Search Publications
Rapid Temperature Changes and the Early Activity on Comet 67P/Churyumov-Gerasimenko
Alí-Lagoa, V.; Delbo', M.; Libourel, G.
The so-called “early activity” of comet 67P/Churyumov-Gerasimenko has been observed to originate mostly in parts of the concave region or “neck” between its two lobes. Since activity is driven by the sublimation of volatiles, this is a puzzling result because this area is less exposed to the Sun and is therefore expected to be cooler on average. W…
New Radio Observations of Anomalous Microwave Emission in the H II Region RCW175
de Bernardis, P.; Masi, S.; Paladini, R. +9 more
We have observed the H II region RCW175 with the 64 m Parkes telescope at 8.4 GHz and 13.5 GHz in total intensity, and at 21.5 GHz in both total intensity and polarization. High angular resolution ranging from 1 to 2.4 arcmin, high sensitivity, and polarization capability enable us to perform a detailed study of the different constituents of the H…
The Dustiest Post-Main Sequence Stars in the Magellanic Clouds
Boyer, Martha L.; Meixner, Margaret; Roman-Duval, Julia +4 more
Using observations from the Herschel Inventory of The Agents of Galaxy Evolution (HERITAGE) survey of the Magellanic Clouds (MC), we have found 35 evolved stars and stellar end products that are bright in the far-infrared. These 28 (LMC) and 7 (SMC) sources were selected from the 529 evolved star candidates in the HERITAGE far-infrared point sourc…
Measuring the Largest Angular Scale CMB B-mode Polarization with Galactic Foregrounds on a Cut Sky
Marriage, Tobias A.; Wollack, Edward J.; Watts, Duncan J. +9 more
We consider the effectiveness of foreground cleaning in the recovery of Cosmic Microwave Background (CMB) polarization sourced by gravitational waves for tensor-to-scalar ratios in the range 0\lt r\lt 0.1. Using the planned survey area, frequency bands, and sensitivity of the Cosmology Large Angular Scale Surveyor (CLASS), we simulate maps of Stok…
Continuous Mid-Infrared Star Formation Rate Indicators: Diagnostics for 0 < z < 3 Star-Forming Galaxies
Elbaz, D.; Calzetti, D.; Johnson, B. D. +1 more
We present continuous, monochromatic star formation rate (SFR) indicators over the mid-infrared wavelength range of 6-70 µm. We use a sample of 58 star-forming galaxies (SFGs) in the Spitzer-SDSS-GALEX Spectroscopic Survey at z < 0.2, for which there is a rich suite of multi-wavelength photometry and spectroscopy from the ultraviolet thro…
Variability of Disk Emission in Pre-main Sequence and Related Stars. III. Exploring Structural Changes in the Pre-transitional Disk in HD 169142
Inoue, Akio K.; Brown, Alexander; Russell, Ray W. +17 more
We present near-IR (NIR) and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ~1.5-10 µm over a maximum t…
On the Origin of Wind Line Variability in O Stars
Massa, D.; Prinja, R. K.
We analyze 10 UV time series for five stars that fulfill specific sampling and spectral criteria to constrain the origin of large-scale wind structure in O stars. We argue that excited state lines must arise close to the stellar surface and are an excellent diagnostic complement to resonance lines which, due to radiative transfer effects, rarely s…
The Evolution of Inner Disk Gas in Transition Disks
France, K.; Schneider, P. C.; Alexander, R. D. +2 more
Investigating the molecular gas in the inner regions of protoplanetary disks (PPDs) provides insight into how the molecular disk environment changes during the transition from primordial to debris disk systems. We conduct a small survey of molecular hydrogen (H2) fluorescent emission, using 14 well-studied Classical T Tauri stars at two…
Testing Density Wave Theory with Resolved Stellar Populations around Spiral Arms in M81
Dolphin, Andrew E.; Skillman, Evan D.; Williams, Benjamin F. +4 more
Stationary density waves rotating at a constant pattern speed {{{Ω }}}{{P}} would produce age gradients across spiral arms. We test whether such age gradients are present in M81 by deriving the recent star formation histories (SFHs) of 20 regions around one of M81's grand-design spiral arms. For each region, we use resolved stellar popu…
Quiescent Compact Galaxies at Intermediate Redshift in the COSMOS Field. II. The Fundamental Plane of Massive Galaxies
Geller, Margaret J.; Damjanov, Ivana; Chilingarian, Igor +1 more
We examine the relation between surface brightness, velocity dispersion, and size—the fundamental plane (FP)—for quiescent galaxies at intermediate redshifts in the COSMOS field. The COSMOS sample consists of ∼150 massive quiescent galaxies with an average velocity dispersion of σ ∼ 250 km s-1 and redshifts between 0.2 < z < 0.8. …