The origin of the dust in high-redshift quasars: the case of SDSS J1148+5251
The origin of the dust in high-redshift quasars: the case of SDSS J1148+5251
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高红移类星体中尘埃的起源：以SDSS J1148 5251为例
DOI：
10.1111/j.1365-2966.2011.19168.x
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发表时间：
2011
影响因子：
4.8
通讯作者：
S. Bianchi
中科院分区：
文献类型：
--
作者：
R. Valiante;R. Schneider;S. Salvadori;S. Bianchi
本文提出了一个高红移类星体（QSO）形成和演化的半解析模型。我们重建了一组10（13）-M-圆点暗物质晕的分层合并历史，并模拟了相应星系及其中心超大质量黑洞的演化。GAMETE/QSODUST程序始终遵循（i）通过与其他黑洞合并和气体吸积的黑洞组装;（ii）由双星合并和质量吸积驱动的类星体宿主星系的建立和星星形成历史;（iii）星际介质（ISM）中气体、恒星和金属的演化，解释了与外部介质的质量交换（iv）在超新星（SN）喷出物和渐近巨星分支（AGB）的恒星大气中的尘埃形成、星际激波对尘埃的破坏和分子云中的颗粒生长;以及（v）活动星系核反馈，为星系级风提供动力，自我调节黑洞的生长并最终停止星星的形成。我们使用这个模型来研究在红移6.4处观测到的SDSS J1148+5251的情况。我们探索了类星体宿主星系不同的星星形成历史，发现在红移> 10的祖星系中，由于ISM快速富集到金属丰度>Z（cr）= 10（-6）-10（-4）Z（圆点），第III族恒星对最终金属和尘埃质量的贡献可以忽略不计。如果II/I星族恒星形成时具有标准的初始质量函数（IMF）和特征恒星质量m（ch）= 0.35 M圆点，则最终恒星质量需要（1-5）x 10（11）M圆点才能重现SDSS J1148+5251观测到的尘埃质量和气体金属丰度。这比从观测中推断的恒星质量高出3-10倍，将使类星体更接近或接近在本宇宙中观察到的恒星膨胀-黑洞关系;或者，假设星族II/I的恒星按照顶重的IMF形成，m（ch）= 5 M（圆点），观测到的化学性质可以与推断的恒星质量相一致。我们发现，SNe占主导地位的早期尘埃富集，并根据形状的星星形成历史和恒星IMF，AGB星的贡献在z <8-10。然而，对于SDSS J1148+ 5251估计的尘埃质量为（2-6）x 10（8）M圆圆点，仅考虑恒星来源无法重现，最终的尘埃质量由分子云中的颗粒生长主导。这一结论与恒星IMF和星星形成历史无关。
We present a semi-analytical model for the formation and evolution of a high-redshift quasar (QSO). We reconstruct a set of hierarchical merger histories of a 10(13)-M-circle dot dark matter halo and model the evolution of the corresponding galaxy and of its central supermassive black hole. The code GAMETE/QSODUST consistently follows (i) the black hole assembly via both coalescence with other black holes and gas accretion; (ii) the build-up and star formation history of the quasar host galaxy, driven by binary mergers and mass accretion; (iii) the evolution of gas, stars and metals in the interstellar medium (ISM), accounting for mass exchanges with the external medium (infall and outflow processes); (iv) the dust formation in supernova (SN) ejecta and in the stellar atmosphere of asymptotic giant branch (AGB) stars, dust destruction by interstellar shocks and grain growth in molecular clouds; and (v) the active galactic nucleus feedback which powers a galactic-scale wind, self-regulating the black hole growth and eventually halting star formation. We use this model to study the case of SDSS J1148+5251 observed at redshift 6.4. We explore different star formation histories for the QSO host galaxy and find that Population III stars give a negligible contribution to the final metal and dust masses due to rapid enrichment of the ISM to metallicities >Z(cr) = 10(-6)-10(-4) Z(circle dot) in progenitor galaxies at redshifts > 10. If Population II/I stars form with a standard initial mass function (IMF) and with a characteristic stellar mass of m(ch) = 0.35 M-circle dot, a final stellar mass of (1-5) x 10(11) M-circle dot is required to reproduce the observed dust mass and gas metallicity of SDSS J1148+5251. This is a factor of 3-10 higher than the stellar mass inferred from observations and would shift the QSO closer or on to the stellar bulge-black hole relation observed in the local Universe; alternatively, the observed chemical properties can be reconciled with the inferred stellar mass, assuming that Population II/I stars form according to a top-heavy IMF with m(ch) = 5M(circle dot). We find that SNe dominate the early dust enrichment and that, depending on the shape of the star formation history and on the stellar IMF, AGB stars contribute at z <8-10. Yet, a dust mass of (2-6) x 10(8) M-circle dot estimated for SDSS J1148+ 5251 cannot be reproduced considering only stellar sources, and the final dust mass is dominated by grain growth in molecular clouds. This conclusion is independent of the stellar IMF and star formation history.
DOI：
10.1111/j.1365-2966.2006.11336.x
发表时间：
2006-11
影响因子：
4.8
作者：
B. Ercolano;M. Barlow;B. Sugerman
通讯作者：
B. Ercolano;M. Barlow;B. Sugerman