Millimeter Radio Continuum Emissions as the Activity of Supermassive Black Holes in Nearby Early-type Galaxies and Low-luminosity Active Galactic Nuclei
Abstract
We conducted millimeter continuum observations for samples of nearby early-type galaxies (21 sources) and nearby low-luminosity active galactic nuclei (LLAGNs; 16 sources) at 100 GHz (λ3 mm) using the Nobeyama Millimeter Array (NMA). In addition, we performed quasi-simultaneous observations at 150 GHz (λ2 mm) and 100 GHz for five LLAGNs. Compact nuclear emissions showing flat or inverted spectra at centimeter-to-millimeter wavelengths were found in many LLAGNs and several early-type galaxies. Moreover, significant flux variability was detected in three LLAGNs. These radio properties are similar to Sgr A*. The observed radio luminosities are consistent with the fundamental plane of black hole activity that was suggested on the basis of samples with black hole masses ranging from 10 to 1010 M sun. This implies nuclear jets powered by radiatively inefficient accretion flows onto black holes.
- Publication:
-
The Astronomical Journal
- Pub Date:
- November 2011
- DOI:
- 10.1088/0004-6256/142/5/167
- arXiv:
- arXiv:1106.5627
- Bibcode:
- 2011AJ....142..167D
- Keywords:
-
- galaxies: active;
- galaxies: elliptical and lenticular;
- cD;
- galaxies: jets;
- radio continuum: galaxies;
- techniques: interferometric;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 11 pages, 2 figures, accepted for publication in the Astronomical Journal