Abstract Details
| Name: Tarang Vashisht Affiliation: Indian Institute of Science Education and Research, Mohali Conference ID: ASI2024_361 Title : The Spectral Variability in ULX-8 NGC4490/4485 Authors and Co-Authors : Tarang Vashisht1, Vikram Rana2, Aru Beri1, Tanuman Ghosh2,3, Aman Upadhyay2 Abstract Type : Poster Abstract Category : Stars, Interstellar Medium, and Astrochemistry in Milky Way Abstract : We will present the results of 14 Chandra and 6 XMM-Newton observations of the Ultraluminous X-ray source NGC4490/4485 ULX-8, which is one of the brightest and most isolated sources in this interacting galaxy pair. Our analysis indicated a long-term spectral variability in this source, with intrinsic luminosity, ranging from 1.99 * 10^(39) to 4.64 * 10^(39) ergs s^(-1). However, no short-term variability or periodicity was detected. The best-fitting spectral parameters obtained using an absorbed diskbb model indicated an evolution in the disk temperature varying between 0.9 and 2 KeV. The nature of the compact object is ambiguous in this source. By means of spectral and timing analysis, our results do not support it not be a pulsar or intermediate-mass black hole. We also performed correlation analysis of fitting parameters and luminosity values. We will discuss the physical implications of our analysis. |