Donald C. Morton

ABSORPTION LINES IN THE SPECTRA OF THE QSO PKS 1448-232

Savage et al. (1977) found that the radio source PKS 1448-232 coincided with a stellar object of about magnitude 16.4 having an ultraviolet excess. A low resolution spectrum obtained with the Anglo-Australian Telescope (AAT) confirmed this object as a QSO with zem = 2.22 and revealed many absorption lines shortward of the La emission. Consequently this object was included in a programme of spectroscopy at intermediate resolution with the AAT to investigate QSO absorption lines. Savage et al. have given a finding chart with an optical position of 144809.3, -23°1710 (1950.0). The radio fluxes are 0.40 Jy at 2.7 GHz and 0.31 Jy at 5.0 GHz.

The absorption lines in the spectra of high redshift qsos

Abstract Based on the spectra of 4 high-redshift quasars (resolution 2A) obtained by us [1–5] using IPCS on the RGO Cassegrain spectrograph of the AAT, we point out the following. 1. Auto-correlation peaks at L α L β and L α L γ in PKS 0805+046 and PKS 1442+101 suggest that the large number of absorption lines shortward of Lα in high redshift quasars are due to absorption by hydrogen clouds. 2. The distribution of absorption lines and the correlation function of L α L β indicate that PKS 0528-250 may be an exception, requiring further observation. 3. Absorption redshift systems containing metallic lines may be produced by either matter ejected from the quasar, or an associated galaxy cluster or an intervening galaxy. 4. The randomness in the column density and the dispersion velocity deduced from the curve of growth of the L α L β pair supports the hypothesis that the pure Lα absorption comes from primitive hydrogen clouds in the early, exploding universe. 5. The number of hydrogen clouds per unit redshift interval is determined by the data of absorption lines of quasars with Z > 3.

Radio Emission from Hot Stars at Two Centimeters

Radio fluxes of 7.2 ± 1.1 and 69 ± 5 mJy at 14.7 GHz have been detected from the stars ζ Pup (04If) and γ Vel (WC8+09I) respectively with the 64-m telescope at Parkes, and upper limits have been determined for 9 more hot stars. The interpretation of these fluxes as free-free emission from a shell of ionized gas resulting from a stellar wind gives mass-loss rates M = (6.5 ± 1.4) x 10−6 M⊙ yr−1 for ζ Pup and (3.9 ± 0.7) x 10−5 M⊙ yr−1 for γ Vel if H/He = 10 by amber and the He is fully ionized. If the gas around γ Vel originates mainly from the WC8 star, the helium predominates and M = (5.2 ± 0.9) x 10−5 or (17 ± 3) x 16−5 M⊙ yr−1 depending on whether the helium is doubly or singly ionized.