Chandra Observation of Point Sources in the X-Ray Elliptical Galaxy NGC 1407

With the Chandra pointing observation of about 50 ks, we have detected41 point sources in the X-ray relatively faint elliptical galaxy NGC 1407, most ofwhich appear to be low mass X-ray binaries. In luminosity flux units, these resolvedpoint sources contribute about 17.8% of the total emission of the galaxy in 0.3-10 keV. Of the remaining diffuse emission, about 53.4% (or 43.9% of total) may arisefrom unresolved point sources. We find six ultraluminous X-ray sources with lumi-nosities above 10~(39) erg s~(-1). This number is less than has been found in NGC 720,but more than in NGC 4697 and NGC 1553, so suggesting a possible correlationbetween the number of ULXs and the total X-ray luminosity of early-type galaxies.A central point-like source is detected whose luminosity (2.36±0.14×10~(39)erg s~(-1))is the highest among all resolved sources. However, because of its relatively lowhardness ratio, we speculate that it is not likely to be a low luminosity AGN.

Chandra Observation of Point Sources in the X-Ray Elliptical Galaxy NGC 1407