Search Publications
The young star cluster system in the Antennae: evidence for a turnover in the luminosity function
de Grijs, R.; Anders, P.; Fritze-v. Alvensleben, U. +2 more
The luminosity functions (LFs) of star cluster (SC) systems (i.e. the number of clusters per luminosity interval) are vital diagnostics to probe the conditions of SC formation. Early studies have revealed a clear dichotomy between old globular clusters and young clusters, with the former characterized by Gaussian-shaped LFs, and the latter followi…
Formation of VLF chorus frequency spectrum: Cluster data and comparison with the backward wave oscillator model
Pickett, J. S.; Trakhtengerts, V. Y.; Demekhov, A. G. +7 more
The dependence of the frequency spectrum of individual chorus elements on the position of the observation point in and near the generation region is analyzed using recent Cluster data obtained on two different geomagnetically active days. The source of night-side chorus is localized using multicomponent measurements of the wave electric and magnet…
A Synthetic Spectrum and Light-Curve Analysis of the Cataclysmic Variable IX Velorum
Szkody, Paula; Sion, Edward M.; Godon, Patrick +2 more
Spectrum synthesis analysis of FUSE and STIS spectra for the cataclysmic variable IX Vel shows that it is possible to achieve a close synthetic spectrum fit with a mass transfer rate of M˙=5×10-9 Msolar yr-1 and a modified standard model temperature profile. The innermost four annuli of the accretion disk model, ex…
Flare magnetic reconnection and relativistic particles in the 2003 October 28 event
Vial, J. -C.; Li, C.; Dai, Y. +2 more
An X17.2 solar flare occurred on 2003 October 28, accompanied by multi-wavelength emissions and a high flux of relativistic particles observed at 1 AU. We present the analytic results of the TRACE, SOHO, RHESSI, ACE, GOES, hard X-ray (INTEGRAL satellite), radio (Ondeřejov radio telescope), and neutron monitor data. It is found that the inferred ma…
Plasma condensation in coronal loops
Doyle, J. G.; Banerjee, D.; O'Shea, E.
Aims:Using temporal series data from the Coronal Diagnostic Spectrometer (CDS) on SOHO, we seek to investigate plasma condensation through the use of spectroscopic analysis.
Methods: Using a space-time (X-T) type plot we show, for a number of transition region (TR) and coronal lines, the variation of intensity (radiant flux) with time in an of…
Upstream whistler-mode waves at planetary bow shocks: A brief review
Russell, C.
Upstream whistler-mode waves appear to be present in front of all collisionless shocks. Because the whistler-mode group velocity exceeds its phase velocity over the frequency range in which the phase velocity increases with frequency, interesting alterations of polarization and frequency spectrum occur in the observer's reference frame. Landau res…
A deconvolution-based algorithm for crowded field photometry with unknown point spread function
Magain, P.; Gillon, M.; Courbin, F. +4 more
A new method is presented for determining the point
spread function (PSF) of images that lack bright and isolated stars. It is based on the same principles as the MCS image deconvolution algorithm. It uses the information contained in all stellar images to achieve the double task of reconstructing the PSFs for single or mu…Solar Trans-equatorial Activity
Harra, Louise K.; Wang, Jingxiu; Zhang, Yuzong +3 more
We have found that solar flares in NOAA active region (AR) 10696 were often associated with large-scale trans-equatorial activities. These trans-equatorial activities appeared to be very common and manifest themselves through i) the formation and eruption of trans-equatorial loops (TELs), ii) the formation and eruption of trans-equatorial filament…
The Linear Sensitivity of Helioseismic Ring Diagrams to Local Flows
Birch, A. C.; Gizon, L.; Hindman, B. W. +1 more
Ring-diagram analysis is a technique of local helioseismology used to infer plasma flows in the solar convection zone which generates intermediate data products known as ring-fitting parameters. Knowing the sensitivity of ring-fitting parameters to actual flows in the Sun is important for interpreting these measurements. Working in plane-parallel …
X-Ray and Optical Variability of the Ultraluminous X-Ray Source NGC 1313 X-2
Falomo, R.; Treves, A.; Turolla, R. +2 more
We present an analysis of recent XMM-Newton and HST archive data of the ultraluminous X-ray source NGC 1313 X-2. Quasi-simultaneous observations taken with XMM-Newton, HST, and VLT allow us to study both the X-ray light curve and its correlation with the optical emission of the two proposed counterparts of the ultraluminous X-ray source (ULX). At …