Search Publications
Search for pulsed γ-ray emission from radio pulsars in the COS-B data.
Caraveo, P. A.; Bignami, G. F.; Strong, A. W. +13 more
Pulsed gamma-ray emission from radio pulsars has been sought in a study of pulsar parameters for 145 radio observations, contemporary with gamma-ray observations, by the COS-B spacecraft. No signal has been detected in the 50 MeV-2 GeV energy range of the study, either globally or from individual pulsars. These results indicate that the average pr…
The ultraviolet excess of luminous quasars. II. Evidence for massive accretion disks.
Malkan, M. A.
This paper presents new infrared, optical, and ultraviolet spectra of three high-redshift quasars. They are analyzed along with three published quasar spectra. After accounting for other sources of radiation, the continua are fitted with spectra predicted for optically thick steady-state accretion disks which include the effects of general relativ…
Peculiar ultraviolet interstellar extinction.
Savage, B. D.; Fitzpatrick, E. L.; Massa, D.
In connection with investigations of the physical characteristics of interstellar dust, a study of objects with peculiar extinction might provide new insights about the composition, size distribution, formation, and destruction of the particulate matter. Meyer and Savage (1981) have found that the dust toward many stars exhibits peculiar UV extinc…
Herbig-haro objects.
Schwartz, R. D.
Progress in the understanding of Herbig-Haro (HH) objects is reviewed. The results of optical studies of the proper motions and alignments, variability, and polarization of HH objects and the results of spectroscopic studies are discussed. Ground-based infrared studies and far-infrared observations are reviewed. Findings on the properties of molec…
Prominent ultraviolet emission lines from type 1 Seyfert galaxies.
Gull, T. R.; Boggess, A.; Wu, C. -C.
IUE Explorer data with a 6-A resolution are reported for Ly-alpha, C IV 1550 A, C III semiforbidden line 1909 A, and Mg II 2800 A, as well as the continuum at 1450 A, for 20 Seyfert galaxies and one quasar. Good correlation is found between the continuum and the line fluxes, indicating that photoionization is the dominant heating mechanism for the…
IUE and other new observations of the slow nova RR Tel.
Penston, M. V.; Jordan, C.; Macchetto, F. +8 more
IUE satellite UV spectra of RR Tel covering 1150-3200 A at high and low dispersion through both large and small apertures are reported, and a list of 431 lines is presented which gives measured wavelength, intensity, and full width at half maximum. Over three-quarters of the lines are identified, and a correlation is noted between line width and i…
R 127 : an S DOR type variable intermediate between Of and WN.
Stahl, O.; Wolf, B.; Cassatella, A. +4 more
The results of extensive photometric and high resolution spectroscopic observations of the S Dor variable R 127 are presented and discussed. These observations show the star to be hotter than any of its type previously discovered. Its bolometric magnitude is 10.6, its effective temperature is 16,000 K, and its radius is 150 solar radii. The stella…
Coordinated Einstein and IUE observations of a disparitions brusques type flare event and quiescent emission from Proxima Centauri.
Golub, L.; Stencel, R. E.; Linsky, J. L. +4 more
The Einstein Imaging Particle Counter observed a major X-ray flare in its entirety during a 5-hr period of simultaneous observations, with the IUE, of the dM5e flare star Proxima Centauri in August, 1980. The detailed X-ray light curve, temperature determinations during various intervals, and UV line fluxes obtained before, during, and after the f…
A far Ultraviolet extinction law : what does it mean ?
Greenberg, J. M.; Chlewicki, G.
The dust grains in the diffuse cloud medium are characterized by a far-ultraviolet (FUV) extinction "law" so that all curves have the same functional form for inverse wavelengths λ-1 ⪆ 6 µm-1. A direct theoretical consequence of this fact is that there is very little scattering by either the particles responsible for th…
Gamma-rays from atomic and molecular gas in the first galactic quadrant
Caraveo, P. A.; Bignami, G. F.; Strong, A. W. +15 more
The fully sampled Columbia 1 deg CO survey and the Berkeley H I survey are compared with the COS B gamma-ray survey. As a first step, the study is limited to the high-energy gamma-rays (E greater than 300 MeV). It is found that a simple model, in which uniformly distributed cosmic rays interact with the interstellar gas, as traced by H I and CO, c…