Search Publications
The Ionized Gas in Nearby Galaxies as Traced by the [N II] 122 and 205 µm Transitions
Boquien, M.; Rigopoulou, D.; Armus, L. +20 more
The [N II] 122 and 205 µm transitions are powerful tracers of the ionized gas in the interstellar medium. By combining data from 21 galaxies selected from the Herschel KINGFISH and Beyond the Peak surveys, we have compiled 141 spatially resolved regions with a typical size of ∼1 kpc, with observations of both [N II] far-infrared lines. We me…
Refining the Dynamical Clock for Star Clusters
Dalessandro, E.; Vesperini, E.; Ferraro, F. R. +3 more
We used a sample of 25 Galactic globular clusters to empirically measure the parameter A + recently introduced by Alessandrini et al., and defined as the area enclosed between the cumulative radial distribution of blue straggler stars (BSSs) and that of a reference population. Based on N-body simulations, this parameter is expected to e…
The Evolution of the Fractions of Quiescent and Star-forming Galaxies as a Function of Stellar Mass Since z = 3: Increasing Importance of Massive, Dusty Star-forming Galaxies in the Early Universe
van Dokkum, Pieter G.; Martis, Nicholas S.; Muzzin, Adam +7 more
Using the UltraVISTA DR1 and 3D-HST catalogs, we construct a stellar-mass-complete sample, unique for its combination of surveyed volume and depth, to study the evolution of the fractions of quiescent galaxies, moderately unobscured star-forming galaxies, and dusty star-forming galaxies as a function of stellar mass over the redshift interval 0.2 …
The Morphologies and Alignments of Gas, Mass, and the Central Galaxies of CLASH Clusters of Galaxies
Donahue, Megan; Voit, G. Mark; Zitrin, Adi +10 more
Morphology is often used to infer the state of relaxation of galaxy clusters. The regularity, symmetry, and degree to which a cluster is centrally concentrated inform quantitative measures of cluster morphology. The Cluster Lensing and Supernova survey with Hubble Space Telescope (CLASH) used weak and strong lensing to measure the distribution of …
A Detection of the Integrated Sachs-Wolfe Imprint of Cosmic Superstructures Using a Matched-filter Approach
Nadathur, Seshadri; Crittenden, Robert
We present a new method for detection of the integrated Sachs-Wolfe (ISW) imprints of cosmic superstructures on the cosmic microwave background (CMB), based on a matched-filtering approach. The expected signal-to-noise ratio for this method is comparable to that obtained from the full cross-correlation, and unlike other stacked filtering technique…
Evidence for Intermediate Polars as the Origin of the Galactic Center Hard X-ray Emission
Hailey, Charles J.; Mori, Kaya; Zhang, Shuo +14 more
Recently, unresolved hard (20-40 keV) X-ray emission has been discovered within the central 10 pc of the Galaxy, possibly indicating a large population of intermediate polars (IPs). Chandra and XMM-Newton measurements in the surrounding ∼50 pc imply a much lighter population of IPs with < {M}{{WD}}> ≈ 0.5{M}⊙ . Here we …
Dissecting the High-z Interstellar Medium through Intensity Mapping Cross-correlations
Lagache, Guilaine; Doré, Olivier; Serra, Paolo
We explore the detection, with upcoming spectroscopic surveys, of three-dimensional power spectra of emission line fluctuations produced in different phases of the interstellar medium (ISM) by forbidden transitions of ionized carbon [C II] (157.7 µm), ionized nitrogen [N II] (121.9 and 205.2 µm), and neutral oxygen [O I] (145.5 µ…
A Case Against Spinning PAHs as the Source of the Anomalous Microwave Emission
Meisner, Aaron M.; Draine, B. T.; Hensley, Brandon S.
We employ an all-sky map of the anomalous microwave emission (AME) produced by component separation of the microwave sky to study correlations between the AME and Galactic dust properties. We find that while the AME is highly correlated with all tracers of dust emission, the best predictor of the AME strength is the dust radiance. Fluctuations in …
NuSTAR Hard X-Ray Survey of the Galactic Center Region. II. X-Ray Point Sources
Hailey, Charles J.; Mori, Kaya; Giommi, Paolo +41 more
We present the first survey results of hard X-ray point sources in the Galactic Center (GC) region by NuSTAR. We have discovered 70 hard (3-79 keV) X-ray point sources in a 0.6 deg{}2 region around Sgr A* with a total exposure of 1.7 Ms, and 7 sources in the Sgr B2 field with 300 ks. We identify clear Chandra counterparts for 58 NuSTAR …
Living with a Red Dwarf: Rotation and X-Ray and Ultraviolet Properties of the Halo Population Kapteyn's Star
Guinan, Edward F.; Engle, Scott G.; Durbin, Allyn
As part of Villanova's Living with a Red Dwarf program, we have obtained UV, X-ray, and optical data of the Population II red dwarf -- Kapteyn's Star. Kapteyn's Star is noteworthy for its large proper motions and high radial velocity of ∼+245 km s-1. As the nearest Pop II red dwarf, it serves as an old age anchor for calibrating activit…