Search Publications

Statistical research on the motion properties of the magnetotail current sheet: Cluster observations

Lucek, E. A.; Rème, H.; Liu, Z. X. +8 more

Side Magnetic Reconnections Induced by Coronal Mass Ejections: Observations and Simulations

Poedts, S.; Bemporad, A.; Landini, F. +2 more

Over the last few years coronagraphic and spectroscopic observations have demonstrated that small-scale eruptions, such as "jets," "narrow coronal mass ejections (CMEs)," "mini CMEs," "streamer puffs," "streamer detachments," and others, occur ubiquitously on the Sun. Nevertheless, the origin of small-scale eruptive events and how these are interr…

Search for Rapid Changes in the Visible-Light Corona during the 21 June 2001 Total Solar Eclipse

Keenan, F. P.; Phillips, K. J. H.; Williams, D. R. +2 more

Some 8000 images obtained with the Solar Eclipse Coronal Imaging System (SECIS) fast-frame CCD camera instrument located at Lusaka, Zambia, during the total eclipse of 21 June 2001 have been analysed to search for short-period oscillations in intensity that could be a signature of solar coronal heating mechanisms by MHD wave dissipation. Images we…

Rotation and lithium abundance of solar-analog stars. Theoretical analysis of observations

de Medeiros, J. R.; da Costa, J. S.; Do Nascimento, J. D.

Context. Rotational velocity, lithium abundance, and the mass depth of the outer convective zone are key parameters in the study of the processes at work in the stellar interior, in particular when examining the poorly understood processes operating in the interior of solar-analog stars.
Aims: We investigate whether the large dispersion in th…

The Faint End of the Galaxy Luminosity Function in A1689: A Steep Red Faint End Upturn at z = 0.18

De Propris, Roberto; Bañados, Eduardo; West, Michael J. +1 more

We present a deep and wide I luminosity function (LF) for galaxies in A1689 (z = 0.183) from a mosaic of Hubble Space Telescope WFPC2 images covering 10' on the side. The main result of this work is the detection of a steep upturn in the dwarf galaxy LF, with α ~ -2. The dwarf-to-giant ratio appears to increase outward, but this is because giant g…

Electrostatic field and ion temperature drop in thin current sheets: A theory

Donovan, E. F.; Liu, W. W.; Liang, J.

The observational evidence presented by Liang et al. (2009) showed that a neutral sheet-pointing electrostatic field frequently arises in the late growth-phase current sheet in the magnetotail. In this paper, we elaborate on the suggestion that this electric field is associated with the thinning of the current sheet to the ion scale at which the e…

Interferometric radius and limb darkening of the asteroseismic red giant η Serpentis with the CHARA Array

Kervella, P.; Barban, C.; Mérand, A. +10 more

Context. The radius of a star is a very important constraint to evolutionary models, particularly when combined with asteroseismology. Diameters can now be measured interferometrically with great precision (better than 1%), but the center-to-limb darkening (CLD) remains a potential source of bias. Measuring this bias is possible by completely reso…

Three-dimensional hybrid simulation of magnetosheath reconnection under northward and southward interplanetary magnetic field

Deng, X. H.; Wang, X. Y.; Pang, Y. +2 more

A three-dimensional (3-D) global hybrid simulation is carried out for the generation and structure of magnetic reconnection in the magnetosheath because of the interaction of an interplanetary tangential discontinuity (TD) with the bow shock and magnetosphere. Runs are performed for solar wind TDs possessing different polarization senses of magnet…

The Complex X-ray Spectrum of the Sefyert 1.5 Source NGC 6860

Mushotzky, Richard; Winter, Lisa M.

The X-ray spectrum of the Seyfert 1.5 source NGC 6860 is among the most complex of the sources detected in the Swift Burst Alert Telescope all-sky survey. A short XMM-Newton follow-up observation of the source revealed a flat spectrum both above and below 2 keV. To uncover the complexity of the source, in this paper we analyze both a 40 ks Suzaku …

The Formation of a Magnetic Channel by the Emergence of Current-carrying Magnetic Fields

Jing, Ju; Wang, Haimin; Chae, Jongchul +2 more

A magnetic channel—a series of polarity reversals separating elongated flux threads with opposite polarities—may be a manifestation of a highly non-potential magnetic configuration in active regions. To understand its formation, we have carried out a detailed analysis of the magnetic channel in AR 10930 using data taken by the Solar Optical Telesc…