Search Publications
O+ ion flow below the magnetic barrier at Venus post terminator
Coates, A. J.; Fedorov, A.; Barabash, S. +5 more
Venus forms an obstacle in the streaming solar wind; inside the obstacle boundary (that is below the magnetic barrier) the ions of planetary origin dominate the plasma. The objective of this study is to investigate the properties of the O+ ions inside the obstacle boundary of Venus in the wake; we are especially interested in the charac…
Automated star-galaxy segregation using spectral and integrated band data for TAUVEX/ASTROSAT satellite data pipeline
Singh, Harinder P.; Gupta, Ranjan; Bora, Archana +1 more
We employ an Artificial Neural Network (ANN) based technique to develop a pipeline for automated segregation of stars from the galaxies to be observed by Tel-Aviv University Ultra-Violet Experiment (TAUVEX). We use synthetic spectra of stars from UVBLUE library and selected International Ultraviolet Explorer (IUE) low-resolution spectra for galaxi…
Dynamics of Lyman Break Galaxies and Their Host Halos
Koo, David C.; Lowenthal, James D.; Simard, Luc +1 more
We present deep two-dimensional spectra of 22 candidate and confirmed Lyman break galaxies (LBGs) at redshifts 2 < z < 4 in the Hubble Deep Field (HDF) obtained at the Keck II telescope. The targets were preferentially selected with spatial extent and/or multiple knot morphologies, and we used slitmasks and individual slits tilted to optimiz…
Near-Ultraviolet Sources in the Hubble Ultra Deep Field: The Catalog
Gardner, Jonathan P.; Teplitz, Harry I.; Siana, Brian +3 more
The catalog from the first high-resolution U-band image of the Hubble Ultra Deep Field, taken with Hubble's Wide-Field Planetary Camera 2 through the F300W filter, is presented. We detect 96 U-band objects and compare and combine this catalog with a Great Observatories Origins Deep Survey B-selected catalog that provides B, V, i, and z photometry,…
Outflowing protons and heavy ions as a source for the sub-keV ring current
Lundin, R.; Yamauchi, M.; Dandouras, I. +11 more
Data from the Cluster CIS instrument have been used for studying proton and heavy ion (O+ and He+) characteristics of the sub-keV ring current. Thirteen events with dispersed heavy ions (O+ and He+) were identified out of two years (2001 and 2002) of Cluster data. All events took place during rather geom…
Multispacecraft observations of a prominence eruption
Andretta, V.; Del Zanna, G.; Bemporad, A. +2 more
On 9 May 2007 a prominence eruption occurred at the West limb. Remarkably, the event was observed by the STEREO/EUVI telescopes and by the HINODE/EIS and SOHO/UVCS spectrometers. We present results from all these instruments. High-cadence (~37 s) data from STEREO/EUVI A and B in the He II λ304 line were used to study the 3-D shape and expansion of…
A serendipitous XMM-Newton observation of MACHO 104.20906.960: A dwarf nova candidate with a 2 h period
Guainazzi, M.; Nucita, A. A.; Carpano, S. +3 more
The binaries known as cataclysmic variables are particular binary systems in which the primary star (a white dwarf) accretes material from a secondary via Roche-lobe mechanism. Usually, these objects have orbital period of a few hours so that a detailed temporal analysis can be performed. Here, we present Chandra and XMM-Newton observations of a d…
Coronal Radiation Belts
Hudson, H. S.; MacKinnon, A. L.; De Rosa, M. L. +1 more
The magnetic field of the solar corona has a large-scale dipole character, which maps into the bipolar field in the solar wind. Using standard representations of the coronal field, we show that high-energy ions can be trapped stably in these large-scale closed fields. The drift shells that describe the conservation of the third adiabatic invariant…
Observations and modeling of particle dispersion signatures at a hot flow anomaly
Dandouras, I.; Lucek, E. A.; Tjulin, A.
We analyze a hot flow anomaly (HFA) event that the Cluster spacecraft encountered on 22 April 2008. HFAs are regions of hot, highly deflected ion flow near planetary bow shocks that are created from interactions between tangential discontinuities in the solar wind and the bow shock. This HFA event is studied in detail because it is flanked by supr…
A Chandra X-ray Observation of L1251B
Simon, Theodore
I report the results of a 60 ks X-ray observation of the L1251 dark cloud in Cepheus, which was acquired with the ACIS-I camera on board the Chandra X-Ray Observatory. Forty-three compact X-ray sources were detected. The field of view was centered on the position of IRAS 22376+7455, an embedded Class 0/I protostar that is closely associated with t…