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The outer atmosphere of α Tau - III. Inhomogeneities deduced from cold CO fluorescence
McMurry, A. D.; Jordan, C.
Ultraviolet spectra of α Tau obtained with the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope show clusters of CO emission lines which are excited by the Oi (uv2) multiplet near 1304Å. Identifications of these fluorescent lines and their pumping routes are presented. The absolute intensities of the CO lines and their rat…
Adaptive optics near-infrared imaging of NGC 2992 - unveiling core structures related to radio figure-of-8 loops
Alonso-Herrero, Almudena; Morris, Simon L.; Chapman, Scott C. +1 more
We present near-infrared adaptive optics, Very Large Array (VLA) radio and Hubble Space Telescope (HST) optical imaging of the nearby Seyfert galaxy NGC 2992. Spiral structure and an extension to the west are traced down to the core region at the limiting resolution of our near-infrared images. A faint, diffuse loop of near-infrared and radio emis…
The infrared counterpart of the Z source GX 5-1
van der Klis, M.; Hambly, N. C.; Fender, R. P. +1 more
We have obtained UK Infrared Telescope infrared observations of the field of the bright Galactic Z source GX 5-1. From an astrometric plate solution tied to Tycho-ACT standards we have obtained accurate positions for the stars in our field which, combined with an accurate radio position, have allowed us to identify the probable infrared counterpar…
The evolution of iron-core white dwarfs
Althaus, L. G.; Panei, J. A.; Benvenuto, O. G.
Recent measurements by Hipparcos present observational evidence supporting the existence of some white dwarf (WD) stars with iron-rich core composition. In connection with this, the present paper is aimed at exploring the structure and evolution of iron-core WDs by means of a detailed and updated evolutionary code. In particular, we examined the e…
Far-infrared-loud quasars - I. Disturbed and quiescent quasars in the PG survey
Clements, D. L.
We use host galaxy imaging studies of the PG quasar survey to compare the far-infrared (FIR) properties of quasars with disturbed and undisturbed host galaxies. By using survival analysis, we show that the quasars with disturbed host galaxies, with morphologies classified from a homogeneous data set, have a 60-µm luminosity distribution that…
Imaging of the merging galaxy NGC 3597 and its population of protoglobular clusters
Forbes, Duncan A.; Hau, G. K. T.
We present wide field-of-view near-infrared imaging from the NTT and very deep optical imaging from the HST of the young merging galaxy NGC 3597. The morphology of the galaxy and the properties of the newly formed protoglobular clusters (PGCs) are examined. Our K-band data reveal the presence of a second nucleus, which provides further evidence th…
The infrared jet in 3C 66B
Hardcastle, M. J.; Birkinshaw, M.; Worrall, D. M. +1 more
We present images of infrared (IR) emission from the radio jet in 3C 66B. Data at three wavelengths (4.5, 6.75 and 14.5µm) were obtained using the Infrared Space Observatory. The 6.75-µm image clearly shows an extension aligned with the radio structure. The jet was also detected in the 14.5-µm image, but not at 4.5µm. The r…
Episodic absorption in the outflow of the old nova V603 Aquilae
Ringwald, F. A.; Prinja, Raman K.; Knigge, Christian +1 more
We report on the time-dependent behaviour of ultraviolet spectral lines in Hubble Space Telescope Goddard High-Resolution Spectrograph data of the classical nova V603 Aql. In particular, episodic blueshifted absorption (extending to ~-2500kms-1) is present, with a variability time-scale down to ~1min. The data provide a rare opportunity…
X-ray analysis of the cluster 3C 129
Leahy, D. A.; Yin, D.
The cluster 3C 129 is classified as a rich cluster. An analysis of the properties of the cluster 3C 129 from ROSAT PSPC and HRI, Einstein IPC, and EXOSAT ME observations is presented. The mean temperature from a joint fit of the ROSAT PSPC and EXOSAT ME data is 5.5(+/-0.2)keV. The luminosity is 0.6x1044ergs-1 in 0.2-2.4keV an…
Composite spectraPaper 10: the equal-mass binary HR 2030 (K0IIb+B8IV)
Griffin, R. E. M.; Griffin, R. F.
We separate the spectra of the individual components of HR 2030, a sixth-magnitude composite-spectrum binary system, and show that they have types close to K0IIb and B8IV, and masses that are equal to within the precision of the measurements (mass ratio=1.00+/-0.03). The orbit appears to have a very small eccentricity, although reasons are given f…