Search Publications
The entropy in groups a clue to galaxy formation
Mushotzky, Richard
The entropy in the hot X-ray gas in groups of galaxies is a fossil of the process of galaxy formation The amount of entropy in these low mass systems considerably exceeds that predicted from structure formation models. To explain these results requires "extra" energy which is a relic of the process of star formation and active galaxy heating. We p…
Probing diffusion parameters of suprathermal ions near heliospheric shocks
Klecker, B.; Hilchenbach, M.; Kallenbach, R. +1 more
The distribution functions of suprathermal ions in the energy range 35-2000 keV/amu associated with the interplanetary coronal mass ejection of 14-16 July 2000 are analyzed. The ion spectra agree with a theoretical model on momentum diffusion in two-dimensional magnetohydrodynamic turbulence.
Measuring the matter distribution within z = 0.2 cluster lenses with XMM-Newton
Smail, I.; Kneib, J. P.; Czoske, O. +4 more
We present an analysis of seven clusters observed by XMM-Newton as part of our survey of 17 most X-ray luminous clusters of galaxies at z ∼ 0.2 selected for a comprehensive and unbiased study of the mass distribution in massive clusters. Using the public software FTOOLS and XMMSAS we have set up an automated pipeline to reduce the EPIC MOS and pn …
A survey of radio jets with Chandra and HST
Sambruna, Rita M.
Relativistic jets are a common property of radio-loud Active Galactic Nuclei (AGN). Understanding jet physical properties is an essential precursor to understanding the mechanisms of energy transport, and ultimately, how energy is extracted from the central black hole. In this paper, I highlight recent developments from Chandra and HST observation…
Ultraviolet images of galaxies from the Optical Monitor on XMM-Newton
Kaastra, J. S.; Branduardi-Raymont, G.; Kahn, S. M. +3 more
A large number of galaxies, both normal and active, have been observed in ultraviolet light by the Optical Monitor on XMM-Newton. These are some of the deepest wide-field ultraviolet images of these galaxies yet obtained, and in many cases the first collected in this waveband. We present images of five active galaxies, and discuss the potential us…
Some comments on the F ring-Prometheus-Pandora environment
Winter, O. C.; Giuliatti Winter, S. M.
The system formed by the F ring and two close satellites, Prometheus and Pandora, has been analysed since the time that Voyager visited the planet Saturn. During the ring plane crossing in 1995 the satellites were found in different positions as predicted by the Voyager data. Besides the mutual effects of Prometheus and Pandora, they are also dist…
Remote infrared observations of parent volatiles in comets: A window on the early solar system
Dello Russo, N.; Mumma, M. J.; DiSanti, M. A. +3 more
Organic volatiles and water in Oort Cloud comets were investigated at infrared wavelengths. The detected species include H 2O, CO, CH 3OH, CH 4, C 2H 2, C 2H 6, OCS, HCN, NH 3, and H 2CO. Several daughter fragments (CN, OH, NH 2, etc.) are…
Relation between the radial speed and theexpansion speed of coronal mass ejections
Schwenn, R.; Gonzalez, W. D.; Dal Lago, A.
We have selected 57 limb coronal mass ejections observed by LASCO during the period of January1997 to April 2001. We used the related EIT activity close to the limb to define these CMEs as "limbs". We measured the radial speed of the leading edge close to the center of these CMEs and the lateral expansion speed of the structures. Comparison of bot…
Discontinuity observations with cluster
Balogh, A.; Neubauer, F. M.; Horbury, T. +1 more
Observations of solar wind magnetic field discontinuities using four spacecraft allow their orientation to be estimated by relative timings referred to as triangulation. From February 1st until May 13th 2001 the Cluster orbit traversed the solar wind. During these periods we identified 489 directional discontinuities (DDs) using the Tsurutani-Smit…
Coronal mass ejections: Initiation and detection
Gopalswamy, N.
Coronal mass ejections (CMEs) are large-scale magnetic structures expelled from the Sun due to MHD processes involving interaction between plasma and magnetic field in closed field regions. I provide a summary of the observational signatures and current models on CME initiation. I also discuss the multiwavelength signatures of CMEs, which have hel…