Related papers: The Deep Silicate Absorption Feature in IRAS 08572…
We present Herschel photometry and spectroscopy, carried out as part of the Herschel ULIRG survey (HERUS), and a model for the infrared to submillimetre emission of the ultraluminous infrared galaxy IRAS 08572+3915. This source shows one of…
The silicate cross section peak near 10um produces emission and absorption features in the spectra of dusty galactic nuclei observed with the Spitzer Space Telescope. Especially in ultraluminous infrared galaxies, the observed absorption…
The 9.7-micron silicate absorption profile in the interstellar medium provides important information on the physical and chemical composition of interstellar dust grains. Measurements in the Milky Way have shown that the profile in the…
We report the detection of strong absorption and weak emission features in the 4--27 micron Spitzer-IRS spectrum of the distant ultraluminous infrared galaxy (ULIRG) IRAS F00183--7111 (z=0.327). The absorption features of CO2 and CO gas,…
High resolution, Hubble Space Telescope (HST) near-infrared and Keck mid-infrared images of the heavily extinguished, infrared luminous galaxy NGC 4418 are presented. These data make it possible to observe the imbedded near-infrared…
Absorption lines in the spectra of distant quasars whose sightlines pass through foreground galaxies provide a valuable tool to probe the dust and gas compositions of the interstellar medium (ISM) in galaxies. The first evidence of silicate…
The first detection of the molecular ion H3+ in an extragalactic object has been made toward the highly obscured ultraluminous galaxy, IRAS 08572+3915. Two absorption features near 3.9 microns in its spectrum are identified as the…
We explore the origin of mid-infrared (mid-IR) dust extinction in all 20 nearby (z < 0.05) bona-fide Compton-thick (N_H > 1.5 x 10^24 cm^-2) AGN with hard energy (E > 10 keV) X-ray spectral measurements. We accurately measure the silicate…
We present a comprehensive study of the silicate features at 9.7 and 18 micron of a sample of almost 800 active galactic nuclei (AGN) with available spectra from the Spitzer InfraRed Spectrograph (IRS). We measure the strength of the…
Mid infrared spectra provide a powerful probe of the conditions in dusty galactic nuclei. They variously contain emission features associated with star forming regions and absorptions by circumnuclear silicate dust plus ices in cold…
We present 8-13 micron imaging and spectroscopy of 9 type 1 and 10 type 2 AGN obtained with the VLT/VISIR instrument at spatial resolution <100 pc. The emission from the host galaxy sources is resolved out in most cases. The silicate…
We confirm the first detection of the molecular ion H3+ in an extragalactic object, the highly obscured ultraluminous galaxy IRAS 08572+3915 NW. We also have detected absorption lines of the fundamental band of CO in this galaxy. The CO…
We have studied the dust along the line-of-sight towards the Galactic Center using Short Wavelength Spectrometer (SWS) data obtained with the Infrared Space Observatory (ISO). We focussed on the wavelength region from 8-13 micron which is…
New moderate-resolution mid-infrared spectroscopy at 10 micron of 27 infrared galaxies is presented. The galaxies have been chosen from three 60 micron selected and one 12 micron selected complete flux-limited catalogs of galaxies; 17 of…
We report the detection of interstellar silicate dust in the z_abs=0.685 absorber along the sightline toward the gravitationally lensed blazar TXS 0218+357. Using Spitzer Space Telescope Infrared Spectrograph data we detect the 10 micron…
Silicates are an important component of interstellar dust and the structure of these grains -- amorphous versus crystalline -- is sensitive to the local physical conditions. We have studied the infrared spectra of a sample of ultra-luminous…
We have analyzed the 9.7 and ``18'' micron interstellar silicate absorption features along the line of sight toward four heavily extincted galactic WC-type Wolf-Rayet (WR) stars. We construct two interstellar extinction curves from 1.25 to…
The \textit{Spitzer}/Infrared Spectrograph spectra of three spectroscopically anomalous galaxies (IRAS~F10398+1455, IRAS~F21013-0739 and SDSS~J0808+3948) are modeled in terms of a mixture of warm and cold silicate dust, and warm and cold…
We have examined the relationship between the optical depth of the 9.7 micron silicate absorption feature (tau_9.7) and the near-infrared color excess, E(J-Ks) in the Serpens, Taurus, IC 5146, Chameleon I, Barnard 59, and Barnard 68 dense…
We have re-analyzed the 6-12 micron ISO spectrum of the ultra-luminous infrared galaxy Arp220 with the conclusion that it is not consistent with that of a scaled up version of a typical starburst. Instead, both template fitting with spectra…