http://bear.ras.ucalgary.ca/abstracts/1989/1989.html (Einblicke ins Internet, ~06/1995)
MERLIN observations of the Wolf-Rayet star AS431 (WR147) - A double radio source
MORAN, J. P., DAVIS, R. J., SPENCER, R. E., BODE, M. F., TAYLOR, A. R.
Nature , vol. 340, Aug. 10, 1989, p. 449, 450. Research supported by SERC.
Abstract: New interferometric observations of the Wolf-Rayet star AS431 using the MERLIN network are presented. These observations had a sensitivity sufficient to map the stellar-thermal continuum radio emission with a beam size of 0.1 arcsec. The object is resolved into two radio source separated by 0.6 arcsec, corresponding to a spatial separation of 1100 AU at the assumed distance of 1.9 kpc. The computed brightness for the two sources, about 10,000 K, is typical of optically thick thermal emission from a stellar wind, and suggests that some part of the emission is nonthermal. One of the radio components corresponds to the position of the single source revealed by accurate optical observations. The observed total radio spectrum is simulated with a two-component model for the emission.
VLA observations of circumnebular neutral hydrogen in IC 418
TAYLOR, A. R., GUSSIE, G. T., GOSS, W. M.
Astrophysical Journal, Part 1 , vol. 340, May 15, 1989, p. 932-942.
Abstract: Neutral hydrogen images of the planetary nebula IC 418 have been made with the Very Large Array. These images show H I emission and absorption in close association with the nebula. Assuming a distance of 1 kpc, the total mass of circumnebular neutral hydrogen is 0.35 + or - 0.05 solar mass. Model fits to the data indicate that the neutral gas falls as a 1/r-squared density distribution, with outflow velocity about 5 km/s less than the expansion rate of the ionized gas. The observations also indicate that there is a region devoid of H I emission between the outer edge of the H II nebula and the inner edge of the H I shell. It is suggested that this gap is comprised of molecular hydrogen and that the surrounding H I shell is produced by photodissociation of H2 by the interstellar radiation field. Physical parameters of the H I gas are derived.
Millimeter observations of the Be stars Psi Persei and Gamma Cassiopeiae
WATERS, L. B. F. M., BOLAND, W., TAYLOR, A. R., VAN DE STADT, H., LAMERS, H. J. G. L. M.
Astronomy and Astrophysics , vol. 213, no. 1-2, April 1989, p. L19-L22. Research supported by the Niels Stensen Foundation.
Abstract: Observations of the Be stars Psi Per (B5 IIIe) and Gamma Cas (B0.5 IVe) at 1.1 mm with the James Clerk Maxwell Telescope. Psi Per was detected at 0.8 and 1.1 mm, while for Gamma Cas an upper limit at 1.1 mm is obtained. The mm observations are combined with existing UV, optical, IR, and radio data in order to investigate the density structure of the outer regions of the winds of Be stars. The observations indicate a steepening of the spectrum in the mm and cm range as compared to the slope of the spectrum found with IRAS, which is interpreted in terms of a steepening of the density distribution of the ionized circumstellar gas at large radii.
X-ray light curves of Be/X-ray binaries
WATERS, L. B. F. M., DE MARTINO, D., HABETS, G. M. H. J., TAYLOR, A. R.
Astronomy and Astrophysics , vol. 223, no. 1-2, Oct. 1989, p. 207-218. Research supported by the Niels Stensen Foundation.
Abstract: The present examination of the X-ray luminosity of wind-fed neutron stars in eccentric orbits around Oe/Be stars gives attention to evolutionary scenarios that lead to the formation of Be/X-ray binaries. Proceeding on the basis of a scenario in which the neutron star's orbital plane tends to be close to the Be star's equatorial plane, an investigation is conducted of the Be star's stellar wind velocities and densities, the effects of the wind geometry, and the effect of neutron star orbital motion on expected X-ray luminosity.
Radial and expansion velocities of compact planetary nebulae
GUSSIE, G. T., TAYLOR, A. R.
Publications Astronomical Society of the Pacific, vol. 101, Oct. 1989, p. 873-876. Research supported by NSERC.
Abstract: Optical spectra centered near 5000 A have been obtained of the compact planetary nebulae M1-6, IC 2149, MI-78, NGC 7027, and CN3-1. The expansion velocities of the ionized outflow and the systemic velocity of each nebula have been determined from the forbidden O III lines at 5007 A and 4958 A.
X-ray and Radio Observations of Flares from the RS CVn System UX Ari
Tsuru, T., Makishima, K., Ohashi, T., Inoue, H., Koyama, K., Turner, M.J.L., Barstow, M.A., McHardy, I.A., Pye, J.J., Tsunemi, H., Kitamoto, S., Taylor, A.R. and Nelson, S.
Publ. Astron. Soc. Japan., 41, 679-695.,1989
VLBI Observations of RS Oph - a recurrent nova with non-spherical ejection
Taylor, A.R., Davis, R.J., Porcas, R.W. and Bode, M.F.
Mon. Not. Roy. astr. Soc, 234, 81-91.,1989
Papers presented at conferences (not included in conference
proceedings)
Theoretical Radio Continuum Spectra of Conical Disk Outflows
Dougherty, S.M and Taylor, A.R.
1989 American Astronomical Society meeting, Boston.
AG Pegasi: A multi-shell radio source
Kenny, H.T., Taylor, A.R. and Seaquist, E.R.
1989 Canadian Astronomical Society meeting, Montreal.
Modelling of the Infrared to Radio Spectra of Be stars
Dougherty, S.M., Taylor, A.R., Clark, T.A. and Waters, L.B.F.M.
,
1989 Canadian Astronomical Society meeting, Montreal.
The Westerbork 327MHz survey of the Galactic Plane
Taylor, A.R. Goss, W.M., Coleman, P.H. and Wallace, B.J.
1989 Canadian Astronomical Society meeting, Montreal.
The University of Calgary Infrared Telescope:
Present Status and Future Developments
Clark, T.A., Milone, E.F., Taylor, A.R., Fry, D.J.I., Dougherty, S.M., Naylor, D.A., Babott, F.M., Emard, T., Griffiths, S.C., Robinson, K.G., Zimmer, E. and Smith, G.
1989 Canadian Astronomical Society meeting, Montreal.
Data Acquisition at the RAO:
Light Curves from the Optical and Infrared Telescopes
Milone, E.F., Clark, T.A., Babott, F.M., Fry, D.J.I., Griffiths, S.C., Penfold, J.E., Robinson, K.G., Taylor, A.R. and van Leeuwen, J.
1989 Canadian Astronomical Society meeting, Montreal.
Technical Reports
The Rothney Astrophysical Observatory Infrared Telescope Control
and Photometric Data Acquisition
Taylor, A.R.
1989 , Calgary.
Prepared by
Glen Young;
young@bear.ras.ucalgary.ca