Search Publications
A New Look at Carbon Abundances in Planetary Nebulae. I. PB 6, HU 2--1, K648, and H4--1
Henry, R. B. C.; Kwitter, K. B.; Howard, J. W.
We introduce and describe a new long-term project whose goal is to employ final archived lUE spectra to study carbon abundances in a sample of planetary nebulae representing a broad range in progenitor mass and metallicity In this paper we report on initial results for PB 6, Hu 2-1, K648, and H4-1. Our UV line strengths for H4-1 are the first such…
Hubble Space Telescope Observations of the Post-- Core-Collapse Globular Cluster NGC 6752: A Search for Cataclysmic Variables
Bailyn, Charles D.; Cool, Adrienne M.; Grindlay, Jonathan E. +4 more
We report the results of HST WFPC2 observations of the core of NGC 6752. We identify two candidate cataclysmic variables (CVs) from their strong narrowband H alpha emission, periodic variability, and, in one case, a UV excess. We interpret the variability of these stars as being double-peaked, ellipsoidal light curves, in which case the orbital pe…
NGC 5195 - a look into the hot dusty ISM of an interacting SB0 galaxy with ISOCAM.
Altieri, B.; Okumura, K.; Sauvage, M. +8 more
We present broad-band images and a CVF spectrum of NGC 5195, the companion of M51. NGC 5195 appears as a very strong point source while its spectrum is dominated by the so-called PAH features at 6.2, 7.7, 8.6, and 11.3µm. No hot continuum is detected longward of 14µm, and infrared ionic lines are absent from the spectrum. We examine in…
A New Look at Carbon Abundances in Planetary Nebulae. II. BB 1, NGC 650, NGC 1535, NGC 2440, and NGC 7027
Henry, R. B. C.; Kwitter, K. B.
This paper is the second in a series that reports on the outcome of a study of carbon abundances in a carefully chosen sample of planetary nebulae representing a large range in progenitor mass and metallicity. We use the Final Archive lUE database containing consistently reduced lUE spectra to measure line strengths of C III] λ1909, along with num…
The Hot Component of RS Ophiuchi
Mikolajewska, Joanna; Kenyon, Scott J.; Wade, Richard A. +2 more
We analyze optical and ultraviolet spectrophotometry of the quiescent recurrent nova RS Ophiuchi. Our preferred model for this binary consists of an M-type giant and a B-type shell star with a luminosity of Lh∼100-600 Lsun. The ejecta from the recent outburst are slightly enhanced in helium relative to the solar abundance, wh…
Magnetic field signatures of unevolved turbulence in solar polar flows
Balogh, A.; Horbury, T. S.; Forsyth, R. J. +1 more
Between late 1993 and the middle of 1994, Ulysses stayed almost constantly within flows from the Sun's southern polar coronal hole, traveling from 44°S to 69°S heliolatitude and between 4.0 and 2.9 AU from the Sun. Magnetic field observations within this region reveal a very different medium from that at similar heliocentric distances near the ecl…
Astro-2 Observations of Interstellar Dust and Gas in the Large Magellanic Cloud
Clayton, Geoffrey C.; Wolff, Michael J.; Davidsen, Arthur F. +5 more
This paper presents the first UV (1400-3200 A) polarimetry and far-UV (950-1200 A) spectrophotometry ever obtained for reddened stars in the Large Magellanic Cloud (LMC). We derive the UV wavelength dependence of interstellar polarization down to 1400 A and that of extinction down to near the Lyman limit. We also measure column densities of H_2_ a…
DA white dwarfs in pointed observations from the ROSAT archive.
Wolff, B.; Jordan, S.; Koester, D.
87 pointed PSPC (Position Sensitive Proportional Counter) observations of hot DA white dwarfs, available in the ROSAT public archive until the end of 1994, have been analyzed together with Wide Field Camera (WFC) and EXOSAT data. From the 57 objects with a significant count rate half of the objects have a temperature below 38,000K and a virtually …
Hubble Space Telescope and Ground-based Imaging of the Bipolar Proto--Planetary Nebula M1-92: Evidence for a Collimated Outflow
Trammell, Susan R.; Goodrich, Robert W.
We present ground-based and Hubble Space Telescope narrowband images of M1-92. M1-92 is a bipolar proto--planetary nebula currently undergoing the transition from asymptotic giant branch star to planetary nebula. Previous spectropolarimetry of this object revealed that the line emission produced in the bipolar lobes is dominated by shock emission.…
ISM parameters in the normal galaxy NGC 5713.
Helou, G.; Lord, S. D.; Malhotra, S. +11 more
We report ISO Long Wavelength Spectrometer (LWS) observations of the Sbc galaxy NGC 5713. We have obtained strong detections of the fine-structure forbidden transitions [CII] 158µm, [OI] 63µm, and [OIII] 88µm, and significant upper limits for [NII] 122µm, [OIII] 52µm, and [NIII] 57µm, and have measured the galax…