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Kinematics of coronal mass ejections between 2 and 30 solar radii. What can be learned about forces governing the eruption?
DOI: 10.1051/0004-6361:20047169 Bibcode: 2004A&A...423..717V

Vršnak, B.; Gopalswamy, N.; Sudar, D. +1 more

Kinematics of more than 5000 coronal mass ejections (CMEs) measured in the distance range 2-30 solar radii is investigated. A distinct anticorrelation between the acceleration, a, and the velocity, v, is found. In the linear form, it can be represented as a=-k1(v-v0), where v0=400 km s-1, i.e., most of C…

2004 Astronomy and Astrophysics
SOHO 136
The distance to the giant elliptical galaxy NGC 5128
DOI: 10.1051/0004-6361:20034031 Bibcode: 2004A&A...413..903R

Rejkuba, M.

The distance to NGC 5128, the central galaxy of the Centaurus group and the nearest giant elliptical to us, has been determined using two independent distance indicators: the Mira period-luminosity (PL) relation and the luminosity of the tip of the red giant branch (RGB). The data were taken at two different locations in the halo of NGC 5128 with …

2004 Astronomy and Astrophysics
Hipparcos 134
XMM-Newton observations of the supernova remnant RX J1713.7-3946 and its central source
DOI: 10.1051/0004-6361:20041154 Bibcode: 2004A&A...427..199C

Ballet, J.; Decourchelle, A.; Giacani, E. +3 more

We present new results from the observations of the supernova remnant (SNR) RX J1713.7-3946 (also G347.3-0.5) performed in five distinct pointings with the EPIC instrument on board the satellite XMM-Newton. RX J1713.7-3946 is a shell-type SNR dominated by synchrotron radiation in the X-rays. Its emission (emis…

2004 Astronomy and Astrophysics
XMM-Newton 133
Dynamics of solar coronal loops. II. Catastrophic cooling and high-speed downflows
DOI: 10.1051/0004-6361:20040403 Bibcode: 2004A&A...424..289M

Peter, H.; Hansteen, V. H.; Müller, D. A. N.

This work addresses the problem of plasma condensation and ``catastrophic cooling'' in solar coronal loops. We have carried out numerical calculations of coronal loops and find several classes of time-dependent solutions (static, periodic, irregular), depending on the spatial distribution of a temporally constant energy deposition in the loop. Dyn…

2004 Astronomy and Astrophysics
SOHO 131
The nature of the Galactic Center source IRS 13 revealed by high spatial resolution in the infrared
DOI: 10.1051/0004-6361:20034147 Bibcode: 2004A&A...423..155M

Rigaut, F.; Paumard, T.; Stolovy, S. R. +1 more

High spatial resolution observations in the 1 to 3.5 µm/ region of the Galactic Center source known historically as IRS 13 are presented. They include ground-based adaptive optics images in the H, Kp (2.12/0.4 µm) and L bands, HST-NICMOS data in filters between 1.1 and 2.2 µm, and integral field spectroscopic d…

2004 Astronomy and Astrophysics
eHST 131
Abundances of Na, Mg and Al in nearby metal-poor stars
DOI: 10.1051/0004-6361:20031582 Bibcode: 2004A&A...413.1045G

Zhao, G.; Liang, Y. C.; Shi, J. R. +2 more

To determine the population membership of nearby stars we explore abundance results obtained for the light neutron-rich elements 23Na and 27 Al in a small sample of moderately metal-poor stars. Spectroscopic observations are limited to the solar neighbourhood so that gravities can be determined from HIPPARCOS parallaxes, and …

2004 Astronomy and Astrophysics
Hipparcos 128
Band-splitting of coronal and interplanetary type II bursts. III. Physical conditions in the upper corona and interplanetary space
DOI: 10.1051/0004-6361:20034060 Bibcode: 2004A&A...413..753V

Magdalenić, J.; Vršnak, B.; Zlobec, P.

We analyse properties of 58 type II radio bursts recorded in the meter-to-kilometer wavelength range, focusing on episodes of band-split emission. The basic two parameters utilized are the frequency drift Df=df/dt and the relative band-split BDW=Δ f/f of type II burst emission lanes. On average, in the meter-to-kilometer wavelength rang…

2004 Astronomy and Astrophysics
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
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