Globular Cluster UVIT Legacy Survey (GlobULeS). III. Omega Centauri in Far-ultraviolet

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dc.contributor.authorPrabhu, Deepthi S.
dc.contributor.authorSubramaniam, Annapurni
dc.contributor.authorSahu, Snehalata
dc.contributor.authorChung, Chul
dc.contributor.authorLeigh, Nathan W. C.
dc.contributor.authorDalessandro, Emanuele
dc.contributor.authorChatterjee, Sourav
dc.contributor.authorRao, N. Kameswara
dc.contributor.authorShara, Michael
dc.contributor.authorCote, Patrick
dc.contributor.authorChoudhury, Samyaday
dc.contributor.authorPandey, Gajendra
dc.contributor.authorValcarce, Aldo A. R.
dc.contributor.authorSingh, Gaurav
dc.contributor.authorPostma, Joesph E.
dc.contributor.authorRani, Sharmila
dc.contributor.authorBandyopadhyay, Avrajit
dc.contributor.authorGeller, Aaron M.
dc.contributor.authorHutchings, John
dc.contributor.authorPuzia, Thomas
dc.contributor.authorSimunovic, Mirko
dc.contributor.authorSohn, Young-Jong
dc.contributor.authorThirupathi, Sivarani
dc.contributor.authorYadav, Ramakant Singh
dc.date.accessioned2025-01-20T21:01:35Z
dc.date.available2025-01-20T21:01:35Z
dc.date.issued2022
dc.description.abstractWe present the first comprehensive study of the most massive globular cluster, Omega Centauri, in the far-ultraviolet (FUV), extending from the center to similar to 28% of the tidal radius using the Ultraviolet Imaging Telescope on board AstroSat. A comparison of the FUV-optical color-magnitude diagrams with available canonical models reveals that horizontal branch (HB) stars bluer than the knee (hHBs) and the white dwarfs (WDs) are fainter in the FUV by similar to 0.5 mag than model predictions. They are also fainter than their counterparts in M13, another massive cluster. We simulated HB with at least five subpopulations, including three He-rich populations with a substantial He enrichment of Y up to 0.43 dex, to reproduce the observed FUV distribution. We find the He-rich younger subpopulations to be radially more segregated than the He-normal older ones, suggesting an in situ enrichment from older generations. The omega Cen hHBs span the same T (eff) range as their M13 counterparts, but some have smaller radii and lower luminosities. This may suggest that a fraction of omega Cen hHBs are less massive than those of M13, similar to the result derived from earlier spectroscopic studies of outer extreme HB stars. The WDs in omega Cen and M13 have similar luminosity-radius-T (eff) parameters, and 0.44-0.46 M (circle dot) He-core WD model tracks evolving from progenitors with Y = 0.4 dex are found to fit the majority of these. This study provides constraints on the formation models of omega Cen based on the estimated range in age, [Fe/H], and Y (in particular) for the HB stars.
dc.fuente.origenWOS
dc.identifier.doi10.3847/2041-8213/ac9901
dc.identifier.eissn2041-8213
dc.identifier.issn2041-8205
dc.identifier.urihttps://doi.org/10.3847/2041-8213/ac9901
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/92915
dc.identifier.wosidWOS:000877846800001
dc.issue.numero2
dc.language.isoen
dc.revistaAstrophysical journal letters
dc.rightsacceso restringido
dc.titleGlobular Cluster UVIT Legacy Survey (GlobULeS). III. Omega Centauri in Far-ultraviolet
dc.typeartículo
dc.volumen939
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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