Surveying Flux Density in Galaxies with Apparent Large Black Holes at Millimeter/Submillimeter Wavelengths

Wen Ping Lo*, Keiichi Asada, Satoki Matsushita, Hung Yi Pu, Masanori Nakamura, Geoffrey C. Bower, Jongho Park, Makoto Inoue


研究成果: 雜誌貢獻期刊論文同行評審

1 引文 斯高帕斯(Scopus)


We present millimeter and submillimeter continuum observations for 36 sources with potentially large black hole shadows at 230 and 345 GHz using the Submillimeter Array. The sources are selected based on the criterion of the large diameter of the black hole shadows. Our motivation is to explore the nature of the accretion flow of the potential candidates of low-luminosity active galactic nuclei (LLAGNs) through photometry at millimeter/submillimeter wavelengths. The detected result serves as the pathfinder of future high-angular resolution observations such as the Event Horizon Telescope. As a result, we successfully detected 17 and eight sources at 230 and 345 GHz, respectively. We reveal that three of the detected sources (IC 310, NGC 1277, and NGC 5846) show significant excess at millimeter/submillimeter wavelengths in comparison with the extrapolation both from low-frequency radio and infrared, which are considered to be attributed to the extended jet and dust component, respectively. One possible explanation is that these excesses are associated with the hot accretion flow onto the supermassive black holes of the LLAGNs. By adopting the advection-dominated accretion flow model's semi-analytic model, we obtained the upper bound of the mass accretion rate. Those are less than 10−2 M ̇ EDD , where M ̇ EDD is the Eddington mass accretion rate computed via the Eddington luminosity. This is in good agreement with the expected range of the LLAGNs. The ∼200 mJy flux densities and negative spectral index of IC 1459 within millimeter and submillimeter wavelengths make it a promising candidate for future submillimeter high-angular resolution experiments for imaging the black hole shadow.

期刊Astrophysical Journal
出版狀態已發佈 - 2023 6月 1

ASJC Scopus subject areas

  • 天文和天體物理學
  • 空間與行星科學


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