http://bear.ras.ucalgary.ca/abstracts/1992/1992.html (Einblicke ins Internet, ~06/1995)
A survey of the milliarcsecond polarization properties of BL Lacertae objects at 5 GHz
GABUZDA, D. C., CAWTHORNE, T. V., ROBERTS, D. H., WARDLE, J. F. C.
Astrophysical Journal, Part 1 , vol. 388, March 20, 1992, p. 40-54.
Abstract: Consideration is given to millarcsecond-resolution total-intensity and linear polarization maps at 5 GHz presented for 11 BL Lacertae objects. In every BL Lacertae object in which polarization structure was detected, the polarization position angle of the knots is nearly parallel to the VLBI structural axis. The direction of the polarization in the cores of these sources appears to be random. The preferred polarization direction in the jets is explained by the fact that plane perpendicular shock waves are common in these sources; the origin of the absence of the preferred polarization direction in the core components is unclear. These results support an early conclusion that it cannot be the case that a significant number of BL Lacertae objects are gravitationally microlensed images of more distant quasars, since the characteristic VLBI polarization structures observed in these two types of objects are very different.
Observations of symbiotic stars at millimeter and submillimeter wavelengths
SEAQUIST, E. R., TAYLOR, A. R.
Astrophysical Journal, Part 1 , vol. 387, March 10, 1992, p. 624-630. Research supported by NSERC.
Abstract: Observations of three symbiotic stars, AG Peg, RX Pup, and V1016 Cyg, made at wavelengths near 1 mm using the James Clerk Maxwell Telescope, are presented, with emphasis on the use of these and other radio and IR data as a means to test models for the radio emission from symbiotic stars, particularly in cases where the binary separation is known. In the case of the S-type symbiotic AG Peg, all data are consistent with a uniform power-law spectrum for the stellar component covering nearly four orders of magnitude in wavelength. The D-type systems RX Pup and V1016 Cyg both exhibit ff emission at centimeter, millimeter, and submillimeter wavelengths, whereas emission from dust dominates at wavelengths near 100 microns and shorter. The turnover frequency at about 100 GHz indicates that the inner diameter of the radio shell representing the interaction zone is about 0.06 arcsec, in agreement with high-resolution radio maps.
1420 and 408 MHz observations of the planetary nebulae BD + 30 deg 3639 and AFGL 618
LIKKEL, LAUREN, GUSSIE, G. T., TAYLOR, A. R., DEWDNEY, P. E.
Astronomical Journal , vol. 103, Feb. 1992, p. 538-543, 688. Research supported by NSERC.
Abstract: 1420 MHz spectral line and continuum observations as well as 408 MHz continuum observations have been made toward the compact planetary nebulae BD + 30 deg 3639 and AFGL 618 with the Synthesis Telescope of the Dominion Radio Astrophysical Observatory. These observations were intended to detect possible circumnebular H I in AFGL 618 and to detect an anticipated extended component of the previously detected circumstellar H I of BD + 30 deg 3639. Neither the planetary nebula AFGL 618 nor the bipolar nebula M1-92 were detected by 1420 or 408 MHz continuum observations, or by 1420 MHz spectroscopic observations. The anticipated extended H I of BD + 30 deg 3639 was not detected, indicating that the H I distribution of this nebula is significantly more compact than that of the planetary nebula IC 418. Compact, dense planetary nebulae such as BD + 30 deg 3639 may have circumnebular envelopes that are primarily molecular rather than atomic.
New Galactic plane supernova remnants
TAYLOR, A. R., WALLACE, B. J., GOSS, W. M.
Astronomical Journal , vol. 103, March 1992, p. 931-942. Research supported by NSERC.
Abstract: A survey of the region 44-90 deg,/b/less than 1.5 deg has been nearly completed using the Westerbork Synthesis Radio Telescope at 327 MHz. The low frequency, high resolution, and high sensitivity of this survey make it ideal for detecting SNRs which previous, primarily single disk, surveys have missed. A total of 24 SNRs have been identified in the survey data, 11 of which are newly discovered. The survey thus nearly doubles the number of known SNRs in this region of the Galactic plane. Because of the characteristics of the survey, these new remnants have lower surface brightness and smaller angular size than previously detected SNRs. Some of the new remnants may be very distant, evolved SNRs. A possible excess of filled-center SNRs in the survey region (compared to the general population) is also noted.
VLBI observations of the X-ray binary LSI +61 deg 303
TAYLOR, A. R., KENNY, H. T., SPENCER, R. E., TZIOUMIS, A.
Astrophysical Journal, Part 1, vol. 395, no. 1, p. 268-274.
Abstract: VLBI observations of LS I +61 deg 303 revealed a resolved source with an angular diameter of 3.2 mas during a period of low flux density. This observation corresponds to the time of onset of a new radio outburst and several days following the previous outburst. Near peak flux density the sources are unresolved, with an upper limit to the angular diameter of 1.6 mas corresponding to a linear diameter of 3.7 AU. The low source expansion velocities implied by these results argue against the supercritical accretion model as proposed by Taylor and Gregory (1984) in which Roche lobe overflow occurs at periastron of a highly eccentric orbit. A modified SA model is suggested in which the compact companion orbits in a moderately eccentric orbit in the environment of a Be star wind and accretes therefrom at supercritical rates for a fraction of the orbit.
Papers Published in Conference Proceedings
Interferometric Observations of Radio Stars
Taylor, A.R.
Sub-arcsecond Radio Astronomy, Manchester, 1992.
(invited).
VLA Imaging of Symbiotic Stars
Kenny, H.T. and Taylor, A.R.
Sub-arcsecond Radio Astronomy, Manchester., 1992
Resolving the Circumstellar Gas of Psi Persei
Dougherty, S.M. and Taylor, A.R.
Sub-arcsecond Radio Astronomy, Manchester., 1992
The Active Phase of the Hot Component of Z Andromedae
Fernandez-Castro, T., Gonzalez-Riestra, R., Cassatella, A., Taylor, A.R. and Seaquist, E.R.
Planetary Nebulae, IAU Symposium 155, Innsbruck ,1992.
Papers presented at conferences (not included in conference
proceedings)
Radio Imaging of Southern Symbiotic Stars
Kenny, H.T., Taylor, A.R. and Tzioumis, A.
1992 Canadian Astronomical Society Meeting, Halifax.
Possibilities for the Future of Millimeter/Submillimeter Interfereometry in Canada:
An Overview
Taylor, A.R.
at workshopThe Future of Millimeter/Submillimeter Interferometry in Canada, McMaster University ,1992. (invited)
Technical Reports
A Space-VLBI Principle Investigator Software Package
Taylor, A.R.
a commissioned report for the Canadian Space Agency.,1992
Prepared by
Glen Young;
young@bear.ras.ucalgary.ca