Search Publications
Herschel/HIFI observations of high-J CO transitions in the protoplanetary nebula CRL 618
Waters, L. B. F. M.; Menten, K. M.; Olofsson, H. +25 more
Aims: We aim to study the physical conditions, particularly the excitation state, of the intermediate-temperature gas components in the protoplanetary nebula CRL 618. These components are particularly important for understanding the evolution of the nebula.
Methods: We performed Herschel/HIFI observations of several CO lines in the far-i…
A Mature Dusty Star-forming Galaxy Hosting GRB 080607 at z = 3.036
Pettini, Max; Cenko, S. Bradley; Wilson, Christine D. +7 more
We report the discovery of the host galaxy of Swift dark burst GRB 080607 at z GRB = 3.036. GRB 080607 is a unique case of a highly extinguished (AV ≈ 3 mag) afterglow that was yet sufficiently bright for high-quality absorption-line spectroscopy. The host galaxy is clearly resolved in deep Hubble Space Telescope (HST) WF3/IR…
Evidence for a truncated accretion disc in the low-luminosity Seyfert galaxy, NGC 7213?
Turner, T. J.; Porquet, D.; Reeves, J. N. +4 more
We present the broad-band 0.6-150keV Suzaku and Swift BAT spectra of the low-luminosity Seyfert galaxy, NGC 7213. The time-averaged continuum emission is well fitted by a single power law of photon index Γ = 1.75, and from consideration of the Fermi flux limit we constrain the high-energy cut-off to be 350keV < Ecut < 25MeV. Line …
Parsec-scale Bipolar X-ray Shocks Produced by Powerful Jets from the Neutron Star Circinus X-1
Brandt, W. N.; Wijnands, R.; Nowak, M. A. +10 more
We report the discovery of multi-scale X-ray jets from the accreting neutron star X-ray binary, Circinus X-1. The bipolar outflows show wide opening angles and are spatially coincident with the radio jets seen in new high-resolution radio images of the region. The morphology of the emission regions suggests that the jets from Circinus X-1 are runn…
Changes in Jupiter’s Great Red Spot (1979-2006) and Oval BA (2000-2006)
Marcus, Philip S.; Shetty, Sushil
We analyze velocity fields of the Great Red Spot (GRS) and Oval BA that were previously extracted from Cassini, Galileo, and Hubble Space Telescope images (Asay-Davis, X.S., Marcus, P.S., Wong, M., de Pater, I. [2009]. Icarus 203, 164-188). Our analyses use reduced-parameter models in which the GRS, Oval BA, and surrounding zonal (east-west) flows…
Evidence for multiple ice deposits on the northeastern rim of Hellas basin, Mars
Neukum, G.; Ivanov, M. A.; Korteniemi, J. +3 more
Four prominent fluvial systems, Dao, Niger, and Harmakhis Valles, and a system of smaller channels between Niger and Harmakhis Valles characterize a wide topographic trough that connects Hesperia Planum and Hellas Planitia (Hesperia-Hellas trough, HHT). The source depressions of the canyons of Dao and Harmakhis Valles are at the lowermost level (a…
Hard X-ray Emission Associated with White Dwarfs. III.
Chu, You-Hua; Bilíková, Jana; Gruendl, Robert A. +1 more
Hard X-ray emission associated with white dwarfs (WDs) can be used to diagnose the presence of late-type binary companions, mass accretion from companions, or physical processes with unknown origins. Since our previous systematic searches for hard X-ray emission associated with WDs, the Galactic WD catalog has been augmented by >10,000 new WDs …
Hubble Space Telescope Spectrophotometry and Models for Solar Analogs
Bohlin, R. C.
Absolute flux distributions for seven solar analog stars are measured from 0.3 to 2.5 µm by Hubble Space Telescope (HST) spectrophotometry. In order to predict the longer wavelength mid-IR fluxes that are required for James Webb Space Telescope calibration, the HST spectral energy distributions are fit with Castelli & Kurucz model atmosp…
Modeling the 2003 Halloween events with EMMREM: Energetic particles, radial gradients, and coupling to MHD
Schwadron, N. A.; Desai, M. I.; Dayeh, M. A. +3 more
The Earth-Moon-Mars Radiation Environment Module (EMMREM) is a comprehensive numerical framework for characterizing and predicting the radiation environment of the inner heliosphere. We present a study of the October/November 2003 Halloween solar energetic particle events with an energetic particle acceleration and propagation model that is part o…
Magnetic Field Topology and the Thermal Structure of the Corona over Solar Active Regions
DeRosa, Marc L.; Title, Alan M.; Schrijver, Carolus J.
Solar extreme ultraviolet (EUV) images of quiescent active-region coronae are characterized by ensembles of bright 1-2 MK loops that fan out from select locations. We investigate the conditions associated with the formation of these persistent, relatively cool, loop fans within and surrounding the otherwise 3-5 MK coronal environment by combining …