Revealing the Interaction between the X-Ray Gas of Starburst Galaxy UGC 6697 and the Hot Intracluster Medium of A1367

Abstract

We present the result from a Chandra observation of an X-ray-luminous starburst galaxy, UGC 6697, which is embedded in the northwest hot region of A1367 (5-6 keV). A very sharp X-ray edge (~13-fold surface brightness jump) at the southeast and a long tail (at least 60 kpc from the nucleus) at the northwest of the galaxy are detected, as expected if the galaxy is moving to the southeast. The X-ray edge, at the midway of the nucleus and the southeast optical disk edge, is also at the same position where the Hα emission is truncated and a radio sharp edge is observed. The X-ray diffuse emission is also enhanced at the southeast, implying ram pressure compression. No extraplanar X-ray component is detected, probably because of the combining effects of weaker outflow activity than that in nuclear starbursts, and external confinement plus stripping. The diffuse thermal gas in UGC 6697 has a temperature of ~0.7 keV and a low iron abundance (~0.1-0.2 solar). An X-ray point source (L_0.5-10keV~2.8×10⁴⁰ ergs s^-1) is detected on the nucleus, but not highly absorbed. Three off-center ultraluminous X-ray sources, all with L_0.5-10keV>10⁴⁰ ergs s^-1, are also detected. Based on the multiwavelength data available, we favor that the interaction between the interstellar medium and the intracluster medium plays a major role in triggering the starburst in UGC 6697.