Search Publications
Helium Line Formation and Abundance during a C-Class Flare
Andretta, Vincenzo; Teriaca, Luca; Mauas, Pablo J. D. +1 more
During a coordinated campaign that took place in 2001 May, a C-class flare was observed both with SOHO instruments and with the Dunn Solar Telescope of the National Solar Observatory at Sacramento Peak. In two previous papers we described the observations and discussed some dynamical aspects of the earlier phases of the flare, as well as the heliu…
The Reddest DR3 SDSS/XMM-Newton Quasars
Elvis, M.; Risaliti, G.; Young, M.
We have cross-correlated the SDSS DR3 Schneider et al. (2005) quasar catalog with the XMM-Newton archive. Color and redshift selections (g - r >= 0.5 and 0.9 < z < 2.1) result in a sample of 17 red, moderate-redshift quasars. The redshift selection minimizes possible contamination due to host galaxy emission and Lyα forest absorption. Bot…
The Solar Eruption of 2005 May 13 and Its Effects: Long-Baseline Interplanetary Scintillation Observations of the Earth-Directed Coronal Mass Ejection
Breen, A. R.; Jackson, B. V.; Bisi, M. M. +7 more
Long-baseline observations of interplanetary scintillation (IPS) provide a unique source of information on solar wind speed and meridional direction across the inner regions of the solar system. We report the results of a series of coordinated IPS observations of an Earth-directed CME. A significant development in the interpretation of these data …
The Chandra ACIS Survey of M33 (ChASeM33): Transient X-Ray Sources Discovered in M33
Mazeh, T.; Williams, Benjamin F.; Sasaki, Manami +7 more
The Chandra ACIS Survey of M33 (ChASeM33) has acquired seven fields of ACIS data covering M33 with 200 ks of exposure in each field. A catalog from the first 10 months of data, along with archival Chandra observations dating back to the year 2000, is currently available. We have searched these data for transient sources that are measured to have a…
Synthetic Spectrum Constraints on a Model of the Cataclysmic Variable QU Carinae
Szkody, Paula; Sion, Edward M.; Godon, Patrick +3 more
Neither standard model SEDs nor truncated standard model SEDs fit observed spectra of QU Carinae with acceptable accuracy over the range 900-3000 Å. Nonstandard model SEDs fit the observation set accurately. The nonstandard accretion disk models have a hot region extending from the white dwarf to R = 1.36RWD, a narrow intermediate-tempe…
An Observation of Low-Level Heating in an Erupting Prominence
Landi, E.; Kucera, T. A.
Here we present multiwavelength observations of low-level heating in an erupting prominence observed in the UV and EUV over a wide range of temperatures and wavelengths by the Solar and Heliospheric Observatory (SOHO) Solar Ultraviolet Measurements of Emitted Radiation (SUMER) instrument and the Transition Region and Coronal Explorer (TRACE), and …
Trouble for AGN Feedback? The Puzzle of the Core of the Galaxy Cluster AWM 4
Buote, David A.; Brighenti, Fabrizio; Mathews, William G. +1 more
The core of the relaxed cluster AWM 4 is characterized by a unique combination of properties which defy a popular scenario for AGN heating of cluster cores. A flat inner temperature profile is indicative of a past, major heating episode which completely erased the cool core, as testified by the high central cooling time (gtrsim3 Gyr) and by the hi…
Evidence for Iroshnikov-Kraichnan-Type Turbulence in the Solar Wind Upstream of Interplanetary Traveling Shocks
Wurz, P.; Hilchenbach, M.; Smith, C. W. +3 more
We analyze suprathermal ions and plasma wave spectra upstream of interplanetary shocks driven by coronal mass ejection events. In particular, we analyze the competition between two processes: (1) the upstream wave generation by suprathermal protons accelerated at the shock, and (2) the cascading of wave energy in the inertial range of solar wind t…
A New Orbit Determination for Bright Sungrazing Comet of 1843
Sekanina, Zdenek; Chodas, Paul W.
Given the critical role of the bright sungrazer C/1843 D1, also called the Great March Comet of 1843, in hypotheses of the origin and evolution of the Kreutz system, a new orbital investigation of this comet was desirable. Closely inspecting Kreutz's classical work, we conclude that his result of 512 yr for the orbital period, which has been endle…
INTEGRAL and BeppoSAX Observations of the Transient Atoll Source 4U 1608-522: From Quiescent to Hard Spectral State
Ubertini, P.; Bazzano, A.; Tarana, A.
We report on the spectral evolution of 4U 1608-522 using observations performed as part of the long-term Galactic bulge monitoring program with INTEGRAL. The data set includes the 2005 April outburst. BeppoSAX archival data (two observations, from 1998 and 2000) are also analyzed and compared with the INTEGRAL data. Three different spectral states…