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The dM4.5e star G124-62 and its binary L dwarf companion DENIS-P J1441-0945. Common proper motion, distance, age, and masses
Neuhäuser, R.; Guenther, E.; Seifahrt, A.
We present astrometric and photometric measurements of the field binary L1 dwarf DENIS-P J1441-0945. Analysis of archival HST images and photometric parallax measurements give a distance of 34±7 pc and a proper motion close to that of the nearby high proper motion star G124-62. Comparison of SuperCOSMOS and 2MASS images confirms that these objects…
A stochastic sea: The source of plasma sheet boundary layer ion structures observed by Cluster
Zelenyi, L. M.; El-Alaoui, M.; Walker, R. J. +4 more
On 14 February 2001 the Cluster Ion Spectrometry (CIS) experiment onboard three of the Cluster spacecraft observed velocity-dispersed ion structures (VDIS) as the spacecraft passed from the tail lobes into the plasma sheet boundary layer. These are the first multiple spacecraft observations of the VDIS phenomenon. The Cluster 1 spacecraft (SC1) ob…
Discovery of nitrogen in Saturn's inner magnetosphere
Johnson, R. E.; Sittler, E. C.; Smith, H. T. +6 more
We detected N+ in Saturn's magnetosphere in the range L ~ 3.5 to ~9.5 Saturn Radii (Rs) using data collected by the Cassini Plasma Spectrometer during Saturn Orbit Insertion and the following orbit (Rev A). The presence of N+ in Saturn's magnetosphere has been a source of much debate since Voyager's detection of unresolved ma…
Temporal and spatial evolution of discrete auroral arcs as seen by Cluster
Nilsson, H.; Karlsson, T.; Fazakerley, A. +7 more
Two event studies are presented in this paper where intense convergent electric fields, with mapped intensities up to 1350 mV/m, are measured in the auroral upward current region by the Cluster spacecraft, at altitudes between 3 and 5 Earth radii. Both events are from May 2003, Southern Hemisphere, with equatorward crossings by the Cluster spacecr…
A complete view of the broad-line radio galaxy 4C +74.26 with XMM-Newton
Ballantyne, D. R.
This paper presents a timing study and broad-band spectral analysis of the broad-line radio galaxy 4C +74.26 based on a 35-ks XMM-Newton observation. As found in previous data sets, the source exhibits no evidence for rapid variability, and its 0.2-10 keV light curve is well fitted by a constant. An excellent fit to the pn 0.3-12 keV spectrum was …
Survey of energetic O+ ions near the dayside mid-latitude magnetopause with Cluster
Sauvaud, J. -A.; Balogh, A.; Klecker, B. +7 more
Since December 2000, the Cluster satellites have been conducting detailed measurements of the magnetospheric boundaries and have confirmed the unambiguous presence of ions of terrestrial origin (e.g. O+ in regions adjacent to the dayside, mid-latitude magnetopause. In the present paper, we focus on the statistical properties of the O
A Possible Detection of M31* with Chandra
Williams, Benjamin F.; Kong, Albert K. H.; Barmby, Pauline +5 more
Two independent sets of Chandra and HST images of the nuclear region of M31 allow registration of X-ray and optical images to ~0.1". This registration shows that none of the bright (~1037 ergs s-1) X-ray sources near the nucleus is coincident with the central supermassive black hole, M31*. A 50 ks Chandra HRC image shows 2.5 …
A survey for Fe 6.4 keV emission in young stellar objects in ρ Oph: The strong fluorescence from Elias 29
Tsujimoto, M.; Micela, G.; Favata, F. +2 more
We report the results of a search for 6.4 keV Fe fluorescent emission in Young Stellar Objects (YSOs) with measured accretion luminosities in the ρ Oph cloud, using the existing Chandra and XMM-Newton observations of the region. A total of nine such YSOs have X-ray data with sufficiently high S/N for the 6.4 keV line to be potentially detected if …
Physical parameters of rich LMC clusters from modeling of deep HST colour-magnitude diagrams
Santiago, B. X.; Kerber, L. O.
We present the analysis of deep colour-magnitude diagrams (CMDs) of five rich LMC clusters. The data were obtained with HST/WFPC2 in the F555W (~V) and F814W (~I) filters, reaching V555 ∼ 25. The sample of clusters is composed of NGC 1805 and NGC 1818, the youngest ones (τ < 100 Myr), NGC 1831 and NGC 1868, of intermediate-age ( 400 …
Observational evidence for the presence of PAHs in distant Luminous Infrared Galaxies using ISO and Spitzer
Elbaz, D.; Le Floc'h, E.; Dole, H. +1 more
We present ISOCAM 15 µm and MIPS 24 µm photometry of a sample of 16 distant Luminous Infrared Galaxies (LIRGs) characterized by a median luminosity L_IR ∼ 2 × 1011~L⊙ and redshift z = 0.7 (distributed from z = 0.1 to 1.2). While some sources display 24/15 µm flux ratios also consistent with a featureless con…