| Name: | K.J. Nikitha |
| Affiliation: | Physical Research Laboratory |
| Conference ID : | ASI2023_257 |
| Title : | Investigation of the blue straggler stars in globular cluster NGC 5053 using AstroSat-UVIT |
| Authors : | K. J. Nikitha [1], S. Vig [1] and S. K. Ghosh[2]
[1] Indian Institute of Space science and Technology, Thiruvananthapuram 695547, India
[2] Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India |
| Mode of Presentation: | Poster |
| Abstract Category : | Stars, ISM and Galaxy |
| Abstract : | Globular clusters serve as ideal laboratories to test stellar evolution theories owing to their ages and densely packed structure. While the studies of these in optical bands have been extensively conducted, the UV regime has been comparatively understudied. One of the primary contributors to the UV flux from a globular cluster are the blue straggler stars (BSSs). The formation and evolution of these stars remain an open issue. They are expected to form either through a mass transfer mechanism or a collisional/merger mechanism. Various studies have demonstrated that it is possible to predict which mechanism would be more prominent in a cluster based on the characteristics of the cluster and these stars. NGC 5053 which is a metal poor and a rather dispersed globular cluster was analyzed using the UV instrument of AstroSat, namely the Ultra Violet Imaging Telescope in three far-UV (F154W, F169M, F172M) and three near-UV (N219M, N245M, N263M) filters. Sixteen known BSSs and eight BSS candidates have been located using the UVIT filters in this cluster. The contention that the candidates belong to the BSS stellar population in the cluster is supported with results from photometry as well as by fitting their spectral energy distributions with stellar atmospheric models. The BSS population of this cluster is estimated to have effective temperatures ranging from 7750– 8250 K, with the mass and radius being between 1.2–1.3 Mⵙ and 0.9–2 Rⵙ, respectively. Based on our analyses of their SEDs and radial distribution, which appears to be more centrally concentrated, we believe the BSS population of this cluster has a collisional origin. |
