M. Clemens, A. Jones, A. Bressan, M. Baes, G. J. Bendo, S. Bianchi, D. J. Bomans, A. Boselli, E. Corbelli, L. Cortese, A. Dariush, J. Davies, I. De Looze, S. Di Serego Alighieri, D. Fadda, J. Fritz, D. A. Garcia-Appadoo, G. Gavazzi, C. Giovanardi, M. Grossi, T. Hughes, L. K. Hunt, S. C. Madden, D. Pierini, M. Pohlen, S. Sabatini, M. W. L. Smith, J. Verstappen, C. Vlahakis, E. M. Xilouris, S. Zibetti
Abstract
Passive early-type galaxies(ETGs) provide an ideal laboratory for studying the interplay between dust formation around evolved stars and its subsequent destruction in a hot gas. Using Spitzer-IRS and Herschel data we compare the dust production rate in the envelopes of evolved AGB stars with a constraint on the total dust mass. Early-type galaxies which appear to be truly passively evolving are not detected by Herschel. We thus derive a distance independent upper limit to the dust grain survival time in the hostile environment of ETGs of< 46±25 Myr for amorphous silicate grains. This implies that ETGs which are detected at far-infrared wavelengths have acquired a cool dusty medium via interaction. Given likely time-scales for ram-pressure stripping, this also implies that only galaxies with dust in a cool(atomic) medium can release dust into the intra-cluster medium. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA
Keywords
galaxies: elliptical: and: lenticular- cD - galaxies: ISM - infrared: galaxies
Astronomy & Astrophysics
Volume 518, Number of pages L50_1
2010 July
