Two New Blazar Redshifts
Abstract
The authors report the initial results of an attempt to detect weak features in the spectra of blazars lacking redshifts. They find a redshift of 0.392 for PKS 2208-137, and a redshift of 0.601 for MC3 2032+107; both objects have broad permitted lines. Using the new redshift, the authors calculate that the double radio lobes of PKS 2208-137 emit 2.7×1033erg/s Hz at 20 cm (for H0 = 75 km/s Mpc and q0 = 1/2), and the projected linear size is 59 kpc. The Hβ emission-line luminosity is ≡2×1043erg/s. These properties are consistent with the "unified scheme" assertion that the parent population for PKS 2208-137 is composed of normal double radio quasars. For MC3 2032+107 the redshift implies that the diffuse radio emission has power 3.1×1032erg/s Hz and projected size 27 kpc. The Hβ luminosity is ≡1043erg/s. The emission-line spectrum has a strong narrow component. This object may be a normal double radio quasar or radio galaxy seen from the jet direction. The projected linear sizes of both objects are consistent with substantial foreshortening.
- Publication:
-
The Astronomical Journal
- Pub Date:
- April 1987
- DOI:
- 10.1086/114362
- Bibcode:
- 1987AJ.....93..785A
- Keywords:
-
- Astronomical Spectroscopy;
- Bl Lacertae Objects;
- Blazars;
- Quasars;
- Radio Emission;
- Radio Sources (Astronomy);
- Red Shift;
- Emission Spectra;
- Signal To Noise Ratios;
- Spectral Line Width;
- Astrophysics;
- RADIO SOURCES: GALAXIES;
- GALAXIES: SEYFERT