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Estimating turbulent velocities in the elliptical galaxies NGC 5044 and NGC 5813
Kaastra, J. S.; de Plaa, J.; Churazov, E. +5 more
Context. The interstellar and intra-cluster medium (ICM) in giant elliptical galaxies and clusters of galaxies is often assumed to be in hydrostatic equilibrium. Numerical simulations, however, show that about 5-30% of the pressure in a cluster is provided by turbulence induced by, for example, the central active galactic nucleus (AGN) and merger …
Radio and X-Ray Observations of SN 2006jd: Another Strongly Interacting Type IIn Supernova
Chandra, Poonam; Fransson, Claes; Chevalier, Roger A. +5 more
We report four years of radio and X-ray monitoring of the Type IIn supernova SN 2006jd at radio wavelengths with the Very Large Array, Giant Metrewave Radio Telescope, and Expanded Very Large Array; at X-ray wavelengths with Chandra, XMM-Newton, and Swift-XRT. We assume that the radio and X-ray emitting particles are produced by shock interaction …
Outer-disk Populations in NGC 7793: Evidence for Stellar Radial Migration
Holwerda, Benne W.; Radburn-Smith, David J.; de Jong, Roelof S. +8 more
We analyzed the radial surface brightness profile of the spiral galaxy NGC 7793 using HST/ACS images from the GHOSTS survey and a new HST/WFC3 image across the disk break. We used the photometry of resolved stars to select distinct populations covering a wide range of stellar ages. We found breaks in the radial profiles of all stellar populations …
The Herschel Virgo Cluster Survey - VIII. The Bright Galaxy Sample
Ciesla, L.; Bianchi, S.; Fritz, J. +20 more
We describe the Herschel Virgo Cluster Survey and the first data that cover the complete survey area (four 4 × 4 deg2 regions). We use these data to measure and compare the global far-infrared properties of 78 optically bright galaxies that are selected at 500 µm and detected in all five far-infrared bands. We show that our measur…
An Observed Link between Active Galactic Nuclei and Violent Disk Instabilities in High-redshift Galaxies
Dickinson, Mark; Daddi, Emanuele; Juneau, Stéphanie +7 more
We provide evidence for a correlation between the presence of giant clumps and the occurrence of active galactic nuclei (AGNs) in disk galaxies. Giant clumps of 108-109 M ⊙ arise from violent gravitational instability in gas-rich galaxies, and it has been proposed that this instability could feed supermassive black…
Multiwavelength campaign on Mrk 509. VIII. Location of the X-ray absorber
Kaastra, J. S.; Kriss, G. A.; Arav, N. +14 more
Aims: More than half of all active galactic nuclei show strong photoionised outflows. A major uncertainty in models for these outflows is the distance of the gas to the central black hole. We use the results of a massive multiwavelength monitoring campaign on the bright Seyfert 1 galaxy Mrk 509 to constrain the location of the outflow compone…
Spitzer Evidence for a Late-heavy Bombardment and the Formation of Ureilites in η Corvi at ~1 Gyr
Manoj, P.; Sitko, M. L.; Watson, D. M. +7 more
We have analyzed Spitzer and NASA/IRTF 2-35 µm spectra of the warm, ~350 K circumstellar dust around the nearby MS star η Corvi (F2V, 1.4 ± 0.3 Gyr). The spectra show clear evidence for warm, water- and carbon-rich dust at ~3 AU from the central star, in the system's terrestrial habitability zone. Spectral features due to ultra-primitive com…
Observations of Binary Stars with the Differential Speckle Survey Instrument. IV. Observations of Kepler, CoRoT, and Hipparcos Stars from the Gemini North Telescope
Howell, Steve B.; Ciardi, David R.; Everett, Mark E. +1 more
We present the results of 71 speckle observations of binary and unresolved stars, most of which were observed with the DSSI speckle camera at the Gemini North Telescope in 2012 July. The main purpose of the run was to obtain diffraction-limited images of high-priority targets for the Kepler and CoRoT missions, but in addition, we observed a number…
Multiwavelength Variations of 3C 454.3 during the 2010 November to 2011 January Outburst
Gurwell, Mark A.; Grupe, Dirk; Agudo, Iván +6 more
We present multiwavelength data of the blazar 3C 454.3 obtained during an extremely bright outburst from 2010 November through 2011 January. These include flux density measurements with the Herschel Space Observatory at five submillimeter-wave and far-infrared bands, the Fermi Large Area Telescope at γ-ray energies, Swift at X-ray, ultraviolet (UV…
Classification of X-Ray Sources in the XMM-Newton Serendipitous Source Catalog
Lin, Dacheng; Webb, Natalie A.; Barret, Didier
We carry out classification of 4330 X-ray sources in the 2XMMi-DR3 catalog. They are selected under the requirement of being a point source with multiple XMM-Newton observations and at least one detection with the signal-to-noise ratio larger than 20. For about one-third of them we are able to obtain reliable source types from the literature. They…