Search Publications

Observational Consequences of a Magnetic Flux Rope Emerging into the Corona
DOI: 10.1086/425294 Bibcode: 2004ApJ...617..600G

Gibson, S. E.; Fan, Y.; Mandrini, C. +2 more

We show that a numerical simulation of a magnetic flux rope emerging into a coronal magnetic field predicts solar structures and dynamics consistent with observations. We first consider the structure, evolution, and relative location and orientation of S-shaped, or sigmoid, active regions and filaments. The basic assumptions are that (1) X-ray sig…

2004 The Astrophysical Journal
SOHO 127
Mid-infrared emission of galactic nuclei. TIMMI2 versus ISO observations and models
DOI: 10.1051/0004-6361:20031633 Bibcode: 2004A&A...414..123S

Siebenmorgen, R.; Krügel, E.; Spoon, H. W. W.

We investigate the mid-infrared radiation of galaxies that are powered by a starburst or by an AGN. For this end, we compare the spectra obtained at different spatial scales in a sample of infrared bright galaxies. ISO observations which include emission of the nucleus as well as most of the host galaxy are compared with TIMMI2 spectra of the nucl…

2004 Astronomy and Astrophysics
ISO 127
Geometry of the non-thermal emission in SN 1006. Azimuthal variations of cosmic-ray acceleration
DOI: 10.1051/0004-6361:20047104 Bibcode: 2004A&A...425..121R

Ballet, J.; Decourchelle, A.; Ferrando, P. +3 more

SN 1006 is the prototype of shell supernova remnants, in which non-thermal synchrotron emission dominates the X-ray spectrum. The non-thermal emission is due to the cosmic-ray electrons accelerated behind the blast wave. The X-ray synchrotron emission is due to the highest energy electrons, and is thus a tracer of the maximum en…

2004 Astronomy and Astrophysics
XMM-Newton 126
On the Relation between Filament Eruptions, Flares, and Coronal Mass Ejections
DOI: 10.1086/423781 Bibcode: 2004ApJ...614.1054J

Xu, Yan; Yang, Guo; Jing, Ju +2 more

We present a statistical study of 106 filament eruptions, which were automatically detected by a pattern recognition program implemented at Big Bear Solar Observatory using Hα full-disk data from 1999 to 2003. We compare these events with Geostationary Operational Environmental Satellite soft X-ray time profiles, solar-geophysical data (SGD) solar…

2004 The Astrophysical Journal
SOHO 126
Three-Dimensional Polarimetric Imaging of Coronal Mass Ejections
DOI: 10.1126/science.1098937 Bibcode: 2004Sci...305...66M

Davila, Joseph M.; Moran, Thomas G.

We present three-dimensional reconstructions of coronal mass ejections (CMEs), which were obtained through polarization analysis of single-view images recorded with the use of the Large Angle and Spectrometric Coronagraph (LASCO) C2 coronagraph on board the Solar and Heliospheric Observatory (SOHO) spacecraft. Analysis of a loop-like CME shows a c…

2004 Science
SOHO 126
Evidence of Black Hole Spin in GX 339-4: XMM-Newton/EPIC-pn and RXTE Spectroscopy of the Very High State
DOI: 10.1086/421263 Bibcode: 2004ApJ...606L.131M

Belloni, T.; Wijnands, R.; Fabian, A. C. +9 more

We have analyzed spectra of the Galactic black hole GX 339-4 obtained through simultaneous 76 ks XMM-Newton/EPIC-pn and 10 ks Rossi X-Ray Timing Explorer observations during a bright phase of its 2002-2003 outburst. An extremely skewed, relativistic Fe Kα emission line and ionized disk reflection spectrum are revealed in these spectra. Self-consis…

2004 The Astrophysical Journal
XMM-Newton 126
Detection of Lyman-α emission from a DLA galaxy: Possible implications for a luminosity-metallicity relation at z = 2-3
DOI: 10.1051/0004-6361:20040194 Bibcode: 2004A&A...422L..33M

Fynbo, J. P. U.; Fall, S. M.; Møller, P.

In an ongoing programme to identify a sample of high z DLA galaxies we have found the long sought for case of a Lyα emitter seen in the centre of a broad DLA trough. This is the predicted ``textbook case'' of an intervening DLA galaxy if DLA galaxies are small, but would not be expected if intervening high redshift DLA galaxies have large gaseous …

2004 Astronomy and Astrophysics
eHST 126
Highly Ionized Gas Surrounding High-Velocity Cloud Complex C
DOI: 10.1086/381024 Bibcode: 2004ApJ...602..738F

Richter, Philipp; Tripp, Todd M.; Sembach, Kenneth R. +3 more

We present Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope observations of high-, intermediate-, and low-ion absorption in high-velocity cloud (HVC) Complex C along the lines of sight toward five active galaxies. Our purpose is to investigate the idea that Complex C is surrounded by an envelope of highly ionized material, arising…

2004 The Astrophysical Journal
eHST 126
Warm dust and aromatic bands as quantitative probes of star-formation activity
DOI: 10.1051/0004-6361:20040963 Bibcode: 2004A&A...419..501F

Förster Schreiber, N. M.; Roussel, H.; Sauvage, M. +1 more

We combine samples of spiral galaxies and starburst systems observed with ISOCAM on board ISO to investigate the reliability of mid-infrared dust emission as a quantitative tracer of star formation activity. The total sample covers very diverse galactic environments and probes a much wider dynamic range in star formation rate density than previous…

2004 Astronomy and Astrophysics
ISO 125
Comet nucleus size distributions from HST and Keck telescopes
DOI: 10.1016/j.icarus.2004.03.014 Bibcode: 2004Icar..170..463M

Marsden, B. G.; Meech, K. J.; Hainaut, O. R.

The Wide Field Camera (WFC) on the Hubble Space Telescope and the Low Resolution Imaging Spectrograph (LRIS) on the Keck II telescope have been used to image 21 distant dynamically new, long-period (LP) and short-period (SP) Jupiter-family (JF) comet nuclei (near aphelion), as part of a long-term program to search for physical differences between …

2004 Icarus
eHST 125