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Radial Flows in Supergranules
Raymond, J.; Hathaway, D. H.; Han, S. +1 more
We determine the radial component of the supergranular flow velocity by examining the center-to-limb variation of the Doppler velocity signal. We acquire individual Doppler images obtained with the MDI instrument on the SOHO spacecraft and process them to remove the p-mode oscillation signal, the axisymmetric flows, the convective blueshift signal…
Discovery of complex narrow X-ray absorption features from the low-mass X-ray binary GX 13+1 with XMM-Newton
Parmar, A. N.; Sidoli, L.; Oosterbroek, T. +1 more
We report the detection of a complex of narrow X-ray absorption features from the low-mass X-ray binary GX 13+1 during 3 XMM-Newton observations in 2000 March and April. The features are consistent with being due to resonant scattering of the Kalpha and Kbeta lines of He- and H-like iron (Fe XXV and Fe XXVI) and H-like calcium (Ca XX) Kalpha . Onl…
The circumstellar dust shell of the post-AGB star HD 161796
Waters, L. B. F. M.; Dominik, C.; Barlow, M. J. +3 more
We have modeled the complete optical to millimeter spectrum of the Post-Asymptotic Giant Branch (Post-AGB) star HD 161796 and its circumstellar dust shell. A full 2-200 mu m spectrum taken with the Infrared Space Observatory was used to constrain the dust properties. A good fit is achieved using only 4 dust components: amorphous silicates, the cry…
Distinguishing Local and Global Influences on Galaxy Morphology: A Hubble Space Telescope Comparison of High and Low X-Ray Luminosity Clusters
Kneib, J. -P.; Smith, G. P.; Smail, Ian +6 more
We present a morphological analysis of 17 X-ray-selected clusters at z~0.25, imaged uniformly with the Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2). Eight of these clusters comprise a subsample selected for their low X-ray luminosities (<~1044 ergs s-1), called the low-LX sample. The remaining ni…
Temperature variations from Hubble Space Telescope imagery and spectroscopy of NGC 7009
Martin, P. G.; Harrington, J. P.; Balick, B. +8 more
We present new Hubble Space Telescope (HST)/WFPC2 imagery and STIS long-slit spectroscopy of the planetary nebula NGC 7009. The primary goal was to obtain high spatial resolution of the intrinsic line ratio [OIII] 4364/5008 and thereby evaluate the electron temperature (Te) and the fractional mean-square Te variation (tA…
ISOCAM observations of the Ursa Major cirrus:. Evidence for large abundance variations of small dust grains
Miville-Deschênes, M. -A.; Boulanger, F.; Falgarone, E. +1 more
We present mid-IR imaging observations of a high Galactic latitude cirrus obtained with the ISO camera ISOCAM at 6'' angular resolution. The observations were done with two filters LW2 (5-8.5 mu m) and LW3 (12-18 mu m) that measure respectively the aromatic carbon bands and the underlying continuum emission from small dust particles. Three 0.05 sq…
Testing the line-driven disc wind model: time-resolved ultraviolet spectroscopy of IX Vel and V3885Sgr
Knigge, C.; Long, K. S.; Proga, D. +2 more
To confront the predictions of the most recent line-driven disc wind models with observational evidence, we have obtained Hubble Space Telescope (HST ) STIS (1180-1700Å) echelle spectra of the nova-like variables IX Vel and V3885Sgr at three epochs. The targets were observed in time-tag mode for ~2000s on each occasion, allowing us to study the sp…
On the Temperature Structure of M87
Molendi, Silvano
We revisit the XMM-Newton observation of M87, focusing our attention on the temperature structure. We find that spectra for most regions of M87 can be adequately fitted by single-temperature models. Only in a few regions, which are cospatial with the east and southwest radio arms, do we find evidence of a second temperature. The cooler component (…
The mineral composition and spatial distribution of the dust ejecta of NGC 6302
Waters, L. B. F. M.; Molster, F. J.; Kemper, F. +1 more
We have analysed the full ISO spectrum of the planetary nebula
Statistics of galaxy warps in the HDF North and South
Battaner, E.; Combes, F.; Jiménez-Vicente, J. +1 more
We present a statistical study of the presence of galaxy warps in the Hubble deep fields. Among a complete sample of 45 edge-on galaxies above a diameter of 1\farcs3, we find 5 galaxies to be certainly warped and 6 galaxies as good candidates. In addition, 4 galaxies reveal a characteristic U-warp. Compared to statistical studies of local warps, a…