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Star Counts in the Globular Cluster ω Centauri. I. Bright Stellar Components
Degl'Innocenti, S.; Castellani, M.; Piersimoni, A. M. +17 more
We present a photometric investigation on HB, RGB, and MSTO stars in ω Cen=NGC 5139. The center of the cluster was covered with a mosaic of F435W, F625W, and F658N band data collected with HST ACS. The outer reaches were covered with a mosaic of U-, B-, V-, and I-band data collected with the 2.2 m ESO/MPI telescope. The final catalog includes ~1.7…
The XMM-Newton Wide-Field Survey in the COSMOS Field. V. Angular Clustering of the X-Ray Point Sources
Comastri, Andrea; Zamorani, Giovanni; Fiore, Fabrizio +9 more
We present the first results of the measurements of angular auto-correlation functions (ACFs) of X-ray point sources detected in the XMM-Newton observations of the ~2 deg2 COSMOS field (COSMOS XMM-Newton). Significant positive signals have been detected in the 0.5-2 (SFT) band, in the angle range of 0.5'-24', while the positive signals …
Combinations of processes responsible for Martian impact crater ``layered ejecta structures'' emplacement
Neukum, Gerhard; Ori, Gian Gabriele; Komatsu, Goro +2 more
We utilized images and stereo-derived topographic data acquired by the High Resolution Stereo Camera (HRSC) and Thermal Emission Imaging System (THEMIS) images together with other data in order to study the geology of ``layered ejecta structures'' associated with relatively pristine Martian impact craters. The geomorphology and morphometric proper…
Origin of the early-type R stars: a binary-merger solution to a century-old problem?
Jeffery, C. S.; Izzard, R. G.; Lattanzio, J.
The early-R stars are carbon-rich K-type giants. They are enhanced in 12C, 13C and 14N, have approximately solar oxygen, magnesium isotopes, s-process and iron abundances, have the luminosity of core-helium burning stars, are not rapid rotators, are members of the Galactic thick disk and, most peculiarly of all, ar…
XMM-Newton observations of HESS J1813-178 reveal a composite Supernova remnant
Funk, S.; Reimer, O.; Vink, J. +10 more
Aims:We present X-ray and 12CO(J=1-0) observations of the very-high-energy (VHE) γ-ray source
Methods: High-angular resolution X-ray studies of the VHE γ-ray emission region are performed using 18.6 ks of XMM-Newton data, taken on HESS …
On the stratified dust distribution of the GG Tauri circumbinary ring
Pinte, C.; Ménard, F.; Duchêne, G. +2 more
Aims:Our objective is to study the vertical dust distribution in the circumbinary ring of the binary system
Methods: We present a simultaneous analysis of four scattered light images spanning a range of wave…
Astrometric Orbits for Hipparcos Stochastic Binaries
Makarov, V. V.; Goldin, A.
Taking advantage of an improved genetic optimization algorithm for fitting unconstrained Kepler orbits to the Hipparcos intermediate astrometric data, we obtain additional orbital solutions for 81 Hipparcos stars with previous stochastic (failed) solutions. The sample includes astrophysically interesting objects, including the old disk wide binary…
Stationary parts of an EIT and Moreton wave: a topological model
Aulanier, G.; Hochedez, J. -F.; Delannée, C.
Context: EIT and Moreton waves came into focus in 1997, when a propagating disturbance on a large area of the solar disc was discovered. The process generating the EIT and Moreton waves has been frequently discussed.
Aims: On May 2, 1998, a halo CME was observed related to an EIT wave, a Moreton wave, a X1 flare, radio emission sources, and di…
An accurate determination of the distance to the Pipe nebula
Franco, G. A. P.; Alves, F. O.
Aims:We seek an accurate distance to the Pipe nebula.
Methods: The B-band linear polarimetry collected for stars from the Hipparcos catalogue is used to investigate the dependence of the measured interstellar polarization as a function of the star's trigonometric parallax.
Results: The linear polarization obtained for 82 Hipparcos stars in…
Charged particle periodicities in Saturn's outer magnetosphere
Krupp, N.; Krimigis, S. M.; Mitchell, D. G. +2 more
A Lomb periodogram analysis is applied to charged particle data from the LEMMS/CHEMS instruments on the Cassini spacecraft. The data represent count rates, averaged within 30 min bins, from electrons (28-330 keV) and protons and oxygen ions (2.8-236 keV) during 350 days in 2005 and all 365 days in 2006. Sun effects, spacecraft maneuvers, and measu…