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Hubble Space Telescope and Very Large Array Observations of the H2O Gigamaser Galaxy TXS 2226-184
Wilson, Andrew S.; Henkel, Christian; Falcke, Heino +2 more
We present Hubble Space Telescope/Wide-Field and Planetary Camera 2 images in Hα + [N II] λλ6548, 6583 lines and continuum radiation and a VLA map at 8 GHz of the H2O gigamaser galaxy TXS 2226-184. This galaxy has the most luminous H2O maser emission known to date. Our red continuum images reveal a highly elongated galaxy wit…
Extended Far-Infrared CO Emission in the OMC-1 Core of Orion
Cernicharo, José; Lefloch, Bertrand; González-Alfonso, Eduardo +2 more
We report on sensitive far-infrared observations of 12CO pure rotational transitions in the OMC-1 core of Orion. The lines were observed with the long-wavelength spectrometer in the grating mode on board the Infrared Space Observatory, covering the 43-197 µm wavelength range. The transitions from Jup=14 up to Jup
The End of the Lines for OX 169: No Binary Broad-Line Region
Halpern, J. P.; Eracleous, M.
We show that unusual Balmer emission-line profiles of the quasar OX 169, frequently described as either self-absorbed or double peaked, are actually neither. The effect is an illusion resulting from two coincidences. First, the forbidden lines are quite strong and broad. Consequently, the [N II] λ6583 line and the associated narrow-line component …
Anticipating High-Resolution STIS Spectra of Four Multiphase Mg II Absorbers: A Test of Photoionization Models
Charlton, Jane C.; Churchill, Christopher W.; Rigby, Jane R. +1 more
In this paper we propose a test of the validity of a photoionization modeling technique that is applicable when a combination of high- and low-resolution spectra are available for various chemical transitions. We apply this technique to the four Mg II systems along the line of sight toward the zem=1.335 quasar PG 1634+706 to infer the p…
Measuring the Ionization of O Star Winds
Sonneborn, George; Hutchings, J. B.; Bianchi, Luciana +6 more
We present an analysis of wind line profiles from Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of two O7 supergiants in the Large and Small Magellanic Clouds (Sk -67°111 and AV 232, respectively). Model fits yield the column densities of S IV, S VI, P IV, P V, N III, and N IV, providing the first direct measurement of the ionization balan…
A Grid of Non-LTE Model Atmospheres for White Dwarfs in Cataclysmic Variables
Baron, E.; Barman, Travis S.; Hauschildt, Peter H. +1 more
We have calculated a grid of non-LTE (NLTE) line-blanketed model atmospheres for white dwarfs in cataclysmic variable (CV) systems using our stellar atmosphere code PHOENIX. The grid covers the temperature range 20,000-500,000 K for solar abundances and 10-2 and 10-4 solar metal abundance. The effective temperature resolution…
First Detection of Submillimeter [C I] Emission in the Small Magellanic Cloud
Jackson, James M.; Bolatto, Alberto D.; Zhang, Xiaolei +1 more
We report the first detection of [C I] (3P1-->3P0) emission at 609 µm in a region of the Small Magellanic Cloud (N27). Environments poor in heavy elements and dust such as the SMC are thought to be dominated by photodissociation regions (PDRs). This is the lowest metallicity source where submill…
The Pattern Speed of the Nuclear Disk of M31 Using a Variant of the Tremaine-Weinberg Method
Sambhus, Niranjan; Sridhar, S.
The twin peaks in the nucleus of M31 have been interpreted by Tremaine as a thick, eccentric disk of stars orbiting a massive dark object; the required alignment of the apoapsides of the stellar orbits could be maintained by self-gravity, and the whole structure might be a discrete, nonlinear eigenmode. The pattern speed of this mode could, in pri…
The Atmosphere of Mira Variables: A View with the Hubble Space Telescope
Luttermoser, Donald G.
Ultraviolet spectra obtained with Hubble Space Telescope (HST) of two Mira-type variable stars, R Leo and R Hya, are presented, along with analysis providing information on their outer atmospheres. These high-dispersion spectra were taken with the Goddard High Resolution Spectrograph (HRS) in two spectral regions: 2320-2368 Å to record the C II] (…
Extended X-Ray Emission from the Planetary Nebula BD +30°3639
Kwok, Sun; Leahy, D. A.; Yin, Donghui
We report the discovery of extended X-ray emission from the planetary nebula BD +30deg3639. Analysis of the ROSAT HRI image shows clearly that BD +30deg3639 has extended X-ray emission which is well fitted with a Gaussian source of σ=1.7"-2.8" (95.4% confidence interval). This size is consistent with being the same as that of…