Search Publications

Erratum: A high-velocity ionized outflow and XUV photosphere in the narrow emission line quasar PG1211+143

O'Brien, P. T.; King, A. R.; Reeves, J. N. +3 more

DEPFET development at the MPI semiconductor laboratory

Lutz, Gerhard

The DEPFET device concept offers unique properties that make it useful for applications in X-ray astronomy and particle physics as well as in other fields. They form the basis for two major projects of the MPI Semiconductor Laboratory. This survey reviews device concepts, potential, technology and properties of devices produced at the laboratory. …

Explosive events in the solar atmosphere seen in extreme-ultraviolet emission lines

Wilhelm, K.; Mendoza-Torres, J. E.; Torres-Papaqui, J. P.

We present observations of explosive events (EEs) in the solar atmosphere obtained with the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the Solar and Heliospheric Observatory (SOHO) in the wavelength range from about 750 Å to 790 Å. Prominent spectral lines in this range are emitted by ions which have temperatures o…

Wavelet Spectrum Analysis Of Eit/Soho Images

Delouille, V.; De Patoul, J.; Hochedez, J. F. +2 more

The extreme ultraviolet imaging telescope (EIT) of SOHO offers a unique record of the solar atmosphere for its sampling in temperature, field of view, resolution, duration, and cadence. To investigate globally and locally its topology and evolution during the solar cycle, we consider a multi-scale approach, and more precisely we use the wavelet sp…

Diffuse galactic sub-MeV γ -ray excess from high-energy electrons

Strong, A. W.; Schlickeiser, R.; Schröder, R.

Recent INTEGRAL observations have confirmed the existence of diffuse sub-MeV radiation from the inner Galaxy. We propose a new explanation for the origin of this diffuse component in terms of electrostatic bremsstrahlung radiation from high-energy electrons. This electrostatic bremsstrahlung interpretation requires a very flat power law energy spe…

Low-Frequency Plasma Waves in the Outer Polar CUSP: A Review of Observations from Prognoz 8, Interball 1, Magion 4, and Cluster

Sauvaud, J. -A.; Santolik, O.; Parrot, M. +7 more

This paper presents a review of the most interesting observations of low-frequency plasma waves together with plasma particles which were made by the Interball 1, Magion 4 and Prognoz 8 satellites in the outer polar cusp. Accelerated plasma particles, hot electron populations and very strong wave activity, particularly at low frequencies, are obse…

Spatial and Temporal Cusp Structures Observed by Multiple Spacecraft and Ground Based Observations

Yeoman, T. K.; Fuselier, S. A.; Reme, H. +6 more

Downward precipitating ions in the cusp regularly exhibit sudden changes in ion energy distributions, forming distinctive structures that can be used to study the temporal/spatial nature of reconnection at the magnetopause. When observed simultaneously with the Polar, FAST, and Interball satellites, such cusp structures revealed remarkably similar…

Detectability of Gamma-Ray Burst Iron Lines by Swift, Chandra, and XMM-Newton

Kallman, T. R.; Mészáros, P.; Gou, L. J.

The rapid acquisition of positions by the upcoming Swift satellite will allow monitoring for X-ray lines in gamma-ray burst (GRB) afterglows at much earlier epochs than was previously feasible. We calculate the possible significance levels of iron-line detections as a function of source redshift and observing time after the trigger for the Swift X…

Coronal mass ejection of 4 April 2000 and associated space weather effects

Jadav, R. M.; Iyer, K. N.; Joshi, H. P. +1 more

The effects of a Halo Coronal Mass Ejection (CME) erupted on 4 April 2000 are studied and reported here. The effect of such CME on the interplanetary medium (IPM) is sensed by the Interplanetary Scintillation (IPS) recorded at Rajkot. The Solar Observations of this CME and associated events, like Solar Energetic Particles (SEP) and flare, are pres…

HT Camelopardalis: the simplest intermediate polar spin pulse

Hellier, Coel; Evans, P. A.

The intermediate polar (IP) HT Cam is unusual in that it shows no evidence for dense absorption in its spectrum. We analyse an XMM-Newton observation of this star, which confirms the absence of absorption and shows that the X-ray spin pulse is energy independent. The modulation arises solely from occultation effects and can be reproduced by a simp…