Search Publications

Methane escape from Titan's atmosphere
DOI: 10.1029/2007JE003031 Bibcode: 2008JGRE..11310003Y

Yelle, R. V.; Cui, J.; Müller-Wodarg, I. C. F.

Measurements of the mole fractions of CH4 and 40Ar by the Ion Neutral Mass Spectrometer on the Cassini orbiter are analyzed to determine the rate of vertical mixing in Titan's atmosphere and the escape flux of CH4. Analysis of the 40Ar data indicates an eddy mixing rate of 2-5 × 107 cm2

2008 Journal of Geophysical Research (Planets)
Cassini 103
Observations of Active Region Loops with the EUV Imaging Spectrometer on Hinode
DOI: 10.1086/592960 Bibcode: 2008ApJ...686L.131W

Warren, Harry P.; Doschek, George A.; Ugarte-Urra, Ignacio +2 more

Previous solar observations have shown that coronal loops near 1 MK are difficult to reconcile with simple heating models. These loops have lifetimes that are long relative to a radiative cooling time, suggesting quasi-steady heating. The electron densities in these loops, however, are too high to be consistent with thermodynamic equilibrium. Mode…

2008 The Astrophysical Journal
Hinode 103
Molecular Gas in a Submillimeter Galaxy at z = 4.5: Evidence for a Major Merger at 1 Billion Years after the Big Bang
DOI: 10.1086/595680 Bibcode: 2008ApJ...689L...5S

Smolčić, V.; Taniguchi, Y.; Yun, M. S. +8 more

We report the detection of CO molecular line emission in the z = 4.5 millimeter-detected galaxy COSMOS J100054+023436 (hereafter J1000+0234) using the IRAM Plateau de Bure interferometer (PdBI) and NRAO's Very Large Array (VLA). The 12CO(4-3) line as observed with PdBI has a full line width of ~1000 km s-1, an integrated line…

2008 The Astrophysical Journal
eHST 103
Heterogeneous chemistry in the atmosphere of Mars
DOI: 10.1038/nature07116 Bibcode: 2008Natur.454..971L

Montmessin, Franck; Bertaux, Jean-Loup; Perrier, Séverine +6 more

Hydrogen radicals are produced in the martian atmosphere by the photolysis of water vapour and subsequently initiate catalytic cycles that recycle carbon dioxide from its photolysis product carbon monoxide. These processes provide a qualitative explanation for the stability of the atmosphere of Mars, which contains 95 per cent carbon dioxide. Bala…

2008 Nature
MEx eHST 103
A SINFONI View of Galaxy Centers: Morphology and Kinematics of Five Nuclear Star Formation-Rings
DOI: 10.1088/0004-6256/135/2/479 Bibcode: 2008AJ....135..479B

Böker, Torsten; Schinnerer, Eva; Falcón-Barroso, Jesús +2 more

We present near-infrared (H- and K-band) integral-field observations of the circumnuclear star formation rings in five nearby spiral galaxies. The data, obtained at the Very Large Telescope with the SINFONI spectrograph, are used to construct maps of various emission lines that reveal the individual star forming regions ("hot spots") delineating t…

2008 The Astronomical Journal
eHST 102
IMAGES. I. Strong evolution of galaxy kinematics since z = 1
DOI: 10.1051/0004-6361:20078219 Bibcode: 2008A&A...477..789Y

Cesarsky, C.; Östlin, G.; Yang, Y. +20 more

Nearly half the stellar mass of present-day spiral galaxies has formed since z = 1, and galaxy kinematics is an ideal tool to identify the underlying mechanisms responsible for the galaxy mass assembly since that epoch. Here, we present the first results of the ESO large program, “IMAGES”, which aims at obtaining robust measurements of the kinemat…

2008 Astronomy and Astrophysics
eHST 102
A Hubble and Spitzer Space Telescope Survey for Gravitationally Lensed Galaxies: Further Evidence for a Significant Population of Low-Luminosity Galaxies beyond z = 7
DOI: 10.1086/591312 Bibcode: 2008ApJ...685..705R

Richard, Johan; Smith, Graham P.; Stark, Daniel P. +4 more

We present the results of a systematic search for gravitationally lensed continuum Lyman break "dropouts" beyond a redshift 7 conducted via very deep imaging through six foreground clusters undertaken with the Hubble and Spitzer space telescopes. The survey has yielded 10 z-band and two J-band dropout candidates to photometric limits of J110<…

2008 The Astrophysical Journal
eHST 102
Pulsar timing for the Fermi gamma-ray space telescope
DOI: 10.1051/0004-6361:200810285 Bibcode: 2008A&A...492..923S

Camilo, F.; Dumora, D.; Guillemot, L. +25 more

We describe a comprehensive pulsar monitoring campaign for the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The detection and study of pulsars in gamma rays give insights into the populations of neutron stars and supernova rates in the Galaxy, into particle acceleration mechanisms in neutron star magnetospher…

2008 Astronomy and Astrophysics
XMM-Newton 102
Coronal magnetic field measurement using loop oscillations observed by Hinode/EIS
DOI: 10.1051/0004-6361:200810186 Bibcode: 2008A&A...487L..17V

Young, P. R.; Nakariakov, V. M.; Verwichte, E. +1 more

We report the first spectroscopic detection of a kink MHD oscillation of a solar coronal structure by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on the Japanese Hinode satellite. The detected oscillation has an amplitude of 1 km s-1 in the Doppler shift of the FeXII 195 Å spectral line (1.3~MK), and a period of 296~s. The unique…

2008 Astronomy and Astrophysics
Hinode 101
Study of nonlinear ion- and electron-acoustic waves in multi-component space plasmas
DOI: 10.5194/npg-15-903-2008 Bibcode: 2008NPGeo..15..903L

Lakhina, G. S.; Singh, S. V.; Verheest, F. +2 more

Large amplitude ion-acoustic and electron-acoustic waves in an unmagnetized multi-component plasma system consisting of cold background electrons and ions, a hot electron beam and a hot ion beam are studied using Sagdeev pseudo-potential technique. Three types of solitary waves, namely, slow ion-acoustic, ion-acoustic and electron-acoustic soliton…

2008 Nonlinear Processes in Geophysics
Cluster 101