Search Publications
Interpretation of a complex CME event: Coupling of scales in multiple flux systems
Pick, M.; Delaboudinière, J. -P.; Aulanier, G. +3 more
Using multi-wavelength observations, in particular in imagery, recorded by SOHO/LASCO-MDI, Yohkoh/SXT, the Meudon spectroheliograph and the Nançay radioheliograph, and performing a linear force-free field extrapolation, we analyzed the triggering and the development of a complex eruptive event in the chromosphere and in the corona. This event incl…
Hα Dimmings Associated with the X1.6 Flare and Halo Coronal Mass Ejection on 2001 October 19
Wang, Haimin; Ji, Haisheng; Chen, Huadong +1 more
As the optical counterpart of coronal dimmings, we present the first direct evidence of Hα dimmings associated with the X1.6 flare, filament eruption, and coronal mass ejection (CME) that occurred on 2001 October 19. As two main Hα flare ribbons parallel to the erupting filament slowly separated, two other ribbons first quickly expanded near the f…
First INTEGRAL observations of Cygnus X-3
Goldoni, P.; Westergaard, N. J.; Kretschmar, P. +10 more
We present the first INTEGRAL results on Cyg X-3 from the PV phase observations of the Cygnus region. The source was clearly detected by the JEM-X, ISGRI and SPI. The INTEGRAL observations were supported by simultaneous pointed RXTE/ observations. Their lightcurves folded over the 4.8 hour binary period are compatible with the mean RXTE/ASM and ga…
Probing the Complex and Variable X-Ray Absorption of Markarian 6 with XMM-Newton
Brandt, W. N.; Bauer, Franz E.; Vignali, Cristian +4 more
We report on an X-ray observation of the Seyfert 1.5 galaxy Mrk 6 obtained with the EPIC instruments on board XMM-Newton. Archival BeppoSAX Phoswich Detection System data from 18-120 keV were also used to constrain the underlying hard power-law continuum. The results from our spectral analyses generally favor a double partial-covering model, altho…
Yet another galaxy identification for an ultraluminous X-ray source
Palazzi, E.; Masetti, N.; Foschini, L. +4 more
We report on the identification of the optical and infrared counterparts of the ultraluminous X-ray source (ULX) XMMU J121214.5+131248 (NGC4168-ULX1). The optical spectrum yields a redshift of z=0.217, which implies that the ULX is not associated with the nearby galaxy NGC 4168, but rather with a background object. Optical spectral line ratios and…
Coronagraphic Imaging of 3C 273 with the Advanced Camera for Surveys
Ford, H. C.; Infante, L.; Zheng, W. +32 more
The nearby and luminous QSO 3C 273 was imaged in 2002 July with the High Resolution Channel (HRC) of the Advanced Camera for Surveys (ACS) in coronagraphic mode in F475W (g), F606W (V), and F814W (I) as part of the Early Release Observations (ERO) program. After subtraction of the remaining PSF of the QSO, these images offer the most detailed view…
Three Super Active Regions in the Descending Phase of Solar Cycle 23
Guo, Juan; Chen, Jie; Zhang, Yin +12 more
We analyze the magnetic configurations of three super active regions, NOAA 10484, 10486 and 10488, observed by the Huairou Multi-Channel Solar Telescope (MCST) from 2003 October 18 to November 4. Many energetic phenomena, such as flares (including a X-28 flare) and coronal mass ejections (CMEs), occurred during this period. We think that strong sh…
X-Ray Spectroscopy of η Carinae with XMM-Newton
Ramsay, Gavin; Leutenegger, Maurice A.; Kahn, Steven M.
We present XMM-Newton observations of the luminous star η Carinae, including a high-resolution soft X-ray spectrum of the surrounding nebula obtained with the Reflection Grating Spectrometer (RGS). The European Photon Imaging Camera (EPIC) image of the field around η Car shows many early-type stars and diffuse emission from hot, shocked gas. The E…
Does the Sun Shrink with Increasing Magnetic Activity?
Antia, H. M.
It has been demonstrated that frequencies of f-modes can be used to estimate the solar radius to a good accuracy. These frequencies have been used to study temporal variations in the solar radius with conflicting results. The variation in f-mode frequencies is more complicated than what is assumed in these studies. If a careful analysis is perform…
An Icy, Bipolar Proto-Planetary Nebula with Knotty Jets: IRAS 22036+5306
Sahai, R.; Sánchez Contreras, C.; Zijlstra, A. +1 more
Using the Hubble Space Telescope's Wide Field Planetary Camera 2, we have discovered that the proto-planetary nebula (PPN) IRAS 22036+5306 (I22036) is an extended (5.7"×1.3") bipolar nebula. A dark, (partial) ringlike band defines the nebular waist region and probably results from a tilted, geometrically thick disk that obscures the central star. …