the Galactic bar with the nuclear stellar disc</title><source>Oxford Open</source><creator>Baba, Junichi ; Kawata, Daisuke</creator><creatorcontrib>Baba, Junichi ; Kawata, Daisuke</creatorcontrib><description>ABSTRACT From the decades of the theoretical studies, it is well known that the formation of the bar triggers the gas funnelling into the central sub-kpc region and leads to the formation of a kinematically cold nuclear stellar disc (NSD). We demonstrate that this mechanism can be used to identify the formation epoch of the Galactic bar, using an N-body/hydrodynamics simulation of an isolated Milky Way–like galaxy. As shown in many previous literature, our simulation shows that the bar formation triggers an intense star formation for ∼1 Gyr in the central region and forms an NSD. As a result, the oldest age limit of the NSD is relatively sharp, and the oldest population becomes similar to the age of the bar. Therefore, the age distribution of the NSD tells us the formation epoch of the bar. We discuss that a major challenge in measuring the age distribution of the NSD in the Milky Way is contamination from other non-negligible stellar components in the central region, such as a classical bulge component. We demonstrate that because the NSD is kinematically colder than the other stellar populations in the Galactic central region, the NSD population can be kinematically distinguished from the other stellar populations, if the 3D velocity of tracer stars is accurately measured. Hence, in addition to the line-of-sight velocities from spectroscopic surveys, the accurate measurements of the transverse velocities of stars are necessary, and hence the near-infrared space astrometry mission, JASMINE, would play a crucial role to identify the formation epoch of the Galactic bar. We also discuss that the accuracy of stellar age estimation is also crucial to measure the oldest limit of the NSD stellar population.</description><identifier>ISSN: 0035-8711</identifier><identifier>EISSN: 1365-2966</identifier><identifier>DOI: 10.1093/mnras/staa140</identifier><language>eng</language><publisher>Oxford University Press</publisher><ispartof>Monthly notices of the Royal Astronomical Society, 2020-03, Vol.492 (3), p.4500-4511</ispartof><rights>2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society 2020</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c270t-f42f2cc92a1676c9aa76cca08009a17bcc2415bfd6fef31ea1d1b19fcdb0bf973</citedby><cites>FETCH-LOGICAL-c270t-f42f2cc92a1676c9aa76cca08009a17bcc2415bfd6fef31ea1d1b19fcdb0bf973</cites><orcidid>0000-0001-8993-101X</orcidid></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>314,780,784,27924,27925</link.rule.ids></links><search><creatorcontrib>Baba, Junichi</creatorcontrib><creatorcontrib>Kawata, Daisuke</creatorcontrib><title>Age dating the Galactic bar with the nuclear stellar disc</title><title>Monthly notices of the Royal Astronomical Society</title><description>ABSTRACT From the decades of the theoretical studies, it is well known that the formation of the bar triggers the gas funnelling into the central sub-kpc region and leads to the formation of a kinematically cold nuclear stellar disc (NSD). We demonstrate that this mechanism can be used to identify the formation epoch of the Galactic bar, using an N-body/hydrodynamics simulation of an isolated Milky Way–like galaxy. As shown in many previous literature, our simulation shows that the bar formation triggers an intense star formation for ∼1 Gyr in the central region and forms an NSD. As a result, the oldest age limit of the NSD is relatively sharp, and the oldest population becomes similar to the age of the bar. Therefore, the age distribution of the NSD tells us the formation epoch of the bar. We discuss that a major challenge in measuring the age distribution of the NSD in the Milky Way is contamination from other non-negligible stellar components in the central region, such as a classical bulge component. We demonstrate that because the NSD is kinematically colder than the other stellar populations in the Galactic central region, the NSD population can be kinematically distinguished from the other stellar populations, if the 3D velocity of tracer stars is accurately measured. Hence, in addition to the line-of-sight velocities from spectroscopic surveys, the accurate measurements of the transverse velocities of stars are necessary, and hence the near-infrared space astrometry mission, JASMINE, would play a crucial role to identify the formation epoch of the Galactic bar. We also discuss that the accuracy of stellar age estimation is also crucial to measure the oldest limit of the NSD stellar population.</description><issn>0035-8711</issn><issn>1365-2966</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2020</creationdate><recordtype>article</recordtype><recordid>eNqFj0FLw0AQhRdRMFaP3nP0snZmN9l0j6VoKxS86DlMJrttJE3L7hbx3xvb3r28B4-PB58QjwjPCFZPd0OgOI2JCAu4EhlqU0pljbkWGYAu5axCvBV3MX4BQKGVyYSdb1zeUuqGTZ62Ll9ST5w6zhsK-XeXtqd1OHLvxiEm1_djt13ke3HjqY_u4dIT8fn68rFYyfX78m0xX0tWFSTpC-UVs1WEpjJsicZkghmAJawaZlVg2fjWeOc1OsIWG7Se2wYabys9EfL8y2EfY3C-PoRuR-GnRqj_vOuTd33xHvmnM78_Hv5BfwGyTlwQ</recordid><startdate>20200301</startdate><enddate>20200301</enddate><creator>Baba, Junichi</creator><creator>Kawata, Daisuke</creator><general>Oxford University Press</general><scope>AAYXX</scope><scope>CITATION</scope><orcidid>https://orcid.org/0000-0001-8993-101X</orcidid></search><sort><creationdate>20200301</creationdate><title>Age dating the Galactic bar with the nuclear stellar disc</title><author>Baba, Junichi ; Kawata, Daisuke</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c270t-f42f2cc92a1676c9aa76cca08009a17bcc2415bfd6fef31ea1d1b19fcdb0bf973</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2020</creationdate><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Baba, Junichi</creatorcontrib><creatorcontrib>Kawata, Daisuke</creatorcontrib><collection>CrossRef</collection><jtitle>Monthly notices of the Royal Astronomical Society</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Baba, Junichi</au><au>Kawata, Daisuke</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Age dating the Galactic bar with the nuclear stellar disc</atitle><jtitle>Monthly notices of the Royal Astronomical Society</jtitle><date>2020-03-01</date><risdate>2020</risdate><volume>492</volume><issue>3</issue><spage>4500</spage><epage>4511</epage><pages>4500-4511</pages><issn>0035-8711</issn><eissn>1365-2966</eissn><abstract>ABSTRACT From the decades of the theoretical studies, it is well known that the formation of the bar triggers the gas funnelling into the central sub-kpc region and leads to the formation of a kinematically cold nuclear stellar disc (NSD). We demonstrate that this mechanism can be used to identify the formation epoch of the Galactic bar, using an N-body/hydrodynamics simulation of an isolated Milky Way–like galaxy. As shown in many previous literature, our simulation shows that the bar formation triggers an intense star formation for ∼1 Gyr in the central region and forms an NSD. As a result, the oldest age limit of the NSD is relatively sharp, and the oldest population becomes similar to the age of the bar. Therefore, the age distribution of the NSD tells us the formation epoch of the bar. We discuss that a major challenge in measuring the age distribution of the NSD in the Milky Way is contamination from other non-negligible stellar components in the central region, such as a classical bulge component. We demonstrate that because the NSD is kinematically colder than the other stellar populations in the Galactic central region, the NSD population can be kinematically distinguished from the other stellar populations, if the 3D velocity of tracer stars is accurately measured. Hence, in addition to the line-of-sight velocities from spectroscopic surveys, the accurate measurements of the transverse velocities of stars are necessary, and hence the near-infrared space astrometry mission, JASMINE, would play a crucial role to identify the formation epoch of the Galactic bar. We also discuss that the accuracy of stellar age estimation is also crucial to measure the oldest limit of the NSD stellar population.</abstract><pub>Oxford University Press</pub><doi>10.1093/mnras/staa140</doi><tpages>12</tpages><orcidid>https://orcid.org/0000-0001-8993-101X</orcidid></addata></record>
fulltext fulltext
identifier ISSN: 0035-8711
ispartof Monthly notices of the Royal Astronomical Society, 2020-03, Vol.492 (3), p.4500-4511
issn 0035-8711
1365-2966
language eng
recordid cdi_crossref_primary_10_1093_mnras_staa140
source Oxford Open
title Age dating the Galactic bar with the nuclear stellar disc
url https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-20T15%3A42%3A12IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-oup_cross&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Age%20dating%20the%20Galactic%20bar%20with%20the%20nuclear%20stellar%20disc&rft.jtitle=Monthly%20notices%20of%20the%20Royal%20Astronomical%20Society&rft.au=Baba,%20Junichi&rft.date=2020-03-01&rft.volume=492&rft.issue=3&rft.spage=4500&rft.epage=4511&rft.pages=4500-4511&rft.issn=0035-8711&rft.eissn=1365-2966&rft_id=info:doi/10.1093/mnras/staa140&rft_dat=%3Coup_cross%3E10.1093/mnras/staa140%3C/oup_cross%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_id=info:pmid/&rft_oup_id=10.1093/mnras/staa140&rfr_iscdi=true