EDP Sciences
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Volume 376, Number 3, September IV 2001
Page(s) L39 - L42
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20011087

A&A 376, L39-L42 (2001)
DOI: 10.1051/0004-6361:20011087

Growth of supermassive black holes and metallicity in quasars

Jian-Min Wang

Laboratory of High Energy Astrophysics, Institute of High Energy Physics, The Chinese Academy of Science, Beijing 100039, and Beijing Astrophysics Center, Beijing University, Beijing 100871, PR China

(Received 18 July 2001 / Accepted 30 July 2001)

The strong correlation between the mass of the central supermassive black hole (SMBH) and the bulge in some galaxies and quasars implies that the formation of the black hole is somehow linked to the bulge. The measurement of metallicity by ${\rm NV/CIV}$ or ${\rm NV/HeII}$ in quasars allows to discuss a possible way of formation of the black hole. In this letter we trace the metallicity along the possible routes in Rees' diagram in order to test the ways by which SMBHs can form. We derive a relation between the metallicity and the mass of the SMBH as $Z\propto M_{\rm BH}$ based on the numerical simulation of the evolution of star clusters. It is in good agreement with the relation determined by the metallicity measured by ${\rm NV/CIV}$ or ${\rm NV/HeII}$ in Hamann & Ferland's sample. This lends observational support to the formation of SMBHs via routes R4 or R5, namely, the evolution of dense star clusters.

Key words: black hole -- metallicity -- quasars

Offprint request: Jian-Min Wang, wangjm@astrosv1.ihep.ac.cn

© ESO 2001