The Herschel Virgo Cluster Survey . VI. The far-infrared view of M 87
Böhringer, H.; Bomans, D. J.; Bianchi, S.; Fritz, J.; De Looze, I.; Hunt, L. K.; Baes, M.; Dariush, A.; Bendo, G. J.; Boselli, A.; Cortese, L.; di Serego Alighieri, S.; Hughes, T. M.; Madden, S.; Pohlen, M.; Clemens, M.; Smith, M. W. L.; Verstappen, J.; Xilouris, E. M.; Gavazzi, G.; Zibetti, S.; Sabatini, S.; Corbelli, E.; Cotton, W. D.; Pierini, D.; Jones, A. P.; Fadda, D.; Vlahakis, C.; Grossi, M.; Giovanardi, C.; Davies, J. I.; Garcia-Appadoo, D. A.
Belgium, Italy, Greece, United States, United Kingdom, Germany, France, Chile, Portugal, Netherlands
Abstract
The origin of the far-infrared emission from the nearby radio galaxy M 87 remains a matter of debate. Some studies find evidence of a far-infrared excess due to thermal dust emission, whereas others propose that the far-infrared emission can be explained by synchrotron emission without the need for an additional dust emission component. We present Herschel PACS and SPIRE observations of M 87, taken as part of the science demonstration phase observations of the Herschel Virgo Cluster Survey. We compare these data with a synchrotron model based on mid-infrared, far-infrared, submm and radio data from the literature to investigate the origin of the far-infrared emission. Both the integrated SED and the Herschel surface brightness maps are adequately explained by synchrotron emission. At odds with previous claims, we find no evidence of a diffuse dust component in M 87, which is not unexpected in the harsh X-ray environment of this radio galaxy sitting at the core of the Virgo cluster.
Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.