Search Publications
Flare Ribbons Observed with G-band and Fe I 6302Å, Filters of the Solar Optical Telescope on Board Hinode
Tsuneta, Saku; Shimizu, Toshifumi; Kubo, Masahito +11 more
The Solar Optical Telescope (SOT) on board the Hinode satellite observed an X3.4 class flare on 2006 December 13. A typical two-ribbon structure was observed, not only in the chromospheric CaII H line, but also in the G-band and FeI 6302Å line. The high-resolution, seeing-free images achieved by SOT revealed, for the first time, sub-arcsec fine st…
Nonstationarity and reformation of high-Mach-number quasiperpendicular shocks: Cluster observations
Dunlop, M.; Schwartz, S. J.; Krasnoselskikh, V. V. +3 more
A set of experimental data is presented for a high-Mach-number (M f = 5) quasiperpendicular ($\theta$ Bn = 81°) bow shock layer crossed by Cluster spacecraft on 24 January 2001 at 07:05-07:09 UT. The measurements of magnetic field, spectra of electric field fluctuations, and ion distributions reveal that the shock is high…
A statistical analysis of X-ray variability in pre-main sequence objects of the Taurus molecular cloud
Audard, M.; Güdel, M.; Micela, G. +5 more
Context: This work is part of a systematic X-ray survey of the Taurus star-forming complex with XMM-Newton.
Aims: We study the time series of all X-ray sources associated with Taurus members, to statistically characterize their X-ray variability, and compare the results to those for pre-main sequence stars in the Orion Nebula Cluster and to ex…
Features and Properties of Coronal Mass Ejection/Flare Current Sheets
Raymond, J. C.; Ko, Y. -K.; Lin, J. +3 more
Solar eruptions occur when magnetic energy is suddenly converted into heat and kinetic energy by magnetic reconnection in a current sheet (CS). It is often assumed that CSs are too thin to be observable because the electric resistivity ηe in CSs is taken to be very small. In this work, we show the implications for the CS thickness d est…
Numerical Investigation of the Homologous Coronal Mass Ejection Events from Active Region 9236
Gombosi, T. I.; Tóth, G.; Lugaz, N. +2 more
We present a three-dimensional compressible magneto-hydrodynamics (MHD) simulation of the three coronal mass ejections (CMEs) of 2000 November 24, originating from NOAA active region 9236. These three ejections, with velocities around 1200 km s-1 and associated with X-class flares, erupted from the Sun in a period of about 16.5 hr. In o…
Topography and geomorphology of the Huygens landing site on Titan
Karkoschka, Erich; Tomasko, Martin G.; Kirk, Randolph L. +16 more
The Descent Imager/Spectral Radiometer (DISR) aboard the Huygens Probe took several hundred visible-light images with its three cameras on approach to the surface of Titan. Several sets of stereo image pairs were collected during the descent. The digital terrain models constructed from those images show rugged topography, in places approaching the…
The blue plume population in dwarf spheroidal galaxies. Genuine blue stragglers or young stellar population?
Gullieuszik, M.; Momany, Y.; Held, E. V. +3 more
Aims:Blue stragglers (BSS) in the Milky Way field and globular/open clusters are thought to be the product of either primordial or collisional binary systems. In the context of dwarf spheroidal galaxies it is hard to firmly disentangle a genuine BSS population from young main sequence (MS) stars tracing a ∼ 1-2 Gyr old star forming episode.
Me…
The Surface Density Profile of NGC 6388: A Good Candidate for Harboring an Intermediate-Mass Black Hole
Dalessandro, E.; Valenti, E.; Ferraro, F. R. +3 more
We have used a combination of HST high-resolution and ground-based wide-field observations of the Galactic globular cluster NGC 6388 to derive its center of gravity, projected density profile, and central surface brightness profile. While the overall projected profiles are well fit by a King model with an intermediate concentration (c=1.8) and a s…
X-ray/ultraviolet observing campaign of the Markarian 279 active galactic nucleus outflow: a close look at the absorbing/emitting gas with Chandra-LETGS
Kaastra, J. S.; Kriss, G. A.; Arav, N. +12 more
We present a Chandra-LETGS observation of the Seyfert 1 galaxy
A Panchromatic Study of the Globular Cluster NGC 1904. I. The Blue Straggler Population
Valenti, E.; Sanna, N.; Beccari, G. +6 more
By combining high-resolution (HST/WFPC2) and wide-field ground-based (2.2 m ESO/WFI) and space (GALEX) observations, we have collected a multiwavelength photometric database (ranging from the far-UV to the near infrared) of the galactic globular cluster NGC 1904 (M79). The sample covers the entire cluster extension, from the very central regions u…