Search Publications

The Ne/O abundance ratio in the quiet Sun
DOI: 10.1051/0004-6361:200500206 Bibcode: 2005A&A...444L..45Y

Young, P. R.

Context: .
Aims: .To determine the neon-to-oxygen abundance in the quiet Sun, a proxy for the photospheric abundance ratio.
Methods: .An emission measure method applied to extreme ultraviolet emission lines of Ne iv-vi and O iii-v ions observed by the Coronal Diagnostic Spectrometer on the SOHO satellite.
Results: .The average Ne/O abu…

2005 Astronomy and Astrophysics
SOHO 78
INTEGRAL spectroscopy of the accreting millisecond pulsar XTE J1807-294 in outburst
DOI: 10.1051/0004-6361:20042575 Bibcode: 2005A&A...436..647F

Goldoni, P.; Bonnet-Bidaud, J. M.; Kuiper, L. +6 more

The transient X-ray accreting millisecond pulsar XTE J1807-294 was observed during its February/March 2003 outburst by INTEGRAL, partly simultaneously with the XMM-Newton and RXTE satellites. We present here the first study of the 0.5-200 keV broad-band spectra of the source. On February 28, the source spectrum was consistent with thermal Comptoni…

2005 Astronomy and Astrophysics
INTEGRAL XMM-Newton 78
Characterizing a new class of variability in GRS 1915+105 with simultaneous INTEGRAL/RXTE observations
DOI: 10.1051/0004-6361:20042250 Bibcode: 2005A&A...435..995H

Belloni, T.; Rodriguez, J.; Mirabel, I. F. +14 more

We report on the analysis of 100 ks INTEGRAL observations of the Galactic microquasar GRS 1915+105. We focus on INTEGRAL Revolution number 48 when the source was found to exhibit a new type of variability as preliminarily reported in Hannikainen (2003, A&A, 411, L415). The variability pattern, which we name ξ, is characteriz…

2005 Astronomy and Astrophysics
INTEGRAL 77
Initiation of hot coronal loop oscillations: Spectral features
DOI: 10.1051/0004-6361:20052680 Bibcode: 2005A&A...435..753W

Solanki, S. K.; Curdt, W.; Innes, D. E. +1 more

We explore the excitation of hot loop oscillations observed with the SUMER spectrograph on SOHO by analysing Fe XIX and Fe XXI spectral line profiles in the initial phase of the events. We investigate all 54 Doppler shift oscillations in 27 flare-like events, whose physical parameters have been measured so far. In nearly 50% of the cases, the spec…

2005 Astronomy and Astrophysics
SOHO 77
Kinetic vs. multi-fluid models of H atoms in the heliospheric interface: a comparison
DOI: 10.1051/0004-6361:20052821 Bibcode: 2005A&A...439.1171A

Izmodenov, V.; Alexashov, D.

The goal of this paper is to illuminate similarities and differences in the kinetic and multi-fluid models of the heliospheric interface, the region of solar wind interaction with the Local Interstellar Cloud (LIC), and then to explore physical reasons for these differences. We present a detailed comparison of two types of models. The first type i…

2005 Astronomy and Astrophysics
SOHO 77
Relationship between X-ray and ultraviolet emission of flares from dMe stars observed by XMM-Newton
DOI: 10.1051/0004-6361:20041201 Bibcode: 2005A&A...431..679M

Raassen, A. J. J.; Mewe, R.; Audard, M. +6 more

We present simultaneous ultraviolet and X-ray observations of the dMe-type flaring stars AT Mic, AU Mic, EV Lac, UV Cet and YZ CMi obtained with the XMM-Newton observatory. During 40 h of simultaneous observation we identify 13 flares which occurred in b…

2005 Astronomy and Astrophysics
XMM-Newton 77
XMM-Newton observations of three poor clusters: Similarity in dark matter and entropy profiles down to low mass
DOI: 10.1051/0004-6361:20041479 Bibcode: 2005A&A...429..791P

Arnaud, M.; Pratt, G. W.

We present an analysis of the mass and entropy profiles of three poor galaxy clusters (A1991, A2717 and MKW9) observed with XMM-Newton. The clusters have very similar temperatures (kT= 2.65, 2.53 and 2.58 keV), and similar redshifts (0.04 ⪉ z ⪉ 0.06). We trace the surface brightness, temperature, entropy and integrated mass profiles with excellent…

2005 Astronomy and Astrophysics
XMM-Newton 77
X-ray absorption lines suggest matter infalling onto the central black-hole of Mrk 509
DOI: 10.1051/0004-6361:20042487 Bibcode: 2005A&A...442..461D

de Rosa, A.; Cappi, M.; Ponti, G. +2 more

Evidence for both red- and blue-shifted absorption lines due to ionized Fe in the X-ray spectrum of the Seyfert 1 galaxy Mrk 509 is reported. These features appear to be transient on time-scales as short as ~20 ks, and have been observed with two different satellites, BeppoSAX and XMM-Newton. The red- and blue-shifted lines are found at E∼5.5 keV …

2005 Astronomy and Astrophysics
XMM-Newton 77
Asteroid target selection for the new Rosetta mission baseline. 21 Lutetia and 2867 Steins
DOI: 10.1051/0004-6361:20041505 Bibcode: 2005A&A...430..313B

Barbieri, C.; Barucci, M. A.; Fornasier, S. +8 more

The new Rosetta mission baseline to the comet 67P/Churyumov-Gerasimenko includes two asteroid fly-bys. To help in target selection we studied all the candidates of all the possible scenarios. Observations have been carried out at ESO-NTT (La Silla, Chile), TNG (Canaries), and NASA-IRTF (Hawaii) telescopes, in order to determine the taxonomy of all…

2005 Astronomy and Astrophysics
Rosetta 76
The XMM-Newton view of PG quasars. II. Properties of the Fe K_α line
DOI: 10.1051/0004-6361:20041623 Bibcode: 2005A&A...435..449J

Guainazzi, M.; Schartel, N.; Rodríguez-Pascual, P. M. +3 more

The properties of the fluorescence Fe Kα emission lines of a sample of 38 quasars (QSOs) observed with XMM-Newton are studied. These objects are included in the optically selected sample from the Palomar-Green (PG) Bright Quasar Survey with an X-ray luminosity 1.3 × 1043 < L2-10~keV < 5.1 × 1045 erg s-1<…

2005 Astronomy and Astrophysics
XMM-Newton 75