Search Publications
A Refined QSO Selection Method Using Diagnostics Tests: 663 QSO Candidates in the Large Magellanic Cloud
Trichas, Markos; Alcock, Charles; Rowan-Robinson, Michael +4 more
We present 663 QSO candidates in the Large Magellanic Cloud (LMC) selected using multiple diagnostics. We started with a set of 2566 QSO candidates selected using the methodology presented in our previous work based on time variability of the MACHO LMC light curves. We then obtained additional information for the candidates by crossmatching them w…
The Nature of the UV/Optical Emission of the Ultraluminous X-Ray Source in Holmberg II
Tao, Lian; Feng, Hua; Grisé, Fabien +1 more
We report on UV and X-ray spectroscopy and broadband optical observations of the ultraluminous X-ray source in Holmberg II. Fitting various stellar spectral models to the combined, non-simultaneous data set, we find that normal metallicity stellar spectra are ruled out by the data, while low-metallicity, Z = 0.1 Z ⊙, late O-star spectra…
The HST/ACS Coma Cluster Survey. VIII. Barred Disk Galaxies in the Core of the Coma Cluster
Ferguson, Henry C.; Mobasher, Bahram; Balcells, Marc +16 more
We use high-resolution (~0farcs1) F814W Advanced Camera for Surveys (ACS) images from the Hubble Space Telescope ACS Treasury survey of the Coma cluster at z ~ 0.02 to study bars in massive disk galaxies (S0s), as well as low-mass dwarf galaxies in the core of the Coma cluster, the densest environment in the nearby universe. Our study helps to con…
Discovery of Crystallized Water Ice in a Silhouette Disk in the M43 Region
Tokunaga, Alan T.; Terada, Hiroshi
We present the 1.9-4.2 µm spectra of the five bright (L <= 11.2) young stars associated with silhouette disks with a moderate to high inclination angle of 39°-80° in the M42 and M43 regions. The water ice absorption is seen toward d121-1925 and d216-0939, while the spectra of d182-316, d183-405, and d218-354 show no water ice feature arou…
Titan's Transport-driven Methane Cycle
Mitchell, Jonathan L.
The mechanisms behind the occurrence of large cloud outbursts and precipitation on Titan have been disputed. A global- and annual-mean estimate of surface fluxes indicated only 1% of the insolation, or ~0.04 W m-2, is exchanged as sensible and/or latent fluxes. Since these fluxes are responsible for driving atmospheric convection, it ha…
First Science Observations with SOFIA/FORCAST: Properties of Intermediate-luminosity Protostars and Circumstellar Disks in OMC-2
Morris, Mark R.; Fischer, William J.; Calvet, Nuria +18 more
We examine eight young stellar objects in the OMC-2 star-forming region based on observations from the SOFIA/FORCAST early science phase, the Spitzer Space Telescope, the Herschel Space Observatory, Two Micron All Sky Survey, Atacama Pathfinder Experiment, and other results in the literature. We show the spectral energy distributions (SED) of thes…
Correlations in the (Sub)millimeter Background from ACT × BLAST
Hilton, Matt; Hasselfield, Matthew; Bond, J. Richard +43 more
We present measurements of the auto- and cross-frequency correlation power spectra of the cosmic (sub)millimeter background at 250, 350, and 500 µm (1200, 860, and 600 GHz) from observations made with the Balloon-borne Large Aperture Submillimeter Telescope (BLAST); and at 1380 and 2030 µm (218 and 148 GHz) from observations made with …
Extreme Star Formation in the Host Galaxies of the Fastest Growing Supermassive Black Holes at z = 4.8
Trakhtenbrot, Benny; Netzer, Hagai; Shemmer, Ohad +2 more
We report new Herschel observations of 25 z ~= 4.8 extremely luminous optically selected active galactic nuclei (AGNs). Five of the sources have extremely large star-forming (SF) luminosities, L SF, corresponding to SF rates (SFRs) of 2800-5600 M ⊙ yr-1 assuming a Salpeter initial mass function. The remaining sourc…
Cosmic Evolution of Star Formation Enhancement in Close Major-merger Galaxy Pairs Since z = 1
Berta, S.; Magnelli, B.; Lutz, D. +22 more
The infrared (IR) emission of "M * galaxies" (1010.4 <= M star <= 1011.0 M ⊙) in galaxy pairs, derived using data obtained in Herschel (PEP/HerMES) and Spitzer (S-COSMOS) surveys, is compared to that of single-disk galaxies in well-matched control samples to study the cosmic evolution of…
Thirty Years of SN 1980K: Evidence for Light Echoes
Barlow, Michael J.; Meixner, Margaret; Clayton, Geoffrey C. +7 more
We report optical and mid-infrared photometry of SN 1980K between 2004 and 2010, which shows slow monotonic fading consistent with previous spectroscopic and photometric observations made 8-17 yr after outburst. The slow rate of change over two decades suggests that this evolution may result from scattered and thermal light echoes off of extended …