Search Publications
HST/NICMOS Detection of HR 8799 b in 1998
Barman, Travis; Doyon, René; Marois, Christian +1 more
Three planets have been directly imaged around the young star HR 8799. The planets are 5-13 M Jup and orbit the star at projected separations of 24-68 AU. While the initial detection occurred in 2007, two of the planets were recovered in a reanalysis of data obtained in 2004. Here we present a detection of the furthest planet of that sy…
The Circum-Hellas Volcanic Province, Mars: Overview
McCord, Thomas B.; HRSC Co-Investigator Team; Xiao, Long +13 more
Building on previous studies of volcanoes around the Hellas basin with new studies of imaging (High-Resolution Stereo Camera (HRSC), Thermal Emission Imaging System (THEMIS), Mars Orbiter Camera (MOC), High-Resolution Imaging Science Experiment (HiRISE), Context Imager (CTX)), multispectral (HRSC, Observatoire pour la Minéralogie, l'Eau, les Glace…
Subaru High-Resolution Spectroscopy of Star G in the Tycho Supernova Remnant
Schmidt, Brian P.; Asplund, M.; Nomoto, Ken'ichi +5 more
It is widely believed that Type Ia supernovae (SNe Ia) originate in binary systems where a white dwarf accretes material from a companion star until its mass approaches the Chandrasekhar mass and carbon is ignited in the white dwarf's core. This scenario predicts that the donor star should survive the supernova (SNe) explosion, providing an opport…
Analysis of Galactic late-type O dwarfs: more constraints on the weak wind problem
Bouret, J. -C.; Martins, F.; Hillier, D. J. +3 more
Aims: We investigate the stellar and wind properties of a sample of late-type O dwarfs. Previous analyses of such stars have found very low mass-loss rates; rates much lower than predicted by theory (the weak wind problem).
Methods: Far-UV to optical spectra of five Galactic O stars were analyzed: HD 216898 (O9IV/O8.5V), HD 326329 (O9V), HD 66…
Revealing the magnetic field in a distant galaxy cluster: discovery of the complex radio emission from MACS J0717.5 +3745
Gentile, G.; Bonafede, A.; Govoni, F. +7 more
Aims: To study at multiple frequencies the radio emission arising from the massive galaxy cluster MACS J0717.5+3745 (z=0.55). Known to be an extremely complex cluster merger, the system is uniquely suited for an investigation of the phenomena at work in the intra-cluster medium (ICM) during cluster collisions.
Methods: We use multi-frequency a…
Recurrent energization of plasma in the midnight-to-dawn quadrant of Saturn's magnetosphere, and its relationship to auroral UV and radio emissions
Gurnett, D. A.; Dougherty, M. K.; Krimigis, S. M. +11 more
We demonstrate that under some magnetospheric conditions protons and oxygen ions are accelerated once per Saturn magnetosphere rotation, at a preferred local time between midnight and dawn. Although enhancements in energetic neutral atom (ENA) emission may in general occur at any local time and at any time in a Saturn rotation, those enhancements …
The Hubble flow around the Local Group
Karachentsev, I. D.; Kashibadze, O. G.; Tully, R. B. +1 more
We use updated data on distances and velocities of galaxies in the proximity of the Local Group (LG) in order to establish properties of the local Hubble flow. For 30 neighbouring galaxies with distances 0.7 < DLG < 3.0 Mpc, the local flow is characterized by the Hubble parameter Hloc = (78 +/- 2)kms-1 Mpc
INPOP08, a 4-D planetary ephemeris: from asteroid and time-scale computations to ESA Mars Express and Venus Express contributions
Laskar, J.; Fienga, A.; Le Poncin-Lafitte, C. +6 more
The latest version of the planetary ephemerides developed at the Paris Observatory and at the Besançon Observatory is presented. INPOP08 is a 4-dimension ephemeris since it provides positions and velocities of planets and the relation between Terrestrial Time and Barycentric Dynamical Time. Investigations to improve the modeling of asteroids are d…
A Deep Hubble Space Telescope H-Band Imaging Survey of Massive Gas-Rich Mergers. II. The QUEST QSOs
Lutz, D.; Genzel, R.; Sturm, E. +11 more
We report the results from a deep Hubble Space Telescope (HST) NICMOS H-band imaging survey of 28 z < 0.3 QSOs from the Palomar-Green (PG) sample. This program is part of QUEST (Quasar/ULIRG Evolution Study) and complements a similar set of data on 26 highly nucleated ULIRGs presented in Paper I. Our analysis indicates that the fraction of QSOs…
An Analysis of the Shapes of Interstellar Extinction Curves. VI. The Near-IR Extinction Law
Fitzpatrick, E. L.; Massa, D.
We combine new observations from the Hubble Space Telescope's Advanced Camera of Survey with existing data to investigate the wavelength dependence of near-IR (NIR) extinction. Previous studies suggest a power law form for NIR extinction, with a "universal" value of the exponent, although some recent observations indicate that significant sight li…