File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: New OB star candidates in the Carina Arm around Westerlund 2 from VPHAS

TitleNew OB star candidates in the Carina Arm around Westerlund 2 from VPHAS
Authors
KeywordsDust, extinction
Galaxy: structure
Open clusters and associations: individual: Westerlund 2
Stars: early-type
Stars: massive
Surveys
Issue Date11-Jul-2015
PublisherOxford University Press
Citation
Monthly Notices of the Royal Astronomical Society, 2015, v. 450, n. 4, p. 3855-3873 How to Cite?
AbstractO and early B stars are at the apex of galactic ecology, but in the Milky Way, only a minority of them may yet have been identified. We present the results of a pilot study to select and parametrize OB star candidates in the Southern Galactic plane, down to a limiting magnitude of g = 20. A 2 deg(2) field capturing the Carina Arm around the young massive star cluster, Westerlund 2, is examined. The confirmed OB stars in this cluster are used to validate our identification method, based on selection from the (u - g, g - r) diagram for the region. Our Markov Chain Monte Carlo fitting method combines VPHAS+ u, g, r, i with published J, H, K photometry in order to derive posterior probability distributions of the stellar parameters log (T-eff) and distance modulus, together with the reddening parameters A(0) and R-V. The stellar parameters are sufficient to confirm OB status while the reddening parameters are determined to a precision of sigma(A(0)) similar to 0.09 and sigma(R-V) similar to 0.08. There are 489 objects that fit well as new OB candidates, earlier than similar to B2. This total includes 74 probable massive O stars, 5 likely blue supergiants and 32 reddened subdwarfs. This increases the number of previously known and candidate OB stars in the region by nearly a factor of 10. Most of the new objects are likely to be at distances between 3 and 6 kpc. We have confirmed the results of previous studies that, at these longer distances, these sight lines require non-standard reddening laws with 3.5 < R-V < 4.
Persistent Identifierhttp://hdl.handle.net/10722/343723
ISSN
2023 Impact Factor: 4.7
2023 SCImago Journal Rankings: 1.621
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorMohr-Smith, M-
dc.contributor.authorDrew, JE-
dc.contributor.authorBarentsen, G-
dc.contributor.authorWright, NJ-
dc.contributor.authorNapiwotzki, R-
dc.contributor.authorCorradi, RLM-
dc.contributor.authorEisloeffel, J-
dc.contributor.authorGroot, P-
dc.contributor.authorKalari, V-
dc.contributor.authorParker, QA-
dc.contributor.authorRaddi, R-
dc.contributor.authorSale, SE-
dc.contributor.authorUnruh, YC-
dc.contributor.authorVink, JS-
dc.contributor.authorWesson, R-
dc.date.accessioned2024-05-28T09:37:27Z-
dc.date.available2024-05-28T09:37:27Z-
dc.date.issued2015-07-11-
dc.identifier.citationMonthly Notices of the Royal Astronomical Society, 2015, v. 450, n. 4, p. 3855-3873-
dc.identifier.issn0035-8711-
dc.identifier.urihttp://hdl.handle.net/10722/343723-
dc.description.abstractO and early B stars are at the apex of galactic ecology, but in the Milky Way, only a minority of them may yet have been identified. We present the results of a pilot study to select and parametrize OB star candidates in the Southern Galactic plane, down to a limiting magnitude of g = 20. A 2 deg(2) field capturing the Carina Arm around the young massive star cluster, Westerlund 2, is examined. The confirmed OB stars in this cluster are used to validate our identification method, based on selection from the (u - g, g - r) diagram for the region. Our Markov Chain Monte Carlo fitting method combines VPHAS+ u, g, r, i with published J, H, K photometry in order to derive posterior probability distributions of the stellar parameters log (T-eff) and distance modulus, together with the reddening parameters A(0) and R-V. The stellar parameters are sufficient to confirm OB status while the reddening parameters are determined to a precision of sigma(A(0)) similar to 0.09 and sigma(R-V) similar to 0.08. There are 489 objects that fit well as new OB candidates, earlier than similar to B2. This total includes 74 probable massive O stars, 5 likely blue supergiants and 32 reddened subdwarfs. This increases the number of previously known and candidate OB stars in the region by nearly a factor of 10. Most of the new objects are likely to be at distances between 3 and 6 kpc. We have confirmed the results of previous studies that, at these longer distances, these sight lines require non-standard reddening laws with 3.5 < R-V < 4.-
dc.languageeng-
dc.publisherOxford University Press-
dc.relation.ispartofMonthly Notices of the Royal Astronomical Society-
dc.rightsThis work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.-
dc.subjectDust, extinction-
dc.subjectGalaxy: structure-
dc.subjectOpen clusters and associations: individual: Westerlund 2-
dc.subjectStars: early-type-
dc.subjectStars: massive-
dc.subjectSurveys-
dc.titleNew OB star candidates in the Carina Arm around Westerlund 2 from VPHAS-
dc.typeArticle-
dc.identifier.doi10.1093/mnras/stv843-
dc.identifier.scopuseid_2-s2.0-84938151878-
dc.identifier.volume450-
dc.identifier.issue4-
dc.identifier.spage3855-
dc.identifier.epage3873-
dc.identifier.eissn1365-2966-
dc.identifier.isiWOS:000360824000036-
dc.publisher.placeOXFORD-
dc.identifier.issnl0035-8711-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats