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
@article{arxiv.1109.5706,
title = {Herschel observations of Cen A: stellar heating of two extragalactic dust clouds},
author = {R. Auld and M. W. L. Smith and G. Bendo and M. Pohlen and C. Wilson and H. Gomez and L. Cortese and R. Morganti and M. Baes and A. Boselli and A. Cooray and J. I. Davies and S. Eales and D. Elbaz and M. Galametz and K. Isaak and T. Oosterloo and M. Page and E. Rigby and L. Spinoglio and C. Struve},
journal= {arXiv preprint arXiv:1109.5706},
year = {2015}
}
Comments
16 pages, 9 figures, Accepted for publication in MNRAS, author email: [email protected]