Search Publications
XMM- Newton observations of open clusters
Pallavicini, R.; Franciosini, E.; Randich, S.
We present observations of stellar clusters obtained with XMM- Newton as part of the Guaranteed Time program. We have obtained EPIC observations of the open clusters Praesepe, a Per, o Ori and Hyades and of the Taurus-Auriga star-forming region. The results of the analysis are presented and discussed, with emphasis on the imaging data. In all clus…
High-resolution XMM-Newton X-ray spectra of τ SCORPII
Raassen, A. J. J.; Mewe, R.; Güdel, M. +3 more
The first high-resolution X-ray spectra of the B0.2V star τ Scorpii obtained during 22.5ks on Aug. 20, 2001 with the RGS GRATING and the EPIC-MOS CCD spectrometers on board XMM-Newton exhibit bright emission lines of the H- and He-like ions of C, N, O, Ne, Mg, and Si, as well as Fe XVII and Fe XVIII lines. The emission line and continuum spectra h…
Shock acceleration of energetic particles in wave heated corona
Laitinen, T.; Vainio, R.
The solar wind wave heating models require substantial amount of wave power in order to efficiently heat and accelerate solar wind. The level of fluctuations is however limited by energetic particle observations. The simplest cyclotron sweep models result in convection-dominated transport, contradicting observations. However, models incorporating …
Solar radio emissions at solar maximum: Interplanetary perspective
Kaiser, M. L.
At frequencies below 10-15 MHz, radio astronomical observations of the sun are routinely performed in space because Earth's ionosphere effectively prohibits these low frequency emissions from reaching the ground. In terms of solar altitude, these frequencies correspond to about 2 Rs to 1 AU.At these low frequencies, a least four counterparts of th…
Use of non-radiation hardened micro-circuits in space — Experience from the cluster digital wave processor
Alleyne, H. St. C.; Yearby, K. H.
The trend for higher performance, lower cost, space instrumentation is leading towards the use commercial or industrial electronic parts, rather than specifically radiation hardened military grade parts. The micro-processor and memory devices used in the Cluster Digital Wave Processor (DWP) are not specifically radiation hardened parts, although t…
Chasing coronaij x-ray emission to the end of the pleiades main sequence … and beyond?
Briggs, K. R.; Pye, J. P.
We have used a 40-ks XMM-Newton observation to examine the X-ray emission of 33 proposed M-type members in. the core of the Pleiades. We reach a limiting X-ray luminosity of LX ≈ × 10 27 erg s -1 in the field centre and detect 17 of 19 members with MIc < 10.5 (where MIc
Far-Ultraviolet light curves of the δ Scuti variable: β Cassiopeiae
Cugier, H.; Daszyńska, J.
XMM-Newton high-resolution x-ray spectroscopy of the Wolf-Rayet object WR25 (WN6HA+04F)
Schmutz, W.; Raassen, A. J. J.; Mewe, R. +5 more
We report the analysis of the X-ray spectrum of the Wolf-Rayet star WR 25, observed by RGS and EPIC-MOS on board XMM-Newton. Temperatures up to 40 MK have been determined. Strong absorption, exceeding the value due to the Inter Stellar Medium (ISM) has been detected and assigned to the dense stellar wind.
AD Leonis, (dM3:l5V): Analysis of the x-ray spectrum
Raassen, A. J. J.; Mewe, R.; Audard, M. +3 more
We report the analysis of the X-ray spectrum of AD Leo (dM3.5 V), observed by RGS and EPIC-MOS on board XMM-Newton and by LETGS on board Chandra. From the lightcurve the presence of flaring states and a quiescent part is noticed. Temperatures up to 20 MIA have been determined. A significant increase of the emission measure (EM) at high temperature…
Analysis of a coronal loop on the limb
Martens, P. C. H.; Cirtain, J. W.; Winter, H. D.
The ability to accurately measure the temperature and density of the solar atmosphere is essential to understanding the physical nature of Coronal loops. After data has been corrected to account for cosmic ray incidents on the CCD and instrumental effects, there are additional sources of error that must also be addressed. We applied a correction t…