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The XMM-Newton view of Mrk 3 and IXO 30
Fabian, Andrew C.; Bianchi, Stefano; Miniutti, Giovanni +1 more
We present the analysis of the XMM-Newton European Photon Imaging Camera (EPIC) pn spectrum of the Seyfert 2 galaxy Mrk 3. We confirm that the source is dominated by a pure Compton reflection component and an iron Kα line, both produced as a reflection from a Compton-thick torus, likely responsible also for the large column density (1.36+0.03…
Discovery of a Nearly Edge-on Disk around HD 32297
Schneider, Glenn; Hines, Dean C.; Silverstone, Murray D.
We report the discovery of a nearly edge-on disk about the A0 star HD 32297 seen in light scattered by the disk grains revealed in NICMOS PSF-subtracted coronagraphic images. The disk extends to a distance of at least 400 AU (3.3") along its major axis with a 1.1 µm flux density of 4.81 +/- 0.57 mJy beyond a radius of 0.3" from the coronagra…
XMM-Newton Observations of Evolution of Cluster X-Ray Scaling Relations at z=0.4-0.7
Vikhlinin, A.; Kotov, O.
We present a spatially resolved analysis of the temperature and gas density profiles of galaxy clusters at z=0.4-0.7 observed with XMM-Newton. These data are used to derive the total cluster mass within the radius r500 without assuming isothermality and also to measure the average temperature and total X-ray luminosity, excluding the co…
A Study of Edge-On Galaxies with the Hubble Space Telescope Advanced Camera for Surveys. I. Initial Results
de Jong, Roelof S.; Seth, Anil C.; Dalcanton, Julianne J.
We present the initial results of a Hubble Space Telescope/Advanced Camera for Surveys snapshot survey of 16 nearby, edge-on, late-type galaxies covering a range in distance from 2 to 19 Mpc. The images of these galaxies show significant resolved stellar populations. We derive F606W and F814W photometry for more than 1.2 million stars and present …
Origin of the Marsden and Kracht Groups of Sunskirting Comets. I. Association with Comet 96P/Machholz and Its Interplanetary Complex
Sekanina, Zdenek; Chodas, Paul W.
Of the three major groups of comets approaching the Sun to between 6 and 12 solar radii and discovered with the coronagraphs on board SOHO, we investigate the Marsden and Kracht groups. We call these comets ``sunskirters'' to distinguish them from the Kreutz system sungrazers. Our objective is to understand the origin, history, and orbital evoluti…
Identifying Lenses with Small-Scale Structure. II. Fold Lenses
Keeton, Charles R.; Gaudi, B. Scott; Petters, A. O.
When the source in a four-image gravitational lens system lies sufficiently close to a ``fold'' caustic, two of the lensed images lie very close together. If the lens potential is smooth on the scale of the separation between the two close images, the difference between their fluxes should approximately vanish, Rfold≡(F+-F
Spectral properties and origin of the radio halo in A3562
Finoguenov, A.; Brunetti, G.; Giacintucci, S. +6 more
We present a new detailed multiband study of the merging cluster A3562, in the core of the Shapley Concentration Supercluster. We analyzed new, low frequency radio data performed at 240 MHz, 332 MHz and 610 MHz with the Giant Metrewave Radio Telescope (GMRT). The new GMRT data allowed us to carry out a detailed study of the radio halo at the centr…
Coronal phenomena at the release of solar energetic electron events
Krucker, S.; Klein, K. -L.; Hoang, S. +1 more
We investigate dynamical processes in the solar corona at the release of electrons (~30-500 keV) detected by the Wind/3DP experiment, with the aim to clarify the relationship between coronal acceleration and the escape of electrons to interplanetary space. Energetic electrons and plasma in the corona are traced using radio, EUV and X-ray observati…
Observations of Separator Reconnection to an Emerging Active Region
Longcope, D. W.; Scott, J.; McKenzie, D. E. +1 more
Extreme-ultraviolet (EUV) observations of an emerging active region are used to study separator reconnection in the corona. We identify each EUV loop connecting the emerging polarity to a nearby existing active region over the 41 hr period beginning at emergence onset. Their geometrical resemblance to post-reconnection field lines from a magnetic …
Groundwater-controlled valley networks and the decline of surface runoff on early Mars
Harrison, Keith P.; Grimm, Robert E.
Fluvial erosion on early Mars was dominated by valley networks created through a combination of groundwater processes and surface runoff. A reduced greenhouse effect due to CO2 loss, together with a declining geothermal heat flux, promoted the growth of a cryosphere and a Hesperian hydrologic regime dominated by outflow channel formatio…