Oral Presentation
The Growth of Far-IR Galaxies and Their Central Supermassive Black Holes at Intermediate Redshift
Presenter: Kota Sakuma (Tohoku University)
Galaxies with extremely high star formation rates (SFRs) exceeding 500 Msun yr^-1 have been found by submillimeter surveys at high redshifts (z > 1), but have not been found in the lower redshift Universe. Such galaxies are faint in optical and have been missed in previous wide-area surveys, possibly due to statistical underestimation. In this study, we construct a catalog of 3592 far-infrared (FIR) sources combining the FIR catalog based on the all-sky survey of the infrared astronomical satellite ``AKARI'' with the SDSS and WISE catalogs. We also conduct follow-up observations for galaxies that have only photometric redshift information using Subaru/FOCAS and Seimei/KOOLS-IFU and perform the SED fitting using CIGALE. From the SED fitting results, we estimate the SFR, stellar mass, AGN luminosity, etc, and find that most of the galaxies in our sample are starburst galaxies, and they have SFR 10 - 100 times higher than those of the same redshift and stellar mass.
We also bin the sample by stellar mass and examine the relationship between stellar mass and black hole (BH) mass accretion rate, finding a flat trend over the stellar mass range of 10^9 - 10^13 Msun. On the other hand, the relationship between stellar mass and BH mass to SFR ratio also shows a flat trend.
This may imply that although supermassive black holes (SMBHs) located in the center of galaxies grow with their host galaxies, the growth of SMBHs varies even among host galaxies with similar stellar mass.
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