M. Baes, M. Clemens, E. M. Xilouris, J. Fritz, W. D. Cotton, J. Davies, G. J. Bendo, S. Bianchi, L. Cortese, I. De Looze, M. Pohlen, J. Verstappen, H. Böhringer, D. J. Bomans, A. Boselli, E. Corbelli, A. Dariush, S. Di Serego Alighieri, D. Fadda, D. A. Garcia-Appadoo, G. Gavazzi, C. Giovanardi, M. Grossi, T. Hughes, L. K. Hunt, A. Jones, S. C. Madden, D. Pierini, S. Sabatini, M. W. L. Smith, C. Vlahakis, S. Zibetti
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.
galaxies: individual: M 87 - radiation: mechanisms: thermal - radiation: mechanisms: non-thermal - infrared: galaxies
Astronomy & Astrophysics
Volume 518, Number of pages L53_1