Abstract Details
| Name: Aswathy S Affiliation: Research scholar Conference ID: ASI2015_845 Title : Analysis of optical counterparts of X-ray point sources in early type galaxies Authors and Co-Authors : Ravikumar C D, Jithesh V, Preetha A U and Dhanya Joseph Department of Physics, University of Calicut Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : Unresolved stellar populations in nearby galaxies contain valuable information regarding the formation of the galaxies. Many of such luminous point sources are detected to be brighter X-ray sources including ultra luminous X-ray sources (ULXs). We perform the optical analysis of the counterparts of X-ray point sources in a number of early type galaxies with an aim to investigate their X-ray to optical association. Our sample includes the galaxies NGC 1399, NGC 4649 and NGC 4552. We observe a strong anti-correlation with a high significance between the optical colours and X-ray luminosities excepting the ULXs included in the sample. As the optical counterparts are definitely multiple sources (most likely globular clusters), the strong trend exhibited by X-ray sources suggests the possibility of existence of multiple sources for the production of X-rays as well. Finally, we attempt to explain the correlation with the help of stellar population synthesis analysis. |