Search Publications
Eclipsing Binary Solutions in Physical Units and Direct Distance Estimation
Wilson, R. E.
Opportunities for extraction of distances and temperatures from eclipsing binary light curves that are in standard flux units, as opposed to traditional arbitrary units, are examined. Benefits include (1) distance becomes an ordinary solution parameter with a standard error, (2) temperatures of both stars may be derivable in favorable circumstance…
Electron density estimations derived from spacecraft potential measurements on Cluster in tenuous plasma regions
Sauvaud, J. -A.; Dandouras, I.; André, M. +13 more
Spacecraft potential measurements by the EFW electric field experiment on the Cluster satellites can be used to obtain plasma density estimates in regions barely accessible to other type of plasma experiments. Direct calibrations of the plasma density as a function of the measured potential difference between the spacecraft and the probes can be c…
Hipparcos distance estimates of the Ophiuchus and the Lupus cloud complexes
Alves, J.; Lombardi, M.; Lada, C. J.
We combine extinction maps from the Two Micron All Sky Survey (2MASS) with Hipparcos and Tycho parallaxes to obtain reliable and high-precision estimates of the distance to the Ophiuchus and Lupus dark complexes. Our analysis, based on a rigorous maximum-likelihood approach, shows that the ρ-Ophiuchi cloud is located at (119 ± 6) pc and the Lupus …
Multi-wavelength observations of Galactic hard X-ray sources discovered by INTEGRAL. II. The environment of the companion star
Pantin, E.; Chaty, S.; Rahoui, F. +1 more
Context: The INTEGRAL mission has led to the discovery of a new type of supergiant X-ray binaries (SGXBs), whose physical properties differ from those of previously known SGXBs. Those sources are in the course of being unveiled by means of multi-wavelength X-rays, optical, near- and mid-infrared observations, and two classes are appearing. The fir…
Compositional mapping of Saturn's satellite Dione with Cassini VIMS and implications of dark material in the Saturn system
Nicholson, Philip D.; Baines, Kevin H.; Buratti, Bonnie J. +9 more
Cassini VIMS has obtained spatially resolved imaging spectroscopy data on numerous satellites of Saturn. A very close fly-by of Dione provided key information for solving the riddle of the origin of the dark material in the Saturn system. The Dione VIMS data show a pattern of bombardment of fine, sub-0.5-µm diameter particles impacting the s…
Constraints on decaying dark matter from XMM-Newton observations of M31
Boyarsky, Alexey; Ruchayskiy, Oleg; Iakubovskyi, Dmytro +1 more
We derive constraints on the parameters of the radiatively decaying dark matter (DM) particle, using the XMM-Newton EPIC spectra of the Andromeda galaxy (M31). Using the observations of the outer (5-13arcmin) parts of M31, we improve the existing constraints. For the case of sterile neutrino DM, combining our constraints with the latest computatio…
Wavelengths and Intensities of Spectral Lines in the 171-211 and 245-291 Å Ranges from Five Solar Regions Recorded by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on Hinode
Brown, C. M.; Hara, H.; Feldman, U. +2 more
We present spectral line wavelengths, identifications, and intensities in the 171-211 and 245-291 Å ranges from five solar plasma regions recorded by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on Hinode. The recorded data were emitted from a quiet region, two active areas on the solar disk, a limb region, and a region 20'' above the limb. …
Polarization of the Crab Pulsar and Nebula as Observed by the INTEGRAL/IBIS Telescope
Grenier, I. A.; Laurent, P.; Lebrun, F. +2 more
Neutron stars generate powerful winds of relativistic particles that form bright synchrotron nebulae around them. Polarimetry provides a unique insight into the geometry and magnetic configuration of the wind, but high-energy measurements have failed until recently. The INTEGRAL/IBIS telescope has been used in its Compton mode to search for linear…
The Spatial Structure of an Accretion Disk
Kochanek, Christopher S.; Poindexter, Shawn; Morgan, Nicholas
Based on the microlensing variability of the two-image gravitational lens HE 1104-1805 observed between 0.4 and 8 µm, we have measured the size and wavelength-dependent structure of the quasar accretion disk. Modeled as a power law in temperature, T propto R-β, we measure a B-band (0.13 µm in the rest frame) half-light radiu…
An update to a Saturnian longitude system based on kilometric radio emissions
Gurnett, D. A.; Kurth, W. S.; Averkamp, T. F. +2 more
The period of Saturn kilometric radiation modulation as determined by Voyager forms the basis for a longitude system (SLS) recognized by the International Astronomical Union. However, Ulysses and Cassini observations have shown that this modulation period varies by the order of one percent on timescales of a few years and, hence, does not represen…