Search For Vertical Stratification Of Metals In Atmospheres Of Blue Horizontal-Branch Stars

Simple item page
dc.contributor.utaustinauthorBehr, B. B.en_US
dc.creatorKhalack, V. R.en_US
dc.creatorLeBlanc, F.en_US
dc.creatorBehr, B. B.en_US
dc.creatorWade, G. A.en_US
dc.creatorBohlender, D.en_US
dc.date.accessioned2016-04-22T19:46:03Z
dc.date.available2016-04-22T19:46:03Z
dc.date.issued2008-01en
dc.description.abstractContext. The observed abundance peculiarities of many chemical species relative to the expected cluster metallicity in blue horizontal-branch (BHB) stars presumably appear as a result of atomic diffusion in the photosphere. The slow rotation (typically upsilon sin i < 10 km s(-1)) of BHB stars with effective temperatures T(eff) > 11500 K supports this idea since the diffusion mechanism is only effective in a stable stellar atmosphere. Aims. In this work we search for observational evidence of vertical chemical stratification in the atmospheres of six hot BHB stars: B84, B267 and B279 in M 15 and WF2-2541, WF4-3085 and WF4-3485 in M 13. Methods. We undertake an abundance stratification analysis of the stellar atmospheres of the aforementioned stars, based on acquired Keck HIRES spectra. Results. We have found from our numerical simulations that three stars (B267, B279 and WF2-2541) show clear signatures of the vertical stratification of iron whose abundance increases toward the lower atmosphere, while the other two stars (B84 and WF4-3485) do not. For WF4-3085 the iron stratification results are inconclusive. B267 also shows a signature of titanium stratification. Our estimates for radial velocity, v sin i and overall iron, titanium and phosphorus abundances agree with previously published data for these stars after taking the measurement errors into account. The results support the hypothesis regarding the efficiency of atomic diffusion in the stellar atmospheres of BHB stars with T(eff) > 11500 K.en_US
dc.description.departmentAstronomyen_US
dc.identifierdoi:10.15781/T28508
dc.identifier.citationKhalack, V. R., F. Leblanc, B. B. Behr, G. A. Wade, and David Bohlender. >Search for vertical stratification of metals in atmospheres of blue horizontal-branch stars.> Astronomy & Astrophysics, Vol. 477, No. 2 (Jan., 2008): pp. 641-647.en_US
dc.identifier.doi10.1051/0004-6361:20078488en_US
dc.identifier.issn0004-6361en_US
dc.identifier.urihttp://hdl.handle.net/2152/34422
dc.language.isoEnglishen_US
dc.relation.ispartofserialAstronomy & Astrophysicsen_US
dc.rightsAdministrative deposit of works to Texas ScholarWorks: This works author(s) is or was a University faculty member, student or staff member; this article is already available through open access or the publisher allows a PDF version of the article to be freely posted online. The library makes the deposit as a matter of fair use (for scholarly, educational, and research purposes), and to preserve the work and further secure public access to the works of the University.en_US
dc.subjectstars : atmospheresen_US
dc.subjectstars : horizontal-branchen_US
dc.subjectstars : chemicallyen_US
dc.subjectpeculiaren_US
dc.subjectline data-baseen_US
dc.subjecthot hb starsen_US
dc.subjectglobular-clustersen_US
dc.subjectabundance anomaliesen_US
dc.subjectphysical parametersen_US
dc.subjectrotation velocitiesen_US
dc.subjectspectrum synthesisen_US
dc.subjectmagnetic-fielden_US
dc.subjectconsequencesen_US
dc.subjectdiffusionen_US
dc.subjectastronomy & astrophysicsen_US
dc.titleSearch For Vertical Stratification Of Metals In Atmospheres Of Blue Horizontal-Branch Starsen_US
dc.typeArticleen_US

Access full-text files

Original bundle

Now showing 1 - 1 of 1
Thumbnail Image
Name:
searchverticalstratification.pdf
Size:
340.99 KB
Format:
Adobe Portable Document Format
Download

Collections

UT Faculty/Researcher Works