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A Far-Ultraviolet Spectroscopic Analysis of the Central Star of the Planetary Nebula Longmore 1
Bianchi, L.; Herald, J. E.
We have performed a non-LTE spectroscopic analysis using far-UV and UV data of the central star of the planetary nebula K1-26 (Longmore 1) and found Teff=120+/-10 kK, logg=6.7+0.3-0.7 cm s-2, and Y~=0.10. The temperature is significantly hotter than previous results based on optical line analyses, highli…
Simulating Titan’s tropospheric circulation with the Portable University Model of the Atmosphere
Keller, H. U.; Grieger, B.; Rodin, A. V. +4 more
The Portable University Model of the Atmosphere (PUMA) is a general circulation model of intermediate complexity. In the model setup used herein, the dynamics is driven by restoration to a prescribed temperature field. Given an observed three-dimensional field of restoration temperatures, the feedback of aerosol distribution to the radiation schem…
The Ultraviolet Spectrum of the High-Field Magnetic Cataclysmic Variable AR Ursae Majoris
Gänsicke, B. T.; Szkody, Paula; Hoard, D. W. +4 more
We have obtained an ultraviolet spectrum covering the range 917-1182 Å of the high-field magnetic cataclysmic variable AR Ursae Majoris when the binary was in its typical low-accretion state. The data reveal an array of deep Zeeman absorption features due to hydrogen Lyα-Lyγ, including several transitions that are normally forbidden but become ena…
Chandra observations of SNR 1987A
McCray, R.; Hasinger, G.; Garmire, G. P. +4 more
We report on the results of our monitoring program of the X-ray remnant of supernova 1987A with the Chandra X-ray Observatory. We have performed two new observations during the Chandra Cycle 3 period, bringing the total to six monitoring observations over the past three years. These six observations provide a detailed time history of the birth of …
Rotational dynamics of subsolar sublimating triaxial comets
Mysen, Eirik
A model with subsolar water sublimation on a triaxial, ellipsoidal comet nucleus is presented for the calculation of reactive torques. The resulting differential equations describing the comet's rotation are then Hamiltonian, and gravity-gradients are trivial to include. While effects derived from a weak perturbing function are neither able to cha…
The discovery of hard X-ray emission in the persistent flux of the Rapid Burster
Frontera, F.; Goldoni, P.; Stella, L. +3 more
We report the first detection with INTEGRAL of persistent hard X-ray emission (20 to 100 keV) from the Rapid Burster (MXB 1730-335), and describe its full spectrum from 3 to 100 keV. The source was detected on February/March 2003 during one of its recurrent outbursts. The source was clearly detected with a high signal to noise ratio during the sin…
Hα kinematics of a z~ 1 disc galaxy from near-infrared integral field spectroscopy
Aragón-Salamanca, A.; Swinbank, A. M.; Abraham, R. G. +6 more
In this Letter we present the first 3D spectroscopic study of Hα emission in a z~ 1 field galaxy with an integral field unit. Using the Cambridge Infrared Panoramic Survey Spectrograph (CIRPASS) on Gemini-South, we map the spatial and velocity distribution of Hα emission in the z= 0.819 galaxy CFRS 22.1313. We detect two Hα emitting regions with a…
The X-ray halo of G21.5 - 0.9
Bocchino, F.; Bandiera, R.
The emission of the plerion G21.5 - 0.9 appears more extended in X-rays than in radio. This is an unexpected result because it would imply that short-lived X-ray electrons may reach distances even larger than radio electrons. Applying an empirical relationship between dust scattering optical depth and photoelectric column density, the measured col…
High frequency ion sound waves associated with Langmuir waves in type III radio burst source regions
MacDowall, R. J.; Thejappa, G.
Short wavelength ion sound waves (2-4kHz) are detected in association with the Langmuir waves (~15-30kHz) in the source regions of several local type III radio bursts. They are most probably not due to any resonant wave-wave interactions such as the electrostatic decay instability because their wavelengths are much shorter than those of Langmuir w…
A study of the electrical charging of the Rosetta orbiter: 2. Experimental tests in a laboratory plasma
Berthelier, Jean-Jacques; Roussel, Jean-FrançOis
Following the numerical simulation presented in the companion paper, we have performed experimental tests in a plasma simulation chamber to check the results of the numerical model and validate its capability to properly predict the electrical equilibrium of the Rosetta orbiter. Since low temperature cometary plasmas cannot be directly reproduced …