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.
The Herschel Virgo Cluster Survey. III. A constraint on dust grain lifetime in early-type galaxies / Clemens, M.S., Jones, A.P., Bressan, A., Baes, M., Bendo, G.J., Bianchi, S., Bomans, D.J., Boselli, A., Corbelli, E., Cortese, L., Dariush, A., Davies, J.I., De Looze, I., Alighieri, S.d.S., Fadda, D., Fritz, J., Garcia-Appadoo, D.A., Gavazzi, G., Giovanardi, C., Grossi, M., et al.. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - 518:(2010), pp. 1-4. [10.1051/0004-6361/201014533]
The Herschel Virgo Cluster Survey. III. A constraint on dust grain lifetime in early-type galaxies
Bressan, A.;
2010-01-01
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.| File | Dimensione | Formato | |
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