Search Publications
Kappa Distributions: Theory and Applications in Space Plasmas
Pierrard, V.; Lazar, M.
The plasma particle velocity distributions observed in the solar wind generally show enhanced (non-Maxwellian) suprathermal tails, decreasing as a power law of the velocity and well described by the family of Kappa distribution functions. The presence of non-thermal populations at different altitudes in space plasmas suggests a universal mechanism…
The AKARI/IRC mid-infrared all-sky survey
García-Lario, P.; Müller, T. G.; Ohyama, Y. +30 more
Context. AKARI is the first Japanese astronomical satellite dedicated to infrared astronomy. One of the main purposes of AKARI is the all-sky survey performed with six infrared bands between 9 µm and 200 µm during the period from 2006 May 6 to 2007 August 28. In this paper, we present the mid-infrared part (9 µm and 18 µm b…
Planetary surface dating from crater size-frequency distribution measurements: Partial resurfacing events and statistical age uncertainty
Neukum, G.; Michael, G. G.
We describe the procedure to fit a cumulative production function polynomial to a partial crater size-frequency distribution. The technique is of particular use in deriving ages for surfaces which have undergone partial resurfacing events: namely, erosional or depositional events which have affected a limited diameter range of the crater populatio…
The Supernova Legacy Survey 3-year sample: Type Ia supernovae photometric distances and cosmological constraints
Sullivan, M.; Lidman, C.; González-Gaitán, S. +31 more
Aims: We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15 < z < 1.1) discovered during the first three years of the Supernova Legacy Survey (SNLS). These events were detected and their multi-colour light curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawa…
The Herschel-Heterodyne Instrument for the Far-Infrared (HIFI)
de Graauw, Th.; Beintema, D. A.; Murphy, J. A. +163 more
Aims: This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI) that was launched onboard ESA's Herschel Space Observatory in May 2009.
Methods: The instrument is a set of 7 heterodyne receivers that are electronically tuneable, covering 480-1250 GHz with SIS mixers and the 1410-1910 GHz range with hot electron bolometer…
The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150Msolar stellar mass limit
Parker, Richard J.; Crowther, Paul A.; Goodwin, Simon P. +4 more
Spectroscopic analyses of hydrogen-rich WN5-6 stars within the young star clusters NGC3603 and R136 are presented, using archival Hubble Space Telescope and Very Large Telescope spectroscopy, and high spatial resolution near-IR photometry, including Multi-Conjugate Adaptive Optics Demonstrator (MAD) imaging of R136. We derive high stellar temperat…
Geologic history of Mars
Head, James W.; Carr, Michael H.
Mars accumulated and differentiated into crust, mantle and core within a few tens of millions of years of Solar System formation. Formation of Hellas, which has been adopted as the base of the Noachian period, is estimated to have occurred around 4.1 to 3.8 Gyr ago, depending on whether or not the planet experienced a late cataclysm. Little is kno…
Formation of Torus-Unstable Flux Ropes and Electric Currents in Erupting Sigmoids
Aulanier, G.; Démoulin, P.; Török, T. +1 more
We analyze the physical mechanisms that form a three-dimensional coronal flux rope and later cause its eruption. This is achieved by a zero-β magnetohydrodynamic (MHD) simulation of an initially potential, asymmetric bipolar field, which evolves by means of simultaneous slow magnetic field diffusion and sub-Alfvénic, line-tied shearing motions in …
The First Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
Ozaki, M.; Caraveo, P. A.; D'Elia, V. +205 more
We present the first catalog of active galactic nuclei (AGNs) detected by the Large Area Telescope (LAT), corresponding to 11 months of data collected in scientific operation mode. The First LAT AGN Catalog (1LAC) includes 671 γ-ray sources located at high Galactic latitudes (|b|>10°) that are detected with a test statistic greater than 25 and …
The Sloan Lens ACS Survey. X. Stellar, Dynamical, and Total Mass Correlations of Massive Early-type Galaxies
Treu, T.; Auger, M. W.; Gavazzi, R. +5 more
We use stellar masses, surface photometry, strong-lensing masses, and stellar velocity dispersions (σ e/2) to investigate empirical correlations for the definitive sample of 73 early-type galaxies (ETGs) that are strong gravitational lenses from the SLACS survey. The traditional correlations (fundamental plane (FP) and its projections) …