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Gaps in the cloud cover? Comparing extinction measures in spiral disks
dust in galaxies spiral galaxies
2014/12/23
Dust in galaxies can be mapped either by the FIR/submillimeter emission, the optical or infrared reddening of starlight, or the extinction of a known background source. We compare two dust extinction ...
The quantity of dust in a spiral disk can be estimated using the dust's typical emission or the extinction of a known source. In this paper we compare two techniques, one based on emission and one on ...
The Evolution of Galaxy Disks in Dense Environments - Lessons from Compact Galaxy Groups
evolution interactions
2014/12/23
Disk galaxies in compact galaxy groups exhibit a remarkable shortfall of neutral hydrogen compared to both isolated spirals and spirals in more loose groups, but the origin of this HI deficiency remai...
Spitzer Observations of the Lambda Orionis cluster I: the frequency of young debris disks at 5 Myr,
formation pre-main sequence
2014/12/22
We present IRAC/MIPS Spitzer observations of intermediate-mass stars in the 5 Myr old Lambda Orionis cluster. In a representative sample of stars earlier than F5 (29 stars), we find a population of 9 ...
The opacity of a spiral disk due to dust absorption influences every measurement we make of it in the UV and optical. Two separate techniques directly measure the total absorption by dust in the disk:...
SPITZER OBSERVATIONS OF THE λ ORIONIS CLUSTER. II. DISKS AROUND SOLAR-TYPE AND LOW-MASS STARS
solar-type the low-mass stellar population
2014/12/22
We present IRAC/MIPS Spitzer Space Telescope observations of the solar-type and the low-mass stellar population of the young (~5 Myr) λ Orionis cluster. Combining optical and Two Micron All Sky Survey...
A GREEN BANK TELESCOPE SURVEY FOR H I 21 cm ABSORPTION IN THE DISKS AND HALOS OF LOW-REDSHIFT GALAXIES
21 cm absorption survey Green Bank Telescope
2014/12/20
We present an H I 21 cm absorption survey with the Green Bank Telescope (GBT) of galaxy-quasar pairs selected by combining galaxy data from the Sloan Digital Sky Survey (SDSS) and radio sources from t...
Evidence for Multiple Pathways to Deuterium Enhancements in Protoplanetary Disks
Evidence Multiple Pathways Deuterium Enhancements Protoplanetary Disks
2012/2/23
The distributions of deuterated molecules in protoplanetary disks are expected to depend on the molecular formation pathways. We use observations of spatially resolved DCN emission from the disk aroun...
Constraints on the Lifetimes of Disks Resulting from Tidally Destroyed Rocky Planetary Bodies
circumstellar matter minor planets asteroids general planetary systems abundances white dwarfs
2012/2/23
Spitzer IRAC observations of 15 metal-polluted white dwarfs reveal infrared excesses in the spectral energy distributions of HE 0110-5630, GD 61, and HE 1349-2305. All three of these stars have helium...
Gaps in Protoplanetary Disks as Signatures of Planets: I. Methodology and Validation
planet disk interactions protoplanetary disks planets and satellites detection radiative
2012/2/23
We examine the observational consequences of partial gaps being opened by planets in protoplanetary disks. We model the disk using a static alpha-disk model with detailed radiative transfer, parametri...
Turbulent Linewidths in Protoplanetary Disks: Predictions from Numerical Simulations
Turbulent Linewidths Protoplanetary Disks: Predictions Numerical Simulations
2011/10/11
Sub-mm observations of protoplanetary disks now approach the acuity needed to measure the turbulent broadening of molecular lines. These measurements constrain disk angular momentum transport, and fur...
The Stability of Low Surface Brightness Disks Based on Multi-Wavelength Modeling
Stability Surface Brightness Disks Based Multi-Wavelength Modeling
2011/10/18
To investigate the structure and composition of the dusty interstellar medium (ISM) of low surface brightness (LSB) disk galaxies, we have used multiwavelength photometry to construct spectral energy ...
To explore the properties of extreme outer stellar disks, we obtained ultra-deep V and GALEX UV images of 4 dwarf irregular galaxies and one Blue Compact Dwarf galaxy and ultra-deep B images of 3 of t...
AMBER high-spectral resolution interferometry of Be stars: More than just stars and disks?
high-spectral resolution interferometry stars disks
2011/10/17
High spectral-resolution Br-gamma VLTI/AMBER observations of classical Be stars reveal complex visibility, phase, and closure phase profiles, which were not seen in previous lower-resolution data. The...
Radio Imaging of the NGC 1333 IRAS 4A Region: Envelope, Disks, and Outflows of a Protostellar Binary System
ISM: individual (NGC 1333 IRAS 4A) — ISM: jets outfl ows — ISM: binaries: general— stars: formation
2011/10/12
The NGC 1333 IRAS 4A protobinary was observed in the 1.3 cm and 6.9 mm continuum and the ammonia and SiO lines, with an angular resolution of about 0.4 arcseconds. The continuum maps show the circumst...