A COMPREHENSIVE X-RAY AND MULTIWAVELENGTH STUDY OF THE COLLIDING GALAXY PAIR NGC 2207/IC 2163

作者：Mineo S^*; Rappaport S; Levine A; Pooley D; Steinhorn B; Homan J

来源：Astrophysical Journal, 2014, 797(2): 91.

DOI：10.1088/0004-637X/797/2/91

• dust, extinction
• galaxies: individual (NGC 2207/IC2163)
• galaxies: interactions
• galaxies: starburst
• stars: formation
• stars: luminosity function, mass function
• stars: neutron
• X-rays: binaries
• X-rays: ISM

We present a comprehensive study of the total X-ray emission from the colliding galaxy pair NGC 2207/IC 2163, based on Chandra, Spitzer, and GALEX data. We detect 28 ultraluminous X-ray sources (ULXs), 7 of which were not detected previously because of X-ray variability. Twelve sources show significant long-term variability, with no correlated spectral changes. Seven sources are transient candidates. One ULX coincides with an extremely blue star cluster (B - V = -0.7). We confirm that the global relation between the number and luminosity of ULXs and the integrated star-formation rate (SFR) of the host galaxy also holds on local scales. We investigate the effects of dust extinction and age on the X-ray binary (XRB) population on subgalactic scales. The distributions of N-X and L-X are peaked at L-IR/L-NUV similar to 1, which may be associated with an age of similar to 10 Myr for the underlying stellar population. We find that approximately one-third of the XRBs are located in close proximity to young star complexes. The luminosity function of the XRBs is consistent with that typical for high-mass XRBs and appears unaffected by variability. We disentangle and compare the X-ray diffuse spectrum with that of the bright XRBs. The hot interstellar medium dominates the diffuse X-ray emission at E less than or similar to 1 keV and has a temperature kT = 0.28(-0.04)(+0.05) keV and intrinsic 0.5-2 keV luminosity of 7.9 x 10(40) erg s(-1), a factor of similar to 2.3 higher than the average thermal luminosity produced per unit SFR in local star-forming galaxies. The total X-ray output of NGC 2207/IC 2163 is 1.5x10(41) erg s(-1), and the corresponding total integrated SFR is 23.7 M-circle dot yr(-1).

• 出版日期2014-12-20
• 单位MIT