AustralieFrV1, Istex, Corpus, bibRecord, 001146

The star formation history in the far outer disc of M33

Identifieur interne : 001146 ( Istex/Corpus ); précédent : 001145; suivant : 001147

The star formation history in the far outer disc of M33

Auteurs : Michael K. Barker ; A. M. N. Ferguson ; A. A. Cole ; R. Ibata ; M. Irwin ; G. F. Lewis ; T. A. Smecker-Hane ; N. R. Tanvir

Source :

Monthly Notices of the Royal Astronomical Society [ 0035-8711 ] ; 2011-01-01.

RBID : ISTEX:5BD198157C610D67687BE97A8A4CA2EAC530C4AC

English descriptors

Abstract

The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use Hubble Space Telescope Advanced Camera for Surveys imaging to study the star formation history (SFH) of two fields at 9.1 and 11.6 kpc along M33's northern major axis. These fields lie at ∼ 4 and 5 V‐band disc scalelengths and straddle the break in M33's surface brightness profile. The colour–magnitude diagrams (CMDs) reach the ancient main‐sequence turn‐off with a signal‐to‐noise ratio of ∼ 5. From detailed modelling of the CMDs, we find that the majority of stars in both fields combined formed at z < 1. The mean age in the inner field, S1, is ∼ 3 ± 1 Gyr and the mean metallicity is [M/H]∼− 0.5 ± 0.2 dex. The SFH of S1 unambiguously reveals how the inside‐out growth previously measured for M33's inner disc out to extends out to the disc edge at . In comparison, the outer field, S2, is older (mean age ∼ 7 ± 2 Gyr), more metal‐poor (mean [M/H]∼− 0.8 ± 0.3 dex), and contains ∼ 30 times less stellar mass. These results provide the most compelling evidence yet that M33's age gradient reverses at large radii near the disc break and that this reversal is accompanied by a break in stellar mass surface density. We discuss several possible interpretations of this behaviour including radial stellar mixing, warping of the gaseous disc, a change in star formation efficiency and a transition to another structural component. These results offer one of the most detailed views yet of the peripheral regions of any disc galaxy and provide a much needed observational constraint on the last major epoch of star formation in the outer disc.

Url:

https://api.istex.fr/document/5BD198157C610D67687BE97A8A4CA2EAC530C4AC/fulltext/pdf

DOI: 10.1111/j.1365-2966.2010.17458.x

Links to Exploration step

ISTEX:5BD198157C610D67687BE97A8A4CA2EAC530C4AC

Le document en format XML

<record><TEI wicri:istexFullTextTei="biblStruct"><teiHeader><fileDesc><titleStmt><title xml:lang="en">The star formation history in the far outer disc of M33</title>
<author><name sortKey="Barker, Michael K" sort="Barker, Michael K" uniqKey="Barker M" first="Michael K." last="Barker">Michael K. Barker</name>
<affiliation><mods:affiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</mods:affiliation>
</affiliation>
<affiliation><mods:affiliation>E-mail: mkb@roe.ac.uk</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Ferguson, A M N" sort="Ferguson, A M N" uniqKey="Ferguson A" first="A. M. N." last="Ferguson">A. M. N. Ferguson</name>
<affiliation><mods:affiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</mods:affiliation>
</affiliation>
<affiliation><mods:affiliation>E-mail: mkb@roe.ac.uk</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Cole, A A" sort="Cole, A A" uniqKey="Cole A" first="A. A." last="Cole">A. A. Cole</name>
<affiliation><mods:affiliation>School of Mathematics & Physics, University of Tasmania, Private Bag 37, Hobart, 7001, TAS, Australia</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Ibata, R" sort="Ibata, R" uniqKey="Ibata R" first="R." last="Ibata">R. Ibata</name>
<affiliation><mods:affiliation>Observatoire Astronomique de Strasbourg, Strasbourg, France</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Irwin, M" sort="Irwin, M" uniqKey="Irwin M" first="M." last="Irwin">M. Irwin</name>
<affiliation><mods:affiliation>Institute of Astronomy, Cambridge University, Cambridge CB3 0HA</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Lewis, G F" sort="Lewis, G F" uniqKey="Lewis G" first="G. F." last="Lewis">G. F. Lewis</name>
<affiliation><mods:affiliation>Sydney Institute of Astronomy, School of Physics, The University of Sydney, Sydney, NSW 2006, Australia</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Smecker Ane, T A" sort="Smecker Ane, T A" uniqKey="Smecker Ane T" first="T. A." last="Smecker-Hane">T. A. Smecker-Hane</name>
<affiliation><mods:affiliation>Department of Physics & Astronomy, University of California, Irvine, CA 92697‐4575, USA</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Tanvir, N R" sort="Tanvir, N R" uniqKey="Tanvir N" first="N. R." last="Tanvir">N. R. Tanvir</name>
<affiliation><mods:affiliation>Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH</mods:affiliation>
</affiliation>
</author>
</titleStmt>
<publicationStmt><idno type="wicri:source">ISTEX</idno>
<idno type="RBID">ISTEX:5BD198157C610D67687BE97A8A4CA2EAC530C4AC</idno>
<date when="2011" year="2011">2011</date>
<idno type="doi">10.1111/j.1365-2966.2010.17458.x</idno>
<idno type="url">https://api.istex.fr/document/5BD198157C610D67687BE97A8A4CA2EAC530C4AC/fulltext/pdf</idno>
<idno type="wicri:Area/Istex/Corpus">001146</idno>
<idno type="wicri:explorRef" wicri:stream="Istex" wicri:step="Corpus" wicri:corpus="ISTEX">001146</idno>
</publicationStmt>
<sourceDesc><biblStruct><analytic><title level="a" type="main">The star formation history in the far outer disc of M33</title>
<author><name sortKey="Barker, Michael K" sort="Barker, Michael K" uniqKey="Barker M" first="Michael K." last="Barker">Michael K. Barker</name>
<affiliation><mods:affiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</mods:affiliation>
</affiliation>
<affiliation><mods:affiliation>E-mail: mkb@roe.ac.uk</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Ferguson, A M N" sort="Ferguson, A M N" uniqKey="Ferguson A" first="A. M. N." last="Ferguson">A. M. N. Ferguson</name>
<affiliation><mods:affiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</mods:affiliation>
</affiliation>
<affiliation><mods:affiliation>E-mail: mkb@roe.ac.uk</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Cole, A A" sort="Cole, A A" uniqKey="Cole A" first="A. A." last="Cole">A. A. Cole</name>
<affiliation><mods:affiliation>School of Mathematics & Physics, University of Tasmania, Private Bag 37, Hobart, 7001, TAS, Australia</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Ibata, R" sort="Ibata, R" uniqKey="Ibata R" first="R." last="Ibata">R. Ibata</name>
<affiliation><mods:affiliation>Observatoire Astronomique de Strasbourg, Strasbourg, France</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Irwin, M" sort="Irwin, M" uniqKey="Irwin M" first="M." last="Irwin">M. Irwin</name>
<affiliation><mods:affiliation>Institute of Astronomy, Cambridge University, Cambridge CB3 0HA</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Lewis, G F" sort="Lewis, G F" uniqKey="Lewis G" first="G. F." last="Lewis">G. F. Lewis</name>
<affiliation><mods:affiliation>Sydney Institute of Astronomy, School of Physics, The University of Sydney, Sydney, NSW 2006, Australia</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Smecker Ane, T A" sort="Smecker Ane, T A" uniqKey="Smecker Ane T" first="T. A." last="Smecker-Hane">T. A. Smecker-Hane</name>
<affiliation><mods:affiliation>Department of Physics & Astronomy, University of California, Irvine, CA 92697‐4575, USA</mods:affiliation>
</affiliation>
</author>
<author><name sortKey="Tanvir, N R" sort="Tanvir, N R" uniqKey="Tanvir N" first="N. R." last="Tanvir">N. R. Tanvir</name>
<affiliation><mods:affiliation>Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH</mods:affiliation>
</affiliation>
</author>
</analytic>
<monogr></monogr>
<series><title level="j" type="main">Monthly Notices of the Royal Astronomical Society</title>
<title level="j" type="alt">MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY</title>
<idno type="ISSN">0035-8711</idno>
<idno type="eISSN">1365-2966</idno>
<imprint><biblScope unit="vol">410</biblScope>
<biblScope unit="issue">1</biblScope>
<biblScope unit="page" from="504">504</biblScope>
<biblScope unit="page" to="516">516</biblScope>
<biblScope unit="page-count">13</biblScope>
<publisher>Blackwell Publishing Ltd</publisher>
<pubPlace>Oxford, UK</pubPlace>
<date type="published" when="2011-01-01">2011-01-01</date>
</imprint>
<idno type="ISSN">0035-8711</idno>
</series>
</biblStruct>
</sourceDesc>
<seriesStmt><idno type="ISSN">0035-8711</idno>
</seriesStmt>
</fileDesc>
<profileDesc><textClass><keywords scheme="KwdEn" xml:lang="en"><term>Aparicio</term>
<term>Basti</term>
<term>Besancon model</term>
<term>Black line</term>
<term>Blue envelope</term>
<term>Blue peak</term>
<term>Blue plume</term>
<term>Bolometric corrections</term>
<term>Cent completeness</term>
<term>Cmds</term>
<term>Colour</term>
<term>Compelling evidence</term>
<term>Constant metallicity</term>
<term>Corbelli schneider</term>
<term>Corrections</term>
<term>Correlated errors</term>
<term>Cosmic rays</term>
<term>Cosmological</term>
<term>Cosmological context</term>
<term>Cosmological simulation</term>
<term>Cosmological simulations</term>
<term>Disc</term>
<term>Disc edge</term>
<term>Disc formation</term>
<term>Disc galaxies</term>
<term>Disc galaxy</term>
<term>Disc scalelengths</term>
<term>Distance modulus</term>
<term>Dominant population</term>
<term>Eld</term>
<term>Elmegreen parravano</term>
<term>Equal logarithmic intervals</term>
<term>Error bars</term>
<term>Foreground stars</term>
<term>Further details</term>
<term>Galaxy</term>
<term>Gallart</term>
<term>Good agreement</term>
<term>Governato</term>
<term>Halo</term>
<term>Harris zaritsky</term>
<term>Hubble space telescope</term>
<term>Hybrid approach</term>
<term>Inner disc</term>
<term>Intermediate ages</term>
<term>Journal compilation</term>
<term>Large radii</term>
<term>Light curves</term>
<term>Linear combination</term>
<term>Magenta line</term>
<term>Magnitude range</term>
<term>Metallicities</term>
<term>Metallicity</term>
<term>Metallicity gradient</term>
<term>Metallicity spread</term>
<term>Mnras</term>
<term>Morphology</term>
<term>Older population</term>
<term>Optical image</term>
<term>Outer disc</term>
<term>Outer disc star formation history</term>
<term>Panels show</term>
<term>Parameter space</term>
<term>Photometric</term>
<term>Photometric errors</term>
<term>Private communication</term>
<term>Radial migration</term>
<term>Random search</term>
<term>Sarajedini</term>
<term>Scalelengths</term>
<term>Sharp drop</term>
<term>Simulation</term>
<term>Small fraction</term>
<term>Solar oxygen abundance</term>
<term>Solid lines</term>
<term>Spiral galaxies</term>
<term>Star</term>
<term>Star formation</term>
<term>Star formation history</term>
<term>Star tests</term>
<term>Steinmetz navarro</term>
<term>Stellar</term>
<term>Stellar mass</term>
<term>Stellar mass density</term>
<term>Stellar mass surface density</term>
<term>Stellar populations</term>
<term>Stellar surface density</term>
<term>Stock implementation</term>
<term>Such stars</term>
<term>Synthetic cmds</term>
<term>Systematic error</term>
<term>Thick disc</term>
<term>Thick discs</term>
<term>Thin disc</term>
<term>Thin discs</term>
<term>Total model</term>
<term>Tting</term>
<term>Tting analysis</term>
<term>Tting region</term>
<term>Upper limit</term>
<term>Upper limits</term>
<term>Variable stars</term>
<term>Vertical clump</term>
<term>Vertical clump morphology</term>
<term>Younger ages</term>
<term>Youngest stars</term>
</keywords>
<keywords scheme="Teeft" xml:lang="en"><term>Aparicio</term>
<term>Basti</term>
<term>Besancon model</term>
<term>Black line</term>
<term>Blue envelope</term>
<term>Blue peak</term>
<term>Blue plume</term>
<term>Bolometric corrections</term>
<term>Cent completeness</term>
<term>Cmds</term>
<term>Colour</term>
<term>Compelling evidence</term>
<term>Constant metallicity</term>
<term>Corbelli schneider</term>
<term>Corrections</term>
<term>Correlated errors</term>
<term>Cosmic rays</term>
<term>Cosmological</term>
<term>Cosmological context</term>
<term>Cosmological simulation</term>
<term>Cosmological simulations</term>
<term>Disc</term>
<term>Disc edge</term>
<term>Disc formation</term>
<term>Disc galaxies</term>
<term>Disc galaxy</term>
<term>Disc scalelengths</term>
<term>Distance modulus</term>
<term>Dominant population</term>
<term>Eld</term>
<term>Elmegreen parravano</term>
<term>Equal logarithmic intervals</term>
<term>Error bars</term>
<term>Foreground stars</term>
<term>Further details</term>
<term>Galaxy</term>
<term>Gallart</term>
<term>Good agreement</term>
<term>Governato</term>
<term>Halo</term>
<term>Harris zaritsky</term>
<term>Hubble space telescope</term>
<term>Hybrid approach</term>
<term>Inner disc</term>
<term>Intermediate ages</term>
<term>Journal compilation</term>
<term>Large radii</term>
<term>Light curves</term>
<term>Linear combination</term>
<term>Magenta line</term>
<term>Magnitude range</term>
<term>Metallicities</term>
<term>Metallicity</term>
<term>Metallicity gradient</term>
<term>Metallicity spread</term>
<term>Mnras</term>
<term>Morphology</term>
<term>Older population</term>
<term>Optical image</term>
<term>Outer disc</term>
<term>Outer disc star formation history</term>
<term>Panels show</term>
<term>Parameter space</term>
<term>Photometric</term>
<term>Photometric errors</term>
<term>Private communication</term>
<term>Radial migration</term>
<term>Random search</term>
<term>Sarajedini</term>
<term>Scalelengths</term>
<term>Sharp drop</term>
<term>Simulation</term>
<term>Small fraction</term>
<term>Solar oxygen abundance</term>
<term>Solid lines</term>
<term>Spiral galaxies</term>
<term>Star</term>
<term>Star formation</term>
<term>Star formation history</term>
<term>Star tests</term>
<term>Steinmetz navarro</term>
<term>Stellar</term>
<term>Stellar mass</term>
<term>Stellar mass density</term>
<term>Stellar mass surface density</term>
<term>Stellar populations</term>
<term>Stellar surface density</term>
<term>Stock implementation</term>
<term>Such stars</term>
<term>Synthetic cmds</term>
<term>Systematic error</term>
<term>Thick disc</term>
<term>Thick discs</term>
<term>Thin disc</term>
<term>Thin discs</term>
<term>Total model</term>
<term>Tting</term>
<term>Tting analysis</term>
<term>Tting region</term>
<term>Upper limit</term>
<term>Upper limits</term>
<term>Variable stars</term>
<term>Vertical clump</term>
<term>Vertical clump morphology</term>
<term>Younger ages</term>
<term>Youngest stars</term>
</keywords>
</textClass>
</profileDesc>
</teiHeader>
<front><div type="abstract" xml:lang="en">The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use Hubble Space Telescope Advanced Camera for Surveys imaging to study the star formation history (SFH) of two fields at 9.1 and 11.6 kpc along M33's northern major axis. These fields lie at ∼ 4 and 5 V‐band disc scalelengths and straddle the break in M33's surface brightness profile. The colour–magnitude diagrams (CMDs) reach the ancient main‐sequence turn‐off with a signal‐to‐noise ratio of ∼ 5. From detailed modelling of the CMDs, we find that the majority of stars in both fields combined formed at z < 1. The mean age in the inner field, S1, is ∼ 3 ± 1 Gyr and the mean metallicity is [M/H]∼− 0.5 ± 0.2 dex. The SFH of S1 unambiguously reveals how the inside‐out growth previously measured for M33's inner disc out to extends out to the disc edge at . In comparison, the outer field, S2, is older (mean age ∼ 7 ± 2 Gyr), more metal‐poor (mean [M/H]∼− 0.8 ± 0.3 dex), and contains ∼ 30 times less stellar mass. These results provide the most compelling evidence yet that M33's age gradient reverses at large radii near the disc break and that this reversal is accompanied by a break in stellar mass surface density. We discuss several possible interpretations of this behaviour including radial stellar mixing, warping of the gaseous disc, a change in star formation efficiency and a transition to another structural component. These results offer one of the most detailed views yet of the peripheral regions of any disc galaxy and provide a much needed observational constraint on the last major epoch of star formation in the outer disc.</div>
</front>
</TEI>
<istex><corpusName>wiley</corpusName>
<keywords><teeft><json:string>metallicity</json:string>
<json:string>eld</json:string>
<json:string>cmds</json:string>
<json:string>mnras</json:string>
<json:string>stellar</json:string>
<json:string>colour</json:string>
<json:string>inner disc</json:string>
<json:string>journal compilation</json:string>
<json:string>gallart</json:string>
<json:string>tting</json:string>
<json:string>star formation</json:string>
<json:string>thin disc</json:string>
<json:string>basti</json:string>
<json:string>sarajedini</json:string>
<json:string>error bars</json:string>
<json:string>disc</json:string>
<json:string>metallicities</json:string>
<json:string>vertical clump</json:string>
<json:string>photometric</json:string>
<json:string>scalelengths</json:string>
<json:string>governato</json:string>
<json:string>thick disc</json:string>
<json:string>blue peak</json:string>
<json:string>bolometric corrections</json:string>
<json:string>galaxy</json:string>
<json:string>aparicio</json:string>
<json:string>disc scalelengths</json:string>
<json:string>stellar surface density</json:string>
<json:string>star tests</json:string>
<json:string>outer disc</json:string>
<json:string>tting analysis</json:string>
<json:string>total model</json:string>
<json:string>simulation</json:string>
<json:string>outer disc star formation history</json:string>
<json:string>synthetic cmds</json:string>
<json:string>spiral galaxies</json:string>
<json:string>distance modulus</json:string>
<json:string>youngest stars</json:string>
<json:string>small fraction</json:string>
<json:string>photometric errors</json:string>
<json:string>optical image</json:string>
<json:string>stellar populations</json:string>
<json:string>thick discs</json:string>
<json:string>good agreement</json:string>
<json:string>such stars</json:string>
<json:string>disc formation</json:string>
<json:string>harris zaritsky</json:string>
<json:string>intermediate ages</json:string>
<json:string>foreground stars</json:string>
<json:string>constant metallicity</json:string>
<json:string>metallicity spread</json:string>
<json:string>stellar mass</json:string>
<json:string>disc edge</json:string>
<json:string>solid lines</json:string>
<json:string>hubble space telescope</json:string>
<json:string>large radii</json:string>
<json:string>halo</json:string>
<json:string>morphology</json:string>
<json:string>compelling evidence</json:string>
<json:string>thin discs</json:string>
<json:string>sharp drop</json:string>
<json:string>corbelli schneider</json:string>
<json:string>light curves</json:string>
<json:string>variable stars</json:string>
<json:string>equal logarithmic intervals</json:string>
<json:string>stellar mass surface density</json:string>
<json:string>radial migration</json:string>
<json:string>cosmological context</json:string>
<json:string>blue envelope</json:string>
<json:string>disc galaxies</json:string>
<json:string>steinmetz navarro</json:string>
<json:string>magnitude range</json:string>
<json:string>black line</json:string>
<json:string>magenta line</json:string>
<json:string>further details</json:string>
<json:string>cosmic rays</json:string>
<json:string>dominant population</json:string>
<json:string>older population</json:string>
<json:string>vertical clump morphology</json:string>
<json:string>cosmological simulations</json:string>
<json:string>elmegreen parravano</json:string>
<json:string>star formation history</json:string>
<json:string>blue plume</json:string>
<json:string>younger ages</json:string>
<json:string>stellar mass density</json:string>
<json:string>linear combination</json:string>
<json:string>cent completeness</json:string>
<json:string>systematic error</json:string>
<json:string>tting region</json:string>
<json:string>parameter space</json:string>
<json:string>stock implementation</json:string>
<json:string>random search</json:string>
<json:string>hybrid approach</json:string>
<json:string>correlated errors</json:string>
<json:string>disc galaxy</json:string>
<json:string>metallicity gradient</json:string>
<json:string>solar oxygen abundance</json:string>
<json:string>panels show</json:string>
<json:string>upper limit</json:string>
<json:string>upper limits</json:string>
<json:string>besancon model</json:string>
<json:string>private communication</json:string>
<json:string>cosmological simulation</json:string>
<json:string>corrections</json:string>
<json:string>cosmological</json:string>
<json:string>star</json:string>
</teeft>
</keywords>
<author><json:item><name>Michael K. Barker</name>
<affiliations><json:string>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</json:string>
<json:string>E-mail: mkb@roe.ac.uk</json:string>
</affiliations>
</json:item>
<json:item><name>A. M. N. Ferguson</name>
<affiliations><json:string>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</json:string>
<json:string>E-mail: mkb@roe.ac.uk</json:string>
</affiliations>
</json:item>
<json:item><name>A. A. Cole</name>
<affiliations><json:string>School of Mathematics & Physics, University of Tasmania, Private Bag 37, Hobart, 7001, TAS, Australia</json:string>
</affiliations>
</json:item>
<json:item><name>R. Ibata</name>
<affiliations><json:string>Observatoire Astronomique de Strasbourg, Strasbourg, France</json:string>
</affiliations>
</json:item>
<json:item><name>M. Irwin</name>
<affiliations><json:string>Institute of Astronomy, Cambridge University, Cambridge CB3 0HA</json:string>
</affiliations>
</json:item>
<json:item><name>G. F. Lewis</name>
<affiliations><json:string>Sydney Institute of Astronomy, School of Physics, The University of Sydney, Sydney, NSW 2006, Australia</json:string>
</affiliations>
</json:item>
<json:item><name>T. A. Smecker‐Hane</name>
<affiliations><json:string>Department of Physics & Astronomy, University of California, Irvine, CA 92697‐4575, USA</json:string>
</affiliations>
</json:item>
<json:item><name>N. R. Tanvir</name>
<affiliations><json:string>Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH</json:string>
</affiliations>
</json:item>
</author>
<subject><json:item><lang><json:string>eng</json:string>
</lang>
<value>galaxies: abundances</value>
</json:item>
<json:item><lang><json:string>eng</json:string>
</lang>
<value>galaxies: evolution</value>
</json:item>
<json:item><lang><json:string>eng</json:string>
</lang>
<value>galaxies: individual: Messier Number: M33</value>
</json:item>
<json:item><lang><json:string>eng</json:string>
</lang>
<value>Local Group</value>
</json:item>
<json:item><lang><json:string>eng</json:string>
</lang>
<value>galaxies: spiral</value>
</json:item>
<json:item><lang><json:string>eng</json:string>
</lang>
<value>galaxies: stellar content</value>
</json:item>
</subject>
<articleId><json:string>MNR17458</json:string>
</articleId>
<arkIstex>ark:/67375/WNG-QNFD9RXZ-G</arkIstex>
<language><json:string>eng</json:string>
</language>
<originalGenre><json:string>article</json:string>
</originalGenre>
<abstract>The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use Hubble Space Telescope Advanced Camera for Surveys imaging to study the star formation history (SFH) of two fields at 9.1 and 11.6 kpc along M33's northern major axis. These fields lie at ∼ 4 and 5 V‐band disc scalelengths and straddle the break in M33's surface brightness profile. The colour–magnitude diagrams (CMDs) reach the ancient main‐sequence turn‐off with a signal‐to‐noise ratio of ∼ 5. From detailed modelling of the CMDs, we find that the majority of stars in both fields combined formed at z > 1. The mean age in the inner field, S1, is ∼ 3 ± 1 Gyr and the mean metallicity is [M/H]∼− 0.5 ± 0.2 dex. The SFH of S1 unambiguously reveals how the inside‐out growth previously measured for M33's inner disc out to extends out to the disc edge at . In comparison, the outer field, S2, is older (mean age ∼ 7 ± 2 Gyr), more metal‐poor (mean [M/H]∼− 0.8 ± 0.3 dex), and contains ∼ 30 times less stellar mass. These results provide the most compelling evidence yet that M33's age gradient reverses at large radii near the disc break and that this reversal is accompanied by a break in stellar mass surface density. We discuss several possible interpretations of this behaviour including radial stellar mixing, warping of the gaseous disc, a change in star formation efficiency and a transition to another structural component. These results offer one of the most detailed views yet of the peripheral regions of any disc galaxy and provide a much needed observational constraint on the last major epoch of star formation in the outer disc.</abstract>
<qualityIndicators><refBibsNative>true</refBibsNative>
<abstractWordCount>314</abstractWordCount>
<abstractCharCount>1837</abstractCharCount>
<keywordCount>6</keywordCount>
<score>10</score>
<pdfWordCount>10147</pdfWordCount>
<pdfCharCount>52459</pdfCharCount>
<pdfVersion>1.4</pdfVersion>
<pdfPageCount>13</pdfPageCount>
<pdfPageSize>595.274 x 782.286 pts</pdfPageSize>
</qualityIndicators>
<title>The star formation history in the far outer disc of M33</title>
<genre><json:string>article</json:string>
</genre>
<host><title>Monthly Notices of the Royal Astronomical Society</title>
<language><json:string>unknown</json:string>
</language>
<doi><json:string>10.1111/(ISSN)1365-2966</json:string>
</doi>
<issn><json:string>0035-8711</json:string>
</issn>
<eissn><json:string>1365-2966</json:string>
</eissn>
<publisherId><json:string>MNR</json:string>
</publisherId>
<volume>410</volume>
<issue>1</issue>
<pages><first>504</first>
<last>516</last>
<total>13</total>
</pages>
<genre><json:string>journal</json:string>
</genre>
</host>
<namedEntities><unitex><date><json:string>2011</json:string>
</date>
<geogName></geogName>
<orgName><json:string>Astronomy, Inc.</json:string>
<json:string>Department of Physics and Astronomy</json:string>
<json:string>Institute of Astronomy, Cambridge University, Cambridge CB</json:string>
<json:string>Department of Physics</json:string>
<json:string>Sydney Institute of Astronomy, School of Physics, The University of Sydney, Sydney, NSW</json:string>
<json:string>University of California</json:string>
<json:string>University of Leicester</json:string>
<json:string>University of Tasmania</json:string>
</orgName>
<orgName_funder></orgName_funder>
<orgName_provider></orgName_provider>
<persName><json:string>Sebastian Hidalgo</json:string>
<json:string>David Thilker</json:string>
<json:string>F. Lewis</json:string>
<json:string>Edouard Bernard</json:string>
<json:string>T. A. Rector</json:string>
<json:string>Gyr</json:string>
<json:string>Michael K. Barker</json:string>
<json:string>D. Thilker</json:string>
<json:string>M. Hanna</json:string>
<json:string>A. A. Cole</json:string>
<json:string>A. Smecker-Hane</json:string>
<json:string>A. M. N. Ferguson</json:string>
<json:string>N. R. Tanvir</json:string>
</persName>
<placeName><json:string>Australia</json:string>
<json:string>Edinburgh</json:string>
<json:string>Strasbourg</json:string>
<json:string>CA</json:string>
<json:string>France</json:string>
<json:string>Irvine</json:string>
</placeName>
<ref_url><json:string>http://purcell.as.arizona.edu/dolphot/</json:string>
<json:string>http://www.edikt.org.uk</json:string>
<json:string>http://www.ecdf.ed.ac.uk/</json:string>
</ref_url>
<ref_bibl><json:string>Harris & Zaritsky 2001</json:string>
<json:string>Bigiel et al. 2008</json:string>
<json:string>Aparicio & Gallart 2004</json:string>
<json:string>Skillman 1987</json:string>
<json:string>Holtzman et al. 1999</json:string>
<json:string>Dalcanton & Bernstein 2002</json:string>
<json:string>McLean & Liu 1996</json:string>
<json:string>van den Bosch 2001</json:string>
<json:string>Thilker et al. (2002)</json:string>
<json:string>Taylor et al. 1994</json:string>
<json:string>Tolstoy & Saha 1996</json:string>
<json:string>Asplund et al. (2009)</json:string>
<json:string>Aparicio, Gallart & Bertelli 1997</json:string>
<json:string>Leroy et al. (2008)</json:string>
<json:string>Schlegel et al. (1998)</json:string>
<json:string>Gallart et al. (1999)</json:string>
<json:string>Gilmore, Wyse & Jones 1995</json:string>
<json:string>Guidoni, Messi & Natali 1981</json:string>
<json:string>White & Rees 1978</json:string>
<json:string>Sommer-Larsen et al. (2003)</json:string>
<json:string>Harris & Zaritsky 2001, 2004</json:string>
<json:string>Galleti, Bellazzini & Ferraro 2004</json:string>
<json:string>Serrano et al. (2009)</json:string>
<json:string>Dolphin 2000</json:string>
<json:string>Krauss & Chaboyer 2003</json:string>
<json:string>Governato et al. 2009</json:string>
<json:string>Burstein 1979</json:string>
<json:string>Brown et al. 2006</json:string>
<json:string>Dunkley et al. 2009</json:string>
<json:string>Abadi et al. 2003</json:string>
<json:string>Minniti, Olszewski & Rieke 1993</json:string>
<json:string>Morrison et al. 1997</json:string>
<json:string>Sarajedini et al. (2006)</json:string>
<json:string>Ferguson et al. 2007</json:string>
<json:string>M. K. Barker et al.</json:string>
<json:string>Martin & Kennicutt 2001</json:string>
<json:string>Girardi et al. (2000)</json:string>
<json:string>Pietrinferni et al. 2004</json:string>
<json:string>Schaye 2004</json:string>
<json:string>Blanton et al. 2003</json:string>
<json:string>Aparicio & Hidalgo 2009</json:string>
<json:string>Charbonneau 1995</json:string>
<json:string>Robertson et al. (2004)</json:string>
<json:string>Tosi et al. 1991</json:string>
<json:string>Neeser et al. 2002</json:string>
<json:string>Okamoto et al. 2005</json:string>
<json:string>Bothun 1992</json:string>
<json:string>Abadi et al. (2003)</json:string>
<json:string>Bresolin et al. (2010)</json:string>
<json:string>Gallart et al. 1999</json:string>
<json:string>Rogstad, Wright & Lockhart 1976</json:string>
<json:string>McConnachie et al. (2009)</json:string>
<json:string>Hernandez, Gilmore & Valls-Gabaud 2000</json:string>
<json:string>Bertelli et al. 1992</json:string>
<json:string>Ferguson et al. 1998</json:string>
<json:string>Corbelli & Schneider 1997</json:string>
<json:string>Mayer, Governato & Kaufmann 2008</json:string>
<json:string>Fall & Efstathiou 1980</json:string>
<json:string>Barker et al.</json:string>
<json:string>Governato et al. (2009)</json:string>
<json:string>Williams et al. 2009a</json:string>
<json:string>Brooks et al. 2009</json:string>
<json:string>Robin et al. 2003</json:string>
<json:string>Peebles 1984</json:string>
<json:string>Sirianni et al. 2005</json:string>
<json:string>Leroy et al. 2008</json:string>
<json:string>van der Kruit 1987</json:string>
<json:string>Elmegreen & Parravano 1994</json:string>
<json:string>Sommer-Larsen et al. 2003</json:string>
<json:string>Dolphin 2002</json:string>
<json:string>Galleti et al. (2004)</json:string>
<json:string>Sarajedini et al. 2000</json:string>
<json:string>de Vaucouleurs et al. 1991</json:string>
<json:string>Gallart et al. 2005</json:string>
<json:string>Kroupa 2002</json:string>
<json:string>Cole et al. 2007</json:string>
<json:string>McConnachie et al. (2006)</json:string>
<json:string>Galleti et al. 2004</json:string>
</ref_bibl>
<bibl></bibl>
</unitex>
</namedEntities>
<ark><json:string>ark:/67375/WNG-QNFD9RXZ-G</json:string>
</ark>
<categories><wos><json:string>1 - science</json:string>
<json:string>2 - astronomy & astrophysics</json:string>
</wos>
<scienceMetrix><json:string>1 - natural sciences</json:string>
<json:string>2 - physics & astronomy</json:string>
<json:string>3 - astronomy & astrophysics</json:string>
</scienceMetrix>
<scopus><json:string>1 - Physical Sciences</json:string>
<json:string>2 - Earth and Planetary Sciences</json:string>
<json:string>3 - Space and Planetary Science</json:string>
<json:string>1 - Physical Sciences</json:string>
<json:string>2 - Physics and Astronomy</json:string>
<json:string>3 - Astronomy and Astrophysics</json:string>
</scopus>
<inist><json:string>1 - sciences appliquees, technologies et medecines</json:string>
<json:string>2 - sciences biologiques et medicales</json:string>
<json:string>3 - sciences biologiques fondamentales et appliquees. psychologie</json:string>
<json:string>4 - invertebres</json:string>
</inist>
</categories>
<publicationDate>2011</publicationDate>
<copyrightDate>2011</copyrightDate>
<doi><json:string>10.1111/j.1365-2966.2010.17458.x</json:string>
</doi>
<id>5BD198157C610D67687BE97A8A4CA2EAC530C4AC</id>
<score>1</score>
<fulltext><json:item><extension>pdf</extension>
<original>true</original>
<mimetype>application/pdf</mimetype>
<uri>https://api.istex.fr/document/5BD198157C610D67687BE97A8A4CA2EAC530C4AC/fulltext/pdf</uri>
</json:item>
<json:item><extension>zip</extension>
<original>false</original>
<mimetype>application/zip</mimetype>
<uri>https://api.istex.fr/document/5BD198157C610D67687BE97A8A4CA2EAC530C4AC/fulltext/zip</uri>
</json:item>
<istex:fulltextTEI uri="https://api.istex.fr/document/5BD198157C610D67687BE97A8A4CA2EAC530C4AC/fulltext/tei"><teiHeader><fileDesc><titleStmt><title level="a" type="main">The star formation history in the far outer disc of M33</title>
</titleStmt>
<publicationStmt><authority>ISTEX</authority>
<publisher>Blackwell Publishing Ltd</publisher>
<pubPlace>Oxford, UK</pubPlace>
<availability><licence>© 2010 The Authors. Journal compilation © 2010 RAS</licence>
</availability>
<date type="published" when="2011-01-01"></date>
</publicationStmt>
<notesStmt><note type="content-type" subtype="article" source="article" scheme="https://content-type.data.istex.fr/ark:/67375/XTP-6N5SZHKN-D">article</note>
<note type="publication-type" subtype="journal" scheme="https://publication-type.data.istex.fr/ark:/67375/JMC-0GLKJH51-B">journal</note>
</notesStmt>
<sourceDesc><biblStruct type="article"><analytic><title level="a" type="main">The star formation history in the far outer disc of M33</title>
<title level="a" type="short">M33's outer disc star formation history</title>
<author xml:id="author-0000" role="corresp"><persName><forename type="first">Michael K.</forename>
<surname>Barker</surname>
</persName>
<affiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</affiliation>
<affiliation>E‐mail: mkb@roe.ac.uk (MKB); ferguson@roe.ac.uk (AMNF)</affiliation>
</author>
<author xml:id="author-0001" role="corresp"><persName><forename type="first">A. M. N.</forename>
<surname>Ferguson</surname>
</persName>
<affiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</affiliation>
<affiliation>E‐mail: mkb@roe.ac.uk (MKB); ferguson@roe.ac.uk (AMNF)</affiliation>
</author>
<author xml:id="author-0002"><persName><forename type="first">A. A.</forename>
<surname>Cole</surname>
</persName>
<affiliation>School of Mathematics & Physics, University of Tasmania, Private Bag 37, Hobart, 7001, TAS, Australia<address><country key="AU"></country>
</address>
</affiliation>
</author>
<author xml:id="author-0003"><persName><forename type="first">R.</forename>
<surname>Ibata</surname>
</persName>
<affiliation>Observatoire Astronomique de Strasbourg, Strasbourg, France<address><country key="FR"></country>
</address>
</affiliation>
</author>
<author xml:id="author-0004"><persName><forename type="first">M.</forename>
<surname>Irwin</surname>
</persName>
<affiliation>Institute of Astronomy, Cambridge University, Cambridge CB3 0HA</affiliation>
</author>
<author xml:id="author-0005"><persName><forename type="first">G. F.</forename>
<surname>Lewis</surname>
</persName>
<affiliation>Sydney Institute of Astronomy, School of Physics, The University of Sydney, Sydney, NSW 2006, Australia<address><country key="AU"></country>
</address>
</affiliation>
</author>
<author xml:id="author-0006"><persName><forename type="first">T. A.</forename>
<surname>Smecker‐Hane</surname>
</persName>
<affiliation>Department of Physics & Astronomy, University of California, Irvine, CA 92697‐4575, USA<address><country key="US"></country>
</address>
</affiliation>
</author>
<author xml:id="author-0007"><persName><forename type="first">N. R.</forename>
<surname>Tanvir</surname>
</persName>
<affiliation>Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH</affiliation>
</author>
<idno type="istex">5BD198157C610D67687BE97A8A4CA2EAC530C4AC</idno>
<idno type="ark">ark:/67375/WNG-QNFD9RXZ-G</idno>
<idno type="DOI">10.1111/j.1365-2966.2010.17458.x</idno>
<idno type="unit">MNR17458</idno>
<idno type="toTypesetVersion">file:MNR.MNR17458.pdf</idno>
</analytic>
<monogr><title level="j" type="main">Monthly Notices of the Royal Astronomical Society</title>
<title level="j" type="alt">MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY</title>
<idno type="pISSN">0035-8711</idno>
<idno type="eISSN">1365-2966</idno>
<idno type="book-DOI">10.1111/(ISSN)1365-2966</idno>
<idno type="book-part-DOI">10.1111/mnr.2010.410.issue-1</idno>
<idno type="product">MNR</idno>
<idno type="publisherDivision">ST</idno>
<imprint><biblScope unit="vol">410</biblScope>
<biblScope unit="issue">1</biblScope>
<biblScope unit="page" from="504">504</biblScope>
<biblScope unit="page" to="516">516</biblScope>
<biblScope unit="page-count">13</biblScope>
<publisher>Blackwell Publishing Ltd</publisher>
<pubPlace>Oxford, UK</pubPlace>
<date type="published" when="2011-01-01"></date>
</imprint>
</monogr>
</biblStruct>
</sourceDesc>
</fileDesc>
<profileDesc><abstract xml:lang="en" style="main"><head>ABSTRACT</head>
<p>The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use <hi rend="italic">Hubble Space Telescope</hi>
 Advanced Camera for Surveys imaging to study the star formation history (SFH) of two fields at 9.1 and 11.6 kpc along M33's northern major axis. These fields lie at <emph><span>∼ 4</span>
</emph>
 and <emph><span>5 <hi rend="italic">V</hi>
</span>
</emph>
‐band disc scalelengths and straddle the break in M33's surface brightness profile. The colour–magnitude diagrams (CMDs) reach the ancient main‐sequence turn‐off with a signal‐to‐noise ratio of <emph><span>∼ 5</span>
</emph>
. From detailed modelling of the CMDs, we find that the majority of stars in both fields combined formed at <emph><span><hi rend="italic">z</hi>
 < 1</span>
</emph>
. The mean age in the inner field, S1, is <emph><span>∼ 3 ± 1</span>
</emph>
 Gyr and the mean metallicity is [M/H]<emph><span>∼− 0.5 ± 0.2</span>
</emph>
 dex. The SFH of S1 unambiguously reveals how the inside‐out growth previously measured for M33's inner disc out to <graphic url="equation/MNR_17458_mu1.gif" rend="inline image"></graphic>
 extends out to the disc edge at <graphic url="equation/MNR_17458_mu2.gif" rend="inline image"></graphic>
. In comparison, the outer field, S2, is older (mean age <emph><span>∼ 7 ± 2</span>
</emph>
 Gyr), more metal‐poor (mean [M/H]<emph><span>∼− 0.8 ± 0.3</span>
</emph>
 dex), and contains <emph><span>∼ 30</span>
</emph>
 times less stellar mass. These results provide the most compelling evidence yet that M33's age gradient reverses at large radii near the disc break and that this reversal is accompanied by a break in stellar mass surface density. We discuss several possible interpretations of this behaviour including radial stellar mixing, warping of the gaseous disc, a change in star formation efficiency and a transition to another structural component. These results offer one of the most detailed views yet of the peripheral regions of any disc galaxy and provide a much needed observational constraint on the last major epoch of star formation in the outer disc.</p>
</abstract>
<textClass><keywords xml:lang="en"><term xml:id="k1">galaxies: abundances</term>
<term xml:id="k2">galaxies: evolution</term>
<term xml:id="k3">galaxies: individual: Messier Number: M33</term>
<term xml:id="k4">Local Group</term>
<term xml:id="k5">galaxies: spiral</term>
<term xml:id="k6">galaxies: stellar content</term>
</keywords>
<keywords rend="tocHeading1"><term>Papers</term>
</keywords>
</textClass>
<langUsage><language ident="en"></language>
</langUsage>
</profileDesc>
</teiHeader>
</istex:fulltextTEI>
<json:item><extension>txt</extension>
<original>false</original>
<mimetype>text/plain</mimetype>
<uri>https://api.istex.fr/document/5BD198157C610D67687BE97A8A4CA2EAC530C4AC/fulltext/txt</uri>
</json:item>
</fulltext>
<metadata><istex:metadataXml wicri:clean="Wiley, elements deleted: body"><istex:xmlDeclaration>version="1.0" encoding="UTF-8" standalone="yes"</istex:xmlDeclaration>
<istex:document><component version="2.0" type="serialArticle" xml:lang="en"><header><publicationMeta level="product"><publisherInfo><publisherName>Blackwell Publishing Ltd</publisherName>
<publisherLoc>Oxford, UK</publisherLoc>
</publisherInfo>
<doi origin="wiley" registered="yes">10.1111/(ISSN)1365-2966</doi>
<issn type="print">0035-8711</issn>
<issn type="electronic">1365-2966</issn>
<idGroup><id type="product" value="MNR"></id>
<id type="publisherDivision" value="ST"></id>
</idGroup>
<titleGroup><title type="main" sort="MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY">Monthly Notices of the Royal Astronomical Society</title>
</titleGroup>
</publicationMeta>
<publicationMeta level="part" position="01101"><doi origin="wiley">10.1111/mnr.2010.410.issue-1</doi>
<numberingGroup><numbering type="journalVolume" number="410">410</numbering>
<numbering type="journalIssue" number="1">1</numbering>
</numberingGroup>
<coverDate startDate="2011-01-01">January 2011</coverDate>
</publicationMeta>
<publicationMeta level="unit" type="article" position="39" status="forIssue"><doi origin="wiley">10.1111/j.1365-2966.2010.17458.x</doi>
<idGroup><id type="unit" value="MNR17458"></id>
</idGroup>
<countGroup><count type="pageTotal" number="13"></count>
</countGroup>
<titleGroup><title type="tocHeading1">Papers</title>
</titleGroup>
<copyright>© 2010 The Authors. Journal compilation © 2010 RAS</copyright>
<eventGroup><event type="xmlConverted" agent="Converter:BPG_TO_WML3G version:2.4 mode:FullText" date="2010-12-14"></event>
<event type="publishedOnlineEarlyUnpaginated" date="2010-10-15"></event>
<event type="firstOnline" date="2010-10-15"></event>
<event type="publishedOnlineFinalForm" date="2010-12-14"></event>
<event type="xmlConverted" agent="Converter:WILEY_ML3G_TO_WILEY_ML3GV2 version:3.8.8" date="2014-02-03"></event>
<event type="xmlConverted" agent="Converter:WML3G_To_WML3G version:4.1.7 mode:FullText,remove_FC" date="2014-10-31"></event>
</eventGroup>
<numberingGroup><numbering type="pageFirst" number="504">504</numbering>
<numbering type="pageLast" number="516">516</numbering>
</numberingGroup>
<correspondenceTo>
E‐mail: <email>mkb@roe.ac.uk</email>
 (MKB); <email>ferguson@roe.ac.uk</email>
 (AMNF)</correspondenceTo>
<linkGroup><link type="toTypesetVersion" href="file:MNR.MNR17458.pdf"></link>
</linkGroup>
</publicationMeta>
<contentMeta><unparsedEditorialHistory>Accepted 2010 July 30. Received 2010 July 26; in original form 2010 June 22</unparsedEditorialHistory>
<countGroup><count type="figureTotal" number="9"></count>
<count type="tableTotal" number="0"></count>
<count type="formulaTotal" number="205"></count>
<count type="referenceTotal" number="95"></count>
<count type="linksCrossRef" number="174"></count>
</countGroup>
<titleGroup><title type="main">The star formation history in the far outer disc of M33</title>
<title type="shortAuthors"><i>M. K. Barker et al.</i>
</title>
<title type="short"><i>M33's outer disc star formation history</i>
</title>
</titleGroup>
<creators><creator creatorRole="author" xml:id="cr1" affiliationRef="#a1" corresponding="yes"><personName><givenNames>Michael K.</givenNames>
<familyName>Barker</familyName>
</personName>
</creator>
<creator creatorRole="author" xml:id="cr2" affiliationRef="#a1" corresponding="yes"><personName><givenNames>A. M. N.</givenNames>
<familyName>Ferguson</familyName>
</personName>
</creator>
<creator creatorRole="author" xml:id="cr3" affiliationRef="#a2"><personName><givenNames>A. A.</givenNames>
<familyName>Cole</familyName>
</personName>
</creator>
<creator creatorRole="author" xml:id="cr4" affiliationRef="#a3"><personName><givenNames>R.</givenNames>
<familyName>Ibata</familyName>
</personName>
</creator>
<creator creatorRole="author" xml:id="cr5" affiliationRef="#a4"><personName><givenNames>M.</givenNames>
<familyName>Irwin</familyName>
</personName>
</creator>
<creator creatorRole="author" xml:id="cr6" affiliationRef="#a5"><personName><givenNames>G. F.</givenNames>
<familyName>Lewis</familyName>
</personName>
</creator>
<creator creatorRole="author" xml:id="cr7" affiliationRef="#a6"><personName><givenNames>T. A.</givenNames>
<familyName>Smecker‐Hane</familyName>
</personName>
</creator>
<creator creatorRole="author" xml:id="cr8" affiliationRef="#a7"><personName><givenNames>N. R.</givenNames>
<familyName>Tanvir</familyName>
</personName>
</creator>
</creators>
<affiliationGroup><affiliation xml:id="a1"><unparsedAffiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</unparsedAffiliation>
</affiliation>
<affiliation xml:id="a2" countryCode="AU"><unparsedAffiliation>School of Mathematics & Physics, University of Tasmania, Private Bag 37, Hobart, 7001, TAS, Australia</unparsedAffiliation>
</affiliation>
<affiliation xml:id="a3" countryCode="FR"><unparsedAffiliation>Observatoire Astronomique de Strasbourg, Strasbourg, France</unparsedAffiliation>
</affiliation>
<affiliation xml:id="a4"><unparsedAffiliation>Institute of Astronomy, Cambridge University, Cambridge CB3 0HA</unparsedAffiliation>
</affiliation>
<affiliation xml:id="a5" countryCode="AU"><unparsedAffiliation>Sydney Institute of Astronomy, School of Physics, The University of Sydney, Sydney, NSW 2006, Australia</unparsedAffiliation>
</affiliation>
<affiliation xml:id="a6" countryCode="US"><unparsedAffiliation>Department of Physics & Astronomy, University of California, Irvine, CA 92697‐4575, USA</unparsedAffiliation>
</affiliation>
<affiliation xml:id="a7"><unparsedAffiliation>Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH</unparsedAffiliation>
</affiliation>
</affiliationGroup>
<keywordGroup xml:lang="en"><keyword xml:id="k1">galaxies: abundances</keyword>
<keyword xml:id="k2">galaxies: evolution</keyword>
<keyword xml:id="k3">galaxies: individual: Messier Number: M33</keyword>
<keyword xml:id="k4">Local Group</keyword>
<keyword xml:id="k5">galaxies: spiral</keyword>
<keyword xml:id="k6">galaxies: stellar content</keyword>
</keywordGroup>
<abstractGroup><abstract type="main" xml:lang="en"><title type="main">ABSTRACT</title>
<p>The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use <i>Hubble Space Telescope</i>
 Advanced Camera for Surveys imaging to study the star formation history (SFH) of two fields at 9.1 and 11.6 kpc along M33's northern major axis. These fields lie at <span type="mathematics">∼ 4</span>
 and <span type="mathematics">5 <i>V</i>
</span>
‐band disc scalelengths and straddle the break in M33's surface brightness profile. The colour–magnitude diagrams (CMDs) reach the ancient main‐sequence turn‐off with a signal‐to‐noise ratio of <span type="mathematics">∼ 5</span>
. From detailed modelling of the CMDs, we find that the majority of stars in both fields combined formed at <span type="mathematics"><i>z</i>
 < 1</span>
. The mean age in the inner field, S1, is <span type="mathematics">∼ 3 ± 1</span>
 Gyr and the mean metallicity is [M/H]<span type="mathematics">∼− 0.5 ± 0.2</span>
 dex. The SFH of S1 unambiguously reveals how the inside‐out growth previously measured for M33's inner disc out to <inlineGraphic alt="inline image" location="equation/MNR_17458_mu1.gif" href=""></inlineGraphic>
 extends out to the disc edge at <inlineGraphic alt="inline image" location="equation/MNR_17458_mu2.gif" href=""></inlineGraphic>
. In comparison, the outer field, S2, is older (mean age <span type="mathematics">∼ 7 ± 2</span>
 Gyr), more metal‐poor (mean [M/H]<span type="mathematics">∼− 0.8 ± 0.3</span>
 dex), and contains <span type="mathematics">∼ 30</span>
 times less stellar mass. These results provide the most compelling evidence yet that M33's age gradient reverses at large radii near the disc break and that this reversal is accompanied by a break in stellar mass surface density. We discuss several possible interpretations of this behaviour including radial stellar mixing, warping of the gaseous disc, a change in star formation efficiency and a transition to another structural component. These results offer one of the most detailed views yet of the peripheral regions of any disc galaxy and provide a much needed observational constraint on the last major epoch of star formation in the outer disc.</p>
</abstract>
</abstractGroup>
</contentMeta>
</header>
</component>
</istex:document>
</istex:metadataXml>
<mods version="3.6"><titleInfo lang="en"><title>The star formation history in the far outer disc of M33</title>
</titleInfo>
<titleInfo type="abbreviated" lang="en"><title>M33's outer disc star formation history</title>
</titleInfo>
<titleInfo type="alternative" contentType="CDATA" lang="en"><title>The star formation history in the far outer disc of M33</title>
</titleInfo>
<name type="personal"><namePart type="given">Michael K.</namePart>
<namePart type="family">Barker</namePart>
<affiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</affiliation>
<affiliation>E-mail: mkb@roe.ac.uk</affiliation>
<role><roleTerm type="text">author</roleTerm>
</role>
</name>
<name type="personal"><namePart type="given">A. M. N.</namePart>
<namePart type="family">Ferguson</namePart>
<affiliation>Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ</affiliation>
<affiliation>E-mail: mkb@roe.ac.uk</affiliation>
<role><roleTerm type="text">author</roleTerm>
</role>
</name>
<name type="personal"><namePart type="given">A. A.</namePart>
<namePart type="family">Cole</namePart>
<affiliation>School of Mathematics & Physics, University of Tasmania, Private Bag 37, Hobart, 7001, TAS, Australia</affiliation>
<role><roleTerm type="text">author</roleTerm>
</role>
</name>
<name type="personal"><namePart type="given">R.</namePart>
<namePart type="family">Ibata</namePart>
<affiliation>Observatoire Astronomique de Strasbourg, Strasbourg, France</affiliation>
<role><roleTerm type="text">author</roleTerm>
</role>
</name>
<name type="personal"><namePart type="given">M.</namePart>
<namePart type="family">Irwin</namePart>
<affiliation>Institute of Astronomy, Cambridge University, Cambridge CB3 0HA</affiliation>
<role><roleTerm type="text">author</roleTerm>
</role>
</name>
<name type="personal"><namePart type="given">G. F.</namePart>
<namePart type="family">Lewis</namePart>
<affiliation>Sydney Institute of Astronomy, School of Physics, The University of Sydney, Sydney, NSW 2006, Australia</affiliation>
<role><roleTerm type="text">author</roleTerm>
</role>
</name>
<name type="personal"><namePart type="given">T. A.</namePart>
<namePart type="family">Smecker‐Hane</namePart>
<affiliation>Department of Physics & Astronomy, University of California, Irvine, CA 92697‐4575, USA</affiliation>
<role><roleTerm type="text">author</roleTerm>
</role>
</name>
<name type="personal"><namePart type="given">N. R.</namePart>
<namePart type="family">Tanvir</namePart>
<affiliation>Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH</affiliation>
<role><roleTerm type="text">author</roleTerm>
</role>
</name>
<typeOfResource>text</typeOfResource>
<genre type="article" displayLabel="article" authority="ISTEX" authorityURI="https://content-type.data.istex.fr" valueURI="https://content-type.data.istex.fr/ark:/67375/XTP-6N5SZHKN-D">article</genre>
<originInfo><publisher>Blackwell Publishing Ltd</publisher>
<place><placeTerm type="text">Oxford, UK</placeTerm>
</place>
<dateIssued encoding="w3cdtf">2011-01-01</dateIssued>
<edition>Accepted 2010 July 30. Received 2010 July 26; in original form 2010 June 22</edition>
<copyrightDate encoding="w3cdtf">2011</copyrightDate>
</originInfo>
<language><languageTerm type="code" authority="rfc3066">en</languageTerm>
<languageTerm type="code" authority="iso639-2b">eng</languageTerm>
</language>
<physicalDescription><extent unit="figures">9</extent>
<extent unit="tables">0</extent>
<extent unit="formulas">205</extent>
<extent unit="references">95</extent>
<extent unit="linksCrossRef">174</extent>
</physicalDescription>
<abstract lang="en">The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use Hubble Space Telescope Advanced Camera for Surveys imaging to study the star formation history (SFH) of two fields at 9.1 and 11.6 kpc along M33's northern major axis. These fields lie at ∼ 4 and 5 V‐band disc scalelengths and straddle the break in M33's surface brightness profile. The colour–magnitude diagrams (CMDs) reach the ancient main‐sequence turn‐off with a signal‐to‐noise ratio of ∼ 5. From detailed modelling of the CMDs, we find that the majority of stars in both fields combined formed at z < 1. The mean age in the inner field, S1, is ∼ 3 ± 1 Gyr and the mean metallicity is [M/H]∼− 0.5 ± 0.2 dex. The SFH of S1 unambiguously reveals how the inside‐out growth previously measured for M33's inner disc out to extends out to the disc edge at . In comparison, the outer field, S2, is older (mean age ∼ 7 ± 2 Gyr), more metal‐poor (mean [M/H]∼− 0.8 ± 0.3 dex), and contains ∼ 30 times less stellar mass. These results provide the most compelling evidence yet that M33's age gradient reverses at large radii near the disc break and that this reversal is accompanied by a break in stellar mass surface density. We discuss several possible interpretations of this behaviour including radial stellar mixing, warping of the gaseous disc, a change in star formation efficiency and a transition to another structural component. These results offer one of the most detailed views yet of the peripheral regions of any disc galaxy and provide a much needed observational constraint on the last major epoch of star formation in the outer disc.</abstract>
<subject lang="en"><genre>keywords</genre>
<topic>galaxies: abundances</topic>
<topic>galaxies: evolution</topic>
<topic>galaxies: individual: Messier Number: M33</topic>
<topic>Local Group</topic>
<topic>galaxies: spiral</topic>
<topic>galaxies: stellar content</topic>
</subject>
<relatedItem type="host"><titleInfo><title>Monthly Notices of the Royal Astronomical Society</title>
</titleInfo>
<genre type="journal" authority="ISTEX" authorityURI="https://publication-type.data.istex.fr" valueURI="https://publication-type.data.istex.fr/ark:/67375/JMC-0GLKJH51-B">journal</genre>
<identifier type="ISSN">0035-8711</identifier>
<identifier type="eISSN">1365-2966</identifier>
<identifier type="DOI">10.1111/(ISSN)1365-2966</identifier>
<identifier type="PublisherID">MNR</identifier>
<part><date>2011</date>
<detail type="volume"><caption>vol.</caption>
<number>410</number>
</detail>
<detail type="issue"><caption>no.</caption>
<number>1</number>
</detail>
<extent unit="pages"><start>504</start>
<end>516</end>
<total>13</total>
</extent>
</part>
</relatedItem>
<identifier type="istex">5BD198157C610D67687BE97A8A4CA2EAC530C4AC</identifier>
<identifier type="ark">ark:/67375/WNG-QNFD9RXZ-G</identifier>
<identifier type="DOI">10.1111/j.1365-2966.2010.17458.x</identifier>
<identifier type="ArticleID">MNR17458</identifier>
<accessCondition type="use and reproduction" contentType="copyright">© 2010 The Authors. Journal compilation © 2010 RAS</accessCondition>
<recordInfo><recordContentSource authority="ISTEX" authorityURI="https://loaded-corpus.data.istex.fr" valueURI="https://loaded-corpus.data.istex.fr/ark:/67375/XBH-L0C46X92-X">wiley</recordContentSource>
<recordOrigin>Blackwell Publishing Ltd</recordOrigin>
</recordInfo>
</mods>
<json:item><extension>json</extension>
<original>false</original>
<mimetype>application/json</mimetype>
<uri>https://api.istex.fr/document/5BD198157C610D67687BE97A8A4CA2EAC530C4AC/metadata/json</uri>
</json:item>
</metadata>
<serie></serie>
</istex>
</record>

Pour manipuler ce document sous Unix (Dilib)

EXPLOR_STEP=$WICRI_ROOT/Wicri/Asie/explor/AustralieFrV1/Data/Istex/Corpus

HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 001146 | SxmlIndent | more

HfdSelect -h $EXPLOR_AREA/Data/Istex/Corpus/biblio.hfd -nk 001146 | SxmlIndent | more

Pour mettre un lien sur cette page dans le réseau Wicri

{{Explor lien
   |wiki=    Wicri/Asie
   |area=    AustralieFrV1
   |flux=    Istex
   |étape=   Corpus
   |type=    RBID
   |clé=     ISTEX:5BD198157C610D67687BE97A8A4CA2EAC530C4AC
   |texte=   The star formation history in the far outer disc of M33
}}

This area was generated with Dilib version V0.6.33.
Data generation: Tue Dec 5 10:43:12 2017. Site generation: Tue Mar 5 14:07:20 2024

	Serveur d'exploration sur les relations entre la France et l'Australie
	Attention, ce site est en cours de développement ! Attention, site généré par des moyens informatiques à partir de corpus bruts. Les informations ne sont donc pas validées.

Serveur d'exploration sur les relations entre la France et l'Australie

The star formation history in the far outer disc of M33

The star formation history in the far outer disc of M33

Source :

English descriptors

Abstract

Links to Exploration step

Le document en format XML

Pour manipuler ce document sous Unix (Dilib)

Pour mettre un lien sur cette page dans le réseau Wicri