X‐Ray Evidence for the Interaction of the Giant Elliptical Galaxy NGC 4472 with its Virgo Cluster Environment

Abstract

We analyze X-ray spatial and spectral data on the giant elliptical galaxy NGC 4472, the brightest galaxy in the Virgo cluster. The X-ray contours of NGC 4472 are elongated in the northeast-southwest direction, perhaps as a result of motion through the Virgo intracluster gas. A bow shocklike structure is evident on the galaxys north side. The temperature at a given radius in this bow shock region is slightly higher than the temperature at the same radius on the galaxys southwest side. Away from this bow shock region, the surface brightness prole of NGC 4472 can be traced out to a radius of 260 kpc in the southwest direction. Beyond 260 kpc, we nd evidence for emission from both the Virgo cluster and the Galactic North Polar Spur (believed to be the rim of a hot Galactic superbubble).