Search Publications
XMM-Newton Observations of the Narrow-Line Seyfert 1 Galaxy Mrk 335 in a Historical Low X-Ray Flux State
Fabian, Andrew C.; Gallo, Luigi C.; Miniutti, Giovanni +5 more
We report the discovery of strong soft X-ray emission lines and a hard continuum above 2 keV in the narrow-line Seyfert 1 galaxy Mrk 335 during an extremely low X-ray flux state. Mrk 335 was observed for 22 ks by XMM-Newton in 2007 July as a Target of Opportunity to examine it in its X-ray low flux state, which was discovered with Swift. Long-term…
Saturn's magnetodisc current sheet
Russell, C. T.; Dougherty, M. K.; Khurana, K. K. +5 more
Pioneer 11 observations from the dawn flank of Saturn's magnetosphere provided evidence for a thin equatorial current sheet. Magnetometer data from the Cassini orbiter have also revealed the presence of this current sheet and shown it to be a consistent feature of the dawn flank. Arridge et al. (2007) recently investigated the stress balance in th…
The Hubble Space Telescope Advanced Camera for Surveys Coma Cluster Survey. I. Survey Objectives and Design
Ferguson, Henry C.; Mobasher, Bahram; Miller, Bryan W. +34 more
We describe the HST ACS Coma Cluster Treasury survey, a deep two-passband imaging survey of one of the nearest rich clusters of galaxies, the Coma Cluster (Abell 1656). The survey was designed to cover an area of 740 arcmin2 in regions of different density of both galaxies and intergalactic medium within the cluster. The ACS failure of …
Depth of a strong jovian jet from a planetary-scale disturbance driven by storms
Hueso, R.; Sánchez-Lavega, A.; Rojas, J. F. +22 more
The atmospheres of the gas giant planets (Jupiter and Saturn) contain jets that dominate the circulation at visible levels. The power source for these jets (solar radiation, internal heat, or both) and their vertical structure below the upper cloud are major open questions in the atmospheric circulation and meteorology of giant planets. Several ob…
A deep X-ray observation of M82 with XMM-Newton
Maiolino, R.; Ranalli, P.; Comastri, A. +1 more
We report on the analysis of a deep (100-ks) observation of the starburst galaxy M82 with the EPIC and RGS instruments onboard the X-ray telescope XMM-Newton. The broad-band (0.5-10 keV) emission is due to at least three spectral components: (i) continuum emission from point sources; (ii) thermal plasma emission from hot gas; and (iii) charge-exch…
The Nature and Origin of Substructure in the Outskirts of M31. I. Surveying the Stellar Content with the Hubble Space Telescope Advanced Camera for Surveys
Chapman, S. C.; Tanvir, N. R.; Ferguson, A. M. N. +8 more
We present the largest and most detailed survey to date of the stellar populations in the outskirts of M31 based on the homogeneous analysis of 14 deep Hubble Space Telescope Advanced Camera for Surveys (HST/ACS) pointings spanning the range 11.5 kpc lsim R proj lsim 45 kpc. Many of these pointings sample coherent substructure discovere…
The Detection of a Light Echo from the Type Ia Supernova 2006X in M100
Filippenko, Alexei V.; Foley, Ryan J.; Smith, Nathan +3 more
We report the discovery of a light echo (LE) from the Type Ia supernova (SN) 2006X in the nearby galaxy M100. The presence of the LE is supported by analysis of both the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) images and the Keck optical spectrum that we obtained at ~300 days after maximum brightness. In the image procedure,…
Globular clusters in the outer halo of M31: the survey
Tanvir, N. R.; Ferguson, A. M. N.; Lewis, G. F. +4 more
We report the discovery of 40 new globular clusters (GCs) that have been found in surveys of the halo of M31 based on the Isaac Newton Telescope/Wide-Field Camera and Canada-France-Hawaii Telescope/Megacam imagery. A subset of these new GCs are of an extended, diffuse nature and include those already found in Huxor et al. The search strategy is de…
Blue Straggler Stars in the Unusual Globular Cluster NGC 6388
Dalessandro, E.; Valenti, E.; Piotto, G. +4 more
We have used multiband high-resolution HST WFPC2 and ACS observations combined with wide-field ground-based observations to study the blue straggler star (BSS) population in the Galactic globular cluster NGC 6388. As in several other clusters we have studied, the BSS distribution is found to be bimodal: highly peaked in the cluster center, rapidly…
XMM-Newton observations of the Lockman Hole: X-ray source catalogue and number counts
Cappelluti, N.; Barcons, X.; Fabian, A. C. +4 more
Context: The Lockman Hole field represents the sky area of lowest Galactic line-of-sight column density N_H=5.7 × 1019 cm-2. It was observed by the XMM-Newton X-ray observatory in 18 pointings for a total of 1.16 Ms (raw EPIC pn observing time) constituting the deepest XMM-Newton exposure so far. After the removal of time int…