SKAO will enable HI and OH absorption surveys to characterize cold gas properties in galaxies from z=0 to beyond z=6.
HI Absorption Toward the Nucleus of the Radio Galaxy PKS 2322-123 in A 2597
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
We present sensitive, high resolution Very Long Baseline Array (VLBA) observations of the central 0.3 arcsec of PKS 2322-123 at 1.3 and 5 GHz. These observations reveal straight and symmetric jets emerging from both sides of an inverted spectrum core. The 21 cm line of atomic hydrogen is detected in absorption against the core and eastern jet with substantial opacities, but is not seen towards the equally strong western jet. Both a narrow (110 km/s FWHM) and a very broad (735 km/s FWHM) line are seen, although the very broad line is seen only against the core. Both lines are redshifted (~220 +/- 100 km/s) with respect to the systemic velocity. The most likely explanation for the observed HI kinematics are an atomic torus centered on the nucleus with considerable turbulence and inward streaming motions. The scale height of this torus is less than 20 pc. Though rare in flux limited samples of compact radio sources, symmetric parsec-scale structure appears nearly ubiquitous among radio galaxies with HI absorption, probably because they are viewed more nearly edge-on through the torus.
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astro-ph.GA 2years
2026 2verdicts
UNVERDICTED 2representative citing papers
SKAO will trace synchrotron jets, thermal emission, and low-column-density HI gas in nearby AGN to characterize duty cycles and multi-phase feeding/feedback linked to star formation.
citing papers explorer
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Tracing Cold Gas in Absorption Across Cosmic Time with the SKA
SKAO will enable HI and OH absorption surveys to characterize cold gas properties in galaxies from z=0 to beyond z=6.
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AGN Feeding & Feedback Over the Galactic Scales
SKAO will trace synchrotron jets, thermal emission, and low-column-density HI gas in nearby AGN to characterize duty cycles and multi-phase feeding/feedback linked to star formation.