Science Archives Publication System

The Statistical Relationship between the Photospheric Magnetic Parameters and the Flare Productivity of Active Regions

DOI: 10.1086/503895 Bibcode: 2006ApJ...644.1273J

Jing, Ju; Wang, Haimin; Song, Hui +2 more

Using line-of-sight Michelson Doppler Imager (MDI) magnetograms of 89 active regions and Solar Geophysical Data (SGD) flare reports, we explored, for the first time, the magnitude scaling correlations between three parameters of magnetic fields and the flare productivity of solar active regions. These parameters are (1) the mean value of spatial m…

2006 • The Astrophysical Journal

SOHO 71

2MASS J22521073-1730134: A Resolved L/T Binary at 14 Parsecs

DOI: 10.1086/499484 Bibcode: 2006ApJ...639.1114R

Burgasser, Adam J.; Reid, I. Neill; Cruz, K. L. +1 more

NICMOS images of the nearby late-type L dwarf 2MASS J22521073-1730134 (DENIS-P J225210.73-173013.4) show that it is a close double, separation 0.13". The companion is 1.0 mag fainter than the primary in the F110W passband and 1.55 mag fainter in the F170M images. The latter passband is centered on the 1.6 µm methane band. The small separatio…

2006 • The Astrophysical Journal

eHST 71

Probing isotopic ratios at z = 0.89: molecular line absorption in front of the quasar PKS 1830-211

DOI: 10.1051/0004-6361:20065187 Bibcode: 2006A&A...458..417M

Combes, F.; Muller, S.; Guélin, M. +2 more

With the Plateau de Bure interferometer, we have measured the C, N, O and S isotopic abundance ratios in the arm of a spiral galaxy with a redshift of 0.89. The galaxy is seen face-on according to HST images. Its bulge intercepts the line of sight to the radio-loud quasar PKS 1830-211, giving rise at mm wavelengths to two Einste…

2006 • Astronomy and Astrophysics

eHST 71

Spectral State Transitions of the Ultraluminous X-Ray Sources X-1 and X-2 in NGC 1313

DOI: 10.1086/508613 Bibcode: 2006ApJ...650L..75F

Feng, Hua; Kaaret, Philip

X-ray spectral state transitions are a key signature of black hole X-ray binaries and follow a well-defined pattern. We examined 12 XMM-Newton observations of the nearby spiral galaxy NGC 1313, which harbors two compact ultraluminous X-ray sources (ULXs), X-1 and X-2, in order to determine if the state transitions in ULXs follow the same pattern. …

2006 • The Astrophysical Journal

XMM-Newton 71

Detection of sporadic impact flashes on the Moon: Implications for the luminous efficiency of hypervelocity impacts and derived terrestrial impact rates

DOI: 10.1016/j.icarus.2006.05.002 Bibcode: 2006Icar..184..319O

Pallé, E.; Aceituno, J.; Ortiz, J. L. +8 more

We present the first redundant detection of sporadic impact flashes on the Moon from a systematic survey performed between 2001 and 2004. Our wide-field lunar monitoring allows us to estimate the impact rate of large meteoroids on the Moon as a function of the luminous energy received on Earth. It also shows that some historical well-documented my…

2006 • Icarus

SMART-1 70

Initial interpretation of Titan plasma interaction as observed by the Cassini plasma spectrometer: Comparisons with Voyager 1

DOI: 10.1016/j.pss.2006.05.029 Bibcode: 2006P&SS...54.1211H

Coates, A. J.; Crary, F.; Johnson, R. E. +15 more

The Cassini plasma spectrometer (CAPS) instrument made measurements of Titan's plasma environment when the Cassini Orbiter flew through the moon's plasma wake October 26, 2004 (flyby TA). Initial CAPS ion and electron measurements from this encounter will be compared with measurements made by the Voyager 1 plasma science instrument (PLS). The comp…

2006 • Planetary and Space Science

Cassini 70

C II Abundances in Early-Type Stars: Solution to a Notorious Non-LTE Problem

DOI: 10.1086/501124 Bibcode: 2006ApJ...639L..39N

Przybilla, N.; Nieva, M. F.

We address a long-standing discrepancy between non-LTE analyses of the prominent C II 4267 and 6578/82 Å multiplets in early-type stars. A comprehensive non-LTE model atom of C II is constructed based on critically selected atomic data. This model atom is used for an abundance study of six apparently slow-rotating main-sequence and giant early B-t…

2006 • The Astrophysical Journal

IUE 70

The host galaxy/AGN connection in nearby early-type galaxies. A new view of the origin of the radio-quiet/radio-loud dichotomy?

DOI: 10.1051/0004-6361:20054490 Bibcode: 2006A&A...453...27C

Capetti, A.; Balmaverde, B.

This is the third in a series of three papers exploring the connection between the multiwavelength properties of AGN in nearby early-type galaxies and the characteristics of their hosts. Starting from an initial sample of 332 galaxies, we selected 116 AGN candidates requiring the detection of a radio source with a flux limit of ~1 mJy, as measured…

2006 • Astronomy and Astrophysics

eHST 70

The UV spectrum of HS 1700+6416. II. FUSE observations of the He II Lyman alpha forest

DOI: 10.1051/0004-6361:20064950 Bibcode: 2006A&A...455...91F

Shull, J. M.; Zheng, W.; Moos, H. W. +11 more

Aims.We present the far-UV spectrum of the quasar HS 1700+6416 taken with FUSE. This QSO provides the second line of sight with the He II absorption resolved into a Lyα forest structure. Since HS 1700+6416 is slightly less redshifted (z_em = 2.72) than HE 2347-4342, we only probe the post-reionizatio…

2006 • Astronomy and Astrophysics

eHST 70

Chandra ACIS Spectroscopy of N157B: A Young Composite Supernova Remnant in a Superbubble

DOI: 10.1086/507017 Bibcode: 2006ApJ...651..237C

Gotthelf, E. V.; Chu, You-Hua; Wang, Q. Daniel +3 more

We present a Chandra ACIS observations of N157B, a young supernova remnant (SNR) located in the 30 Doradus star formation region of the Large Magellanic Cloud. This remnant contains the most energetic pulsar known (PSR J053747.39-691020.2 E˙=4.8×10³⁸ ergs s^-1), which is surrounded by a X-ray-bright nonthermal nebula that like…

2006 • The Astrophysical Journal

eHST 70