Proceedings of the International Astronomical Union

Table of Contents - 2009 - Volume 5, Symposium S267 (Co-Evolution of Central Black Holes and Galaxies)  

Contributed Papers

Dust Masses in Early-Type AGN and Inactive Galaxies

Ramiro D. Simões-Lopesa1a2, Paul Martinia2 and Thaisa Storchi-Bergmanna1

a1 Instituto de Física, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Porto Alegre, RS, Brazil Email: ramirosl@if.ufrgs.br

a2 Department of Astronomy and Center for Cosmology and Astroparticle Physics, The Ohio State University, 140 W 18th Avenue, Columbus, Ohio 43210-1173, USA Email: martini@astronomy.ohio-state.edu

It has been known for some time that elliptical galaxies have some form of dust structure at their centers (Kormendy & Djorgovski 1989; van Dokkum & Franx 1995). Nevertheless the exact amount and the origin of the dust is still unknown. In a previous paper, we have shown that all early-type galaxies hosting an AGN have dust at their centers as opposed to only a quarter of the inactive galaxies in a pair-matched sample (Simões Lopes et al. 2007). Here we use Spitzer (IRAC and MIPS) observations of the same sample — 32 active and 32 inactive early-type galaxies — and state-of-the-art spectral modelling from Draine & Li (2007) to estimate the dust mass present in these galaxies. We have also created PAH images by estimating and subtracting the stellar-only contribution to the flux at the 7.9 μm image from the 3.6 μm image.

Keywords

  • galaxies: active;
  • galaxies: elliptical;
  • galaxies: ISM;
  • galaxies: photometry;
  • infrared: galaxies;
  • infrared: ISM