Science Archives Publication System

Saturnian magnetospheric dynamics: Elucidation of a camshaft model

DOI: 10.1029/2007JA012254 Bibcode: 2007JGRA..11212222S

Southwood, D. J.; Kivelson, M. G.

Periodic modulation of magnetospheric phenomena at Earth and Jupiter results principally from the tilt of the dipole axis relative to the rotation axis. Saturn's nearly aligned dipole moment is tilted by less than 0.5° from the spin axis, yet the power of radio-frequency emissions, the orientation of the magnetic field, and many properties of the …

2007 • Journal of Geophysical Research (Space Physics)

Cassini 107

The ACS Fornax Cluster Survey. II. The Central Brightness Profiles of Early-Type Galaxies: A Characteristic Radius on Nuclear Scales and the Transition from Central Luminosity Deficit to Excess

DOI: 10.1086/522822 Bibcode: 2007ApJ...671.1456C

Jordán, Andrés; Infante, Leopoldo; Tonry, John L. +9 more

We analyze brightness profiles for 143 early-type galaxies in the Virgo and Fornax Clusters, observed with the Advanced Camera for Surveys on the Hubble Space Telescope. Sérsic models are found to provide accurate representations of the global profiles with a notable exception: the observed profiles deviate systematically inside a characteristic `…

2007 • The Astrophysical Journal

eHST 107

A Saturnian longitude system based on a variable kilometric radiation period

DOI: 10.1029/2006GL028336 Bibcode: 2007GeoRL..34.2201K

Gurnett, D. A.; Kurth, W. S.; Averkamp, T. F. +2 more

This paper describes a longitude system for Saturn which is locked to the period of Saturn kilometric radiation. Because the apparent radio emission period varies with time, the period used in the system is allowed to vary. The resulting system results in the 'diurnal' peak of the radio emission occurring when the subsolar longitude is 100°, as wa…

2007 • Geophysical Research Letters

Cassini 106

Simultaneous Multiwavelength Observations of the Low/Hard State of the X-Ray Transient Source SWIFT J1753.5-0127

DOI: 10.1086/512004 Bibcode: 2007ApJ...659..549C

D'Avanzo, P.; Frontera, F.; Goldoni, P. +11 more

We report the results of simultaneous multiwavelength observations of the X-ray transient source SWIFT J1753.5-0127 performed with INTEGRAL, RXTE, NTT, REM, and VLA on 2005 August 10-12. The source, which underwent an X-ray outburst since 2005 May 30, was observed during the INTEGRAL Target of Opportunity program dedicated to new X-ray novae locat…

2007 • The Astrophysical Journal

INTEGRAL 106

Interaction between a Fast Rotating Sunspot and Ephemeral Regions as the Origin of the Major Solar Event on 2006 December 13

DOI: 10.1086/519280 Bibcode: 2007ApJ...662L..35Z

Zhang, Jun; Li, Leping; Song, Qiao

The major solar event on 2006 December 13 is characterized by the approximately simultaneous occurrence of a heap of hot ejecta, a great two-ribbon flare, and an extended Earth-directed coronal mass ejection. We examine the magnetic field and sunspot evolution in NOAA AR 10930, the source region of the event, while it transited the solar disk cent…

2007 • The Astrophysical Journal

SOHO 106

The Discovery of Cepheids and a Distance to NGC 5128

DOI: 10.1086/506612 Bibcode: 2007ApJ...654..186F

Ajhar, Edward A.; Stetson, Peter B.; Tonry, John L. +3 more

We discuss a new distance to NGC 5128 (Centaurus A) based on Cepheid variables observed with the Hubble Space Telescope. Twelve F555W (V) and six F814W (I) epochs of cosmic-ray-split WFPC2 observations were obtained. A total of 56 bona fide Cepheids were discovered, with periods ranging from 5 to ~50 days; five of these are likely Population II Ce…

2007 • The Astrophysical Journal

eHST 106

A Connection between Bulge Properties and the Bimodality of Galaxies

DOI: 10.1086/519441 Bibcode: 2007ApJ...664..640D

Drory, Niv; Fisher, David B.

The global colors and structure of galaxies have recently been shown to follow a bimodal distribution: a ``red sequence'' populated prototypically by early-type galaxies, and a ``blue cloud'' whose typical objects are late-type disk galaxies. Intermediate-type (Sa-Sbc) galaxies populate both regions. It has been suggested that this bimodality refl…

2007 • The Astrophysical Journal

eHST 106

WEBT and XMM-Newton observations of 3C 454.3 during the post-outburst phase. Detection of the little and big blue bumps

DOI: 10.1051/0004-6361:20078289 Bibcode: 2007A&A...473..819R

Lee, C. -U.; Nishiyama, S.; Pian, E. +73 more

Context: The quasar-type blazar 3C 454.3 was observed to undergo an unprecedented optical outburst in spring 2005, affecting the source brightness from the near-IR to the X-ray frequencies. This was first followed by a millimetric and then by a radio outburst, which peaked in February 2006.
Aims: In this paper we report on f…

2007 • Astronomy and Astrophysics

INTEGRAL XMM-Newton 105

Constraints on Thermal X-Ray Radiation from SAX J1808.4-3658 and Implications for Neutron Star Neutrino Emission

DOI: 10.1086/513140 Bibcode: 2007ApJ...660.1424H

Wijnands, R.; Heinke, C. O.; Jonker, P. G. +1 more

Thermal X-ray radiation from neutron star soft X-ray transients in quiescence provides the strongest constraints on the cooling rates of neutron stars and thus on the interior composition and properties of matter in the cores of neutron stars. We analyze new (2006) and archival (2001) XMM-Newton observations of the accreting millisecond pulsar SAX…

2007 • The Astrophysical Journal

XMM-Newton 105

The Evolution of the Number Density of Large Disk Galaxies in COSMOS

DOI: 10.1086/516584 Bibcode: 2007ApJS..172..434S

Kneib, J. -P.; Taniguchi, Y.; Sargent, M. T. +17 more

We study a sample of approximately 16,500 galaxies with I_ACS,AB<=22.5 in the central 38% of the COSMOS field, which are extracted from a catalog constructed from the Cycle 12 ACS F814W COSMOS data set. Structural information on the galaxies is derived by fitting single Sérsic models to their two-dimensional surface brightness distrib…

2007 • The Astrophysical Journal Supplement Series

eHST 105