Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-12-09
Astronomy and Astrophysics
Astrophysics
51 pages and 12 figures. Accepted for publication in ApJS
Scientific paper
10.1086/381963
We describe far infrared observations of early-type galaxies selected from the ISO archive. This rather inhomogeneous sample includes 39 giant elliptical galaxies and 14 S0 (or later) galaxies. These galaxies were observed using a variety of different observing modes, each of which requires different and often rather elaborate photometric reduction procedures. The ISO background data agrees well with COBE-DIRBE results to which we have renormalized our calibrations. As a further check, the ISO fluxes from galaxies at 60 and 100 microns agree very well with those previously observed with IRAS at these wavelengths. The spatial resolution of ISO is several times greater than that of IRAS and the ISO observations extend out to 200 microns which views a significantly greater mass of colder dust not assessable to IRAS. Most of the galaxies are essentially point sources at ISO resolution, but a few are clearly extended at FIR wavelengths with image sizes that increase with FIR wavelength. The integrated far infrared luminosities do not correlate with optical luminosities, suggesting that the dust may have an external, merger-related origin. In general the far infrared spectral energy distributions can be modeled with dust at two temperatures, ~ 43 K and ~ 20 K, which probably represent limits of a continuous range of temperatures. The colder dust component dominates the total mass of dust, which is typically more than ten times larger than the dust masses previously estimated for the same galaxies using IRAS observations. For S0 galaxies we find that the optically normalized far-infrared luminosity $L_{FIR} / L_B$ correlates strongly with the mid-infrared luminosity $L_{15\mu\rm{m}} / L_B$, but that correlation is weaker for elliptical galaxies.
Bregman Jesse D.
Brighenti Fabrizio
Mathews William G.
Temi Pasquale
No associations
LandOfFree
Cold Dust in Early-Type Galaxies. I. Observations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Cold Dust in Early-Type Galaxies. I. Observations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cold Dust in Early-Type Galaxies. I. Observations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-460115