Search Publications

Dynamics, evolution, and structure of Uranus' brightest cloud feature
DOI: 10.1016/j.icarus.2007.05.015 Bibcode: 2007Icar..192..558S

Sromovsky, L. A.; Fry, P. M.; Showalter, M. R. +3 more

The brightest cloud feature ever observed on Uranus at near-infrared wavelengths was detected on 14 and 15 August 2005, in images obtained with the NIRC2 instrument and adaptive optics (AO) at the 10-m Keck II telescope. The feature has been tracked forward and backward in time, and appears to have existed almost certainly from 5 November 2004 (po…

2007 Icarus
eHST 23
Aggregate impacts in Saturn's rings
DOI: 10.1016/j.icarus.2007.02.009 Bibcode: 2007Icar..189..523K

Karjalainen, Raine

Ring particle aggregates are formed in the outer parts of Saturn's main rings. We study how collisions between aggregates can lead to destruction or coalescence of these aggregates, with local N-body simulations taking into account the dissipative impacts and gravitational forces between particles. Impacts of aggregates with different mass ratios …

2007 Icarus
Cassini 23
XMM-Newton observation of the deep minimum state of PG 2112+059. A spectrum dominated by reflection from the accretion disk?
DOI: 10.1051/0004-6361:20077812 Bibcode: 2007A&A...474..431S

Clavel, J.; Guainazzi, M.; Schartel, N. +5 more

Context: Highly ionised absorbers and the frequent occurrence of relativistically broad iron fluorescence lines characterize the 0.2-10 keV spectra of (soft) X-ray weak quasars.
Aims: We constrain the physical conditions of the absorber and the broad iron line of the X-ray weak quasar PG 2112+059 in greater detail than in pr…

2007 Astronomy and Astrophysics
XMM-Newton 23
Structure of Titan's mid-range magnetic tail: Cassini magnetometer observations during the T9 flyby
DOI: 10.1029/2007GL030865 Bibcode: 2007GeoRL..3424S02B

Coates, A. J.; Dougherty, M. K.; Kurth, W. S. +5 more

We analyze the magnetic structure of Titan's mid-range magnetic tail (5-6 Titan radii downstream from the moon) during Cassini's T9 flyby. Cassini magnetometer (MAG) measurements reveal a well-defined, induced magnetic tail consisting of two lobes and a distinct central current sheet. MAG observations also indicate that Saturn's background magneti…

2007 Geophysical Research Letters
Cassini 23
Is There Enhanced Depletion of Gas-Phase Nitrogen in Moderately Reddened Lines of Sight?
DOI: 10.1086/509096 Bibcode: 2007ApJ...654..955J

Snow, Theodore P.; Rachford, Brian L.; Jensen, Adam G.

We report on the abundance of interstellar neutral nitrogen (N I) for 30 sight lines, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Hubble Space Telescope (HST). N I column densities are derived by measuring the equivalent widths of several ultraviolet absorption lines and subsequently fitting those to a curve of growth…

2007 The Astrophysical Journal
eHST 23
Field distributions and shapes of Langmuir wave packets observed by Ulysses in an interplanetary type III burst source region
DOI: 10.1029/2006JA011873 Bibcode: 2007JGRA..112.5107N

Nulsen, A. L.; Cairns, Iver H.; Robinson, P. A.

There is no consensus on the mechanisms producing the intense bursty Langmuir wave packets routinely observed in source regions of interplanetary type III radio bursts. Using data from the Ulysses Fast Envelope Sampler (FES) near 4 AU, new analyses of the distributions of wavefields clearly separate the Langmuir waves into "intense localized struc…

2007 Journal of Geophysical Research (Space Physics)
Ulysses 23
Nondetection of Gravitationally Redshifted Absorption Lines in the X-Ray Burst Spectra of GS 1826-24
DOI: 10.1086/524137 Bibcode: 2007ApJ...670L..17K

Kong, Albert K. H.; Miller, Jon M.; Kuulkers, Erik +6 more

During a 200 ks observation with the XMM-Newton Reflection Grating Spectrometer, we detected 16 type I X-ray bursts from GS 1826-24. We combined the burst spectra in an attempt to measure the gravitational redshifts from the surface of the neutron star. We divided the composite GS 1826-24 burst spectrum into three groups based on the blackbody tem…

2007 The Astrophysical Journal
XMM-Newton 23
The Metallicity of Intergalactic Gas in Cosmic Voids
DOI: 10.1086/522920 Bibcode: 2007ApJ...671..146S

Shull, J. Michael; Danforth, Charles W.; Stocke, John T. +2 more

We have used the Hubble STIS and FUSE archives of ultraviolet spectra of bright AGNs to identify intergalactic Lyα absorbers in nearby (z<=0.1) voids. From a parent sample of 651 Lyα absorbers, we identified 61 ``void absorbers'' located >1.4 h-170 Mpc from the nearest L* or brighter galaxy. Searching for met…

2007 The Astrophysical Journal
eHST 23
Photospheric flows around a quiescent filament
DOI: 10.1051/0004-6361:20066649 Bibcode: 2007A&A...467.1289R

Bommier, V.; Schmieder, B.; Rondi, S. +7 more

Context: The horizontal photospheric flows below and around a filament are one of the components in the formation and evolution of filaments. Few studies exist because they require multiwalength time sequences at high spatial resolution.
Aims: Our objective is to measure the horizontal photospheric flows associated with the evolution and erupt…

2007 Astronomy and Astrophysics
SOHO 23
Hubble Ultra Deep Field-JD2: Mid-Infrared Evidence for a z ~ 2 Luminous Infrared Galaxy
DOI: 10.1086/519243 Bibcode: 2007ApJ...665..257C

Papovich, Casey; Dickinson, Mark E.; Teplitz, Harry I. +5 more

The Hubble Ultra Deep Field source JD2 presented in Mobasher et al. is an unusual galaxy that is very faint at all wavelengths shortward of 1.1 µm. Photometric redshift fits to data between 0.4 and 8 µm yield a significant probability that it is an extremely massive galaxy at z~6.5. In this paper we present new photometry at 16 and 22 …

2007 The Astrophysical Journal
eHST 23