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A Candidate Active Galactic Nucleus with a Pure Soft Thermal X-Ray Spectrum
Ueda, Yoshihiro; Awaki, Hisamitsu; Terashima, Yuichi +2 more
We report the discovery of a candidate active galactic nucleus (AGN), 2XMM J123103.2+110648 at z = 0.13, with an X-ray spectrum represented purely by soft thermal emission reminiscent of Galactic black hole (BH) binaries in the disk-dominated state. This object was found in the second XMM-Newton serendipitous source catalog as a highly variable X-…
Efficient deconvolution methods for astronomical imaging: algorithms and IDL-GPU codes
Prato, M.; Cavicchioli, R.; Zanni, L. +2 more
Context. The Richardson-Lucy method is the most popular deconvolution method in astronomy because it preserves the number of counts and the non-negativity of the original object. Regularization is, in general, obtained by an early stopping of Richardson-Lucy iterations. In the case of point-wise objects such as binaries or open star clusters, iter…
Evolution in the Continuum Morphological Properties of Lyα-emitting Galaxies from z = 3.1 to z = 2.1
Gronwall, Caryl; Gawiser, Eric; Ciardullo, Robin +4 more
We present a rest-frame ultraviolet morphological analysis of 108 z ~= 2.1 Lyα emitters (LAEs) in the Extended Chandra Deep Field South and compare it to a similar sample of 171 LAEs at z ~= 3.1. Using Hubble Space Telescope images from the Galaxy Evolution from Morphology and SEDs survey, Great Observatories Origins Deep Survey, and Hubble Ultrad…
Rest-frame UV-Optically Selected Galaxies at 2.3 <~ z <~ 3.5: Searching for Dusty Star-forming and Passively Evolving Galaxies
Dickinson, Mark; Ferguson, Henry C.; Fontana, Adriano +17 more
A new set of color selection criteria (VJL) analogous with the BzK method is designed to select both star-forming galaxies (SFGs) and passively evolving galaxies (PEGs) at 2.3 <~ z <~ 3.5 by using rest-frame UV-optical (V - J versus J - L) colors. The criteria are thoroughly tested with theoretical stellar population synthesis models and rea…
HS 1700+6416: the first high-redshift unlensed narrow absorption line-QSO showing variable high-velocity outflows
Cappi, M.; Vignali, C.; Dadina, M. +4 more
We present a detailed analysis of the X-ray emission of HS 1700+6416, a high-redshift (z = 2.7348) luminous quasar classified as a narrow absorption line (NAL) quasar on the basis of its SDSS spectrum. The source has been observed nine times by Chandra and once by XMM-Newton from 2000 to 2007. Long-term variability is clearly detected between the …
Intercomparison of the LASCO-C2, SECCHI-COR1, SECCHI-COR2, and Mk4 Coronagraphs
Vourlidas, Angelos; Lamy, Philippe; Frazin, Richard A. +5 more
In order to assess the reliability and consistency of white-light coronagraph measurements, we report on quantitative comparisons between polarized brightness [pB] and total brightness [B] images taken by the following white-light coronagraphs: LASCO-C2 on SOHO, SECCHI-COR1 and -COR2 on STEREO, and the ground-based MLSO-Mk4. The data for this comp…
The roles of charge exchange and dissociation in spreading Saturn's neutral clouds
Delamere, P. A.; Bagenal, F.; Fleshman, B. L. +1 more
Neutrals sourced directly from Enceladus's plumes are initially confined to a dense neutral torus in Enceladus's orbit around Saturn. This neutral torus is redistributed by charge exchange, impact/photodissociation, and neutral-neutral collisions to produce Saturn's neutral clouds. Here we consider the former processes in greater detail than in pr…
Dayside magnetic topology at the Earth's magnetopause for northward IMF
Lavraud, B.; Fuselier, S. A.; Trattner, K. J. +1 more
When the Interplanetary Magnetic Field is northward, magnetic reconnection occurs at the Earth's high latitude magnetopause in regions poleward of the Earth's magnetospheric cusps. Observations at the high latitude magnetopause appear to support reconnection poleward of both northern and southern hemisphere cusps, forming closed field lines in the…
Magnification by Galaxy Group Dark Matter Halos
Leauthaud, Alexie; Rhodes, Jason; Capak, Peter +6 more
We report on the detection of gravitational lensing magnification by a population of galaxy groups, at a significance level of 4.9σ. Using X-ray-selected groups in the COSMOS 1.64 deg2 field, and high-redshift Lyman break galaxies as sources, we measure a lensing-induced angular cross-correlation between the samples. After satisfying co…
Hot flow anomalies at Venus
Coates, A. J.; Barabash, S.; Zhang, T. L. +8 more
We present a multi-instrument study of a hot flow anomaly (HFA) observed by the Venus Express spacecraft in the Venusian foreshock, on 22 March 2008, incorporating both Venus Express Magnetometer and Analyzer of Space Plasmas and Energetic Atoms (ASPERA) plasma observations. Centered on an interplanetary magnetic field discontinuity with inward co…