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Radio observations of HD 93129A: The earliest O star with the highest mass loss?
Benaglia, P.; Koribalski, B.
We present the results of radio continuum observations towards the open cluster Tr 14, where our main targets are the early-type O stars HD 93129A/B and HD 93128. The observations were carried out at 3 cm (8.64 GHz) and 6 cm (4.80 GHz) with the Australia Telescope Compact Array. Only HD 93129A (type O2 If*) was detected; we measure flux densities …
A giant molecular cloud falling through the heart of Cygnus A: clues to the triggering of the activity
Tadhunter, C. N.; Bellamy, M. J.
We present intermediate-resolution near-infrared long-slit spectroscopic data for the nearby radio galaxy Cygnus A (3C 405) (obtained with the NIRSPEC spectrograph on the Keck II telescope). The data reveal considerable complexity in the near-infrared emission-line kinematics, including line splittings of 200-350 km s-1 and a mixture of…
Modeling the Heating and Cooling of WZ Sagittae Following the 2001 July Outburst
Sion, Edward M.; Godon, Patrick; Cheng, Fuhua +5 more
Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope Space Telescope Imaging Spectograph spectra of the dwarf nova WZ Sge, obtained during and following the early superoutburst of 2001 July over a time span of 20 months, monitor changes in the components of the system during its different phases. The synthetic spectral fits to the dat…
Solar Fast-Wind Regions as Sources of Shock Energetic Particle Production
Kahler, S. W.
If the production of solar energetic particles (SEPs) near the Sun is due to shocks driven by coronal mass ejections (CMEs), then two factors might favor SEP acceleration in slow rather than fast solar wind streams. The first is that both the MHD fast-mode and solar wind flow speeds are higher in the fast-wind streams. The second is that shock see…
The Spectrum of the Solar Supergranulation: Multiple Nonwave Components
Toomre, Juri; Lisle, Jason P.; Rast, Mark P.
It has recently been suggested that the solar supergranulation undergoes oscillations, with a spectrum of superposed traveling waves of unknown origin showing excess prograde power to yield superrotation. We show here that the observed supergranular spectrum does not necessarily imply a wave origin but is instead consistent with two components of …
An XMM-Newton Observation of the High Magnetic Field Radio Pulsar PSR B0154+61
Lyne, A. G.; Gonzalez, M. E.; Kaspi, V. M. +1 more
We present the results obtained from a 31 ks XMM-Newton observation of the high magnetic field radio pulsar PSR B0154+61. This relatively nearby pulsar has an inferred dipole surface magnetic field strength of 2.1×1013 G, among the highest in the population. This makes the pulsar a possible transition object between the classical radio …
X-ray emitting class I protostars in the Serpens dark cloud
Preibisch, T.
We analyze a set of three individual XMM-Newton X-ray observation of the Serpens dark cloud. In addition to the 45 sources already reported in the analysis of the first of these XMM-Newton observations by Preibisch (\cite{Preibisch2003), the complete combined data set leads to the detection of X-ray emission from four of the 19 known class I proto…
Shocked Clouds in the Vela Supernova Remnant
Nichols, Joy S.; Slavin, Jonathan D.
Unusually strong high-excitation C I has been detected in 11 lines of sight through the Vela supernova remnant (SNR) by means of UV absorption line studies of IUE data. Most of these lines of sight lie near the western edge of the bright X-ray region of the SNR in a spatially distinct band approximately 1° by 4° oriented approximately north-south.…
Complexity of magnetic structures: Flares and cycle phase dependence
Meunier, N.
A long data set of MDI/SOHO full-disk magnetograms is analyzed to provide a large sample of active regions. The objective is to study the variations of the fractal dimension of these structures on different time scales: in relation to their activity level (spots, flares) and during the solar cycle. First, the variations of the fractal dimension of…
An intense soft excess and evidence for light bending in the luminous narrow-line quasar PHL 1092
Brandt, W. N.; Fabian, A. C.; Boller, Th. +2 more
The narrow-line quasar PHL 1092 was observed by XMM-Newton at two epochs separated by nearly 30 months. Timing analyses confirm the extreme variability observed during previous X-ray missions. A measurement of the radiative efficiency is in excess of what is expected from a Schwarzschild black hole. In addition to the rapid X-ray variability, the …