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The symbiotic star CH Cygni - I. Non-thermal bipolar jets
Davis, R. J.; Eyres, S. P. S.; Bode, M. F. +4 more
Very Large Array surface brightness and spectral index maps of the evolving extended emission of the triple symbiotic star CH Cygni are presented. These are derived from observations at 4.8, 8.4 and 14GHz between 1985 and 1999. The maps are dominated by thermal emission around the central bright peak of the nebula, but we also find unambiguous non…
High Temporal Resolution XMM-Newton Monitoring of PKS 2155-304
Markowitz, Alex; Edelson, Rick; Sembay, Steve +3 more
The bright, strongly variable BL Lacertae object PKS 2155-304 was observed by XMM-Newton for two essentially uninterrupted periods of ~11 and 16 hr on 2000 May 30-31. The strongest variations occurred in the highest energy bands. After scaling for this effect, the three softest bands (0.1-1.7 keV) showed strong correlation with no measurable lag t…
Multiple shocks around the low-luminosity protostar IRAS 16293-2422
Ceccarelli, C.; Caux, E.; Lefloch, B. +2 more
Using the IRAM 30 m and SEST 15 m telescopes we mapped an area covering 300''x220'' around IRAS 16293-2422 in the N2H+ J=1-->0, H2CO J = 31,3-->21,2, SiO J=2-->1 J=3-->2, and J=5-->4 molecular transitions. Five positions were also observed in the FIR, between 45 µm and 200…
Multiwavelength Observations of the Low-Metallicity Blue Compact Dwarf Galaxy SBS 0335-052
Neugebauer, Gerry; Dale, Daniel A.; Soifer, B. T. +3 more
New infrared and millimeter observations from Keck, Palomar, ISO, and OVRO and archival data from the NRAO6 VLA and IRAS are presented for the low-metallicity blue compact dwarf galaxy SBS 0335-052. Mid-infrared imaging shows this young star-forming system is compact (0.31" 80 pc) at 12.5 µm. The large Brγ equivalent width (235 Å) measured f…
Far-Ultraviolet Observations of Flares on the dM0e Star AU Microscopii
Robinson, Richard D.; Woodgate, Bruce E.; Linsky, Jeffrey L. +1 more
We report on far-ultraviolet (FUV) observations of flares on the dM0e star AU Microscopii obtained on 1998 September 6 with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. The data consist of medium-resolution echelle spectra covering the wavelength region from 1170 to 1730 Å with a spectral resolution of λ/Δλ=45,800. …
Active region transient brightenings. A simultaneous view by SXT, EIT and TRACE
Berghmans, D.; Clette, F.; McKenzie, D.
This paper reports on a qualitative study on the weakest flarelike brightenings in active region that can be observed with current coronal imagers. Specificallly, we investigate the correspondence of the ``active region transient brightenings'' (ARTB) first observed almost a decade ago with SXT with similar brightenings in the EUV that are now obs…
A Search for OH Megamasers at Z>0.1. II. Further Results
Giovanelli, Riccardo; Darling, Jeremy
We present current results of an ongoing survey for OH megamasers in luminous infrared galaxies at the Arecibo Observatory.1 The survey is now two-thirds complete, and has resulted in the discovery of 35 new OH megamasers at z>0.1, 24 of which are presented in this paper. We discuss the properties of each source in detail, including an exhausti…
The Accuracy of the Born and Ray Approximations in Time-Distance Helioseismology
Kosovichev, A. G.; Birch, A. C.; Price, G. H. +1 more
Time-distance helioseismology measures the time for acoustic wave packets to travel, through the solar interior, from one location on the solar surface to another. Interpretation of travel times requires an understanding of their dependence on subsurface inhomogeneities. Traditionally, time-distance measurements have been modeled in the ray approx…
A Search for H I in E+A Galaxies
Zabludoff, Ann I.; Zaritsky, Dennis; Mihos, J. Christopher +2 more
We present the results of H I line and radio continuum observations of five nearby E+A galaxies. These galaxies have spectra that are dominated by a young stellar component but lack the emission lines characteristic of significant ongoing star formation. They are selected from a unique sample of 21 E+A's identified by Zabludoff et al. in their spe…
Microwave Detection of Umbral Oscillation in NOAA Active Region 8156: Diagnostics of Temperature Minimum in Sunspot
Shibasaki, Kiyoto
A radio brightness oscillation of 3 minutes at 17 GHz was detected in a compact radio source associated with a sunspot umbra in the NOAA active region 8156. We interpret the radio brightness oscillation by the density and temperature fluctuations due to upward-traveling acoustic waves through the third harmonic gyroresonance layer (2000 G). SOHO/S…