The Symmetric Parsec-Scale Jets of the Radio Galaxy Hydra A

Abstract

view Abstract Citations (85) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Symmetric Parsec-Scale Jets of the Radio Galaxy Hydra A Taylor, Gregory B. Abstract Sensitive, high-resolution VLBA observations of the nuclear region of the radio galaxy Hydra A are presented at 1.3, 5, and 15 GHz. These observations reveal a surprising degree of symmetry in the central 100 mas (140 pc). Jet-to-counterjet ratios at all three frequencies are in the range 1.1-1.2. The VLBI jets are straight and well aligned with the inner VLA jets at 1.3 and 5 GHz, but there is a 6^deg^ bend in the inner jet axis visible in the highest resolution 15 GHz image. There is strong evidence that the core and inner jets are free-free absorbed by an ionized gas with a density of 300 cm^-3^. Hydra A is also unusual in that the 21 cm atomic hydrogen line is seen in absorption against the nucleus. I present VLBA observations that spatially and spectrally resolve the H I in absorption against the inner nucleus and jets. This gas is most likely distributed in a disk having a rotation axis closely aligned with the jet axis and with a height of ~30 pc. Publication: The Astrophysical Journal Pub Date: October 1996 DOI: 10.1086/177874 Bibcode: 1996ApJ...470..394T Keywords: GALAXIES: ACTIVE; GALAXIES: ELLIPTICAL AND LENTICULAR; CD; GALAXIES: CLUSTERS: INDIVIDUAL NAME: HYDRA A; GALAXIES: JETS; GALAXIES: STRUCTURE; RADIO LINES: GALAXIES full text sources ADS | data products SIMBAD (3) NED (2)