Search Publications
Study of Hα Macrospicules in Coronal Holes: Magnetic Structure and Evolution in Relation to Photospheric Magnetic Setting
Wang, H.; Moore, R. L.; Jiang, Y. +2 more
Small-scale solar dynamic events such as spicules, macrospicules, and microflares may play an important role in the coronal heating and solar wind acceleration in coronal holes. In these regions, the network fields concentrated along edges of supergranules are probably the source of the fine-scale activity that may drive the heating and accelerati…
Coronal mass ejection kinematics deduced from white light (Solar Mass Ejection Imager) and radio (Wind/WAVES) observations
Webb, D. F.; Kaiser, M. L.; Jackson, B. V. +3 more
White-light and radio observations are combined to deduce the coronal and interplanetary kinematics of a fast coronal mass ejection (CME) that was ejected from the Sun at about 1700 UT on 2 November 2003. The CME, which was associated with an X8.3 solar flare from W56°, was observed by the Mauna Loa and Solar and Heliospheric Observatory (SOHO) La…
Cosmic-ray diffusion in the inner heliosphere
McKibben, R. B.
For about the last 40 years, we have been trying to understand the propagation of cosmic rays and other energetic charged particles through the interplanetary medium. Identification of the basic processes affecting the propagation, namely diffusion, convection by the solar wind, adiabatic deceleration, and gradient and curvature drifts, was attain…
State Transition and Flaring Activity of IGR J17464-3213/H1743-322 with INTEGRAL SPI
Capitanio, F.; Ubertini, P.; Malzac, J. +4 more
IGR J17464-3213, already known as the HEAO 1 transient source H1743-322, has been detected during a state transition by INTEGRAL SPI. We describe the spectral evolution and flaring activity of IGR J17464-3213/H1743-322 from 2003 March 21 to 2003 April 22. During the first part, the source followed a continuous spectral softening, with the peak of …
Spectroscopic behaviour of the unusual Ae star HD 190073
Pogodin, M. A.; Franco, G. A. P.; Lopes, D. F.
The results of high-resolution spectroscopy of the peculiar Ae star HD 190073 obtained within the framework of a cooperative observing programme in 1994-2002 are presented. The temporal behaviour of the Hα, Hβ, Hγ, Hδ, He i λ 5876 Å, Na i D and other circumstellar line profiles are investigated in detail. Special attention has been paid to the ana…
2D Feature Recognition And 3d Reconstruction In Solar Euv Images
Aschwanden, Markus J.
EUV images show the solar corona in a typical temperature range of T >rsim 1 MK, which encompasses the most common coronal structures: loops, filaments, and other magnetic structures in active regions, the quiet Sun, and coronal holes. Quantitative analysis increasingly demands automated 2D feature recognition and 3D reconstruction, in order to…
Correlation patterns between 11 diffuse interstellar bands and ultraviolet extinction
Krełowski, J.; Megier, A.; Weselak, T.
We relate the equivalent widths of 11 diffuse interstellar bands, measured in the spectra of 49 stars, to different colour excesses in the ultraviolet. We find that most of the observed bands correlate positively with the extinction in the neighbourhood of the 2175-Åbump. Correlation with colour excesses in other parts of the extinction curve is m…
XMM-Newton data processing for faint diffuse emission. Proton flares, exposure maps and report on EPIC MOS1 bright CCDs contamination
Kerp, J.; Pradas, J.
We present a study of the in-flight performance of the XMM-Newton EPIC MOS and pn detectors, with focus on the influence of proton flares and vignetting on the data. The very wide range in the conditions of our sample of observations, in terms of exposure length and background intensities, allows the detection of a wide range in the spectra of the…
Outflowing material in the compact steep-spectrum source quasar 3C 48: evidence of jet-cloud interaction?
Saikia, D. J.; Srianand, R.; Gupta, Neeraj
We report on the detection of a zabs= 0.3654 associated absorption-line system in the ultraviolet spectrum of the compact steep-spectrum source (CSS) quasar 3C 48. The absorbing material is blueshifted with respect to the quasar emission-line redshift, zem= 0.3700, suggesting an outflow velocity of ~1000 km s-1. We…
The Discovery of Oxygen Kα X-Ray Emission from the Rings of Saturn
Bhardwaj, Anil; Gladstone, G. Randall; Cravens, Thomas E. +3 more
Using the Advanced CCD Imaging Spectrometer (ACIS), the Chandra X-Ray Observatory observed the Saturnian system for one rotation of the planet (~37 ks) on 2004 January 20 and again on January 26-27. In this Letter we report the detection of X-ray emission from the rings of Saturn. The X-ray spectrum from the rings is dominated by emission in a nar…