Search Publications
Measurements of Cyclotron Features and Pulse Periods in the High-mass X-Ray Binaries 4U 1538-522 and 4U 1907+09 with the International Gamma-Ray Astrophysics Laboratory
Hemphill, Paul B.; Rothschild, Richard E.; Fürst, Felix +4 more
We present a spectral and timing analysis of International Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of two high-mass X-ray binaries, 4U 1538-522 and 4U 1907+09. Our timing measurements for 4U 1538-522 find the pulse period to have exhibited a spin-up trend until approximately 2009, after which there is evidence for a torque revers…
One Moon, many measurements 1: Radiance values
Yokota, Y.; Mall, U.; Besse, S. +10 more
Several modern optical instruments orbited the Moon during 2008 and 2009 onboard the SELENE and Chandrayaan-1 spacecraft and provided a welcomed feast of spectroscopic data to be used for scientific analyses. The different spatial and spectral resolutions of these sensors along with diverse illumination geometry during data acquisition make each s…
Suzaku View of the Swift/BAT Active Galactic Nuclei. V. Torus Structure of Two Luminous Radio-loud Active Galactic Nuclei (3C 206 and PKS 0707-35)
Ueda, Yoshihiro; Terashima, Yuichi; Tombesi, Francesco +2 more
We present the results from broadband X-ray spectral analysis of 3C 206 and PKS 0707-35 with Suzaku and Swift/BAT, two of the most luminous unobscured and obscured radio-loud active galactic nuclei (AGNs) with hard X-ray luminosities of 1045.5 erg s-1 and 1044.9 erg s-1 (14-195 keV), respectively. Based …
Analysis of Saturn’s thermal emission at 2.2-cm wavelength: Spatial distribution of ammonia vapor
Janssen, M. A.; Allison, M.; Ingersoll, A. P. +3 more
This work focuses on determining the latitudinal structure of ammonia vapor in Saturn’s cloud layer near 1.5 bars using the brightness temperature maps derived from the Cassini RADAR (Elachi et al. [2004], Space Sci. Rev. 115, 71-110) instrument, which works in a passive mode to measure thermal emission from Saturn at 2.2-cm wavelength. We perform…
A comprehensive near- and far-ultraviolet spectroscopic study of the hot DA white dwarf G191-B2B
Barstow, M. A.; Holberg, J. B.; Preval, S. P. +1 more
We present a detailed spectroscopic analysis of the hot DA white dwarf G191-B2B, using the best signal-to-noise ratio, high-resolution near- and far-UV spectrum obtained to date. This is constructed from co-added Hubble Space Telescope (HST) Space Telescope Imaging Spectrometer (STIS) E140H, E230H and FUSE observations, covering the spectral range…
Rotating Motions and Modeling of the Erupting Solar Polar-crown Prominence on 2010 December 6
van Ballegooijen, Adriaan; Su, Yingna
A large polar-crown prominence composed of different segments spanning nearly the entire solar disk erupted on 2010 December 6. Prior to the eruption, the filament in the active region part split into two layers: a lower layer and an elevated layer. The eruption occurs in several episodes. Around 14:12 UT, the lower layer of the active region fila…
Gas-phase Sequestration of Noble Gases in the Protosolar Nebula: Possible Consequences on the Outer Solar System Composition
Mousis, O.; Ali-Dib, M.; Pauzat, F. +2 more
We address the problem of the sequestration of Ar, Kr, and Xe by H_3^+ in the gas-phase conditions encountered during the cooling of protoplanetary disks when H_3^+ is competing with other species present in the same environment. Using high-level ab initio simulations, we try to quantify other sequestration possibilities involving He, H_5^+, H
Determination of the far-infrared dust opacity in a prestellar core
Juvela, M.; White, G. J.; André, Ph. +5 more
Context. Mass estimates of interstellar clouds from far-infrared and submillimetre mappings depend on the assumed dust absorption cross-section for radiation at those wavelengths.
Aims: The aim is to determine the far-IR dust absorption cross-section in a starless, dense core located in Corona Australis. The value is needed for determining of…
Study of a Prominence Eruption using PROBA2/SWAP and STEREO/EUVI Data
Mierla, M.; Zhukov, A. N.; Berghmans, D. +6 more
Observations of the early rise and propagation phases of solar eruptive prominences can provide clues about the forces acting on them through the behavior of their acceleration with height. We have analyzed such an event, observed on 13 April 2010 by SWAP on PROBA2 and EUVI on STEREO. A feature at the top of the erupting prominence was identified …
The role of compressional Pc5 pulsations in modulating precipitation of energetic electrons
Ohtani, S.; Motoba, T.; Takahashi, K. +2 more
Pc5 (1.67-6.67 mHz) magnetic pulsations and the modulation of energetic electron precipitation are often observed simultaneously in the morning auroral-latitude data. Here we have investigated a conjunction event of Cluster spacecraft and Canadian auroral-latitude ground stations to identify the role of compressional Pc5 pulsations in modulating p…