Search Publications
Modeling the distribution of H2O and HDO in the upper atmosphere of Venus
Liang, Mao-Chang; Yung, Yuk L.
The chemical and dynamical processes in the upper atmosphere of Venus are poorly known. Recently obtained vertical profiles of trace species from the Venus Express mission, such as HCl, H2O, and HDO, provide new information to constrain these processes. Here, we simulate these profiles, using the model we have developed and described in…
Discovery of a large and bright bow shock nebula associated with low-mass X-ray binary SAX J1712.6-3739
Read, A. M.; Degenaar, N.; Wijnands, R. +6 more
In a multiwavelength programme dedicated to identifying optical counterparts of faint persistent X-ray sources in the Galactic bulge, we find an accurate X-ray position of SAX J1712.6-3739 through Chandra observations, and discover its faint optical counterpart using our data from EFOSC2 on the ESO 3.6-m telescope. We find this source to be a high…
Suzaku and XMM-Newton Observations of Diffuse X-Ray Emission from the Eastern Tip Region of the Carina Nebula
Hamaguchi, Kenji; Corcoran, Michael F.; Petre, Robert +3 more
The eastern tip region of the Carina Nebula was observed with the Suzaku XIS for 77ks to conduct a high-precision spectral study of extended X-ray emission. XMM-Newton EPIC data of this region were also utilized to detect point sources. The XIS detected strong extended X-ray emission from the entire field-of-view with a 0.2--5keV flux of 0.7--4 × …
Spatial Distributions of Absorption, Local Suppression, and Emissivity Reduction of Solar Acoustic Waves in Magnetic Regions
Zhao, Hui; Liang, Zhi-Chao; Chou, Dean-Yi +2 more
Observed acoustic power in magnetic regions is lower than the quiet Sun because of absorption, emissivity reduction, and local suppression of solar acoustic waves in magnetic regions. In the previous studies, we have developed a method to measure the coefficients of absorption, emissivity reduction, and local suppression of sunspots. In this study…
How the Solar Wind Ties to its Photospheric Origins
McIntosh, Scott W.; Leamon, Robert J.
We present a new method of visualizing the solar photospheric magnetic field based on the "Magnetic Range of Influence" (MRoI). The MRoI is a simple realization of the magnetic environment in the photosphere, reflecting the distance required to balance the integrated magnetic field contained in any magnetogram pixel. It provides a new perspective …
Coronal current sheet signatures during the 17 May 2002 CME-flare
Landini, F.; Poletto, G.; Aurass, H.
Context: The relation between current sheets (CSs) associated with flares, revealed by characteristic radio signatures, and current sheets associated with coronal mass ejections (CMEs), detected in coronal ultraviolet (UV) and white light data, has not been analyzed, yet.
Aims: We aim at establishing the relationship between CSs associated wit…
Broad-band X-ray spectral evolution of GX 339-4 during a state transition
Gehrels, N.; Homan, J.; van der Klis, M. +8 more
We report on X-ray and soft γ-ray observations of the black hole candidate GX 339-4 during its 2007 outburst, performed with the RXTE and INTEGRAL satellites. The hardness-intensity diagram of all RXTE/PCA data combined shows a q-shaped track similar to that observed in previous outbursts. The evolution in the diagram suggested that a transition f…
Hubble Space Telescope NICMOS Polarization Observations of Three Edge-on Massive Young Stellar Objects
Hines, Dean C.; Colgan, Sean W. J.; Burton, Michael G. +4 more
Massive young stellar objects (YSOs), like low-mass YSOs, appear to be surrounded by optically thick envelopes and/or disks and have regions, often bipolar, that are seen in polarized scattered light at near-infrared wavelengths. We are using the 0farcs2 spatial resolution of the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on Hubbl…
The Variable Star Population of the Globular Cluster B514 in the Andromeda Galaxy
Kinemuchi, Karen; Marconi, Marcella; Pritzl, Barton J. +8 more
A rich harvest of RR Lyrae stars has been identified for the first time in B514, a metal-poor ([Fe/H] ~- 1.95 ± 0.10 dex) globular cluster (GC) of the Andromeda galaxy (M31), based on Hubble Space Telescope Wide Field Planetary Camera 2 and Advanced Camera for Surveys time-series observations. We have detected and derived periods for 89 RR Lyrae s…
Photometric and spectroscopic investigation of 2867 Steins, target of the Rosetta mission. Ground-based results prior to the Rosetta fly-by
Barucci, M. A.; Fornasier, S.; Dotto, E. +8 more
Context: Rosetta is the cornerstone mission of ESA devoted to the study of minor bodies of the Solar System. During its journey to the comet 67P Churyumov-Gerasimenko, the main target, Rosetta also investigates two main belt asteroids, 2867 Steins (fly-by in September 2008) and 21 Lutetia (fly-by in July 2010).
Aims: In Spring 2008, we perform…