Search Publications
The Genesis of Morphologies in Extended Radio Sources: X-Shapes, Off-Axis Distortions, and Giant Radio Sources
Saripalli, Lakshmi; Subrahmanyan, Ravi
We examine relationships between the morphology in double radio sources and the radio-optical position angle offset—the relative orientation of the radio axis with respect to the major axis of the host galaxy. The study was done for a representative sample of radio sources, the nearby (redshift z < 0.5) 3CRR sources, and separately for samples …
Deep XMM-Newton Spectroscopic and Timing Observations of the Isolated Radio Millisecond Pulsar PSR J0030+0451
Bogdanov, Slavko; Grindlay, Jonathan E.
We present deep XMM-Newton European Photon Imaging Camera spectroscopic and timing X-ray observations of the nearby solitary radio millisecond pulsar, PSR J0030+0451. Its emission spectrum in the 0.1-10 keV range is found to be remarkably similar to that of the nearest and best-studied millisecond pulsar, PSR J0437-4715, being well described by a …
The Roadmap for Unification in Galaxy Group Selection. I. A Search for Extended X-ray Emission in the CNOC2 Survey
Finoguenov, A.; Saglia, R. P.; Connelly, J. L. +6 more
X-ray properties of galaxy groups can unlock some of the most challenging research topics in modern extragalactic astronomy: the growth of structure and its influence on galaxy formation. Only with the advent of the Chandra and XMM-Newton facilities have X-ray observations reached the depths required to address these questions in a satisfactory ma…
X-Ray Cavities, Filaments, and Cold Fronts in the Core of the Galaxy Group NGC 5044
Buote, David A.; Brighenti, Fabrizio; Mathews, William G. +3 more
We present a two-dimensional analysis of the bright nearby galaxy group NGC 5044 using the currently available Chandra and XMM data. In the inner 10 kpc, a pair of cavities are evident together with a set of bright X-ray filaments. If the cavities are interpreted as gas displaced by relativistic plasma inflated by an active galactic nucleus, even …
The Temperature and Density Structure of the Solar Corona. I. Observations of the Quiet Sun with the EUV Imaging Spectrometer on Hinode
Warren, Harry P.; Brooks, David H.
Measurements of the temperature and density structure of the solar corona provide critical constraints on theories of coronal heating. Unfortunately, the complexity of the solar atmosphere, observational uncertainties, and the limitations of current atomic calculations, particularly those for Fe, all conspire to make this task very difficult. A cr…
High-Ionization Fe K Emission From Luminous Infrared Galaxies
Sanders, D. B.; Surace, J. A.; Armus, L. +3 more
The Chandra component of the Great Observatories All-Sky Luminous Infrared Galaxy Survey (GOALS) presently contains 44 luminous and ultraluminous infrared galaxies (ULIRGs) with log (L IR/L sun) = 11.73-12.57. Omitting 15 obvious active galactic nuclei (AGNs), the other galaxies are, on average, underluminous in the 2-10 keV …
Silicon Carbide Absorption Features: Dust Formation in the Outflows of Extreme Carbon Stars
Wheeler, Caleb H.; Speck, Angela K.; Corman, Adrian B. +2 more
Infrared carbon stars without visible counterparts are generally known as extreme carbon stars. We have selected a subset of these stars with absorption features in the 10-13 µm range, which has been tentatively attributed to silicon carbide (SiC). We add three new objects meeting these criterion to the seven previously known, bringing our t…
A Spectroscopic Census of the M82 Stellar Cluster Population
Bastian, N.; Smith, L. J.; Gallagher, J. S., III +3 more
We present a spectroscopic study of the stellar cluster population of M82, the archetype starburst galaxy, based primarily on new Gemini-North multi-object spectroscopy of 49 star clusters. These observations constitute the largest to date spectroscopic data set of extragalactic young clusters, giving virtually continuous coverage across the galax…
The Infrared Luminosity Functions of Rich Clusters
Rieke, George H.; Zabludoff, Ann I.; Rieke, Marcia J. +2 more
We present Multiband Imaging Photometer observations of the cluster A3266. About 100 spectroscopic cluster members have been detected at 24 µm. The infrared (IR) luminosity function (LF) in A3266 is very similar to that in the Coma cluster down to the detection limit L IR ~ 1043 erg s-1, suggesting a universa…
XMM-Newton Observations of a Complete Sample of Optically Selected Type 2 Seyfert Galaxies
Heckman, Timothy M.; Hornschemeier, Ann; Tremonti, Christy +4 more
The majority of active galactic nuclei (AGNs) suffer from significant obscuration by surrounding dust and gas. The penetrating power and sensitivity of hard X-ray observations allow obscured AGNs to be probed out to high redshifts. However, X-ray surveys in the 2-10 keV band will miss the most heavily obscured AGNs in which the absorbing column de…