XMM-Newton Observation of NGC1407/1400 Complex

Yuanyuan Su, University of Alabama - Tuscaloosa
Liyi Gu, University of Tokyo
Raymond White III, University of Alabama - Tuscaloosa
Jimmy A. Irwin, University of Alabama - Tuscaloosa
Evan T. Million, University of Alabama - Tuscaloosa
Ka-Wah Wong, Minnesota State University Mankato

Abstract

The nearby group centered on the elliptical galaxy NGC 1407 is one of the darkest systems in the local universe. This system is also notable for having a second-brightest galaxy (NGC 1400) with a large velocity difference (at least 1100 km/s) with respect to NGC 1407. Our analysis of XMM-Newton data of this group suggests a potentially violent collision between NGC1407 and NGC1400. An region of enhanced brightness associated with NGC1400 is also found to the direction of NGC 1407, which is probably a cold front.