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Detection of Surface Brightness Fluctuations in Elliptical Galaxies Imaged with the Advanced Camera for Surveys: B- and I-Band Measurements
Blakeslee, John P.; Cantiello, Michele; Raimondo, Gabriella +2 more
Taking advantage of the exceptional capabilities of the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST), we derive surface brightness fluctuation (SBF) measurements in the B and I bands from images of six elliptical galaxies with 1500<=cz<=3500. Given the low signal-to-noise ratio (S/N) of the SBF signal in the bl…
Searching High-Redshift Large-Scale Structures: Photometry of Four Fields around Quasar Pairs at z ~ 1
Cypriano, E. S.; West, M.; Santos, W. A. +3 more
We have studied the photometric properties of four fields around the high-redshift quasar pairs QP 1310+0007, QP 1355-0032, QP 0110-0219, and QP 0114-3140 at z~1 with the aim of identifying large-scale structures (galaxy clusters or groups) around them. This sample was observed with the Gemini Multi-Object Spectograph (GMOS) at the Gemini North an…
Synchrotron Radio Emission from a Fast Halo Coronal Mass Ejection
Bastian, T. S.
An interplanetary (IP) type II-like radio burst is analyzed. It occurred on 2003 June 17-18 in association with a fast halo coronal mass ejection (CME), an M6.8 soft-X-ray (SXR) flare, and it produced a solar proton event. Unlike coronal type II bursts and the majority of IP type II radio emissions, the IP type-II-like event associated with the fa…
Probing Unification with Chandra HETGS and XMM-Newton EPIC and RGS Spectroscopy of the Narrow Emission Line Galaxy NGC 2110
Lee, Julia C.; Weaver, Kimberly A.; Marshall, Herman L. +2 more
We present results from Chandra HETGS (250 ks over two epochs) and XMM-Newton EPIC and RGS (60 ks) observations of NGC 2110, which has been historically classified as a narrow emission line galaxy. Our results support the interpretation that the source is a Seyfert 2 viewed through a patchy absorber. The nuclear X-ray spectrum of the source is bes…
Transition Region Emission and Energy Input to Thermal Plasma during the Impulsive Phase of Solar Flares
Raymond, John C.; Ciaravella, A.; Kohl, J. +3 more
The energy released in a solar flare is partitioned between thermal and nonthermal particle energy and lost to thermal conduction and radiation over a broad range of wavelengths. It is difficult to determine the conductive losses and the energy radiated at transition region temperatures during the impulsive phases of flares. We use UVCS measuremen…
Is There Enhanced Depletion of Gas-Phase Nitrogen in Moderately Reddened Lines of Sight?
Snow, Theodore P.; Rachford, Brian L.; Jensen, Adam G.
We report on the abundance of interstellar neutral nitrogen (N I) for 30 sight lines, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Hubble Space Telescope (HST). N I column densities are derived by measuring the equivalent widths of several ultraviolet absorption lines and subsequently fitting those to a curve of growth…
Nondetection of Gravitationally Redshifted Absorption Lines in the X-Ray Burst Spectra of GS 1826-24
Kong, Albert K. H.; Miller, Jon M.; Kuulkers, Erik +6 more
During a 200 ks observation with the XMM-Newton Reflection Grating Spectrometer, we detected 16 type I X-ray bursts from GS 1826-24. We combined the burst spectra in an attempt to measure the gravitational redshifts from the surface of the neutron star. We divided the composite GS 1826-24 burst spectrum into three groups based on the blackbody tem…
The Metallicity of Intergalactic Gas in Cosmic Voids
Shull, J. Michael; Danforth, Charles W.; Stocke, John T. +2 more
We have used the Hubble STIS and FUSE archives of ultraviolet spectra of bright AGNs to identify intergalactic Lyα absorbers in nearby (z<=0.1) voids. From a parent sample of 651 Lyα absorbers, we identified 61 ``void absorbers'' located >1.4 h-170 Mpc from the nearest L* or brighter galaxy. Searching for met…
Hubble Ultra Deep Field-JD2: Mid-Infrared Evidence for a z ~ 2 Luminous Infrared Galaxy
Papovich, Casey; Dickinson, Mark E.; Teplitz, Harry I. +5 more
The Hubble Ultra Deep Field source JD2 presented in Mobasher et al. is an unusual galaxy that is very faint at all wavelengths shortward of 1.1 µm. Photometric redshift fits to data between 0.4 and 8 µm yield a significant probability that it is an extremely massive galaxy at z~6.5. In this paper we present new photometry at 16 and 22 …
IGR J08408-4503: A New Recurrent Supergiant Fast X-Ray Transient
Götz, D.; von Kienlin, A.; De Luca, A. +3 more
The supergiant fast X-ray transient IGR J08408-4503 was discovered by INTEGRAL on 2006 May 15 during a bright flare. The source shows sporadic recurrent short bright flares, reaching a peak luminosity of 1036 ergs s-1 within less than 1 hr. The companion star is HD 74194, an Ob5Ib(f) supergiant star located at 3 kpc in the Ve…