Search Publications
Detection of a Transient X-ray Absorption Line Intrinsic to the BL Lacertae Object H 2356-309
Canizares, Claude R.; Humphrey, Philip J.; Buote, David A. +1 more
Since the launch of the Einstein X-ray Observatory in the 1970s, a number of broad absorption features have been reported in the X-ray spectra of BL Lac objects. These features are often interpreted as arising from high-velocity outflows intrinsic to the BL Lac object, therefore providing important information about the inner environment around th…
Coronal Mass Ejection Dynamics Regarding Radial and Expansion Speeds
Dal Lago, Alisson; Rigozo, Nivaor R.; Nordeman, D. J. R.
A new technique for the detection of coronal mass ejection (CME) speeds using image processing was applied. This technique permits us to determine the CME dynamics: radial and expansion distances, velocities, and accelerations. The CME dynamics is determined by the selection of a radial direction in a given Large Angle and Spectroscopic Coronagrap…
X-Ray Spectroscopy of AS1101 with Chandra, XMM-Newton, and ROSAT: Bandpass Dependence of the Temperature Profile and Soft Excess Emission
Bonamente, Massimiliano; Nevalainen, Jukka
We present spatially resolved spectroscopy of the galaxy cluster AS1101, also known as Sèrsic 159-03, with Chandra, XMM-Newton, and ROSAT, and investigate the presence of soft X-ray excess emission above the contribution from the hot intracluster medium. In earlier papers we reported an extremely bright soft excess component that reached 100% of t…
Flares Producing Well-organized Post-flare Arcades (Slinkies) Have Early Precursors
Berger, T.; Frank, Z.; Ryutova, M. P. +1 more
Exploding loop systems producing X-ray flares often, but not always, bifurcate into a long-living, well-organized system of multi-threaded loop arcades resembling solenoidal slinkies. The physical conditions that cause or prevent this process are not known. To address this problem, we examined most of the major (X-class) flares that occurred durin…
Detection of Outflowing and Extraplanar Gas in Disks in an Assembling Galaxy Cluster at z = 0.37
Saintonge, Amélie; Tran, Kim-Vy H.; Gonzalez, Anthony H. +5 more
We detect ionized gas characteristics indicative of winds in three disk-dominated galaxies that are members of a super-group at z = 0.37 that will merge to form a Coma-mass cluster. All three galaxies are IR luminous (L IR > 4 × 1010 L ⊙, SFR > 8 M ⊙ yr-1) and lie outside the X-ray cores…
The Dirt on Dry Mergers
Dey, Arjun; Soifer, B. T.; Desai, Vandana +2 more
Using data from the Spitzer Space Telescope, we analyze the mid-infrared (3-70 µm) spectral energy distributions of dry merger candidates in the Boötes field of the NOAO Deep Wide-Field Survey. These candidates were selected by previous authors to be luminous, red, early-type galaxies with morphological evidence of recent tidal interactions.…
XMM-Newton, Swift, and ROSAT Observations of LBQS 0102-2713
Schady, P.; Boller, Th.; Heftrich, T.
We have analyzed the first XMM-Newton, Swift, and archival ROSAT PSPC observations of the quasar LBQS 0102-2713. The object was selected from the ROSAT archive as being notable due to the steep soft X-ray photon index and due to the UV brightness based on Hubble Space Telescope and optical spectroscopic observations. The first XMM-Newton observati…
Strong Gravitational Lens Modeling with Spatially Variant Point-spread Functions
Rogers, Adam; Fiege, Jason D.
Astronomical instruments generally possess spatially variant point-spread functions, which determine the amount by which an image pixel is blurred as a function of position. Several techniques have been devised to handle this variability in the context of the standard image deconvolution problem. We have developed an iterative gravitational lens m…
Multiple Absorption-line Spectroscopy of the Intergalactic Medium. I. Model
Shull, J. Michael; Danforth, Charles W.; Stocke, John T. +2 more
We present a physically based absorption-line model for the spectroscopic study of the intergalactic medium (IGM). This model adopts results from Cloudy simulations and theoretical calculations by Gnat & Sternberg to examine the resulting observational signatures of the absorbing gas with the following ionization scenarios: collisional ionizat…
Black Hole Mass Limits for Optically Dark X-ray Bright Sources in Elliptical Galaxies
Jithesh, V.; Jeena, K.; Misra, R. +4 more
Estimation of the black hole mass in bright X-ray sources of nearby galaxies is crucial to the understanding of these systems and their formation. However, the present allowed black hole mass range spans five orders of magnitude (10 M sun < M < 105 M sun) with the upper limit obtained from dynamical friction …