Search Publications
Decay of Planetary Debris Disks
Bryden, G.; Stapelfeldt, K. R.; Rieke, G. H. +9 more
We report new Spitzer 24 µm photometry of 76 main-sequence A-type stars. We combine these results with previously reported Spitzer 24 µm data and 24 and 25 µm photometry from the Infrared Space Observatory and the Infrared Astronomy Satellite. The result is a sample of 266 stars with mass close to 2.5 Msolar, all detec…
Infrared Spectral Energy Distributions of Nearby Galaxies
Helou, G.; Roussel, H.; Leitherer, C. +25 more
The Spitzer Infrared Nearby Galaxies Survey (SINGS) is carrying out a comprehensive multiwavelength survey on a sample of 75 nearby galaxies. The 1-850 µm spectral energy distributions (SEDs) are presented using broadband imaging data from Spitzer, 2MASS, ISO, IRAS, and SCUBA. The infrared colors derived from the globally integrated Spitzer …
Ices in the Edge-on Disk CRBR 2422.8-3423: Spitzer Spectroscopy and Monte Carlo Radiative Transfer Modeling
van Dishoeck, Ewine F.; Dullemond, Cornelis P.; Pontoppidan, Klaus M. +5 more
We present 5.2-37.2 µm spectroscopy of the edge-on circumstellar disk CRBR 2422.8-3423 obtained using the Infrared Spectrograph (IRS) of the Spitzer Space Telescope. The IRS spectrum is combined with ground-based 3-5 µm spectroscopy to obtain a complete inventory of solid-state material present along the line of sight toward the source…
8-13 µm Spectroscopy of Young Stellar Objects: Evolution of the Silicate Feature
Meyer, Michael R.; Hillenbrand, Lynne A.; Blake, Geoffrey A. +1 more
Silicate features arising from material around pre-main-sequence stars are useful probes of the star and planet formation process. In order to investigate possible connections between dust processing and disk properties, 8-13 µm spectra of 34 young stars, exhibiting a range of circumstellar environments and including spectral types A-M, were…
The Link between Star Formation and Accretion in LINERs: A Comparison with Other Active Galactic Nucleus Subclasses
O'Halloran, B.; Dudik, R. P.; Satyapal, S. +1 more
We present archival high-resolution X-ray imaging observations of 25 nearby LINERs observed by ACIS on board Chandra. This sample builds on our previously published proprietary and archival X-ray observations and includes the complete set of LINERs with published black hole masses and FIR luminosities that have been observed by Chandra. Of the 82 …
Variations of the Mid-Infrared Emission Spectrum in Reflection Nebulae
Temi, Pasquale; Bregman, Jesse
Using spatial-spectral data cubes of reflection nebulae obtained by ISOCAM, we have observed a shift in the central wavelength of the 7.7 µm band within several reflection nebulae. This band, composed of components at 7.85 and 7.65 µm, shows a centroid shift from 7.75 µm near the edge of the nebulae to 7.65 µm toward the ce…
Detection of Water in the Shocked Gas Associated with IC 443: Constraints on Shock Models
Wang, Z.; Bergin, E. A.; Melnick, G. J. +5 more
We have used the Submillimeter Wave Astronomy Satellite (SWAS) to observe the ground-state 110-->101 transition of ortho-H2O at 557 GHz in three of the shocked molecular clumps associated with the supernova remnant IC 443. We also observed simultaneously the 487 GHz line (3,1-->3,2) of O2, the 492 …
Far-Infrared Observations of Radio Quasars and FR II Radio Galaxies
Egami, E.; Gordon, K. D.; Rieke, G. H. +6 more
We report MIPS photometry of 20 radio-loud quasars and galaxies at 24 and 70 µm (and of five at 160 µm). We combine this sample with additional sources detected in the far-infrared by IRAS and ISO for a total of 47 objects, including 23 steep-spectrum type I AGNs: radio-loud quasars and broad-line radio galaxies; and 24 type II AGNs: n…
The Far-Infrared Emission Line and Continuum Spectrum of the Seyfert Galaxy NGC 1068
Smith, Howard A.; González-Alfonso, Eduardo; Spinoglio, Luigi +2 more
We report on the analysis of the first complete far-infrared spectrum (43-197 µm) of the Seyfert 2 galaxy NGC 1068 as observed with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). In addition to the seven expected ionic fine-structure emission lines, the OH rotational lines at 79, 119, and 163 µm w…
The Effect of Stellar Evolution on SiC Dust Grain Sizes
Speck, Angela K.; Thompson, Grant D.; Hofmeister, Anne M.
Stars on the asymptotic giant branch (AGB) produce dust in their circumstellar shells. The nature of the dust-forming environment is influenced by the evolution of the stars, in terms of both chemistry and density, leading to an evolution in the nature of the dust that is produced. Carbon-rich AGB stars are known to produce silicon carbide (SiC). …