Search Publications
Coronal Holes and Solar Wind High-Speed Streams: I. Forecasting the Solar Wind Parameters
Veronig, Astrid M.; Temmer, Manuela; Vršnak, Bojan
We analyze the relationship between the coronal hole (CH) area/position and physical characteristics of the associated corotating high-speed stream (HSS) in the solar wind at 1 AU. For the analysis we utilize the data in the period DOY 25 - 125 of 2005, characterized by a very low coronal mass ejection (CME) activity. Distinct correlations between…
Statistical properties of a sample of periodically variable B-type supergiants. Evidence for opacity-driven gravity-mode oscillations
Aerts, C.; Puls, J.; Lefever, K.
Aims:We have studied a sample of 28 periodically variable B-type supergiants selected from the HIPPARCOS mission and 12 comparison stars covering the whole B-type spectral range. Our goal is to test if their variability is compatible with opacity-driven non-radial oscillations.
Methods: We have used the NLTE atmosphere code FASTWIND to derive …
Quasi-periodic Variability in NGC 5408 X-1
Cropper, Mark; Soria, Roberto; Mushotzky, Richard F. +3 more
We report the discovery with XMM-Newton of quasi-periodic variability in the 0.2-10 keV X-ray flux from the ULX NGC 5408 X-1. The average power spectrum of all EPIC-pn data reveals a strong 20 mHz QPO with an average amplitude (rms) of 9% and a coherence Q≡ν0/σ~6. In a 33 ks time interval when the 20 mHz QPO is strongest we also find ev…
The Star Formation Epoch of the Most Massive Early-Type Galaxies
van Dokkum, Pieter G.; van der Marel, Roeland P.
We present new spatially resolved Keck spectroscopy of early-type galaxies in three galaxy clusters at z~0.5. We focus on the fundamental plane (FP) relation and combine the kinematics with structural parameters determined from HST images. The galaxies obey clear FP relations, which are offset from the FP of the nearby Coma Cluster due to passive …
Energetic electron acceleration in the downstream reconnection outflow region
Balogh, A.; RèMe, H.; Daly, P. W. +5 more
Energetic electrons in an earthward reconnection outflow region have been observed by Cluster/Research with Adaptive Particle Imaging Detectors. We found a good correlation between the energetic electron enhancement and a normal magnetic field (Bz) enhancement within a 0.25-s time resolution. The large normal magnetic field is thought t…
The XMM-Newton Wide-Field Survey in the COSMOS Field. II. X-Ray Data and the logN-logS Relations
Finoguenov, A.; Böhringer, H.; Fiore, F. +13 more
We present data analysis and X-ray source counts for the first season of XMM-Newton observations in the COSMOS field. The survey covers ~2 deg2 within the region of sky bounded by 09h57m30s<R.A.<10h03m30s, 01deg27'30''<decl.<02…
The XMM-Newton EPIC background and the production of background blank sky event files
Read, A. M.; Carter, J. A.
Aims:We describe in detail the nature of XMM-Newton EPIC background and its various complex components, summarising the new findings of the XMM-Newton EPIC background working group, and provide XMM-Newton background blank sky event files for use in the data analysis of diffuse and extended sources.
Methods: Blank sky event file data sets are p…
MIRO: Microwave Instrument for Rosetta Orbiter
Rauer, H.; Hartogh, P.; Lellouch, E. +30 more
The European Space Agency Rosetta Spacecraft, launched on March 2, 2004 toward Comet 67P/Churyumov-Gerasimenko, carries a relatively small and lightweight millimeter-submillimeter spectrometer instrument, the first of its kind launched into deep space. The instrument will be used to study the evolution of outgassing water and other molecules from …
Eclipsing binaries observed with the WIRE satellite. II. β Aurigae and non-linear limb darkening in light curves
Southworth, J.; Bruntt, H.; Buzasi, D. L.
Aims:We present the most precise light curve ever obtained of a detached eclipsing binary star and use it investigate the inclusion of non-linear limb darkening laws in light curve models of eclipsing binaries. This light curve, of the bright eclipsing system β Aurigae, was obtained using the star tracker aboard the wire satellite and contains 30 …
Discovery of multiple Lorentzian components in the X-ray timing properties of the Narrow Line Seyfert 1 Ark 564
Papadakis, I. E.; Page, M. J.; Uttley, P. +4 more
We present a power spectral analysis of a 100-ks XMM-Newton observation of the Narrow Line Seyfert 1 galaxy Ark 564. When combined with earlier RXTE and ASCA observations, these data produce a power spectrum covering seven decades of frequency which is well described by a power law with two very clear breaks. This shape is unlike the power spectra…