Search Publications
Probing small scale structure in the atmosphere of V471 Tauri
Walter, F. M.
The white dwarf in the eclipsing binary system V471 Tau is viewed through the atmosphere of the active K star prior to ingress and after egress. In the far UV the surface brightness of the hot white dwarf far outshines the K star emission. We can use this to probe the structure of the extended K star atmosphere along one line of sight, in absorpti…
Reconstruction of the magnetopause and low-latitude boundary layer topology using Cluster multi-point measurements
Roth, M.; Rème, H.; de Keyser, J. +6 more
Available from http://www.copernicus.org/site/EGU/annales/22/7/2381.htm?FrameEngine=false;
On the analysis of band 3 of the ISO-SWS calibration sources
Shipman, R. F.; Decin, L.; Kester, D. +4 more
We analyse ISO-SWS 01 (R ∼ 1500) 12-27.5 µm (band 3) spectra of the 10 standard calibration stars with the highest flux using synthetic spectra generated from (MARCS) atmosphere models. The comparison between the observed and synthetic spectra reveals the quality of (1) the atmospheric model construction and subsequent synthetic spectra comp…
Broadband X-ray Spectrum of XTE J1550-564 during the Outburst of 2003
Sunyaev, R. A.; Lutovinov, A. A.; Revnivtsev, M. G. +1 more
We present the INTEGRAL and RXTE X-ray observations of XTE J1550-564, a Galactic microquasar and a black hole candidate, during its outburst in the spring of 2003. The source during the outburst was in a canonical hard state, and its spectrum remained constant in both the rise and decay phases.
The Collective UV Behavior of Old Novae
Selvelli, P.
The UV spectral properties of 18 old-novae observed with IUE are examined. The de-reddened continuum energy distribution is well described by either a power-law distribution Fλ ∼λ -α with α in the range 0.3--2.5 or by a single black-body distribution with T in the range 15 000--38 000 K. The new values of EB-V ha…
Multivariate Monte Carlo Methods for the Reflection Grating Spectrometers on XMM-Newton
Kahn, S. M.; Peterson, J. R.; Jernigan, J. G.
We propose a novel multivariate Monte Carlo method as an efficient and flexible approach to analyzing extended X-ray sources with the reflection grating spectrometers (RGS) on XMM-Newton. A multidimensional interpolation method is used to efficiently calculate the response function for the RGS in conjunction with an arbitrary spatially varying spe…
η Carinae: The 1998 brightening and the smearing-out effect
Sterken, C.; van Genderen, A. M.
A comparison of broad-band photometry of the Homunculus (ground-based data) and of broad-band and narrow-band photometry of the central region (HST-based) from 1997 to 2003 reveals that, apart from the brightening in 1998, the Homunculus as well as the central star varied in a very similar way. This excludes smearing-out effects as an explanation …
Local Modulation of Solar Oscillations by Magnetic Fields
Thompson, M. J.; Rajaguru, S. P.; Nicholas, C. J.
The amplitudes of solar oscillations measured in Doppler velocity are modulated by the presence of a strong photospheric magnetic field. Here we show that the amount of modulation cannot be predicted solely on the local photospheric magnetic field strength. Qualitatively, magnetic fields of similar strength have similar effects on the oscillations…
Broadband Observations of the Transient X-ray Pulsar SAX J2103.5+4545
Sunyaev, R. A.; Lutovinov, A. A.; Revnivtsev, M. G. +5 more
We investigated the optical, X-ray, and gamma-ray variability of the pulsar SAX J2103.5+4545. Our timing and spectral analyses of the X-ray and gamma-ray emissions from the source using RXTE and INTEGRAL data show that the shape of its spectrum in the energy range 3-100 keV is virtually independent of its intensity and the orbital phase. Based on …
Relationship between horizontal flow velocity and cell lifetime for supergranulation from SOHO Dopplergrams
Singh, Jagdev; Paniveni, U.; Krishan, V. +1 more
A study of 50 supergranular cells obtained from Solar and Heliospheric Observatory (SOHO) Dopplergrams was undertaken in order to investigate the relationship between the lifetime (T) and the horizontal flow velocity (vh) of the cells. For this sample, we find that the two parameters are correlated with a relation vh~T1/…