Search Publications

A description of sources detected by INTEGRAL during the first 4 years of observations
DOI: 10.1051/0004-6361:20077091 Bibcode: 2007A&A...467..585B

Rodriguez, J.; Kuulkers, E.; Produit, N. +6 more

Context: In its first 4 years of observing the sky above 20 keV, INTEGRAL-ISGRI has detected 500 sources, around half of which are new or unknown at these energies. Follow-up observations at other wavelengths revealed that some of these sources feature unusually large column densities, long pulsations, and other interesting characteristics.
Ai…

2007 Astronomy and Astrophysics
INTEGRAL 95
The Metallicity Distribution of Intracluster Stars in Virgo
DOI: 10.1086/510149 Bibcode: 2007ApJ...656..756W

Ferguson, Henry C.; Williams, Benjamin F.; Gerhard, Ortwin +11 more

We have used the Hubble Space Telescope's Advanced Camera for Surveys (ACS) to detect and measure ~5300 stars in a single intracluster field in the Virgo Cluster. By performing F606W and F814W photometry on these stars, we have determined their metallicity distribution function and constrained the types of stars present in this portion of Virgo's …

2007 The Astrophysical Journal
eHST 95
On the origin of gypsum in the Mars north polar region
DOI: 10.1029/2006JE002862 Bibcode: 2007JGRE..112.7002F

Bibring, Jean-Pierre; Langevin, Yves; Poulet, François +2 more

We describe the distribution and concentration of the largest Martian gypsum deposit discovered to date by the Mars Express OMEGA (Observatoire pour le Mineralogie, l'Eau, les Glaces et l'Activité) imaging spectrometer, its relationship to the late Amazonian-aged north polar dunes in which it is found, and its likely origin. Gypsum has not been di…

2007 Journal of Geophysical Research (Planets)
MEx 95
The UDF05 Follow-up of the Hubble Ultra Deep Field. I. The Faint-End Slope of the Lyman Break Galaxy Population at z ~ 5
DOI: 10.1086/522423 Bibcode: 2007ApJ...671.1212O

Panagia, N.; Gardner, Jonathan P.; Ferguson, H. C. +14 more

We present the UDF05 HST program, which consists of three disjoint fields-NICP12, NICP34, plus the HUDF-with deep ACS (F606W, F775W, and F850LP) and NICMOS (F110W and F160W) imaging. Here we use the ACS data for the NICP12 and HUDF fields to implement a (V-i)-(i-z) selection criterion that allows us to identify a sample of 101 (133) z~5 Lyman brea…

2007 The Astrophysical Journal
eHST 95
The structure of Venus' middle atmosphere and ionosphere
DOI: 10.1038/nature06239 Bibcode: 2007Natur.450..657P

Pätzold, M.; Bird, M. K.; Asmar, S. W. +8 more

The atmosphere and ionosphere of Venus have been studied in the past by spacecraft with remote sensing or in situ techniques. These early missions, however, have left us with questions about, for example, the atmospheric structure in the transition region from the upper troposphere to the lower mesosphere (50-90km) and the remarkably variable stru…

2007 Nature
VenusExpress 95
Multispacecraft Measurement of Anisotropic Correlation Functions in Solar Wind Turbulence
DOI: 10.1086/510906 Bibcode: 2007ApJ...654L.103O

Horbury, T. S.; Osman, K. T.

Multispacecraft measurements in the solar wind are used to determine the field-aligned anisotropy of magnetohydrodynamic inertial range turbulence. The ratio of the parallel to perpendicular correlation lengths is measured by using time-lagged two-point correlations to construct a spatial autocorrelation function. The mean ratio obtained, 1.79+/-0…

2007 The Astrophysical Journal
Cluster 95
South-polar features on Venus similar to those near the north pole
DOI: 10.1038/nature06209 Bibcode: 2007Natur.450..637P

Baines, K. H.; Langevin, Y.; Lopez-Valverde, M. A. +102 more

Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright `dipole' feature surrounded by a cold `collar' at its north pole. The polar dipole is a `double-eye' feature at the centre of a vas…

2007 Nature
VenusExpress 95
The Intrinsically X-Ray-weak Quasar PHL 1811. II. Optical and UV Spectra and Analysis
DOI: 10.1086/519768 Bibcode: 2007ApJS..173....1L

Jenkins, Edward B.; Halpern, Jules P.; Leighly, Karen M. +1 more

This is the second of two papers reporting observations and analysis of the unusually bright (mb=14.4), luminous (MB=-25.5), nearby (z=0.192) narrow-line quasar PHL 1811. The first paper reported that PHL 1811 is intrinsically X-ray-weak and presented a spectral energy distribution (SED). Here we present HST STIS optical and …

2007 The Astrophysical Journal Supplement Series
eHST 95
The Globular Cluster Luminosity Function and Specific Frequency in Dwarf Elliptical Galaxies
DOI: 10.1086/522323 Bibcode: 2007ApJ...670.1074M

Miller, Bryan W.; Lotz, Jennifer M.

The globular cluster luminosity function, specific globular cluster frequency, SN, specific globular cluster mass, TMP, and globular cluster mass fraction in dwarf elliptical galaxies are explored using the full 69 galaxy sample of the HST WFPC2 Dwarf Elliptical Galaxy Snapshot Survey. The GCLFs of the dEs are well represente…

2007 The Astrophysical Journal
eHST 95
X-ray precursors to flares and filament eruptions
DOI: 10.1051/0004-6361:20077771 Bibcode: 2007A&A...472..967C

Mason, H. E.; Dennis, B. R.; Tripathi, D. +1 more

Aims:To study preflare X-ray brightenings as diagnostics of the destabilisation of flare-associated erupting filaments/prominences.
Methods: We combine new observations from the Transition Region and Coronal Explorer (TRACE) and the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), as well as revisit events reported in the literat…

2007 Astronomy and Astrophysics
SOHO 95