Search Publications
Non-LTE infrared observations at Venus: From NIMS/Galileo to VIRTIS/Venus Express
Drossart, Pierre; López-Valverde, M. A.; Carlson, Robert +2 more
Recent improvements in a comprehensive non-local thermodynamic equilibrium (non-LTE) model of CO 2 atmospheres has permitted a better understanding of a number of Venusian atmospheric measurements taken more than a decade ago by the "Near Infrared Mapping Spectrometer" (NIMS) on board the Galileo spacecraft during its Venus fly-by. Thos…
Wind variations in Jupiter's equatorial atmosphere: A QQO counterpart?
Simon-Miller, Amy A.; Orton, Glenn S.; Poston, Bradley W. +1 more
Jupiter's equatorial atmosphere, much like the Earth's, is known to show quasi-periodic variations in temperature, particularly in the stratosphere, but variations in other jovian atmospheric tracers have not been studied for any correlations to these oscillations. Data taken at NASA's Infrared Telescope Facility (IRTF) from 1979 to 2000 were used…
Optical Spectroscopy of the Environment of a ULX in NGC 7331
Tennant, Allyn F.; Swartz, Douglas A.; Ghosh, Kajal K. +3 more
Optical photometric and spectroscopic data are presented that show an association of an ultraluminous X-ray source in NGC 7331 with a young star cluster of mass M=(1.1+/-0.2)×105 Msolar and age tc=4.25+/-0.25 Myr. If the ULX is part of the bright stellar cluster, then the mass of the progenitor of the compact accre…
The XMM-Newton/INTEGRAL monitoring campaign of IGR J16318-4848
Guainazzi, M.; Jiménez-Bailón, E.; Rodriguez, J. +5 more
Context: IGR J16318-4848 is the prototype and one of the more extreme examples of the new class of highly obscured Galactic X-ray sources discovered by INTEGRAL. A monitoring campaign on this source has been carried out using XMM-Newton and INTEGRAL, consisting of three simultaneous observations performed in February, March and August 2004.
Ai…
Beam-plasma interaction in randomly inhomogeneous plasmas and statistical properties of small-amplitude Langmuir waves in the solar wind and electron foreshock
Pickett, J. S.; Soucek, J.; Krasnoselskikh, V. V. +3 more
A numerical model for wave propagation in an unstable plasma with inhomogeneities is developed. This model describes the linear interaction of Langmuir wave packets with an electron beam and takes into account the angular diffusion of the wave vector due to wave scattering on small-amplitude density fluctuations, as well as suppression of the inst…
Magnetic properties of flare-CME productive active regions and CME speed
Zhang, H. Q.; Guo, J.; Chumak, O. V.
Aims:We study the properties of magnetic field of flare-coronal-mass-ejection (flare-CME) productive active regions and their statistic correlations with CME speed.
Methods: We used a sample of 86 flare-CMEs in 55 solar active regions. Four measures, including the tilt angle (Tilt), total flux (Ft), length of the strong-field and strong-gradie…
The Dynamical Distinction between Elliptical and Lenticular Galaxies in Distant Clusters: Further Evidence for the Recent Origin of S0 Galaxies
Treu, Tommaso; Ellis, Richard S.; Moran, Sean M. +3 more
We examine resolved spectroscopic data obtained with the Keck II telescope for 44 spheroidal galaxies in the fields of two rich clusters, Cl 0024+16 (z=0.40) and MS 0451-03 (z=0.54) and contrast this with similar data for 23 galaxies within the redshift interval 0.3<z<0.65 in the GOODS northern field. For each galaxy we examine the case for …
Discovery of the Pre-Main-Sequence Population of the Stellar Association LH 95 in the Large Magellanic Cloud with Hubble Space Telescope Advanced Camera for Surveys Observations
Henning, Thomas; Gouliermis, Dimitrios A.; Dolphin, Andrew E. +3 more
We report the discovery of an extraordinary number of pre-main-sequence (PMS) stars in the vicinity of the stellar association LH 95 in the Large Magellanic Cloud (LMC). Using the Advanced Camera for Surveys on board the Hubble Space Telescope in wide-field mode, we obtained deep high-resolution imaging of the main body of the association and of a…
The secrets of T Pyxidis. I. UV observations
Selvelli, P.; Gilmozzi, R.
Aims:We study the UV spectral behavior of the recurrent nova T Pyx during 16 years of <sl>IUE observations.</sl>
Methods: We examined both the <sl>IUE line-by-line images and the extracted spectra in order to understand the reality and the origin of the observed spectral variations. We compare different extraction methods and…
Hubble Space Telescope NICMOS Observations of NGC 1333: The Ratio of Stars to Substellar Objects
Schneider, Glenn; Meyer, Michael R.; Greene, Thomas P. +4 more
We present an analysis of NICMOS photometry and low-resolution grism spectroscopy of low-mass stars and substellar objects in the young star-forming region NGC 1333. Our goal is to constrain the ratio of low-mass stars to substellar objects down to 20MJup in the cluster, as well as constrain the cluster initial mass function (IMF) down …