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Searching for X-ray luminous "normal" galaxies in 2dFGRS
Georgakakis, A.; Georgantopoulos, I.; Tzanavaris, P.
Aims.We cross-correlated the Chandra XASSIST and XMM-Newton Serendipitous Source Catalogues with the 2 degree Field Galaxy Redshift Survey (2dFGRS) database. Our aim was to identify the most X-ray luminous (LX > 1042 erg s-1) examples of galaxies in the local Universe whose X-ray emission is dominated by stellar…
Solar wind speed within 20 RS of the Sun estimated from limb coronal mass ejections
Gopalswamy, Nat; Yashiro, Seiji; Nakagawa, Tomoko
An estimation of the solar wind speed in the vicinity of the Sun is carried out using the initial speed and acceleration of coronal mass ejections (CMEs) that appeared close to the solar limb. A linear relationship was found between the initial acceleration and the speed of the limb CMEs. It appears that a dragging force is acting on the CMEs, dep…
Reconnection and energetic particles at the edge of the exterior cusp
Asikainen, T.; Mursula, K.
In this paper we study flux transfer events (FTE) observed at the post-noon edge of the exterior cusp region by Cluster satellites. During the outbound dayside orbit on 2 February 2003, intense bursts of energetic particles were observed in close conjuction with magnetic field FTE signatures by the RAPID instrument onboard the Cluster 4. The pitch…
Distributions of suprathermal ions near hot flow anomalies observed by RAPID aboard Cluster
Dandouras, I.; Facskó, G.; Daly, P. +4 more
A series of events having signatures of hot flow anomalies (HFA) observed by the magnetic field, plasma, and energetic particle instruments aboard the Cluster spacecraft upstream of the Earth's bow shock in February-April 2003 are investigated. During this period, the separation of the four satellites (up to about 10,000 km) allowed determining th…
The Astrometric-Spectroscopic Binary System HIP 50796: An Overmassive Companion
Torres, Guillermo
We report spectroscopic observations of the star HIP 50796, previously considered (but later rejected) as a candidate member of the TW Hya association. Our measurements reveal it to be a single-lined binary with an orbital period of 570 days and an eccentricity of e=0.61. The astrometric signature of this orbit was previously detected by Hipparcos…
Star formation in the Cepheus Flare region: implications from morphology and infrared properties of optically selected clouds
Krause, O.; Kun, M.; Stickel, M. +2 more
Aims.A complex study of visual and infrared properties of ISM and an examination of cloud morphology was carried out using USNO, 2MASS, DIRBE, IRAS, and ISO data of an extended region in Cepheus to explore the conditions of cloud and star formation.
Methods: .We mapped the distribution of visual extinction in a 256 square degree area of Cepheu…
Resolving the Dusty Circumstellar Structure of the Enigmatic Symbiotic Star CH Cygni with the MMT Adaptive Optics System
Bieging, John H.; Marengo, Massimo; Hoffmann, William F. +6 more
We imaged the symbiotic star CH Cyg and two PSF calibration stars using the unique 6.5 m MMT deformable secondary adaptive optics system. Our high-resolution (FWHM = 0.3"), very high Strehl (98%+/-2%), mid-infrared (9.8 and 11.7 µm) images of CH Cyg allow us to probe finer length scales than ever before for this object. CH Cyg is significant…
Surface photometry and structure of high redshift disk galaxies in the HDF-S NICMOS field
Tamm, A.; Tenjes, P.
Aims.We report on a photometric study of a sample of 22 disk galaxies in the Hubble Deep Field South NICMOS parallel field. The redshift range of the galaxies is z=0.5{-}2.6.Methods.We use deep NICMOS J and H band and STIS open mode images, taken as part of the HDF-S project, to construct rest-frame B-profiles and (U-V) color profiles of the galax…
The First Direct Spectroscopic Detection of a White Dwarf Primary in an AM CVn System
Szkody, Paula; Howell, Steve B.; Sion, Edward M. +2 more
We report the results of a synthetic spectral analysis of HST STIS spectra of the AM CVn-type cataclysmic variable CP Eri obtained when the system was in quiescence. The FUV spectrum is best fitted by a helium-dominated, hybrid composition (DBAZ) white dwarf with Teff~17,000+/-1000 K, logg~8, He/H abundance ratio by number ~1000, metall…
High redshift Lyα halos
De Breuck, C.; van Breugel, W.; Croft, S. +5 more
We review current evidence for the existence of large emission-line halos around high redshift radio galaxies. Detailed narrow-band imaging and spectroscopic studies of these systems may help us understand the early stages of massive forming galaxies and AGN feedback.