Search Publications
AMUSE-Virgo. II. Down-sizing in Black Hole Accretion
Treu, Tommaso; Marshall, Philip J.; Antonucci, Robert +3 more
We complete the census of nuclear X-ray activity in 100 early-type Virgo galaxies observed by the Chandra X-ray Telescope as part of the AMUSE-Virgo survey, down to a (3σ) limiting luminosity of 3.7 × 1038 erg s-1 over 0.5-7 keV. The stellar mass distribution of the targeted sample, which is mostly composed of formally "inact…
A Catalog of Halo Coronal Mass Ejections from SOHO
Howard, R. A.; Gopalswamy, N.; Michalek, G. +4 more
Coronal mass ejections (CMEs) that appear to surround the occulting disk of the observing coronagraph are known as halo CMEs. Halos constitute a subset of energetic CMEs that have important heliospheric consequences. Here we describe an on-line catalog that contains all the halo CMEs that were identified in the images obtained by the Solar and Hel…
Origin of Saturn's rings and inner moons by mass removal from a lost Titan-sized satellite
Canup, Robin M.
The origin of Saturn's rings has not been adequately explained. The current rings are more than 90 to 95 per cent water ice, which implies that initially they were almost pure ice because they are continually polluted by rocky meteoroids. In contrast, a half-rock, half-ice mixture (similar to the composition of many of the satellites in the outer …
Abell 370 revisited: refurbished Hubble imaging of the first strong lensing cluster
Kneib, J. -P.; Jullo, E.; Richard, J. +2 more
We present a strong lensing analysis of the galaxy cluster Abell 370 (z= 0.375) based on the recent multicolour images by Advanced Camera for Surveys obtained as part of the Early Release Observation (ERO) that followed the Hubble Service Mission #4. Back in 1987, the giant gravitational arc (z= 0.725) in Abell 370 was one of the first pieces of e…
High-redshift elliptical galaxies: are they (all) really compact?
Aussel, H.; Cimatti, A.; Daddi, E. +10 more
We investigate the properties of 12 ultramassive passively evolving early-type galaxies (ETGs) at zphot > 1.4 in the COSMOS 2 deg2 field. These 12 ETGs were selected as pBzKs, have accurate 1.4 <~ zphot <~ 1.7, high Sérsic index profiles typical of ellipticals, no detection at 24µm, resulting in a co…
Cosmic Evolution of Black Holes and Spheroids. IV. The M BH-L sph Relation
Treu, Tommaso; Auger, Matthew W.; Malkan, Matthew A. +5 more
From high-resolution images of 23 Seyfert-1 galaxies at z = 0.36 and z = 0.57 obtained with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST), we determine host-galaxy morphology, nuclear luminosity, total host-galaxy luminosity, and spheroid luminosity. Keck spectroscopy is used to estimate black hol…
The recent formation of Saturn's moonlets from viscous spreading of the main rings
Charnoz, Sébastien; Crida, Aurélien; Salmon, Julien
The regular satellites of the giant planets are believed to have finished their accretion concurrent with the planets, about 4.5Gyr ago. A population of Saturn's small moons orbiting just outside the main rings are dynamically young (less than 107yr old), which is inconsistent with the formation timescale for the regular satellites. The…
Substructure of the galaxy clusters in the REXCESS sample: observed statistics and comparison to numerical simulations
Böhringer, H.; Arnaud, M.; Pratt, G. W. +6 more
We study the substructure statistics of a representative sample of galaxy clusters by means of two currently popular substructure characterisation methods, power ratios and centroid shifts. We use the 31 clusters from the REXCESS sample, compiled from the southern ROSAT All-Sky cluster survey (REFLEX) with a morphologically unbiased selection in X…
The Interstellar H Flow: Updated Analysis of SOHO/SWAN Data
Bertaux, Jean-Loup; Lallement, Rosine; Lamy, Philippe +4 more
We update two kinds of results obtained with the SWAN instrument on board SOHO. First, we use H cell data recorded in 2001 and derive the H flow direction in the same way the study was done at solar minimum. We again compare with the Helium flow direction and doing so correct for the coordinate system change between the Ulysses and SOHO missions. …
A comparison of global models for the solar wind interaction with Mars
Kallio, E.; Barabash, S.; Lammer, H. +24 more
We present initial results from the first community-wide effort to compare global plasma interaction model results for Mars. Seven modeling groups participated in this activity, using MHD, multi-fluid, and hybrid assumptions in their simulations. Moderate solar wind and solar EUV conditions were chosen, and the conditions were implemented in the m…