Molecular Gas and Star Formation in Local Early-Type Galaxies
| Autor: | Bureau, M., Davis, T. A., Alatalo, K., Crocker, A. F., Blitz, L., Young, L. M., Combes, F., Bois, M., Bournaud, F., Cappellari, M., Davies, R. L., de Zeeuw, P. T., Duc, P. -A., Emsellem, E., Khochfar, S., Krajnovic, D., Kuntschner, H., Lablanche, P. -Y., McDermid, R. M., Morganti, R., Naab, T., Oosterloo, T., Sarzi, M., Scott, N., Serra, P., Weijmans, A. |
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| Rok vydání: | 2011 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1017/S1743921311022459 |
| Popis: | The molecular gas content of local early-type galaxies is constrained and discussed in relation to their evolution. First, as part of the Atlas3D survey, we present the first complete, large (260 objects), volume-limited single-dish survey of CO in normal local early-type galaxies. We find a surprisingly high detection rate of 22%, independent of luminosity and at best weakly dependent on environment. Second, the extent of the molecular gas is constrained with CO synthesis imaging, and a variety of morphologies is revealed. The kinematics of the molecular gas and stars are often misaligned, implying an external gas origin in over a third of the systems, although this behaviour is drastically diffferent between field and cluster environments. Third, many objects appear to be in the process of forming regular kpc-size decoupled disks, and a star formation sequence can be sketched by piecing together multi-wavelength information on the molecular gas, current star formation, and young stars. Last, early-type galaxies do not seem to systematically obey all our usual prejudices regarding star formation, following the standard Schmidt-Kennicutt law but not the far infrared-radio correlation. This may suggest a greater diversity in star formation processes than observed in disk galaxies. Using multiple molecular tracers, we are thus starting to probe the physical conditions of the cold gas in early-types. Comment: Proceedings of the IAU Symposium 277 "Tracing the Ancestry of Galaxies". 4 pages, 3 figures |
| Databáze: | arXiv |
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