Search Publications
Dark Matter in the Galaxy Cluster CL J1226+3332 at z = 0.89
Tyson, J. Anthony; Jee, M. James
We present a weak-lensing analysis of the galaxy cluster CL J1226+3332 at z sime 0.89 using Hubble Space Telescope Advanced Camera for Surveys images. The cluster is the hottest (>10 keV), most X-ray luminous system at z > 0.6 known to date. The relaxed X-ray morphology, as well as its high temperature, is unusual at such a high redshift. Ou…
New EUV Fe IX Emission Line Identifications from Hinode/EIS
Young, P. R.
Four Fe IX transitions in the wavelength range 188-198 Å are identified for the first time in spectra from the EUV Imaging Spectrometer on board the Hinode satellite. In particular the emission line at 197.86 Å is unblended and close to the peak of the EIS sensitivity curve, making it a valuable diagnostic of plasma at around 800,000 K — a critica…
Suzaku Observations of Near-Relativistic Outflows in the BAL Quasar APM 08279+5255
Brandt, W. N.; Chartas, G.; Saez, C.
We present results from three Suzaku observations of the z = 3.91 gravitationally lensed broad absorption line quasar APM 08279+5255. We detect strong and broad absorption at rest-frame energies of lsim2 keV (low energy) and 7-12 keV (high energy). The detection of these features confirms the results of previous long-exposure (80-90 ks) Chandra an…
90 GHz and 150 GHz Observations of the Orion M42 Region. A Submillimeter to Radio Analysis
Ade, P. A. R.; Martin, P. G.; Sievers, A. +13 more
We have used the new 90 GHz MUSTANG camera on the Robert C. Byrd Green Bank Telescope (GBT) to map the bright Huygens region of the star-forming region M42 with a resolution of 9'' and a sensitivity of 2.8 mJy beam-1. Ninety GHz is an interesting transition frequency, as MUSTANG detects both the free-free emission characteristic of the …
Nonthermal X-Rays from Supernova Remnant G330.2+1.0 and the Characteristics of its Central Compact Object
Pavlov, George G.; Kargaltsev, Oleg; Hughes, John P. +5 more
We present results from our X-ray data analysis of the supernova remnant (SNR) G330.2+1.0 and its central compact object (CCO), CXOU J160103.1-513353 (J1601 hereafter). Using our XMM-Newton and Chandra observations, we find that the X-ray spectrum of J1601 can be described by neutron star atmosphere models (T ∞ ~ 2.5-5.5 MK). Assuming t…
A Chandra View of NGC 3621: A Bulgeless Galaxy Hosting an AGN in Its Early Phase?
Eracleous, Michael; Satyapal, Shobita; Gliozzi, Mario +2 more
We report the detection of a weak X-ray point-source coincident with the nucleus of the bulgeless disk galaxy NGC 3621, recently discovered by Spitzer to display high-ionization mid-infrared lines typically associated with active galactic nucleus (AGN). These Chandra observations provide confirmation for the presence of an AGN in this galaxy, addi…
Chandra and XMM Observations of the Composite Supernova Remnant G327.1-1.1
Temim, Tea; Hughes, John P.; Slane, Patrick +2 more
We present new X-ray imaging and spectroscopy of a composite supernova remnant G327.1-1.1 using the Chandra and XMM-Newton X-ray observatories. G327.1-1.1 has an unusual morphology consisting of a symmetric radio shell and an off center nonthermal component that indicates the presence of a pulsar wind nebula (PWN). Radio observations show a narrow…
Evidence for the Missing Baryons in the Angular Correlation of the Diffuse X-Ray Background
Gupta, A.; Galeazzi, M.; Ursino, E.
The amount of detected baryons in the local universe is at least a factor of 2 smaller than that measured at high redshift. It is believed that a significant fraction of the baryons in the current universe is "hiding" in a hot filamentary structure filling the intergalactic space, the warm-hot intergalactic medium (WHIM). We found evidence of the …
On the Nonrelativistic Origin of Red-skewed Iron Lines in Cataclysmic Variable, Neutron Star, and Black Hole Sources
Laurent, Philippe; Titarchuk, Lev; Shaposhnikov, Nikolai
We perform the analysis of the iron Kα lines detected in three sources representing three types of accreting compact sources: cataclysmic variable (CV) GK Per, neutron star (NS) Serpens X-1, and black hole (BH) GX 339-4. We find, using data from Epic-PN Camera onboard XMM-Newton observatory, that the iron Kα emission line in …
Redshift Evolution in the Iron Abundance of the Intracluster Medium
Bregman, Joel N.; Anderson, Michael E.; Mullis, C. R. +1 more
Clusters of galaxies provide a closed box within which one can determine the chemical evolution of the gaseous baryons with cosmic time. We studied this metallicity evolution in the hot X-ray emitting baryons through an analysis of XMM-Newton observations of 29 galaxy clusters in the redshift range, 0.3 < z < 1.3. Taken alone, this data set …