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Infrared Spectroscopy of NGC 1068: Probing the Obscured Ionizing AGN Continuum
Lutz, Dieter; Netzer, Hagai; Alexander, Tal +3 more
The ISO-SWS4 2.5-45 µm infrared spectroscopic observations of the nucleus of the Seyfert 2 galaxy NGC 1068 (see companion paper) are combined with a compilation of UV to IR narrow emission line data to determine the spectral energy distribution (SED) of the obscured extreme-UV continuum that photoionizes the narrow-line-emitting gas in the a…
Low-frequency p- and g-mode solar oscillations
Provost, J.; Berthomieu, G.; Morel, P.
In order to help the detection and identification of low-frequency p- and g-modes in the solar spectrum observed by ground-based networks and SoHO experiments, we study the properties of low degree (l=0 - 6) low-frequency (100 - 2000 mu Hz) solar oscillations. The frequencies of p- and g-modes have been computed for a set of solar models with upda…
ISO Spectroscopy of the young bipolar nebulae S106 IR and Cep A East
Tielens, A. G. G. M.; van den Ancker, M. E.; Wesselius, P. R.
We present the results of ISO SWS and LWS grating scans towards the embedded Young Stellar Objects (YSOs) S106 IR and Cep A East. Emission from the pure rotational lines of H_2 and the infrared fine structure lines of [C ii], [O i], [S i], [Si ii] and [Fe ii], as well as absorption bands due to H_2O, CO and CO_2 ice were detected toward Cep A. In …
Mode Identification of Pulsating White Dwarfs Using the Hubble Space Telescope
Kepler, S. O.; Clemens, J. C.; Jiang, X. J. +3 more
We have obtained time-resolved ultraviolet spectroscopy for the pulsating DAV stars G226-29 and G185-32 and for the pulsating DBV star PG 1351+489 with the Hubble Space Telescope Faint Object Spectrograph to compare the ultraviolet to the optical pulsation amplitude and determine the pulsation indices. We find that for essentially all observed pul…
The discovery of a low-mass, pre-main-sequence stellar association around γ Velorum
Jeffries, R. D.; Naylor, T.; Pozzo, M. +3 more
We report the serendipitous discovery of a population of low-mass, pre-main-sequence (PMS) stars in the direction of the Wolf-Rayet/O-star binary system γ2Vel and the Vela OB2 association. We argue that γ2Vel and the low-mass stars are truly associated and approximately coeval, and that both are at distances between 360 and 4…
Infrared Spectroscopy of Molecular Supernova Remnants
Reach, William T.; Rho, Jeonghee
We present Infrared Space Observatory spectroscopy of sites in the supernova remnants W28, W44, and 3C 391, where blast waves are impacting molecular clouds. The complete wavelength range from 42 to 188 µm was observed with the Long Wavelength Spectrometer, as well as narrow ranges centered on 4.695, 9.665, 25.98, and 34.82 µm with the…
Keck Mid-Infrared Imaging of QSO 2237+0305
Agol, Eric; Jones, Barbara; Blaes, Omer
Using the Long Wavelength Spectrometer on Keck, we have imaged the gravitationally lensed radio-quiet quasi-stellar object QSO 2237+0305 at 8.9 and 11.7 µm for the first time. The mid-IR flux ratios are inconsistent with the optical flux ratios but agree with the radio flux ratios and with some published gravitational lens models. These flux…
Inner source distributions: Theoretical interpretation, implications, and evidence for inner source protons
Geiss, J.; Schwadron, N. A.; Zurbuchen, T. H. +3 more
A new and important source of pickup ions has been recently observed for the first time, the so-called inner source. We examine properties of inner source ions at high heliographic latitudes through analysis of data from the Solar Wind Ion Composition Spectrometer on the Ulysses satellite for a period extending through the year of 1994 while Ulyss…
SN 1987A's Circumstellar Envelope. II. Kinematics of the Three Rings and the Diffuse Nebula
Crotts, Arlin P. S.; Heathcote, Stephen R.
We present several different measurements of the velocities of structures within the circumstellar envelope of SN 1987A, including the inner, equatorial ring (ER), the outer rings (ORs), and the diffuse nebulosity at radii <~5 pc, based on CTIO 4 m and Hubble Space Telescope (HST) data. A comparison of STIS and WFPC2 [N II] λ6583 loci for the r…
O-bearing Molecules in Carbon-rich Proto-Planetary Objects
Cernicharo, J.; Herpin, F.
We present Infrared Space Observatory long-wavelength spectrometer observations of the proto-planetary nebula CRL 618, a star evolving very fast toward the planetary nebula stage. In addition to the lines of 12CO, 13CO, HCN, and HNC, we report on the detection of H2O and OH emission together with the fine-structure…