International E-publication: Publish Projects, Dissertation, Theses, Books, Souvenir, Conference Proceeding with ISBN.  International E-Bulletin: Information/News regarding: Academics and Research

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.


  1. Oppenheimer B.D., Feedback and recycled wind accretion: assembling the z = 0 galaxy mass function, MNRAS, 406, 2325 (2010)
  2. Tang S., et al. Feedback from galactic stellar bulges and hot gaseous haloes of galaxies, MNRAS 392, 77 (2009)
  3. Forman W. and Jones C., Clusters of galaxies and cooling hot gas, NATO ASIC Proc. 229, 17 (1988)
  4. Zhang Z., Gilfanov M., Bogd. Dependence of the low-mass X-ray binary population on stellar age,AandA, 546, A36 (2012)
  5. Kaaret P., Prestwich A.H., Zezas A., Murray S.S., Kim D.W., Kilgard R.E., Schlegel E. M., Ward M. J. Chandra High-Resolution Camera observations of the luminous X-ray source in the starburst galaxy M82, MNRAS, 321, L29(2001)
  6. Colbert E. J. M., Mushotzky R. F. The Nature of Accreting Black Holes in Nearby Galaxy Nuclei, ApJ, 519, 89 (1999)
  7. Makishima K., et al. The Nature of Ultraluminous Compact X-Ray Sources in Nearby Spiral Galaxies, ApJ, 535, 632 (2000)
  8. de Vaucouleurs G. Recherches sur les Nebuleuses Extragalactiques, AnAp, 11, 247 (1948)
  9. Freeman K.C. On the Disks of Spiral and so Galaxies, ApJ, 160, 811 (1970)
  10. Kormendy J. Brightness distributions in compact andnormal galaxies. III - Decomposition of observed profiles into spheroid and disk components, ApJ, 217, 406 (1977)
  11. Burstein D. Structure and origin of S0 galaxies. II - Disk-to-bulge ratios, ApJ, 234, 435 (1979)
  12. Byun Y. I., Freeman K.C. Two-dimensional Decomposition of Bulge and Disk, ApJ, 448, 563 (1995)
  13. Shaw M. A., Gilmore G. The luminosity distributions of edge-on spiral galaxies. I - A two-dimensional model and its application to NGC 891 and 4565, MNRAS, 237, 903 (1989)
  14. Peng C. Y., Ho L.C., Impey C.D. and Rix H.W, Detailed Structural Decomposition of Galaxy Images, AJ, 124, 266(2002)
  15. de Souza R. E., Gadotti D.A. and dos Anjos S. BUDDA, A New Two-dimensional Bulge/Disk Decomposition Code for Detailed Structural Analysis of Galaxies, ApJS, 153, 411 (2004)
  16. Press W. H., Teukolsky S.A., Vetterling W.T. and Flannery B.P. Numerical recipes in C. The art of scientific computing, (1992)
  17. Swartz D. A., Ghosh K. K., Tennant A.F. and Wu K., The Ultraluminous X-Ray Source Population from the Chandra Archive of Galaxies, ApJS,154, 519 (2004)
  18. Swartz D.A., Soria R., Tennant A.F. and Yukita M., A. Complete Sample of Ultraluminous X-ray Source Host Galaxies, ApJ, 741, 49 (2011)
  19. Stobbart A. M., Roberts T. P. and Warwick R. S., The X-ray properties of the dwarf Magellanic-type galaxy NGC 55, MNRAS, 370, 25 (2006)
  20. Devi A.S., Misra R., Agrawal V.K. and Singh K.Y., The Dependence of the Estimated Luminosities of Ultraluminous X-Ray Sources on Spectral Models, ApJ, 664, 458 (2007)