Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton
Autor(a) principal: | |
---|---|
Data de Publicação: | 2018 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/195656 |
Resumo: | Aims. The Canis Major OB1 Association has an intriguing scenario of star formation, especially in the region called Canis Major R1 (CMa R1) traditionally assigned to a reflection nebula, but in reality an ionized region. This work is focussed on the young stellar population associated with CMa R1, for which our previous results from ROSAT, optical, and near-infrared data had revealed two stellar groups with di erent ages, suggesting a possible mixing of populations originated from distinct star formation episodes. Methods. The X-ray data allow the detected sources to be characterized according to hardness ratios, light curves, and spectra. Estimates of mass and age were obtained from the 2MASS catalogue and used to define a complete subsample of stellar counterparts for statistical purposes. Results. A catalogue of 387 XMM-Newton sources is provided, of which 78% are confirmed as members or probable members of the CMa R1 association. Flares (or similar events) were observed for 13 sources and the spectra of 21 bright sources could be fitted by a thermal plasma model. Mean values of fits parameters were used to estimate X-ray luminosities. We found a minimum value of log(LX [erg=s]) = 29:43, indicating that our sample of low-mass stars (M? 0:5 M ), which are faint X-ray emitters, is incomplete. Among the 250 objects selected as our complete subsample (defining our “best sample”), 171 are found to the east of the cloud, near Z CMa and dense molecular gas, of which 50% of them are young (<5 Myr) and 30% are older (>10 Myr). The opposite happens to the west, near GU CMa, in areas lacking molecular gas: among 79 objects, 30% are young and 50% are older. These findings confirm that a first episode of distributed star formation occurred in the whole studied region 10 Myr ago and dispersed the molecular gas, while a second, localized episode (<5 Myr) took place in the regions where molecular gas is still present. |
id |
UFRGS-2_c2480d956450e7a3299f7b51e1e8bd83 |
---|---|
oai_identifier_str |
oai:www.lume.ufrgs.br:10183/195656 |
network_acronym_str |
UFRGS-2 |
network_name_str |
Repositório Institucional da UFRGS |
repository_id_str |
|
spelling |
Silva, Thais dos SantosGregorio-Hetem, J.Montmerle, ThierrySoares, Beatriz Fernandes LopesStelzer, Beate2019-06-12T02:31:52Z20180004-6361http://hdl.handle.net/10183/195656001091345Aims. The Canis Major OB1 Association has an intriguing scenario of star formation, especially in the region called Canis Major R1 (CMa R1) traditionally assigned to a reflection nebula, but in reality an ionized region. This work is focussed on the young stellar population associated with CMa R1, for which our previous results from ROSAT, optical, and near-infrared data had revealed two stellar groups with di erent ages, suggesting a possible mixing of populations originated from distinct star formation episodes. Methods. The X-ray data allow the detected sources to be characterized according to hardness ratios, light curves, and spectra. Estimates of mass and age were obtained from the 2MASS catalogue and used to define a complete subsample of stellar counterparts for statistical purposes. Results. A catalogue of 387 XMM-Newton sources is provided, of which 78% are confirmed as members or probable members of the CMa R1 association. Flares (or similar events) were observed for 13 sources and the spectra of 21 bright sources could be fitted by a thermal plasma model. Mean values of fits parameters were used to estimate X-ray luminosities. We found a minimum value of log(LX [erg=s]) = 29:43, indicating that our sample of low-mass stars (M? 0:5 M ), which are faint X-ray emitters, is incomplete. Among the 250 objects selected as our complete subsample (defining our “best sample”), 171 are found to the east of the cloud, near Z CMa and dense molecular gas, of which 50% of them are young (<5 Myr) and 30% are older (>10 Myr). The opposite happens to the west, near GU CMa, in areas lacking molecular gas: among 79 objects, 30% are young and 50% are older. These findings confirm that a first episode of distributed star formation occurred in the whole studied region 10 Myr ago and dispersed the molecular gas, while a second, localized episode (<5 Myr) took place in the regions where molecular gas is still present.application/pdfengAstronomy and astrophysics. Les Ulis. Vol. 609 (Feb. 2018), A127, 37 p.Formacao de estrelasPopulacoes estelaresCatalogos astronomicosStar formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-NewtonEstrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSTEXT001091345.pdf.txt001091345.pdf.txtExtracted Texttext/plain194038http://www.lume.ufrgs.br/bitstream/10183/195656/2/001091345.pdf.txt3c3716028b063bf16d04b3677c0acd15MD52ORIGINAL001091345.pdfTexto completo (inglês)application/pdf4191166http://www.lume.ufrgs.br/bitstream/10183/195656/1/001091345.pdfd8893d28841a1daca32907d8a118661bMD5110183/1956562021-06-13 04:34:23.399519oai:www.lume.ufrgs.br:10183/195656Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2021-06-13T07:34:23Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton |
title |
Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton |
spellingShingle |
Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton Silva, Thais dos Santos Formacao de estrelas Populacoes estelares Catalogos astronomicos |
title_short |
Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton |
title_full |
Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton |
title_fullStr |
Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton |
title_full_unstemmed |
Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton |
title_sort |
Star formation history of Canis Major OB1 : II. A bimodal X-ray population revealed by XMM-Newton |
author |
Silva, Thais dos Santos |
author_facet |
Silva, Thais dos Santos Gregorio-Hetem, J. Montmerle, Thierry Soares, Beatriz Fernandes Lopes Stelzer, Beate |
author_role |
author |
author2 |
Gregorio-Hetem, J. Montmerle, Thierry Soares, Beatriz Fernandes Lopes Stelzer, Beate |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Silva, Thais dos Santos Gregorio-Hetem, J. Montmerle, Thierry Soares, Beatriz Fernandes Lopes Stelzer, Beate |
dc.subject.por.fl_str_mv |
Formacao de estrelas Populacoes estelares Catalogos astronomicos |
topic |
Formacao de estrelas Populacoes estelares Catalogos astronomicos |
description |
Aims. The Canis Major OB1 Association has an intriguing scenario of star formation, especially in the region called Canis Major R1 (CMa R1) traditionally assigned to a reflection nebula, but in reality an ionized region. This work is focussed on the young stellar population associated with CMa R1, for which our previous results from ROSAT, optical, and near-infrared data had revealed two stellar groups with di erent ages, suggesting a possible mixing of populations originated from distinct star formation episodes. Methods. The X-ray data allow the detected sources to be characterized according to hardness ratios, light curves, and spectra. Estimates of mass and age were obtained from the 2MASS catalogue and used to define a complete subsample of stellar counterparts for statistical purposes. Results. A catalogue of 387 XMM-Newton sources is provided, of which 78% are confirmed as members or probable members of the CMa R1 association. Flares (or similar events) were observed for 13 sources and the spectra of 21 bright sources could be fitted by a thermal plasma model. Mean values of fits parameters were used to estimate X-ray luminosities. We found a minimum value of log(LX [erg=s]) = 29:43, indicating that our sample of low-mass stars (M? 0:5 M ), which are faint X-ray emitters, is incomplete. Among the 250 objects selected as our complete subsample (defining our “best sample”), 171 are found to the east of the cloud, near Z CMa and dense molecular gas, of which 50% of them are young (<5 Myr) and 30% are older (>10 Myr). The opposite happens to the west, near GU CMa, in areas lacking molecular gas: among 79 objects, 30% are young and 50% are older. These findings confirm that a first episode of distributed star formation occurred in the whole studied region 10 Myr ago and dispersed the molecular gas, while a second, localized episode (<5 Myr) took place in the regions where molecular gas is still present. |
publishDate |
2018 |
dc.date.issued.fl_str_mv |
2018 |
dc.date.accessioned.fl_str_mv |
2019-06-12T02:31:52Z |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/195656 |
dc.identifier.issn.pt_BR.fl_str_mv |
0004-6361 |
dc.identifier.nrb.pt_BR.fl_str_mv |
001091345 |
identifier_str_mv |
0004-6361 001091345 |
url |
http://hdl.handle.net/10183/195656 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Astronomy and astrophysics. Les Ulis. Vol. 609 (Feb. 2018), A127, 37 p. |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFRGS instname:Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS |
instname_str |
Universidade Federal do Rio Grande do Sul (UFRGS) |
instacron_str |
UFRGS |
institution |
UFRGS |
reponame_str |
Repositório Institucional da UFRGS |
collection |
Repositório Institucional da UFRGS |
bitstream.url.fl_str_mv |
http://www.lume.ufrgs.br/bitstream/10183/195656/2/001091345.pdf.txt http://www.lume.ufrgs.br/bitstream/10183/195656/1/001091345.pdf |
bitstream.checksum.fl_str_mv |
3c3716028b063bf16d04b3677c0acd15 d8893d28841a1daca32907d8a118661b |
bitstream.checksumAlgorithm.fl_str_mv |
MD5 MD5 |
repository.name.fl_str_mv |
Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS) |
repository.mail.fl_str_mv |
|
_version_ |
1801224968085700608 |