Search Publications
Is There a Maximum Star Formation Rate in High-redshift Galaxies?
Sanders, D. B.; Wang, W. -H.; Lee, N. +6 more
We use the James Clerk Maxwell Telescope's SCUBA-2 camera to image a 400 arcmin2 area surrounding the GOODS-N field. The 850 µm rms noise ranges from a value of 0.49 mJy in the central region to 3.5 mJy at the outside edge. From these data, we construct an 850 µm source catalog to 2 mJy containing 49 sources detected above t…
The Moving Group Targets of the SEEDS High-contrast Imaging Survey of Exoplanets and Disks: Results and Observations from the First Three Years
Tamura, M.; Ishii, M.; Kudo, T. +52 more
We present results from the first three years of observations of moving group (MG) targets in the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) high-contrast imaging survey of exoplanets and disks using the Subaru telescope. We achieve typical contrasts of ~105 at 1'' and ~106 beyond 2'' around 63 proposed…
Nitrogen Abundances and Multiple Stellar Populations in the Globular Clusters of the Fornax dSph
Brodie, Jean P.; Strader, Jay; Larsen, Søren S. +1 more
We use measurements of nitrogen abundances in red giants to search for multiple stellar populations in the four most metal-poor globular clusters (GCs) in the Fornax dwarf spheroidal galaxy (Fornax 1, 2, 3, and 5). New imaging in the F343N filter, obtained with the Wide Field Camera 3 on the Hubble Space Telescope, is combined with archival F555W …
NuSTAR Reveals an Intrinsically X-Ray Weak Broad Absorption Line Quasar in the Ultraluminous Infrared Galaxy Markarian 231
Rigby, J. R.; Veilleux, S.; Harrison, F. A. +24 more
We present high-energy (3-30 keV) NuSTAR observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5-8 keV) data from Chandra. The source was detected, though at much fainter levels than previously reported, likely due to contamination in the large ap…
Globular Cluster Systems in Brightest Cluster Galaxies: A Near-universal Luminosity Function?
Bailin, Jeremy; Whitmore, Bradley C.; Côté, Patrick +10 more
We present the first results from our Hubble Space Telescope brightest cluster galaxy (BCG) survey of seven central supergiant cluster galaxies and their globular cluster (GC) systems. We measure a total of 48,000 GCs in all seven galaxies, representing the largest single GC database. We find that a log-normal shape accurately matches the observed…
Observations of Environmental Quenching in Groups in the 11 GYR since z = 2.5: Different Quenching for Central and Satellite Galaxies
van Dokkum, Pieter G.; Franx, Marijn; Illingworth, Garth D. +16 more
We present direct observational evidence for star formation quenching in galaxy groups in the redshift range 0 < z < 2.5. We utilize a large sample of nearly 6000 groups, selected by fixed cumulative number density from three photometric catalogs, to follow the evolving quiescent fractions of central and satellite galaxies over roughly 11 Gy…
Measurement of Galaxy Clustering at z ~ 7.2 and the Evolution of Galaxy Bias from 3.8 < z < 8 in the XDF, GOODS-S, and GOODS-N
Trenti, M.; Oesch, P. A.; Carollo, C. M. +8 more
Lyman-break galaxy (LBG) samples observed during reionization (z >~ 6) with the Hubble Space Telescope's Wide Field Camera 3 are reaching sizes sufficient to characterize their clustering properties. Using a combined catalog from the Hubble eXtreme Deep Field and CANDELS surveys, containing N = 743 LBG candidates at z >= 6.5 at a mean redshi…
Evolution of Thermally Pulsing Asymptotic Giant Branch Stars. IV. Constraining Mass loss and Lifetimes of Low Mass, Low Metallicity AGB Stars
Williams, Benjamin F.; Dolphin, Andrew; Girardi, Léo +7 more
The evolution and lifetimes of thermally pulsating asymptotic giant branch (TP-AGB) stars suffer from significant uncertainties. In this work, we analyze the numbers and luminosity functions of TP-AGB stars in six quiescent, low metallicity ([Fe/H] <~ -0.86) galaxies taken from the ACS Nearby Galaxy Survey Treasury sample, using Hubble Space Te…
Carbon-rich Dust Past the Asymptotic Giant Branch: Aliphatics, Aromatics, and Fullerenes in the Magellanic Clouds
Sahai, R.; Zijlstra, A. A.; Peeters, E. +10 more
Infrared spectra of carbon-rich objects that have evolved off the asymptotic giant branch reveal a range of dust properties, including fullerenes, polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons, and several unidentified features, including the 21 µm emission feature. To test for the presence of fullerenes, we used the positi…
The INTEGRAL High-energy Cut-off Distribution of Type 1 Active Galactic Nuclei
Bird, A. J.; Ubertini, P.; Malizia, A. +4 more
In this Letter we present the primary continuum parameters, the photon index Γ, and the high-energy cut-off E c of 41 type-1 Seyfert galaxies extracted from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) complete sample of active galactic nuclei (AGNs). We performed broadband (0.3-100 keV) spectral analysis by simultaneo…