Search Publications
The outflow in Mrk 509. A method to calibrate XMM-Newton EPIC-pn and RGS
Kaastra, J. S.; Cappi, M.; Costantini, E. +3 more
We analyzed three XMM-Newton observations of the Seyfert 1 galaxy Mrk 509, with the goal of detecting small variations in the ionized outflow properties. Measurements such as these are limited by the quality of the cross-calibration between RGS, the best instrument for characterizing the spectrum, and EPIC-pn, the best instrument for characterizin…
TRACE Observations of Changes in Coronal Hole Boundaries
Kahler, S.; Jibben, P.; DeLuca, E. E.
Solar coronal holes (CHs) are large regions of the corona magnetically open to interplanetary space. The nearly rigid north - south CH boundaries (CHBs) of equatorward extensions of polar CHs are maintained while the underlying photospheric fields rotate differentially, so interchange magnetic reconnection is presumed to be occurring continually a…
Properties of a Polar Coronal Hole During the Solar Minimum in 2007
Hahn, M.; Savin, D. W.; Landi, E. +2 more
We report measurements of a polar coronal hole during the recent solar minimum using the Extreme Ultraviolet Imaging Spectrometer on Hinode. Five observations are analyzed that span the polar coronal hole from the central meridian to the boundary with the quiet-Sun corona. We study the observations above the solar limb in the height range of 1.03-…
Dark Matter Distribution in Galaxy Groups from Combined Strong Lensing and Dynamics Analysis
Crampton, David; Thanjavur, Karun; Willis, Jon
Using a combined analysis of strong lensing and galaxy dynamics, we characterize the mass distributions and the mass-to-light (M/L) ratios of galaxy groups, virialized structures in the mass range of few × 1014 M sun, which form an important transition regime in the hierarchical assembly of mass in ΛCDM cosmology. Our goals a…
Modified Coronal Index of the Solar Activity
Lukáč, B.; Rybanský, M.
The original coronal index of the solar activity (CI) has been constructed on the basis of ground-based measurements of the intensities of the coronal line of 530.3 nm (Rybanský in Bull. Astron. Inst. Czechoslov., 28, 367, 1975; Rybanský et al. in J. Geophys. Res., 110, A08106, 2005). In this paper, CI is compared with the EUV measurements on the …
The flyby of Rosetta at asteroid Šteins - mission and science operations
Accomazzo, Andrea; Lodiot, Sylvain; Küppers, Michael +2 more
The international Rosetta mission, a cornerstone mission of the european space agency scientific Programme, was launched on 2nd March 2004 on its 10 years journey towards a rendezvous with comet Churyumov-Gerasimenko ( Gardini et al., 1999). During its interplanetary flight towards its target Rosetta crosses the asteroid belt twice with the opport…
The Multiple Pre-main-sequence System HBC 515 in L1622
Reipurth, Bo; Aspin, Colin; Herbig, George
The bright pre-main-sequence star HBC 515 (HD 288313) located in the L1622 cometary cloud in Orion has been studied extensively with optical/infrared imaging and ultraviolet/optical/infrared spectroscopy. The spectra indicate that HBC 515 is a weakline T Tauri star (TTS) of spectral type K2V. Adaptive optics imaging in the K band reveals that HBC …
HESS J1632-478: an energetic relic
Tramacere, A.; Walter, R.; Pohl, M. +4 more
Aims: HESS J1632-478 is an extended and still unidentified TeV source in the galactic plane.
Methods: In order to identify the source of the very high energy emission and to constrain its spectral energy distribution, we used a deep observation of the field obtained with XMM-Newton together with data from Molonglo, Spitzer and Fermi to d…
Comprehensive ground-based and in situ observations of substorm expansion phase onset
Zhang, T. L.; Fazakerley, A. N.; Volwerk, M. +8 more
In this paper, we present comprehensive ground-based and space-based in situ geosynchronous observations of a substorm expansion phase onset on 1 October 2005. The Double Star TC-2 and GOES-12 spacecraft were both located within the substorm current wedge during the substorm expansion phase onset, which occurred over the Canadian sector. We find t…
Unveiling the hard X-ray spectrum from the `burst-only' source SAX J1753.5-2349 in outburst
Mereghetti, S.; Degenaar, N.; Wijnands, R. +4 more
Discovered in 1996 by BeppoSAX during a single type-I burst event, SAX J1753.5-2349 was classified as `burst-only' source. Its persistent emission, either in outburst or in quiescence, had never been observed before 2008 October, when SAX J1753.5-2349 was observed for the first time in outburst. Based on INTEGRAL observations, we present here the …