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Morphological analysis of Early type Galaxies hosting X-ray point sources

Author Affiliations

  • 1Department of Physics, University of Calicut, Kerala, INDIA

Res. J. Recent Sci., Volume 3, Issue (ISC-2013), Pages 89-92, (2014)


We report a strong association of X-ray point sources with the Sérsic index of bulges, analyzing a complete sample of nearby 28 early type galaxies with X-ray and K band observations from Chandra and 2MASS archives, respectively. From the X-ray spectral analysis, we construct a flux limited sample of 371 bright (LX = 0.24X1039 – 0.12X1041 ergs/s ) X-ray point sources. Morphological analysis of these galaxies (in K band) was conducted using the code GALFIT assuming a Sérsic bulge and an exponential disk for their surface brightness profiles. The extracted structural parameters show presence of strong disk component in all these galaxies with Bulge-to-Total K band light ratio, B/T < 0.5, even though they are classified as early type galaxies in the RC3 catalog. The average Sérsic index, n shown by the sample is 1.44 ± 0.33, suggesting the existence of pseudo bulges in these systems. Further, we find that the maximum luminosity of X-ray point source is strongly correlated with Sérsic index, suggesting that the existence of X-ray point sources has strong influence from the nature of hosting bulges.


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