A broad HCO+ absorption line associated with the circumnuclear torus of NGC 1052

Abstract

In the circumnuclear region of the nearby radio galaxy NGC~1052. Our $\lambda$3mm VLBI observations with the Korean VLBI Network have spatially resolved the broad HCO${}^{+}$ absorption at a velocity range of 1350--1850 km~s${}^{-1}$ against a double-sided nuclear jet, and have revealed that the HCO${}^{+}$ absorption is concentrated on the receding jet and the nuclear components. The distribution of the HCO${}^{+}$ absorbing gas strongly supports the circumnuclear torus surrounding the supermassive black hole. From the estimations of the column density and the volume density of molecular hydrogen, the size of the molecular gas region in the torus is at least 1~pc. The broad spectral profile of HCO${}^{+}$ is likely to be a blend of multiple gas clumps with various velocities. The HCO${}^{+}$ absorption of NGC~1052 could trace complex kinematics in the vicinity of the active galactic nucleus, such as inflow, outflow, turbulence, and so on.

8 pages, 3 figures, To appear in ApJ Letters

References in corpus (6)

• Molecular line emission in NGC1068 imaged with ALMA. I An AGN-driven outflow in the dense molecular gas
• DiFX: A software correlator for very long baseline interferometry using multi-processor computing environments
• Molecular line emission in NGC1068 imaged with ALMA: II. The chemistry of the dense molecular gas
• Positional Coincidence of H2O Maser and a Plasma Obscuring Torus in Radio Galaxy NGC 1052
• A New Hardware Correlator in Korea: Performance Evaluation using KVN observations
• Spatially Resolved HCN Absorption Features in the Circumnuclear Region of NGC 1052

Cited by in corpus (6)

• The Two-sided Jet Structures of NGC 1052 at Scales from 300 to $4\times 10^7$ Schwarzschild Radii
• A Massive Molecular Torus inside a Gas-Poor Cirnumnuclear Disk in the Radio Galaxy NGC 1052 Discovered with ALMA
• Properties of the Obscuring Torus in NGC 1052 from Multi-epoch Broadband X-ray Spectroscopy
• Probing Jet-Torus Interaction in the Radio Galaxy NGC 1052 by Sulfur-Bearing Molecules
• ALMA Detection of 321 GHz water maser emission in the radio galaxy NGC 1052
• Very Long Baseline Interferometry imaging of H2O maser emission in the nearby radio galaxy NGC 4261