Search Publications
A comprehensive study of large-scale structures in the GOODS-SOUTH field up to z ∼ 2.5
Fiore, F.; Castellano, M.; Pentericci, L. +14 more
Aims: The aim of the present paper is to identify and study the properties and galactic content of groups and clusters in the GOODS-South field up to z∼ 2.5, and to analyse the physical properties of galaxies as a continuous function of environmental density up to high redshift.
Methods: We used the deep (z850∼ 26), multi-wavelength…
Speckle Interferometry at Mount Wilson Observatory: Observations Obtained in 2006-2007 and 35 New Orbits
Mason, Brian D.; Hartkopf, William I.
Results are presented for 607 speckle interferometric observations of double stars, as well as 222 measures of single stars or unresolved pairs. All data were obtained in 2006 and 2007 at the Mount Wilson Observatory, using the 2.5 m Hooker telescope. Separations range from 0farcs06 to 6farcs31, with a median of 0farcs34. These three observing run…
A Statistical Study of Hard X-Ray Footpoint Motions in Large Solar Flares
Krucker, Säm; Ip, W. H.; Lin, R. P. +2 more
A statistical analysis of the temporal evolution of hard X-ray (HXR) footpoint motions in 27 M- and X-class solar flares observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager is presented. Extreme UV images from TRACE and SOHO/EIT, Hα images, and magnetograms from SOHO/MDI are used to put the HXR footpoint motions in context of flar…
Long-Term Stability of Nonthermal X-Ray Modulation in the Gamma-Ray Binary LS 5039
Takahashi, Tadayuki; Uchiyama, Yasunobu; Tanaka, Takaaki +1 more
We report on long-term stability of X-ray modulation apparently synchronized with an orbital period of 3.9 days in the γ-ray binary LS 5039. Recent observations with the Suzaku satellite in the year 2007, which continuously covered more than one orbital period, have provided us with detailed characterization of X-ray flux and spectral shape as a f…
Disappearing induced magnetosphere at Venus: Implications for close-in exoplanets
Russell, C. T.; Lammer, H.; Zhang, T. L. +4 more
The solar wind interaction with a planetary atmosphere produces a magnetosphere-like structure near the planet whether or not the planet has an intrinsic global magnetic field. In the case of planets like Venus or Mars, which have no global intrinsic magnetic field but possess a significant atmosphere, a magnetosphere is induced in the highly cond…
Color Distributions, Number, and Mass Densities of Massive Galaxies at 1.5 < z < 3: Comparing Observations with Merger Simulations
van Dokkum, Pieter G.; Franx, Marijn; Labbé, Ivo +9 more
We present a comparison between the observed color distribution, number, and mass density of massive galaxies at 1.5 < z < 3 and a model by Hopkins et al. that relates the quasar and galaxy population on the basis of gas-rich mergers. In order to test the hypothesis that quiescent red galaxies are formed after a gas-rich merger involving qua…
Multiwavelength Observations of 3C 454.3. II. The AGILE 2007 December Campaign
Antonelli, L. A.; Costa, E.; Mereghetti, S. +76 more
We report on the second Astrorivelatore Gamma a Immagini Leggero (AGILE) multiwavelength campaign of the blazar 3C 454.3 during the first half of 2007 December. This campaign involved AGILE, Spitzer, Swift, Suzaku, the Whole Earth Blazar Telescope (WEBT) consortium, the Rapid Eye Mount (REM), and the Multicolor Imaging Telescopes for Survey and Mo…
Fermi Large Area Telescope Detection of Pulsed γ-rays from the Vela-like Pulsars PSR J1048-5832 and PSR J2229+6114
Ozaki, M.; Caraveo, P. A.; Halpern, J. +173 more
We report the detection of γ-ray pulsations (>=0.1 GeV) from PSR J2229+6114 and PSR J1048-5832, the latter having been detected as a low-significance pulsar by EGRET. Data in the γ-ray band were acquired by the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope, while the radio rotational ephemerides used to fold the γ-ray li…
The causality between the rapid rotation of a sunspot and an X3.4 flare
Yan, Xiao-Li; Qu, Zhong-Quan; Xu, Cheng-Lin +2 more
Using multi-wavelength data of Hinode, the rapid rotation of a sunspot in active region NOAA 10930 is studied in detail. We found extraordinary counterclockwise rotation of the sunspot with positive polarity before an X3.4 flare. From a series of vector magnetograms, it is found that magnetic force lines are highly sheared along the neutral line a…
Uranus at equinox: Cloud morphology and dynamics
Sromovsky, L. A.; Fry, P. M.; Showalter, M. R. +5 more
As the 7 December 2007 equinox of Uranus approached, collaboration between ring and atmosphere observers in the summer and fall of 2007 produced a substantial collection of ground-based observations using the 10-m Keck telescope with adaptive optics and space-based observations with the Hubble Space Telescope. Both near-infrared and visible-wavele…