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A Saturnian longitude system based on a variable kilometric radiation period
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…
Simultaneous Multiwavelength Observations of the Low/Hard State of the X-Ray Transient Source SWIFT J1753.5-0127
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…
Interaction between a Fast Rotating Sunspot and Ephemeral Regions as the Origin of the Major Solar Event on 2006 December 13
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…
The Discovery of Cepheids and a Distance to NGC 5128
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…
A Connection between Bulge Properties and the Bimodality of Galaxies
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…
WEBT and XMM-Newton observations of 3C 454.3 during the post-outburst phase. Detection of the little and big blue bumps
Lee, C. -U.; Nishiyama, S.; Pian, E. +73 more
Context: The quasar-type blazar
Aims: In this paper we report on f…
Constraints on Thermal X-Ray Radiation from SAX J1808.4-3658 and Implications for Neutron Star Neutrino Emission
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…
The Evolution of the Number Density of Large Disk Galaxies in COSMOS
Kneib, J. -P.; Taniguchi, Y.; Sargent, M. T. +17 more
We study a sample of approximately 16,500 galaxies with IACS,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…
Kinematics and stellar populations of the dwarf elliptical galaxy IC 3653
Afanasiev, V. L.; Chilingarian, I. V.; Sil'Chenko, O. K. +1 more
We present the first 3D observations of a diffuse elliptical galaxy (dE). The good quality data (S/N up to 40) reveal the kinematical signature of an embedded stellar disc, reminiscent of what is commonly observed in elliptical galaxies, though similarity of their origins is questionable. Colour map built from Hubble Space Telescope Advanced Camer…
Slipping Magnetic Reconnection in Coronal Loops
Golub, Leon; DeLuca, Edward E.; Narukage, Noriyuki +6 more
Magnetic reconnection of solar coronal loops is the main process that causes solar flares and possibly coronal heating. In the standard model, magnetic field lines break and reconnect instantaneously at places where the field mapping is discontinuous. However, another mode may operate where the magnetic field mapping is continuous but shows steep …