1. Herschel observations of Cen A: stellar heating of two extragalactic dust clouds
- Author
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Baes, M., Boselli, A., Cooray, A., Davies, J. I., Eales, S., Elbaz, D., Galametz, M., Isaak, K., Oosterloo, T., Page, M., Rigby, E., Spinoglio, L., Struve, C., Auld, R., Smith, M. W. L., Bendo, G., Pohlen, M., Wilson, C., Gomez, H., Cortese, L., Morganti, R., Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Astronomy
- Subjects
EMISSION-LINE FILAMENTS ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,CENTAURUS-A EVIDENCE ,INTERSTELLAR-MEDIUM ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,extinction ,Astrophysics::High Energy Astrophysical Phenomena ,galaxies: active ,ENERGY PARTICLE-ACCELERATION ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,galaxies: jets ,160 MU-M ,submillimetre: ISM ,INDUCED STAR-FORMATION ,X-RAY-EMISSION ,MULTIBAND IMAGING PHOTOMETER ,NGC 5128 ,Astrophysics::Solar and Stellar Astrophysics ,dust ,FORMATION RATE INDICATORS ,submillimetre: galaxies ,galaxies: ISM ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present the first results of a multi-wavelength survey, incoporating Herschel-SPIRE, Spitzer, GALEX and ATCA observations, of a 1 deg x 1 deg field centred on Centaurus A. As well as detecting the inner lobes of the active galactic nucleus (AGN) jet and counterjet, we have found two clouds, bright at sub-mm wavelengths, ~15 kpc from the centre of Cen A that are co-aligned with the jets. Flux measurements at Herschel wavelengths have proved vital in constraining fits to the Spectral Energy Distributions (SEDs). The clouds are well fit by a single-temperature, modified blackbody spectrum (beta=2) indicating that we are looking at two cold dust clouds on the outskirts of Cen A. The temperature and masses of the clouds are: T_{north} = 12.6^{+1.1}_{-1.2} K, T_{south} = 15.1^{+1.7}_{-1.6} K; log(M_{north} / M_o) = 5.8^{+0.2}_{-0.2}, log(M_{south} / M_o) = 5.6^{+0.2}_{-0.2} and the gas-dust ratio for both clouds is ~100. The measured values for the northern dust cloud are consistent with previous measurements from ISO while the southern cloud is a new sub-mm detection. The two dust clouds are located at the termini of the partial HI ring that surrounds Cen A which is also where the gas column density peaks... abridged, Comment: 16 pages, 9 figures, Accepted for publication in MNRAS, author email: robbie.auld@astro.cf.ac.uk
- Published
- 2012
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