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arXiv · 0905.3320

MOIRCS Deep Survey III: Active Galactic Nuclei in Massive Galaxies at z=2-4

T. Yamada·M. Kajisawa·M. Akiyama·T. Ichikawa·M. Konishi·T. Nishimura·K. Omata·R. Suzuki·I. Tanaka·C. Tokoku·Y. K. Uchimoto·T. Yoshikawa
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Abstract

We investigate the X-ray properties of the K-band-selected galaxies at redshift 2 < z < 4 by using our deep near-infrared images obtained in the MOIRCS Deep Survey project and the published Chandra X-ray source catalog. 61 X-ray sources with the 2-10 keV luminosity L_X = 10^{42}-10^{44} erg/s are identified with the K-selected galaxies and we found that they are exclusively (90%) associated with the massive objects with stellar mass larger than 10^{10.5} Msun. Our results are consistent with the idea that the M_BH/M_str ratio of the galaxies at z=2-4 is similar to the present-day value. On the other hand, the AGN detection rate among the very massive galaxies with the stellar mass larger than 10^{11} Msun is high, 33% (26/78). They are active objects in the sense that the black-hole mass accretion rate is ~ 1-50% of the Eddington limit if they indeed have similar M_BH/M_str ratio with those observed in the local universe. The active duration in the AGN duty cycle of the high-redshift massive galaxies seems large.

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T. Yamada, M. Kajisawa, M. Akiyama, T. Ichikawa, M. Konishi, T. Nishimura, K. Omata, R. Suzuki, I. Tanaka, C. Tokoku, Y. K. Uchimoto, T. Yoshikawa. 2009-05-20. MOIRCS Deep Survey III: Active Galactic Nuclei in Massive Galaxies at z=2-4. https://doi.org/10.1088/0004-637x%2F699%2F2%2F1354

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