Publications
Normal galaxies in the XMM-Newton fields: X-rays as a star formation indicator
E. Rovilos, I. Georgantopoulos, P. Tzanavaris, M. Pracy, M. Whiting, D. Woods, and C. Goudis
Context. We use the first XMM serendipitous source catalogue (1XMM) to compile a sample of normal X-ray galaxies
Aims. We seek to expand the database of X-ray selected normal galaxies at intermediate redshifts and examine the relation between X-ray emission and star formation for late-type systems
Methods. The candidates are selected based on their X-ray (soft spectra), X-ray to optical (log( fx/ fo) < -2) and optical (extended sources) properties. 44 candidates are found and 35 are spectroscopically observed with the Australian National University's 2.3m telescope to examine their nature.
Results. Of the 35 sources observed, 2 are AGN, 11 emission line galaxies, 12 absorption line galaxies, 6 have featureless spectra while 4 are associated with Galactic stars. We combine our emission line sample with earlier works forming the most comprehensive X-ray selected galaxy sample for the study of the X-ray luminosity to the Hα luminosity - a well-calibrated star-formation indicator - relation.
Conclusions. We find that the X-ray luminosity strongly correlates with the Hα luminosity, suggesting that the X-rays efficiently trace the star-formation.
| back |