Search Publications
A Possible Cepheid-like Luminosity Estimator for the Long Gamma-Ray Bursts
Ramirez-Ruiz, Enrico; Hurley, Kevin; Reichart, Daniel E. +3 more
We present a possible Cepheid-like luminosity estimator for the long gamma-ray bursts based on the variability of their light curves. To construct the luminosity estimator, we use CGRO/BATSE data for 13 bursts, Wind/Konus data for five bursts, Ulysses/GRB data for one burst, and NEAR/XGRS data for one burst. Spectroscopic redshifts, peak fluxes, a…
The heliospheric current sheet
Smith, Edward J.
The heliospheric current sheet (HCS) is the boundary between open oppositely directed magnetic field lines which commonly originate as the outward extension of the solar magnetic dipole. The dipole tilt, the rotation of the Sun, and the outward propagation of the solar wind cause peaks and valleys in the current sheet which spiral outward. The HCS…
The afterglow of the short/intermediate-duration gamma-ray burst GRB 000301C : A jet at z=2.04
Greiner, J.; Cline, T.; Hurley, K. +23 more
We present Ulysses and NEAR data from the detection of the short or intermediate duration (2 s) gamma-ray burst GRB 000301C (2000 March 1.41 UT). The gamma-ray burst (GRB) was localised by the Inter Planetary Network (IPN) and RXTE to an area of ~50 arcmin2. A fading optical counterpart was subsequently discovered with the Nordic Optica…
Evidence for a Sudden Magnetic Field Reconfiguration in Soft Gamma Repeater 1900+14
Hurley, Kevin; Kouveliotou, Chryssa; Göǧüş, Ersin +5 more
We report the detection of large flux changes in the persistent X-ray flux of soft gamma repeater (SGR) 1900+14 during its burst active episode in 1998. Most notably, we find a factor of ~700 increase in the nonburst X-ray flux following the August 27 flare, which decayed in time as a power law. Our measurements indicate that the pulse fraction re…
The Giant Flare of 1998 August 27 from SGR 1900+14. I. An Interpretive Study of BeppoSAX and Ulysses Observations
Hurley, K.; Feroci, M.; Duncan, R. C. +1 more
The giant flare of 1998 August 27 from SGR 1900+14 was extraordinary in many ways: it was the most intense flux of gamma rays ever detected from a source outside our solar system; it was longer than any previously detected burst from a soft gamma repeater (SGR) in our Galaxy by more than an order of magnitude; and it showed a remarkable four-peake…
Modulation of Jovian and galactic electrons in the heliosphere: 1. Latitudinal transport of a few MeV electrons
Fichtner, H.; Ferreira, S. E. S.; Potgieter, M. S. +2 more
The heliospheric modulation of galactic and Jovian electrons is studied using a fully three-dimensional, steady state model based on Parker's transport equation including the Jovian source. The modulation of low-energy electrons is a handy tool to establish and to construct a suitable diffusion tensor to assure compatibility between model computat…
Modulation of Cosmic Rays in the Heliosphere From Solar Minimum to Maximum: a Theoretical Perspective
Ferreira, S. E. S.; Potgieter, M. S.; Burger, R. A.
The modulation of galactic cosmic rays in the heliosphere seems to be dominated by four major mechanisms: convection, diffusion, drifts (gradient, curvature and current sheet), and adiabatic energy losses. In this regard the global structure of the solar wind, the heliospheric magnetic field (HMF), the current sheet (HCS), and that of the heliosph…
Ulysses in the south polar cap at solar maximum: Heliospheric magnetic field
Balogh, A.; McComas, D. J.; Forsyth, R. J. +1 more
Observations during the recent ascent of Ulysses to the south polar region are reported. Large variations in field magnitude are associated principally with solar wind interaction regions. The observed spiral angle agrees reasonably well with the Parker model. The magnetic flux, the product of the radial field component and the square of the radia…
Helium energetics in the high-latitude solar wind: Ulysses observations
Reisenfeld, D. B.; McComas, D. J.; Steinberg, J. T. +4 more
We present a study of the interplanetary evolution of solar wind helium (alpha particle) energetics. The analysis of Ulysses observations of the fast high-latitude solar wind concentrates on the radial evolution of the alpha-proton differential streaming vαp, the alpha temperature, and the alpha temperature anisotropy. Ulysses observati…
Ionization state and magnetic topology of coronal mass ejections
Woch, J.; Schwenn, R.; Balogh, A. +5 more
Charge state distributions of heavy solar wind ions measured in interplanetary space can be used to probe the physical conditions in the solar corona. This paper presents a study of the charge state distributions and the magnetic topology of 56 coronal mass ejections (CMEs) observed in interplanetary space by the Ulysses spacecraft. The analysis o…