Search Publications
Solar wind proton flux latitudinal variations: Comparison between Ulysses in situ data and indirect measurements from interstellar Lyman α mapping
Lallement, Rosine; Quémerais, Eric; Summanen, Tuula
We compare the solar wind proton flux latitude dependence derived in the past from the interstellar neutral H distribution in the inner heliosphere from Lyman α observations with recent ``in situ'' solar wind observations by Ulysses [Goldstein et al., 1995, Phillips et al., 1995, 1996, J. L. Phillips, private communication, 1996]. We find common f…
Polarization sensitivity of the SUMER instrument on SOHO
Lemaire, P.; Hassler, D. M.; Longval, Y.
A Self-consistent Photoionization-Dust Continuum-Molecular Line Transfer Model of NGC 7027
Volk, Kevin; Kwok, Sun
A model to simulate the entire spectrum (1000 Å to 1 cm) of the high-excitation young planetary nebula NGC 7027 is presented. The ionized, dust, and molecular components of the object are modeled using geometric parameters obtained from visible, radio, infrared, and CO data. The physical processes considered include recombination lines of H and He…
Non-spherical source-surface model of the heliosphere: a scalar formulation
Schulz, M.
The source-surface method offers an alternative to full MHD simulation of the heliosphere. It entails specification of a surface from which the solar wind flows normally outward along straight lines. Compatibility with MHD results requires this (source) surface to be non-spherical in general and prolate (aligned with the solar dipole axis) in prot…
High Dynamic Range VLA Observations of the Gravitationally Lensed Quasar 0957+561
Stocke, John T.; Morse, Jon A.; Harvanek, Michael +1 more
We present 2, 3.6, 6, and 20 cm radio maps of the gravitationally leased quasar 0957+561 obtained with the VLA in A configuration. Besides the well-known jet and lobe structure associated with image A and the point sources associated with image B and the radio source G, the new 3.6 cm maps show interesting extensions of radio source G towards and …
New Perspectives on AX Monocerotis
Wilson, R. E.; Güdel, Manuel; Guinan, Edward F. +6 more
AX Moncerotis is a 232d, noneclipsing, interacting binary star that consists of a K giant, a Be-like giant, and large amounts of circumstellar material. The K star is almost certainly a synchronous rotator and is probably in contact with its critical lobe. The Be star was believed to be a rapid rotator based on extremely wide absorption…
Cosmic ray latitudinal effects predicted by a three-dimensional drift model
Potgieter, M. S.; Burger, R. A.; Hattingh, M. +1 more
The Ulysses spacecraft measured surprisingly small latitudinal gradients during its first passage through the polar regions of the heliosphere. This is in contrast to predictions made with two-dimensional drift models for A > 0 magnetic polarity epochs during solar minimum modulation conditions. Several modifications to drift models have been i…
Simultaneous Hubble Space Telescope and ASCA Observations of LMC X-4: X-Ray Ionization Effects on a Stellar Wind
McCray, R.; Cheng, F. H.; Boroson, B. +2 more
We present first results from simultaneous ultraviolet (HST/GHRS) and X-ray (ASCA) observations of the 13.5 s pulsar LMC X-4, taken in 1996 May. The ASCA observations covered 1.12 binary orbits (1.58 days), and the Hubble Space Telescope observations were centered on this for roughly 0.4 orbital phase coverage (0.56 days). The Goddard High Resolut…
The ultraviolet to X-ray spectrum of the Seyfert 1 galaxy E 1615+061: accretion disk and reflection models.
Piro, L.; Perola, G. C.; Fiore, F. +4 more
The Seyfert 1 galaxy E 1615+061 is a candidate for the strongest variability in soft X-rays, changing from a very steep high state ({GAMMA}=~4), as implied by HEAO1 observations performed in 1977, to a two orders of magnitude dimmer state with a flatter spectrum ({GAMMA}=~2), as observed by EXOSAT in 1985. In this paper we present the results of a…
The mass-loss history of the symbiotic nova RR Telescopii.
Nussbaumer, H.; Dumm, T.
Mass loss in symbiotic novae is of interest to the theory of nova-like events as well as to the question whether symbiotic novae could be precursors of type Ia supernovae. RR Tel began its outburst in 1944. It spent five years in an extended state with no mass-loss before slowly shrinking and increasing its effective temperature. This transition w…