71 research outputs found

    The Centimeter to Submillimeter Broad Band Radio Spectrum of the Central Compact Component in A Nearby Type-II Seyfert Galaxy NGC 1068

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    We analyze all the available Atacama Large Millimeter / submillimeter Array archival data of the nearby Type-II Seyfert galaxy NGC 1068, including new 100 GHz data with the angular resolution of 0\farcs05, which was not included in previous continuum spectral analysis. By combining with the literature data based on the Very Large Array, we investigate the broadband radio continuum spectrum of the central 7\lesssim7 pc region of NGC 1068. We found that the flux density is between \approx10-20 mJy at 5-700 GHz. Due to the inability of the model in previous studies to account for the newly added 100 GHz data point, we proceeded to update the models and make the necessary adjustments to the parameters. One possible interpretation of this broadband radio spectrum is a combination of emission from the jet base, the dusty torus, and the compact X-raying corona with the magnetic field strength of 20\approx20 G on scales of 30\approx30 Schwarzschild radii from the central black hole. In order to firmly identify the compact corona by omitting any other possible extended components (e.g., free-free emission from ionized gas around), high-resolution/sensitivity observations achieved by next-generation interferometers will be necessary.Comment: 10 pages, 4 figures, 3 tables, accepted for publication in PAS

    Nobeyama 45-m CO J=1-0 Observations of Luminous Type 1 AGNs at z0.3z\approx0.3

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    We have performed CO J =1-0 observations of ten galaxies hosting luminous (Lbol>1046ergs1L_{\rm bol} > 10^{46}\,{\rm erg\,s^{-1}}) type 1 active galactic nuclei (AGNs) with the Nobeyama 45-m radio telescope. The targets are selected because they are expected to be rich in molecular gas based on their high nebular dust extinction (AVA_{\rm V}). However, no significant CO emission lines were detected in any of the targets. The upper limits of the CO J=1-0 luminosities are lower than expected given the molecular gas mass inferred from the nebular AVA_{\rm V}. This inconsistency may be due to overestimated AVA_{\rm V} values due to the lack of stellar absorption correction. Considering more reliable AVA_{\rm V} values, the CO J=1-0 non-detections by Nobeyama 45-m are natural. This suggests that our results do not contradict the conversion methods from AVA_{\rm V} to molecular gas mass proposed in the literature. This survey suggests that careful AVA_{\rm V} measurements as well as CO observations are still needed to improve the measurements or estimates of the molecular gas content of galaxies hosting luminous AGNs.Comment: 8 pages, 6 figures, Accepted for publication in PAS
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