Search Publications

Open magnetic flux tubes in the corona and the transport of solar energetic particles
DOI: 10.1051/0004-6361:20079228 Bibcode: 2008A&A...486..589K

Krucker, S.; Klein, K. -L.; Lointier, G. +1 more

We investigate how magnetic fields guide energetic particles through the corona into interplanetary space and eventually to a spacecraft near the Earth. A set of seven simple particle events is studied, where energetic electrons (30-500 keV; Wind spacecraft) or protons (5-55 MeV; SoHO) were released together with low-energy electron beams producin…

2008 Astronomy and Astrophysics
SOHO 73
A Molecular Einstein Ring at z = 4.12: Imaging the Dynamics of a Quasar Host Galaxy Through a Cosmic Lens
DOI: 10.1086/591434 Bibcode: 2008ApJ...686..851R

Lewis, Geraint F.; Walter, Fabian; Carilli, Christopher L. +4 more

We present high-resolution (0.3'') Very Large Array imaging of the molecular gas in the host galaxy of the high-redshift quasar PSS J2322+1944 (z = 4.12). These observations confirm that the molecular gas (CO) in the host galaxy of this quasar is lensed into a full Einstein ring and reveal the internal gas dynamics in this system. The ring has a d…

2008 The Astrophysical Journal
eHST 73
The dark matter environment of the Abell 901/902 supercluster: a weak lensing analysis of the HST STAGES survey
DOI: 10.1111/j.1365-2966.2008.12919.x Bibcode: 2008MNRAS.385.1431H

Bell, Eric F.; Wisotzki, Lutz; Wolf, Christian +21 more

We present a high-resolution dark matter reconstruction of the z = 0.165 Abell 901/902 supercluster from a weak lensing analysis of the Hubble Space Telescope STAGES survey. We detect the four main structures of the supercluster at high significance, resolving substructure within and between the clusters. We find that the distribution of dark matt…

2008 Monthly Notices of the Royal Astronomical Society
eHST 72
V838 Monocerotis: A Geometric Distance from Hubble Space Telescope Polarimetric Imaging of its Light Echo
DOI: 10.1088/0004-6256/135/2/605 Bibcode: 2008AJ....135..605S

White, Richard L.; Sparks, William B.; Bond, Howard E. +10 more

Following the outburst of the unusual variable star V838 Monocerotis in 2002, a spectacular light echo appeared. A light echo provides the possibility of direct geometric distance determination, because it should contain a ring of highly linearly polarized light at a linear radius of ct, where t is the time since the outburst. We present imaging p…

2008 The Astronomical Journal
eHST 72
HDO and H2O vertical distributions and isotopic ratio in the Venus mesosphere by Solar Occultation at Infrared spectrometer on board Venus Express
DOI: 10.1029/2008JE003146 Bibcode: 2008JGRE..113.0B22F

Montmessin, F.; Fedorova, A.; Korablev, O. +8 more

Vertical distributions of the molecular density and mixing ratios of H2O and HDO in the Venus mesosphere have been obtained using Solar Occultation at Infrared (SOIR), a high-resolution (with λ/δλ ~ 20,000) echelle spectrometer on Venus Express. The atmosphere is sounded in solar occultation in the range of altitudes from 65 to 130 km. …

2008 Journal of Geophysical Research (Planets)
VenusExpress 72
Spatial Relationship between Solar Flares and Coronal Mass Ejections
DOI: 10.1086/524927 Bibcode: 2008ApJ...673.1174Y

Howard, R. A.; Gopalswamy, N.; Michalek, G. +2 more

We report on the spatial relationship between solar flares and coronal mass ejections (CMEs) observed during 1996-2005 inclusive. We identified 496 flare-CME pairs considering limb flares (distance from central meridian >=45°) with soft X-ray flare size >=C3 level. The CMEs were detected by the Large Angle and Spectrometric Coronagraph (LASC…

2008 The Astrophysical Journal
SOHO 72
The drying of Titan's dunes: Titan's methane hydrology and its impact on atmospheric circulation
DOI: 10.1029/2007JE003017 Bibcode: 2008JGRE..113.8015M

Mitchell, Jonathan L.

We explore the effect of a finite reservoir of methane on Titan's atmospheric circulation, precipitation patterns, and surface methane content. We develop a soil model that accounts for the methane cycle in the surface-atmosphere system, and we implement this surface model in a two-dimensional model of the Titan's atmosphere. Seasonal oscillations…

2008 Journal of Geophysical Research (Planets)
Huygens 72
Hubble Space Telescope Snapshot Survey of Post-AGB Objects
DOI: 10.1086/529115 Bibcode: 2008ApJ...677..382S

Szczerba, R.; Meixner, M.; Ueta, T. +3 more

The results of a Hubble Space Telescope (HST) snapshot survey of post-AGB objects are shown. The aim of the survey is to complement existing HST images of protoplanetary nebulae and to connect various types of nebulosities with the physical and chemical properties of their central stars. Nebulosities are detected in 15 of 33 sources. Images and ph…

2008 The Astrophysical Journal
eHST 71
Thermal X-Rays from Millisecond Pulsars: Constraining the Fundamental Properties of Neutron Stars
DOI: 10.1086/592341 Bibcode: 2008ApJ...689..407B

Bogdanov, Slavko; Grindlay, Jonathan E.; Rybicki, George B.

We model the X-ray properties of millisecond pulsars (MSPs) by considering hot-spot emission from a weakly magnetized neutron star (NS) covered by a hydrogen atmosphere. We investigate the limitations of using the thermal X-ray pulse profiles of MSPs to constrain the mass-to-radius (M/R) ratio of the NS. The accuracy is strongly dependent on the v…

2008 The Astrophysical Journal
XMM-Newton 71
Relationship between Rotating Sunspots and Flares
DOI: 10.1007/s11207-007-9089-0 Bibcode: 2008SoPh..247...39Z

Zhang, Hongqi; Liu, Jihong; Zhang, Yin

Active Region (AR) NOAA 10486 was a super AR in the declining phase of solar cycle 23. Dominated by the rapidly rotating positive polarity of an extensive δ sunspot, it produced several powerful flare-CMEs. We study the evolution and properties of the rotational motion of the major poles of positive polarities and estimate the accumulated helicity…

2008 Solar Physics
SOHO 71