Search Publications
The Gravitational Lens Candidate FBQ 1633+3134
White, Richard L.; Gregg, Michael D.; Morgan, Nicholas D. +2 more
We present our ground-based optical imaging, spectral analysis, and high-resolution radio mapping of the gravitational lens candidate FBQ 1633+3134. This z=1.52, B=17.7 quasar appears double on CCD images with an image separation of 0.66" and a relatively constant flux ratio of ~3:1 across B, V, R, and I filters. A single 0.27 mJy radio source is …
The Extreme-Ultraviolet Structure and Properties of a Newly Emerged Active Region
Gallagher, Peter T.; Phillips, Kenneth J. H.; Lee, Jeongwoo +2 more
The structure and properties of a newly emerged solar active region (NOAA Active Region 7985) are discussed using the Coronal Diagnostic Spectrometer (CDS) and the Extreme-Ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheric Observatory. CDS obtained high-resolution EUV spectra in the 308-381 Å and 513-633 Å wavelength ranges, w…
Low-angle scattering of protons on the XMM-Newton optics and effects on the on-board CCD detectors
Evans, H.; Nieminen, P.; Daly, E. +3 more
Monte Carlo simulations are presented where protons are shown to propagate through X-ray telescope optics by grazing incidence scattering processes. If these protons reach charge coupled device (CCD) detectors in sufficient numbers, they can induce a radiation background, and at certain energies, the nonionising dose can cause degradation of the c…
Earthward directed CMEs seen in large-scale coronal magnetic field changes, SOHO LASCO coronagraph and solar wind
Plunkett, S. P.; Mulligan, T.; Hoeksema, J. Todd +4 more
One picture of coronal mass ejection (CME) initiation relates these events to the expansion into space of previously closed coronal magnetic fields, often part of the helmet streamer belt. The work described here makes use of the potential field source surface model based on updated synoptic photospheric field maps to study the large-scale coronal…
Injection of energetic protons during solar eruption on 1999 May 9: Effect of flare and coronal mass ejection
Torsti, J.; Innes, D. E.; Kocharov, L. +2 more
A solar energetic particle (SEP) event was observed on 1999 May 9 by the Energetic and Relativistic Nuclei and Electron instrument (ERNE) onboard the Solar and Heliospheric Observatory (SOHO) spacecraft in association with a coronal mass ejection (CME) and X-ray flare at the western limb. Near flare onset the active region coronal loop structure w…
Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the Quasar PG 1351+64
Zheng, W.; Kriss, G. A.; Wang, J. X. +7 more
We present a moderate-resolution (~20 km s-1) spectrum of the mini-broad absorption line quasar (QSO) PG 1351+64 between 915 and 1180 Å, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telesc…
Fast Dust in the Heliosphere
Grün, E.; Landgraf, M.
The dynamics of dust particles in the solar system is dominated by solar gravity, by solar radiation pressure, or by electromagnetic interaction of charged dust grains with the interplanetary magnetic field. For micron-sized or bigger dust particles solar gravity leads to speeds of about 30 to 40 km s^-1 at the Earth's distance. Smaller particles …
ISOCAM observations of the deep IRAS 60 micron sample in the NEP region. II. Comparison of ISO and IRAS galaxy counts
Aussel, H.; Franceschini, A.; De Zotti, G. +3 more
We have determined IRAS flux densities at positions of sources detected by our ISOCAM LW3 observations of the IRAS deep survey sample in the north ecliptic polar region [ApJS 63 (1987) 311]. Exploiting the higher angular resolution of ISOCAM to deal with confusion effects and properly correcting the fluxes for observational biases, we show that 60…
Absolute Magnitudes and Kinematic Parameters of the Subsystem of RR Lyrae Variables
Dambis, A. K.; Rastorguev, A. S.
The statistical parallax technique is applied to a sample of 262 RRab Lyrae variables with published photoelectric photometry, metallicities, and radial velocities and with measured absolute proper motions. Hipparcos, PPM, NPM, and the Four-Million Star Catalog (Volchkov et al. 1992) were used as the sources of proper motions; the proper motions f…
Spectral imaging maps of AR Lacertae . I. Results from IUE observations in 1994 October
Pagano, I.; Linsky, J. L.; Rodonò, M. +4 more
In October 1994 the RS CVn eclipsing binary