Search Publications
The Tucana/Horologium, Columba, AB Doradus, and Argus Associations: New Members and Dusty Debris Disks
Zuckerman, B.; Song, Inseok; Bessell, M. S. +1 more
We propose 35 star systems within ~70 pc of Earth as newly identified members of nearby young stellar kinematic groups; these identifications include the first A- and late-B-type members of the AB Doradus moving group and field Argus Association. All but one of the 35 systems contain a bright solar- or earlier-type star that should make an excelle…
Evidence for an FU Orionis-like Outburst from a Classical T Tauri Star
Filippenko, Alexei V.; Cenko, S. Bradley; Law, Nicholas M. +28 more
We present pre- and post-outburst observations of the new FU Orionis-like young stellar object PTF 10qpf (also known as LkHα 188-G4 and HBC 722). Prior to this outburst, LkHα 188-G4 was classified as a classical T Tauri star (CTTS) on the basis of its optical emission-line spectrum superposed on a K8-type photosphere and its photometric variabilit…
Detection of the Cosmic Far-infrared Background in AKARI Deep Field South
Clements, D. L.; White, G. J.; Burgarella, D. +14 more
We report new limits on the absolute brightness and spatial fluctuations of the cosmic infrared background (CIB) via the AKARI satellite. We carried out observations at 65, 90, 140, and 160 µm as a cosmological survey in AKARI Deep Field South, which is one of the lowest cirrus regions with a contiguous area of the sky. After removing bright…
AKARI Observation of the Fluctuation of the Near-infrared Background
Lee, H. M.; Jeong, W. -S.; Matsuhara, H. +6 more
We report a search for fluctuations of the sky brightness toward the north ecliptic pole with the Japanese infrared astronomical satellite AKARI, at 2.4, 3.2, and 4.1 µm. We obtained circular maps with 10' diameter fields of view, which clearly show a spatial structure on the scale of a few hundred arcseconds. A power spectrum analysis shows…
Molecular Gas in Young Debris Disks
Apai, D.; Pascucci, I.; Ábrahám, P. +7 more
Gas-rich primordial disks and tenuous gas-poor debris disks are usually considered as two distinct evolutionary phases of the circumstellar matter. Interestingly, the debris disk around the young main-sequence star 49 Ceti possesses a substantial amount of molecular gas and possibly represents the missing link between the two phases. Motivated to …
Formation of Dust in the Ejecta of Type Ia Supernovae
Nomoto, Ken'ichi; Maeda, Keiichi; Tanaka, Masaomi +3 more
We investigate the formation of dust grains in the ejecta of Type Ia supernovae (SNe Ia), adopting the carbon-deflagration W7 model. In the calculations of dust formation, we apply the nucleation and grain growth theory and consider the two extreme cases of the formation of CO and SiO molecules: complete formation and no formation. The results of …
The Circumstellar Environment of R Coronae Borealis: White Dwarf Merger or Final-helium-shell Flash?
Ivison, R. J.; Olofsson, G.; Bond, Howard E. +21 more
In 2007, R Coronae Borealis (R CrB) went into a historically deep and long decline. In this state, the dust acts like a natural coronagraph at visible wavelengths, allowing faint nebulosity around the star to be seen. Imaging has been obtained from 0.5 to 500 µm with Gemini/GMOS, Hubble Space Telescope/WFPC2, Spitzer/MIPS, and Herschel/SPIRE…
Dust Production and Mass Loss in the Galactic Globular Cluster 47 Tucanae
van Loon, J. Th.; Zijlstra, A. A.; Boyer, M. L. +1 more
Dust production among post-main-sequence stars is investigated in the Galactic globular cluster 47 Tucanae (NGC 104) based on infrared photometry and spectroscopy. We identify metallic iron grains as the probable dominant opacity source in these winds. Typical evolutionary timescales of asymptotic giant branch stars suggest the mass-loss rates we …
Infrared Spectra and Spectral Energy Distributions for Dusty Starbursts and Active Galactic Nuclei
Lebouteiller, Vianney; Weedman, Daniel; Sargsyan, Lusine +4 more
We present spectroscopic results for all galaxies observed with the Spitzer Infrared Spectrograph (IRS) that also have total infrared fluxes f IR measured with the Infrared Astronomical Satellite (IRAS), also using AKARI photometry when available. Infrared luminosities and spectral energy distributions (SEDs) from 8 µm to 160 &mic…
The Infrared Continuum Sizes of Be Star Disks
Gies, D. R.; Schaefer, G. H.; Touhami, Y.
We present an analysis of the near-infrared continuum emission from the circumstellar gas disks of Be stars using a radiative transfer code for a parameterized version of the viscous decretion disk model. This isothermal gas model creates predicted images that we use to estimate the half-width at half-maximum emission radius along the major axis o…