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Physical and chemical structure of the IC 63 nebula. II. Chemical models.
van Dishoeck, E. F.; Spaans, M.; Black, J. H. +2 more
Chemical models are presented for the photon dominated region (PDR) IC 63, a small isolated molecular cloud located close to the B0.5 IVpe star γ Cas for which we have presented observations of various molecular species in an earlier paper, and for which observations of ionized and neutral atomic carbon, as well as additional CO observations, are …
Ulysses observations of microstreams in the solar wind from coronal holes
Balogh, A.; McComas, D. J.; Goldstein, B. E. +2 more
During its south polar passage in 1994, the Ulysses spacecraft continuously sampled the properties of the solar wind emanating from the south polar coronal hole. At latitudes poleward of ~-60°, the solar wind speed had an average value of 764 km/s and a range of 700-833 km/s. The principal variations in the vector velocity were associated with eit…
Hubble Space Telescope Imaging Polarimetry of the Inner Nuclear Region of NGC 1068
Boksenberg, A.; Capetti, A.; Sparks, W. B. +2 more
We present the results of further Hubble Space Telescope (HST) imaging polarimetry of the inner region of NGC 1068 taken with the COSTAR corrected Faint Object Camera (FOC) in the ultraviolet (2400--2700 A). The centro-symmetric polarization pattern revealed by previous HST imaging polarimetry is shown to extend even closer to the illumination sou…
The Heating of Dust in Starburst Galaxies: The Contribution of the Nonionizing Radiation
Heckman, Timothy M.; Calzetti, D.; Storchi-Bergmann, T. +2 more
The IUE UV and optical spectra and the far-infrared (FIR) IRAS flux densities of a sample of starburst and blue compact galaxies are used to investigate the relationship between dust obscuration and dust emission. The amount of dust obscuration at UV wavelengths correlates with the FIR- to-blue ratio; and an analysis of the correlation indicates t…
Ulysses observation of a noncoronal mass ejection flux rope: Evidence of interplanetary magnetic reconnection
Balogh, A.; McComas, D. J.; Forsyth, R. J. +5 more
A well-defined, small-scale (~0.05 AU) magnetic flux rope was observed by Ulysses at about 5 AU in close proximity to a heat flux dropout (HFD) at the heliospheric current sheet (HCS). This magnetic flux rope is characterized by a rotation of the field in the plane approximately perpendicular to the ecliptic (and containing the Sun and the spacecr…
C+ pickup ions in the heliosphere and their origin
Geiss, J.; Gloeckler, G.; Fisk, L. A. +1 more
C+ pickup ions were discovered with the solar wind ion composition spectrometer flying on Ulysses. Whereas the other nonlocally occurring pickup ions are produced from the interstellar gas penetrating deep into the heliosphere, C+ comes from an ``inner source'' which is located at a solar distance of a few AU and extends over…
Discovery of an ultrasoft transient ROSAT AGN: WPVS 007.
de Martino, D.; Grupe, D.; Mannheim, K. +3 more
We have identified the ROSAT source RX J0039.2-5117 with the previously almost unknown 'narrow line' Seyfert 1 galaxy WPVS007 (z = 0.028). The X-ray source displays quite unusual properties for an AGN. It was bright and ultrasoft in the ROSAT All-Sky Survey (RASS) and found at a level lower by a factor of ~400 in PSPC count rate in 1993. The impli…
Interstellar MG II Absorption Lines from Low-Redshift Galaxies
Bowen, David V.; Pettini, Max; Blades, J. Chris
We have used the GHRS aboard HST to search for interstellar Mg II 2796, 2803 absorption from the disks and halos of 17 low-redshift galaxies, using as probes QSOs and extragalactic supernovae whose sight lines pass close to, or through, intervening galaxies. The galaxies studied are of diverse morphological type, reside in different environments, …
The Polarized Spectrum of the Fe II-rich Broad Absorption Line QSO IRAS 07598+6508
Hines, Dean C.; Wills, Beverley J.
We present IUE spectrophotometry and optical spectropolarimetry of the ultraluminous, extreme Fe II--emitting QSO IRAS 07598+6508. We find broad absorption troughs from high- and low-ionization species, showing that this object is a member of the class of rare low-ionization broad absorption line (BAL) QSOs. Compared with non-BAL QSOs, the spectra…
Performance and Preliminary Calibration of the Hopkins Ultraviolet Telescope on the Astro-2 Mission
Blair, William P.; Kriss, Gerard A.; Davidsen, Arthur F. +4 more
An improved version of the Hopkins Ultraviolet Telescope (HUT) made its second flight on the Astro-2 mission aboard the Space Shuttle Endeavour from 1995 March 2--18. The longer mission duration and greatly improved pointing stability relative to Astro-1 made possible 385 observations of 265 celestial targets at far-ultraviolet wavelengths. Observ…