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On the Anomalous Temperature Distribution of the Intergalactic Medium in the NGC 3411 Group of Galaxies
O'Sullivan, E.; Ponman, T. J.; Vrtilek, J. M. +1 more
We present XMM-Newton, Chandra, and VLA observations of the USGC S152 group and its central elliptical NGC 3411. Imaging of the group X-ray halo suggests that it is relaxed with little apparent structure. We investigate the temperature and metal abundance structure of the group halo and find that while the abundance distribution is fairly typical,…
General Relativistic Flux Modulations from Disk Instabilities in Sagittarius A*
Melia, Fulvio; Goldwurm, Andrea; Bélanger, Guillaume +2 more
Near-IR and X-ray flares have been detected from the supermassive black hole Sgr A* at the center of our Galaxy with a (quasi-)period of ~17-20 minutes, suggesting an emission region only a few Schwarzschild radii above the event horizon. The latest X-ray flare, detected with XMM-Newton, is notable for its detailed light curve, yielding not only t…
IR Background Anisotropies in Spitzer GOODS Images and Constraints on First Galaxies
Dickinson, Mark; Ferguson, Henry C.; Wright, Edward L. +6 more
We describe the angular power spectrum of unresolved 3.6 µm IR light in Spitzer GOODS fields. The amplitude of the anisotropy spectrum decreases with the decreasing flux threshold to which resolved sources are removed from images. When all pixels above a flux threshold of 24.6 Vega magnitudes are removed, the power spectrum of the remaining …
The gaseous atmosphere of M 87 seen with XMM-Newton
Finoguenov, A.; Böhringer, H.; Simionescu, A. +1 more
Aims:M 87 is a key object whose study can reveal the complex phenomena in cooling cores. We use a deep XMM-Newton observation of M 87 to produce detailed temperature, pressure and entropy maps in order to analyze the physical processes of cooling cores and of their heating mechanisms.
Methods: We employed both broad-band fitting and full spect…
AEGIS: The Diversity of Bright Near-IR-selected Distant Red Galaxies
Cooper, M. C.; Georgakakis, A.; Koekemoer, A. +10 more
We use deep and wide near-infrared (NIR) imaging from the Palomar telescope combined with DEEP2 spectroscopy and HST and Chandra imaging to investigate the nature of galaxies that are red in NIR colors. We locate these ``distant red galaxies'' (DRGs) through the color cut (J-K)Vega>2.3 over 0.7 deg2, where we find 1010 DRG…
Morphologies of Galaxies in and around a Protocluster at z = 2.300
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +4 more
We present results from the first robust investigation of galaxy morphology as a function of environment at z>1.5. Our study is motivated by the fact that star-forming galaxies contained within a protocluster at z=2.3 in the HS 1700+64 field have significantly older ages and larger stellar masses on average than those at similar redshifts but m…
Evidence for spiral pattern in Saturn's magnetosphere using the new SKR longitudes
Krupp, N.; Krimigis, S. M.; Mitchell, D. G. +1 more
The periodicities in electrons observed in Saturn's magnetosphere are examined using the new longitude system based on a drifting signal of Saturn kilometric radiation (SKR). When averaged into longitude and range bins over 50-day time periods, 28-48 keV electron intensities clearly evidence patterns that peak at successively increasing longitudes…
Fine Structures in the White-Light Solar Corona at the 2006 Eclipse
Rušin, V.; Druckmüller, M.; Saniga, M. +1 more
Observations of the total solar eclipse of 2006 March 29, as it crossed Africa from southwest to northeast into a Greek island and beyond, allowed correlations with near-simultaneous coronal observations from several spacecraft, including SOHO and TRACE. New methods of compositing images allow the recovery of higher resolution (1"-2") on coronal f…
HST observations of azimuthal asymmetry in Saturn's rings
French, Richard G.; Dones, Luke; Salo, Heikki +1 more
From 378 Hubble Space Telescope WFPC2 images obtained between 1996-2004, we have measured the detailed nature of azimuthal brightness variations in Saturn's rings. The extensive geometric coverage, high spatial resolution ( ∼300 kmpx), and photometric precision of the UBVRI images have enabled us to determine the dependence of the asymmetry amplit…
Modelling dications in the diurnal ionosphere of Venus
Witasse, O.; Gronoff, G.; Lilensten, J. +4 more
Context: Previous studies have shown that doubly-charged positive ions, including molecular ions, can have detectable densities in the ionospheres of Mars, Titan, and the Earth.
Aims: In the present paper, we continue our approach by modelling the Venusian ionosphere. The neutral atmosphere of Venus has a similar composition to the ones encoun…