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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 …
Temporal Relation Between the Disappearance of Penumbral Fine-scale Structure and Evershed Flow
Kubo, M.; Lites, B. W.; Ichimoto, K. +1 more
We investigate the temporal relation between the Evershed flow, dot-like bright features (penumbral grain), the complex magnetic field structure, and dark lanes (dark core) along bright filaments in a sunspot penumbra. We use a time series of high spatial resolution photospheric intensity, vector magnetic field maps, and Doppler velocity maps obta…