Search Publications
Measurements of Flux Cancellation During Filament Formation
Wood, Paul; Martens, Piet
We study the process of flux cancellation and filament formation in a nest of three decaying active regions, using data from SOHO MDI and EIT, and Hα images from Meudon and Big Bear. We find that there are no apparent EUV loops connecting the two poles of a cancelling feature prior to and during cancellation, suggesting an absence of coronal magne…
The INTEGRAL Mass Model - TIMM
Hill, A. B.; Bird, A. J.; Dean, A. J. +8 more
The INTEGRAL Mass Model (TIMM) was started in 1995 and aimed to create a detailed geometrical model of the whole INTEGRAL satellite on computer. In parallel, a comprehensive Monte Carlo simulation code (called GGOD) has been developed. The mass model and the Monte Carlo code together enable the in-flight operation of INTEGRAL to be simulated at th…
Imaging and Demography of the Host Galaxies of High-Redshift Type Ia Supernovae
Filippenko, Alexei V.; Williams, Benjamin F.; Garnavich, Peter +24 more
We present the results of a study of the host galaxies of high-redshift Type Ia supernovae (SNe Ia). We provide a catalog of 18 hosts of SNe Ia observed with the Hubble Space Telescope (HST) by the High-z Supernova Search Team, including images, scale lengths, measurements of integrated (Hubble-equivalent) BVRIZ photometry in bands where the galax…
Serendipitous active galactic nuclei in the XMM-Newton fields of Markarian 205 and QSO 0130-403
O'Brien, P. T.; Reeves, J. N.; Page, K. L. +2 more
The X-ray spectra of serendipitously observed active galactic nuclei (AGN) in the XMM-Newton fields of Mrk 205 and QSO 0130-403 are analysed. The sample consists of 23 objects, none of which is detected at radio frequencies, with a median X-ray luminosity of ~4 × 1044 erg s-1 and redshifts ranging from ~0.1 to just over 3. Th…
Photoionized O VI absorbers toward the bright QSO HE 0515-4414
Reimers, D.; Baade, R.; Levshakov, S. A. +1 more
We report on detailed Monte Carlo inversion analysis of five O Vi systems from the spectrum of the bright quasar HE 0515-4414 (zem = 1.71). The associated system at zabs = 1.697 with the neutral hydrogen column density N(H I) = 4.4*E13 cm-2, shows pronounced absorption from highly ionized transitions of …
Near-Infrared Adaptive Optics Imaging of the Embedded Cluster NGC 2024
Beck, Tracy L.; Close, L. M.; Simon, M.
We present the results of a high-resolution near-infrared adaptive optics survey of the young obscured star-forming region NGC 2024. Out of the total 73 stars detected in the adaptive optics survey of the cluster, we find three binaries and one triple. The resulting companion star fraction, 7%+/-3% in the separation range of 0.35"-2.3" (145-950 AU…
Solar Wind Effects on the Transport of 3-10 MeV Cosmic-Ray Electrons from Solar Minimum to Solar Maximum
Fichtner, H.; Ferreira, S. E. S.; Potgieter, M. S. +2 more
We investigate the effects on the transport of a few MeV (~7 MeV) Jovian and Galactic electrons for different solar wind speed scenarios applicable to different heliospheric conditions. A three-dimensional, steady state model is used based on numerically solving Parker's transport equation, including the Jovian electron source, to compare model co…
Origins of the Highly Ionized Gas along the Line of Sight toward HD 116852
Richter, Philipp; Sembach, Kenneth R.; Savage, Blair D. +5 more
We present Hubble Space Telescope Imaging Spectrograph (HST/STIS) and Far Ultraviolet Spectroscopic Explorer (FUSE) observations of high ion interstellar ultraviolet absorption along the sight line to HD 116852. At a distance of 4.8 kpc, HD 116852 is an O9 III star lying in the low Galactic halo, -1.3 kpc from the plane of the Galaxy in the direct…
Density and Temperature Measurements in a Solar Active Region
Winebarger, Amy R.; Warren, Harry P.
We present electron density and temperature measurements from an active region observed above the limb with the Solar Ultraviolet Measurements of Emitted Radiation spectrometer on the Solar and Heliospheric Observatory. Density-sensitive line ratios from Si VIII and S X indicate densities greater than 108 cm-3 as high as 200"…
Dust in Hot Gas: Far-Infrared Emission from Three Local Elliptical Galaxies
Brighenti, Fabrizio; Mathews, William G.; Bregman, Jesse D. +1 more
We present far-IR Infrared Space Observatory observations of three early-type galaxies in the Virgo Cluster. The data were recorded using the ISOPHOT instrument in both the P32 oversampled maps and the P39/37 sparse maps. The maps reach the limiting sensitivity of the ISOPHOT instrument at 60, 90, and 180 µm. Two of the most prominent ellipt…