Back to Search Start Over

UVIT study of UV bright stars in the globular cluster NGC 4147.

Authors :
Kumar, Ranjan
Pradhan, Ananta C.
Parthasarathy, Mudumba
Ojha, Devendra K.
Mohapatra, Abhisek
Murthy, Jayant
Cassisi, Santi
Source :
Journal of Astrophysics & Astronomy; Oct2021, Vol. 42 Issue 2, p1-10, 10p
Publication Year :
2021

Abstract

We present far ultraviolet (FUV) observations of globular cluster NGC 4147 using three FUV filters, BaF 2 (F154W), sapphire (F169M), and silica (F172M) of Ultra-Violet Imaging Telescope (UVIT) on-board the AstroSat satellite. We confirmed the cluster membership of the UVIT observed sources using proper motions from Gaia data release 2 (GAIA DR2). We identified 37 blue horizontal branch stars (BHBs), one blue straggler star (BSS) and 15 variable stars using UV-optical color magnitude diagrams (CMDs). We find that all the FUV bright BHBs are second generation population stars. Using UV-optical CMDs, we identify two sub-populations, BHB1 and BHB2, among the UV-bright BHBs in the cluster with stars count ratio of 24:13 for BHB1 and BHB2. The effective temperatures ( T eff ) of BHB1 and BHB2 were derived using color-temperature relation of BaSTI-IAC zero-age horizontal branch (ZAHB). We found that BHB1 stars are more centrally concentrated than BHB2 stars. We also derive physical parameters of the detected FUV bright BSS by fitting younger age BaSTI-IAC isochrones on optical and UV-optical CMDs. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
02506335
Volume :
42
Issue :
2
Database :
Complementary Index
Journal :
Journal of Astrophysics & Astronomy
Publication Type :
Academic Journal
Accession number :
150934016
Full Text :
https://doi.org/10.1007/s12036-020-09687-y