Large grains in discs around young stars : ATCA observations of WW Chamaeleontis, RU Lupi, and CS Chamaeleontis
Identifieur interne : 008245 ( Main/Exploration ); précédent : 008244; suivant : 008246Large grains in discs around young stars : ATCA observations of WW Chamaeleontis, RU Lupi, and CS Chamaeleontis
Auteurs : D. Lommen [Pays-Bas] ; S. T. Maddison [Australie, France] ; C. M. Wright [Australie] ; E. F. Van Dishoeck [Pays-Bas, Allemagne] ; D. J. Wilner [États-Unis] ; T. L. Bourke [États-Unis]Source :
- Astronomy and astrophysics : (Berlin. Print) [ 0004-6361 ] ; 2009.
Descripteurs français
- Pascal (Inist)
- Etoile jeune, Planétésimales, Vent stellaire, Etoile type T Tauri, Croissance grain, Disque circumstellaire, Borne supérieure, Objet stellaire jeune, Rapport signal bruit, Indice spectral, Variabilité, Densité spectrale énergie, Plasma optiquement mince, Matière circumstellaire, Système planétaire, Nébuleuse proto planétaire, Formation stellaire.
English descriptors
- KwdEn :
- Circumstellar disks, Circumstellar matter, Grain growth, Optically thin plasma, Planetary system, Planetesimals, Proto planetary nebula, Signal-to-noise ratio, Spectral energy distribution, Spectral index, Star formation, Stellar winds, T Tauri stars, Upper bound, Variability, Young stars, Young stellar object.
Abstract
Context. Grains in discs around young stars grow from interstellar submicron sizes to planetesimals, up to thousands of kilometres in size, over the course of several Myr. Thermal emission of large grains or pebbles can be best observed at centimetre wavelengths. However, other emission mechanisms can contribute, most notably free-free emission from stellar winds and chromospheric activity. Aims. We aim to determine the mechanisms of centimetre emission for three T Tauri stars. WW Cha and RU Lup have recently been found to have grain growth at least up to millimetre sizes in their circumstellar discs, based on millimetre data up to 3.3 mm. CS Cha has similar indications of grain growth in its circumbinary disc. Methods. The T Tauri stars WW Cha and RU Lup were monitored over the course of several years at millimetre and centimetre wavelengths, using the Australia Telescope Compact Array (ATCA). The new ATCA 7 mm system was also used to observe CS Cha at 7 mm. Results. WW Cha was detected on several occasions at 7 and 16 mm. We obtained one detection of WW Cha at 3.5 cm and upper limits only for 6.3 cm. The emission at 16 mm was stable over periods of days, months, and years, whereas the emission at 3.5 cm is found to be variable. A second young stellar object, Ced 112 IRS 4, was found in the field of WW Cha at 16 mm. RU Lup was detected at 7 mm. It was observed at 16 mm three times and at 3 and 6 cm four times and found to be variable in all three wavebands. CS Cha was detected at 7 mm, but the signal-to-noise ratio was not high enough to resolve the gap in the circumbinary disc. The typical resolution of the 7 and 16 mm observations was 5-10 arcsec with rms ∼0.2 mJy. Conclusions. The emission at 3, 7, and 16 mm for WW Cha is explained well by thermal emission from millimetre and centimetre-sized "pebbles". The cm spectral index between 3.5 and 6.3 cm is consistent with the emission from an optically-thick ionised wind, although the high variability of the cm emission points to a non-thermal contribution. The spectral energy distributions of both RU Lup and CS Cha from 1 to 7 mm are consistent with thermal emission from mm-sized grains. The variability of the longer-wavelength emission for RU Lup and the negative spectral index suggests non-thermal emission, arising from an optically-thin plasma.
Affiliations:
Links toward previous steps (curation, corpus...)
- to stream PascalFrancis, to step Corpus: 002F08
- to stream PascalFrancis, to step Curation: 003111
- to stream PascalFrancis, to step Checkpoint: 002A31
- to stream Main, to step Merge: 008A00
- to stream Main, to step Curation: 008245
Le document en format XML
<record><TEI><teiHeader><fileDesc><titleStmt><title xml:lang="en" level="a">Large grains in discs around young stars : ATCA observations of WW Chamaeleontis, RU Lupi, and CS Chamaeleontis</title><author><name sortKey="Lommen, D" sort="Lommen, D" uniqKey="Lommen D" first="D." last="Lommen">D. Lommen</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Leiden Observatory, Leiden University, PO Box 9513</s1><s2>2300 RA Leiden</s2><s3>NLD</s3><sZ>1 aut.</sZ><sZ>4 aut.</sZ></inist:fA14><country>Pays-Bas</country><wicri:noRegion>2300 RA Leiden</wicri:noRegion></affiliation></author><author><name sortKey="Maddison, S T" sort="Maddison, S T" uniqKey="Maddison S" first="S. T." last="Maddison">S. T. Maddison</name><affiliation wicri:level="1"><inist:fA14 i1="02"><s1>Centre for Astrophysics and Supercomputing, Swinburne University of Technology, PO Box 218</s1><s2>Hawthorn, VIC 3122</s2><s3>AUS</s3><sZ>2 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Hawthorn, VIC 3122</wicri:noRegion></affiliation><affiliation wicri:level="1"><inist:fA14 i1="03"><s1>Centre de Recherche Astrophysique de Lyon, École Normale Supérieure de Lyon, 46 allée d'Italie</s1><s2>69364 Lyon</s2><s3>FRA</s3><sZ>2 aut.</sZ></inist:fA14><country>France</country><wicri:noRegion>69364 Lyon</wicri:noRegion><placeName><settlement type="city">Lyon</settlement><region type="region" nuts="2">Auvergne-Rhône-Alpes</region><region type="old region" nuts="2">Rhône-Alpes</region></placeName></affiliation></author><author><name sortKey="Wright, C M" sort="Wright, C M" uniqKey="Wright C" first="C. M." last="Wright">C. M. Wright</name><affiliation wicri:level="1"><inist:fA14 i1="04"><s1>School of Physical, Environmental and Mathematical Sciences, UNSW@ADFA</s1><s2>Canberra ACT 2600</s2><s3>AUS</s3><sZ>3 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Canberra ACT 2600</wicri:noRegion></affiliation></author><author><name sortKey="Van Dishoeck, E F" sort="Van Dishoeck, E F" uniqKey="Van Dishoeck E" first="E. F." last="Van Dishoeck">E. F. Van Dishoeck</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Leiden Observatory, Leiden University, PO Box 9513</s1><s2>2300 RA Leiden</s2><s3>NLD</s3><sZ>1 aut.</sZ><sZ>4 aut.</sZ></inist:fA14><country>Pays-Bas</country><wicri:noRegion>2300 RA Leiden</wicri:noRegion></affiliation><affiliation wicri:level="1"><inist:fA14 i1="05"><s1>Max-Planck-Institut für Extraterrestrische Physik (MPE), Giessenbachstr. 1</s1><s2>85748 Garching</s2><s3>DEU</s3><sZ>4 aut.</sZ></inist:fA14><country>Allemagne</country><wicri:noRegion>85748 Garching</wicri:noRegion><wicri:noRegion>Giessenbachstr. 1</wicri:noRegion><wicri:noRegion>85748 Garching</wicri:noRegion></affiliation></author><author><name sortKey="Wilner, D J" sort="Wilner, D J" uniqKey="Wilner D" first="D. J." last="Wilner">D. J. Wilner</name><affiliation wicri:level="1"><inist:fA14 i1="06"><s1>Harvard-Smithsonian Center for Astrophysics, 60 Garden Street</s1><s2>02138 Cambridge, MA</s2><s3>USA</s3><sZ>5 aut.</sZ><sZ>6 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>02138 Cambridge, MA</wicri:noRegion></affiliation></author><author><name sortKey="Bourke, T L" sort="Bourke, T L" uniqKey="Bourke T" first="T. L." last="Bourke">T. L. Bourke</name><affiliation wicri:level="1"><inist:fA14 i1="06"><s1>Harvard-Smithsonian Center for Astrophysics, 60 Garden Street</s1><s2>02138 Cambridge, MA</s2><s3>USA</s3><sZ>5 aut.</sZ><sZ>6 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>02138 Cambridge, MA</wicri:noRegion></affiliation></author></titleStmt><publicationStmt><idno type="wicri:source">INIST</idno><idno type="inist">09-0148863</idno><date when="2009">2009</date><idno type="stanalyst">PASCAL 09-0148863 INIST</idno><idno type="RBID">Pascal:09-0148863</idno><idno type="wicri:Area/PascalFrancis/Corpus">002F08</idno><idno type="wicri:Area/PascalFrancis/Curation">003111</idno><idno type="wicri:Area/PascalFrancis/Checkpoint">002A31</idno><idno type="wicri:explorRef" wicri:stream="PascalFrancis" wicri:step="Checkpoint">002A31</idno><idno type="wicri:doubleKey">0004-6361:2009:Lommen D:large:grains:in</idno><idno type="wicri:Area/Main/Merge">008A00</idno><idno type="wicri:Area/Main/Curation">008245</idno><idno type="wicri:Area/Main/Exploration">008245</idno></publicationStmt><sourceDesc><biblStruct><analytic><title xml:lang="en" level="a">Large grains in discs around young stars : ATCA observations of WW Chamaeleontis, RU Lupi, and CS Chamaeleontis</title><author><name sortKey="Lommen, D" sort="Lommen, D" uniqKey="Lommen D" first="D." last="Lommen">D. Lommen</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Leiden Observatory, Leiden University, PO Box 9513</s1><s2>2300 RA Leiden</s2><s3>NLD</s3><sZ>1 aut.</sZ><sZ>4 aut.</sZ></inist:fA14><country>Pays-Bas</country><wicri:noRegion>2300 RA Leiden</wicri:noRegion></affiliation></author><author><name sortKey="Maddison, S T" sort="Maddison, S T" uniqKey="Maddison S" first="S. T." last="Maddison">S. T. Maddison</name><affiliation wicri:level="1"><inist:fA14 i1="02"><s1>Centre for Astrophysics and Supercomputing, Swinburne University of Technology, PO Box 218</s1><s2>Hawthorn, VIC 3122</s2><s3>AUS</s3><sZ>2 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Hawthorn, VIC 3122</wicri:noRegion></affiliation><affiliation wicri:level="1"><inist:fA14 i1="03"><s1>Centre de Recherche Astrophysique de Lyon, École Normale Supérieure de Lyon, 46 allée d'Italie</s1><s2>69364 Lyon</s2><s3>FRA</s3><sZ>2 aut.</sZ></inist:fA14><country>France</country><wicri:noRegion>69364 Lyon</wicri:noRegion><placeName><settlement type="city">Lyon</settlement><region type="region" nuts="2">Auvergne-Rhône-Alpes</region><region type="old region" nuts="2">Rhône-Alpes</region></placeName></affiliation></author><author><name sortKey="Wright, C M" sort="Wright, C M" uniqKey="Wright C" first="C. M." last="Wright">C. M. Wright</name><affiliation wicri:level="1"><inist:fA14 i1="04"><s1>School of Physical, Environmental and Mathematical Sciences, UNSW@ADFA</s1><s2>Canberra ACT 2600</s2><s3>AUS</s3><sZ>3 aut.</sZ></inist:fA14><country>Australie</country><wicri:noRegion>Canberra ACT 2600</wicri:noRegion></affiliation></author><author><name sortKey="Van Dishoeck, E F" sort="Van Dishoeck, E F" uniqKey="Van Dishoeck E" first="E. F." last="Van Dishoeck">E. F. Van Dishoeck</name><affiliation wicri:level="1"><inist:fA14 i1="01"><s1>Leiden Observatory, Leiden University, PO Box 9513</s1><s2>2300 RA Leiden</s2><s3>NLD</s3><sZ>1 aut.</sZ><sZ>4 aut.</sZ></inist:fA14><country>Pays-Bas</country><wicri:noRegion>2300 RA Leiden</wicri:noRegion></affiliation><affiliation wicri:level="1"><inist:fA14 i1="05"><s1>Max-Planck-Institut für Extraterrestrische Physik (MPE), Giessenbachstr. 1</s1><s2>85748 Garching</s2><s3>DEU</s3><sZ>4 aut.</sZ></inist:fA14><country>Allemagne</country><wicri:noRegion>85748 Garching</wicri:noRegion><wicri:noRegion>Giessenbachstr. 1</wicri:noRegion><wicri:noRegion>85748 Garching</wicri:noRegion></affiliation></author><author><name sortKey="Wilner, D J" sort="Wilner, D J" uniqKey="Wilner D" first="D. J." last="Wilner">D. J. Wilner</name><affiliation wicri:level="1"><inist:fA14 i1="06"><s1>Harvard-Smithsonian Center for Astrophysics, 60 Garden Street</s1><s2>02138 Cambridge, MA</s2><s3>USA</s3><sZ>5 aut.</sZ><sZ>6 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>02138 Cambridge, MA</wicri:noRegion></affiliation></author><author><name sortKey="Bourke, T L" sort="Bourke, T L" uniqKey="Bourke T" first="T. L." last="Bourke">T. L. Bourke</name><affiliation wicri:level="1"><inist:fA14 i1="06"><s1>Harvard-Smithsonian Center for Astrophysics, 60 Garden Street</s1><s2>02138 Cambridge, MA</s2><s3>USA</s3><sZ>5 aut.</sZ><sZ>6 aut.</sZ></inist:fA14><country>États-Unis</country><wicri:noRegion>02138 Cambridge, MA</wicri:noRegion></affiliation></author></analytic><series><title level="j" type="main">Astronomy and astrophysics : (Berlin. Print)</title><title level="j" type="abbreviated">Astron. astrophys. : (Berl., Print)</title><idno type="ISSN">0004-6361</idno><imprint><date when="2009">2009</date></imprint></series></biblStruct></sourceDesc><seriesStmt><title level="j" type="main">Astronomy and astrophysics : (Berlin. Print)</title><title level="j" type="abbreviated">Astron. astrophys. : (Berl., Print)</title><idno type="ISSN">0004-6361</idno></seriesStmt></fileDesc><profileDesc><textClass><keywords scheme="KwdEn" xml:lang="en"><term>Circumstellar disks</term><term>Circumstellar matter</term><term>Grain growth</term><term>Optically thin plasma</term><term>Planetary system</term><term>Planetesimals</term><term>Proto planetary nebula</term><term>Signal-to-noise ratio</term><term>Spectral energy distribution</term><term>Spectral index</term><term>Star formation</term><term>Stellar winds</term><term>T Tauri stars</term><term>Upper bound</term><term>Variability</term><term>Young stars</term><term>Young stellar object</term></keywords><keywords scheme="Pascal" xml:lang="fr"><term>Etoile jeune</term><term>Planétésimales</term><term>Vent stellaire</term><term>Etoile type T Tauri</term><term>Croissance grain</term><term>Disque circumstellaire</term><term>Borne supérieure</term><term>Objet stellaire jeune</term><term>Rapport signal bruit</term><term>Indice spectral</term><term>Variabilité</term><term>Densité spectrale énergie</term><term>Plasma optiquement mince</term><term>Matière circumstellaire</term><term>Système planétaire</term><term>Nébuleuse proto planétaire</term><term>Formation stellaire</term></keywords></textClass></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">Context. Grains in discs around young stars grow from interstellar submicron sizes to planetesimals, up to thousands of kilometres in size, over the course of several Myr. Thermal emission of large grains or pebbles can be best observed at centimetre wavelengths. However, other emission mechanisms can contribute, most notably free-free emission from stellar winds and chromospheric activity. Aims. We aim to determine the mechanisms of centimetre emission for three T Tauri stars. WW Cha and RU Lup have recently been found to have grain growth at least up to millimetre sizes in their circumstellar discs, based on millimetre data up to 3.3 mm. CS Cha has similar indications of grain growth in its circumbinary disc. Methods. The T Tauri stars WW Cha and RU Lup were monitored over the course of several years at millimetre and centimetre wavelengths, using the Australia Telescope Compact Array (ATCA). The new ATCA 7 mm system was also used to observe CS Cha at 7 mm. Results. WW Cha was detected on several occasions at 7 and 16 mm. We obtained one detection of WW Cha at 3.5 cm and upper limits only for 6.3 cm. The emission at 16 mm was stable over periods of days, months, and years, whereas the emission at 3.5 cm is found to be variable. A second young stellar object, Ced 112 IRS 4, was found in the field of WW Cha at 16 mm. RU Lup was detected at 7 mm. It was observed at 16 mm three times and at 3 and 6 cm four times and found to be variable in all three wavebands. CS Cha was detected at 7 mm, but the signal-to-noise ratio was not high enough to resolve the gap in the circumbinary disc. The typical resolution of the 7 and 16 mm observations was 5-10 arcsec with rms ∼0.2 mJy. Conclusions. The emission at 3, 7, and 16 mm for WW Cha is explained well by thermal emission from millimetre and centimetre-sized "pebbles". The cm spectral index between 3.5 and 6.3 cm is consistent with the emission from an optically-thick ionised wind, although the high variability of the cm emission points to a non-thermal contribution. The spectral energy distributions of both RU Lup and CS Cha from 1 to 7 mm are consistent with thermal emission from mm-sized grains. The variability of the longer-wavelength emission for RU Lup and the negative spectral index suggests non-thermal emission, arising from an optically-thin plasma.</div></front></TEI><affiliations><list><country><li>Allemagne</li><li>Australie</li><li>France</li><li>Pays-Bas</li><li>États-Unis</li></country><region><li>Auvergne-Rhône-Alpes</li><li>Rhône-Alpes</li></region><settlement><li>Lyon</li></settlement></list><tree><country name="Pays-Bas"><noRegion><name sortKey="Lommen, D" sort="Lommen, D" uniqKey="Lommen D" first="D." last="Lommen">D. Lommen</name></noRegion><name sortKey="Van Dishoeck, E F" sort="Van Dishoeck, E F" uniqKey="Van Dishoeck E" first="E. F." last="Van Dishoeck">E. F. Van Dishoeck</name></country><country name="Australie"><noRegion><name sortKey="Maddison, S T" sort="Maddison, S T" uniqKey="Maddison S" first="S. T." last="Maddison">S. T. Maddison</name></noRegion><name sortKey="Wright, C M" sort="Wright, C M" uniqKey="Wright C" first="C. M." last="Wright">C. M. Wright</name></country><country name="France"><region name="Auvergne-Rhône-Alpes"><name sortKey="Maddison, S T" sort="Maddison, S T" uniqKey="Maddison S" first="S. T." last="Maddison">S. T. Maddison</name></region></country><country name="Allemagne"><noRegion><name sortKey="Van Dishoeck, E F" sort="Van Dishoeck, E F" uniqKey="Van Dishoeck E" first="E. F." last="Van Dishoeck">E. F. Van Dishoeck</name></noRegion></country><country name="États-Unis"><noRegion><name sortKey="Wilner, D J" sort="Wilner, D J" uniqKey="Wilner D" first="D. J." last="Wilner">D. J. Wilner</name></noRegion><name sortKey="Bourke, T L" sort="Bourke, T L" uniqKey="Bourke T" first="T. L." last="Bourke">T. L. Bourke</name></country></tree></affiliations></record>Pour manipuler ce document sous Unix (Dilib)
EXPLOR_STEP=$WICRI_ROOT/Wicri/Asie/explor/AustralieFrV1/Data/Main/Exploration
HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 008245 | SxmlIndent | more
Ou
HfdSelect -h $EXPLOR_AREA/Data/Main/Exploration/biblio.hfd -nk 008245 | SxmlIndent | more
Pour mettre un lien sur cette page dans le réseau Wicri
{{Explor lien
|wiki= Wicri/Asie
|area= AustralieFrV1
|flux= Main
|étape= Exploration
|type= RBID
|clé= Pascal:09-0148863
|texte= Large grains in discs around young stars : ATCA observations of WW Chamaeleontis, RU Lupi, and CS Chamaeleontis
}}
| This area was generated with Dilib version V0.6.33. |  |