dc.contributor.author |
Kumar, Ranjan |
|
dc.contributor.author |
Pradhan, Ananta C |
|
dc.contributor.author |
Sahu, Snehalata |
|
dc.contributor.author |
Subramaniam, A |
|
dc.contributor.author |
Piridi, Sonika |
|
dc.contributor.author |
Cassisi, Santi |
|
dc.contributor.author |
Ojha, Devendra K |
|
dc.date.accessioned |
2023-04-26T08:18:37Z |
|
dc.date.available |
2023-04-26T08:18:37Z |
|
dc.date.issued |
2023-06 |
|
dc.identifier.citation |
Monthly Notices of the Royal Astronomical Society, Vol. 522, No. 1, pp. 847–862 |
en_US |
dc.identifier.issn |
1365-2966 |
|
dc.identifier.uri |
http://hdl.handle.net/2248/8182 |
|
dc.description |
Restricted Access |
en_US |
dc.description.abstract |
We present a far-ultraviolet (FUV) study of hot stellar populations in the second parameter pair globular clusters (GCs) M3 and
M13, as a part of the GC UVIT Legacy Survey programme (GlobULeS). We use observations made with F148W and F169M
filters of the Ultraviolet Imaging Telescope (UVIT) onboard AstroSat along with ground-based data (UBVRI filters), Hubble
Space Telescope (HST) GC catalogue, and Gaia EDR3 catalogue. Based on the FUV-optical colour–magnitude diagrams, we
classify the sources into the horizontal branch (HB) stars, post-HB stars, and hot white dwarfs (WDs) in both the GCs. The
comparison of synthetic and observed colours of the observed HB stars suggests that the mass-loss at the red giant branch and
He spread in both clusters have a simultaneous effect on the different HB distributions detected in M3 and M13, such that HB
stars of M13 require a larger spread in He (0.247–0.310) than those of M3 (Y = 0.252–0.266). The evolutionary status of HB
stars, post-HB stars, and WDs are studied using SED fit parameters and theoretical evolutionary tracks on the H–R diagram. We
found that the observed post-HB stars have evolved from zero-age HB (ZAHB) stars of the mass range of 0.48−0.55 M in M3
and M13. We detect 24 WD candidates in each cluster having log(Lbol/L) in the range of −0.8 to +0.6 and log(Teff/K) in the
range of 4.2–5.0. Placing the WDs on the H–R diagram and comparing them with models, it is found that M13 has a population
of low-mass WDs, probably originating from binary evolution. |
en_US |
dc.language.iso |
en |
en_US |
dc.publisher |
Oxford University Press on behalf of Royal Astronomical Society |
en_US |
dc.relation.uri |
https://doi.org/10.1093/mnras/stad1009 |
|
dc.rights |
© Royal Astronomical Society |
|
dc.subject |
Hertzsprung-Russell and colour-magnitude diagrams |
en_US |
dc.subject |
Stars: horizontal branch |
en_US |
dc.subject |
White dwarfs |
en_US |
dc.subject |
Globular clusters: individual: NGC 5272 (M3) and NGC 6205 (M13) |
en_US |
dc.subject |
Ultraviolet: stars |
en_US |
dc.title |
Globular Cluster UVIT Legacy Survey (GlobULeS) – II. Evolutionary status of hot stars in M3 and M13 |
en_US |
dc.type |
Article |
en_US |