Search Publications
First Science Results from SOFIA/FORCAST: The Mid-infrared View of the Compact H II Region W3A
Schoenwald, J.; Zinnecker, H.; Tielens, A. G. G. M. +10 more
The massive star-forming region W3 was observed with the faint object infrared camera for the SOFIA telescope as part of the Short Science program. The 6.4, 6.6, 7.7, 19.7, 24.2, 31.5, and 37.1 µm bandpasses were used to observe the emission of polycyclic aromatic hydrocarbon (PAH) molecules, very small grains, and big grains. Optical depth …
Are Large, Cometary-shaped Proplyds Really (Free-floating) Evaporating Gas Globules?
Sahai, R.; Morris, M. R.; Güsten, R.
We report the detection of strong and compact molecular line emission (in the CO J = 3-2, 4-3, 6-5, 7-6, 13CO J = 3-2, HCN, and HCO+ J = 4-3 transitions) from a cometary-shaped object (Carina-frEGG1) in the Carina star-forming region (SFR) previously classified as a photoevaporating protoplanetary disk (proplyd). We derive a …
Prospect of Studying Hard X- and Gamma-Rays from Type Ia Supernovae
Yamaguchi, H.; Diehl, R.; Tamagawa, T. +9 more
We perform multi-dimensional, time-dependent radiation transfer simulations for hard X-ray and γ-ray emissions, following radioactive decays of 56Ni and 56Co, for two-dimensional delayed-detonation models of Type Ia supernovae (SNe Ia). The synthetic spectra and light curves are compared with the sensitivities of current and …
The Atacama Cosmology Telescope: High-resolution Sunyaev-Zel'dovich Array Observations of ACT SZE-selected Clusters from the Equatorial Strip
Hilton, Matt; Hasselfield, Matthew; Sifón, Cristóbal +41 more
We present follow-up observations with the Sunyaev-Zel'dovich Array (SZA) of optically confirmed galaxy clusters found in the equatorial survey region of the Atacama Cosmology Telescope (ACT): ACT-CL J0022-0036, ACT-CL J2051+0057, and ACT-CL J2337+0016. ACT-CL J0022-0036 is a newly discovered, massive (sime 1015 M ⊙), high-re…
A Direct Measurement of the Total Gas Column Density in Orion KL
Comito, C.; Schilke, P.; Lis, D. C. +7 more
The large number of high-J lines of C18O available via the Herschel Space Observatory provide an unprecedented ability to model the total CO column density in hot cores. Using the emission from all the observed lines (up to J = 15-14), we sum the column densities in each individual level to obtain the total column after correcting for t…
Supergranules as Probes of Solar Convection Zone Dynamics
Hathaway, David H.
Supergranules are convection cells seen at the Sun's surface as a space filling pattern of horizontal flows. While typical supergranules have diameters of about 35 Mm, they exhibit a broad spectrum of sizes from ~10 Mm to ~100 Mm. Here we show that supergranules of different sizes can be used to probe the rotation rate in the Sun's outer convectio…
Polycyclic Aromatic Hydrocarbon Processing in the Blast Wave of the Supernova Remnant N132D
Rho, J.; Boersma, C.; Tappe, A. +1 more
We present Spitzer Infrared Spectrograph 14-36 µm mapping observations of the supernova remnant N132D in the Large Magellanic Cloud. This study focuses on the processing of polycyclic aromatic hydrocarbons (PAHs) that we previously identified in the southern blast wave. The mid-infrared spectra show strong continuum emission from shock-heate…
The Evolution and Environments of X-Ray Emitting Active Galactic Nuclei in High-redshift Large-scale Structures
Fassnacht, C. D.; Kocevski, D. D.; Lemaux, B. C. +5 more
We use deep Chandra imaging and an extensive optical spectroscopy campaign on the Keck 10 m telescopes to study the properties of X-ray point sources in two isolated X-ray-selected clusters, two superclusters, and one "supergroup" at redshifts of z ~ 0.7-0.9. We first study X-ray point sources using the statistical measure of cumulative source cou…
The Panchromatic Hubble Andromeda Treasury. II. Tracing the Inner M31 Halo with Blue Horizontal Branch Stars
Bell, Eric F.; Williams, Benjamin F.; Gilbert, Karoline M. +7 more
We attempt to constrain the shape of M31's inner stellar halo by tracing the surface density of blue horizontal branch (BHB) stars at galactocentric distances ranging from 2 kpc to 35 kpc. Our measurements make use of resolved stellar photometry from a section of the Panchromatic Hubble Andromeda Treasury survey, supplemented by several archival H…
Flash Mixing on the White Dwarf Cooling Curve: Spectroscopic Confirmation in NGC 2808
Brown, Thomas M.; Hubeny, Ivan; Sweigart, Allen V. +3 more
We present new Hubble Space Telescope far-UV spectroscopy of two dozen hot evolved stars in NGC 2808, a massive globular cluster with a large population of "blue-hook" (BHk) stars. The BHk stars are found in ultraviolet color-magnitude diagrams of the most massive globular clusters, where they fall at luminosities immediately below the hot end of …