Search Publications

Periodicity of Twisting Motions in Sunspot Penumbral Filaments

Cao, Wenda; Ning, Zongjun; Goode, Philip R.

We study the periodicity of twisting motions in sunspot penumbral filaments, which were recently discovered from space (Hinode) and ground-based (SST) observations. A sunspot was well observed for 97 minutes by Hinode/SOT in the G-band (4305 Å) on 12 November 2006. By the use of the time - space gradient applied to intensity space - time plots, tw…

Asymmetric precipitation in a coronal loop as explanation of a singular observed spectrum

Mandrini, C. H.; Giménez de Castro, C. G.; Cristiani, G. +2 more

Almost 10 years of solar submillimeter observations have shown new aspects of solar activity, such as the presence of rapid solar spikes associated with the launch of coronal mass ejections and an increasing submillimeter spectral component in flares. We analyse the singular microwave-submillimeter spectrum of an M class solar flare on 20 December…

On the ionospheric coupling of auroral electric fields

Marklund, G. T.

The quasi-static coupling of high-altitude potential structures and electric fields to the ionosphere is discussed with particular focus on the downward field-aligned current (FAC) region. Results are presented from a preliminary analysis of a selection of electric field events observed by Cluster above the acceleration region. The degree of coupl…

The core fundamental plane of B2 radio galaxies

Falomo, R.; Fanti, R.; Parma, P. +2 more

Context: The photometric, structural and kinematical properties of the centers of elliptical galaxies harbour important information on the formation history of galaxies. In the case of non-active elliptical galaxies, these properties are linked in a way that surface brightness, break radius and velocity dispersion of the core lie on a fundamental …

Foreshock-like density cavity in the outflow region of magnetotail reconnection

Dandouras, I.; Rème, H.; Cao, J. B. +4 more

During Cluster spacecraft crossing of the magnetotail, a novel density depleted cavity in association with magnetic compressions in the outflow region of reconnection was observed. It contains intense reflected field-aligned particles, which are produced by a generation mechanism similar to that of the terrestrial foreshock, and hence manifests a …

ERRATUM: "The Fifth Data Release Sloan Digital Sky Survey/XMM-Newton Quasar Survey" (2009, ApJS, 183, 17)

Elvis, M.; Risaliti, G.; Young, M.

We have discovered an error in Column 9 of Table 2 in the original paper. This column reports the fit flags, indicating which model a source prefers: a simple power-law (SPL; flag = 1), a fixed power-law plus intrinsic absorption (FPL; flag = 2), or an absorbed power-law (APL; flag = 3). The table of the original paper mistakenly reports all flag …

Detecting metal-rich intermediate-age globular clusters in NGC4570 using K-band photometry

Kotulla, Ralf; Anders, Peter; Fritze, Uta

Globular cluster systems (GCSs) of most early-type galaxies feature two peaks in their optical colour distributions. Blue-peak globular clusters (GCs) are believed to be old and metal-poor, whereas the ages, metallicities, and the origin of the red-peak GCs are still being debated. We obtained deep K-band photometry and combined it with Hubble Spa…

Solar wind entry via flux tube into magnetosphere observed by Cluster measurements at dayside magnetopause during southward IMF

Balogh, A.; Fazakerley, A. N.; Dunlop, M. W. +5 more

Study of Bubble nebula using IUE high resolution spectra

Murthy, Jayant; Anand, M. Y.; Kagali, B. A.

In this paper, we have analyzed IUE high resolution spectra of the central star (BD+602522) of the Bubble nebula. We discuss velocities of the different regions along the line of sight to the bubble. We find that the Bubble nebula is younger (by a factor of 100) than the exciting star suggesting that either the bubble is expanding into an inhomoge…

Search for a Redshifted 2.2 MeV Neutron Capture Line from A0535+262 in Outburst

Kretschmar, Peter; Çalişkan, Şirin; Kalemci, Emrah +2 more

The Be/X-ray binary system A0535+262 underwent a giant outburst in 2005 May-June, followed by a dimmer outburst in 2005 August-September. This increased intensity provided an opportunity to search for redshifted neutron capture lines from the surface of the neutron star. If discovered, such lines would constrain the neutron star equation of state,…