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Star Formation Rates in Cooling Flow Clusters: A UV Pilot Study with Archival XMM-Newton Optical Monitor Data
Mushotzky, R.; Hicks, A. K.
We have analyzed XMM-Newton Optical Monitor UV (180-400 nm) data for a sample of 33 galaxies. Thirty are cluster member galaxies, and nine are central cluster galaxies (CCGs) in cooling flow clusters having mass deposition rates between 8 and 525 Msolar yr-1. By comparing the ratio of UV to 2MASS J-band fluxes, we find a sign…
Discovery of a flank caldera and very young glacial activity at Hecates Tholus, Mars
HRSC Co-Investigator Team; Head, James W.; Greeley, Ronald +8 more
The majority of volcanic products on Mars are thought to be mafic and effusive. Explosive eruptions of basic to ultrabasic chemistry are expected to be common, but evidence for them is rare and mostly confined to very old surface features. Here we present new image and topographic data from the High Resolution Stereo Camera that reveal previously …
Molecular Hydrogen in the Damped Lyα Absorber of Q1331+170
Ge, Jian; Meyer, David M.; Bechtold, Jill +1 more
We used HST STIS to obtain the spectrum of molecular hydrogen associated with the damped Lyα system at zabs=1.7765 toward the quasar Q1331+170 at zem=2.084. Strong H2 absorption was detected, with a total H2 column density of N(H2)=(4.45+/-0.36)×1019 cm-2. The molecular h…
In situ observations of a solar wind compression-induced hot plasma injection in Saturn's tail
Coates, A. J.; Krupp, N.; Dougherty, M. K. +5 more
During the Saturn orbit insertion (SOI) fly-through of the Cassini spacecraft, Saturn's magnetosphere underwent a significant corotating interaction region (CIR) related compression. Such compressions have recently been suggested to produce rapid bursts of tail reconnection, enhanced Saturn kilometric radiation (SKR), and consequent auroral dynami…
Detection of Radial Surface Brightness Fluctuations and Color Gradients in Elliptical Galaxies with the Advanced Camera for Surveys
Blakeslee, John P.; Mei, Simona; Cantiello, Michele +3 more
We study surface brightness fluctuations (SBFs) in a sample of eight elliptical galaxies using the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) data drawn from the Hubble Space Telescope archive. SBF magnitudes in the F814W bandpass and galaxy colors from F814W, F435W, and F606W images, when available, are presented. Galaxy surface b…
The XMM-Newton view of PG quasars. II. Properties of the Fe K_α line
Guainazzi, M.; Schartel, N.; Rodríguez-Pascual, P. M. +3 more
The properties of the fluorescence Fe Kα emission lines of a sample of 38 quasars (QSOs) observed with XMM-Newton are studied. These objects are included in the optically selected sample from the Palomar-Green (PG) Bright Quasar Survey with an X-ray luminosity 1.3 × 1043 < L2-10~keV < 5.1 × 1045 erg s-1<…
X-ray properties of active M dwarfs as observed by XMM-Newton
Schmitt, J. H. M. M.; Robrade, J.
We present a comparative study of X-ray emission from a sample of active M dwarfs with spectral types using XMM-Newton observations of two single stars, AD Leonis and EV Lacertae, and two unresolved binary systems, AT Microscopii and EQ Pegasi. The light curves reveal frequent flaring during all four observations. We perform a uniform spectral ana…
A search for changing-look AGN in the Grossan catalog
Maiolino, R.; Fiore, F.; Bianchi, S. +4 more
We observed with XMM-Newton 4 objects selected from the Grossan (1992, Ph.D. Thesis) catalog, with the aim to search for new "changing-look" AGN. The sample includes all the sources which showed in subsequent observations a flux much lower than the one measured with HEAO A-1: NGC 7674, NGC 4968, IRAS 13218+0552 and NGC 1667. None of the sources wa…
Submillimetre photometry of X-ray absorbed quasi-stellar objects: their formation and evolutionary status
Ivison, R. J.; Smail, Ian; Page, M. J. +4 more
We present an analysis of the submillimetre/X-ray properties of 19 X-ray absorbed, Compton-thin quasi-stellar objects (QSOs) selected to have luminosities and redshifts that represent the peak of cosmic QSO activity, i.e. ~L* objects at 1 < z < 3. Of these, we present new data for 11 objects not previously observed at submillimetre wavelengt…
A Wide-Field Hubble Space Telescope Survey of the Cluster Cl 0024+16 at z = 0.4. III. Spectroscopic Signatures of Environmental Evolution in Early-Type Galaxies
Smith, Graham P.; Treu, Tommaso; Smail, Ian +4 more
We report results from a panoramic spectroscopic survey of 955 objects in the field of the rich cluster Cl 0024+1654 (z~=0.4), complementing the HST imaging presented in the first paper in this series. Combining with previous work, we compile a catalog of 1394 unique redshifts in the field of this cluster, including 486 cluster members spread acro…