@article{trakhtenbrot_accretion_2016,
	title = {On the {Accretion} {Rates} and {Radiative} {Efficiencies} of the {Highest} {Redshift} {Quasars}},
	url = {http://arxiv.org/abs/1611.00772},
	abstract = {We estimate the accretion rates onto the super-massive black holes powering 20 of the highest-redshift quasars, at z{\textgreater}5.8, including the quasar with the highest redshift known to date -- ULAS J1120 at z=7.09. The analysis is based on the observed (rest-frame) optical luminosities and reliable "virial" estimates of the BH masses (M\_BH) of the sources, and utilizing scaling relations derived from thin accretion disk theory. The mass accretion rates through the postulated disks cover a wide range, dM\_disk/dt{\textasciitilde}4-190 Msol/yr, with most of the objects (80\%) having dM\_disk/dt{\textasciitilde}10-65 Msol/yr. By combining our estimates of dM\_disk/dt with conservative estimates of the bolometric luminosities of the quasars in our sample, we investigate which alternative values of {\textbackslash}eta{\textbackslash} best account for all the available data. We find that the vast majority of quasars ({\textasciitilde}85\%) can be explained with radiative efficiencies in the range {\textbackslash}eta{\textasciitilde}0.03-0.3. In particular, we find conservative estimates of {\textbackslash}eta{\textgreater}0.14 for ULAS J1120 and SDSS J0100 (at z=6.3), and of {\textgreater}0.19 for SDSS J1148 (at z=6.41). The implied accretion timescales are generally in the range t\_acc=M\_BH / dM\_BH/dt {\textasciitilde}0.1-1 Gyr, and suggest that most quasars had enough time for {\textasciitilde}1-10 mass e-foldings since BH seed formation. Our analysis suggests that the available luminosities and masses for the highest-redshift quasars can be explained self-consistently within the thin, radiatively efficient accretion disk paradigm, without invoking radiatively inefficient accretion flows, at the observed epoch. Such episodes of radiatively inefficient, "super-critical" accretion, may have occurred at significantly earlier epochs (i.e., z{\textasciitilde}10).},
	urldate = {2016-12-19},
	journal = {arXiv:1611.00772 [astro-ph]},
	author = {Trakhtenbrot, Benny and Volonteri, Marta and Natarajan, Priyamvada},
	month = nov,
	year = {2016},
	note = {arXiv: 1611.00772},
	keywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},
}

{"_id":"gks9CHypnWZEkuCHa","bibbaseid":"trakhtenbrot-volonteri-natarajan-ontheaccretionratesandradiativeefficienciesofthehighestredshiftquasars-2016","author_short":["Trakhtenbrot, B.","Volonteri, M.","Natarajan, P."],"bibdata":{"bibtype":"article","type":"article","title":"On the Accretion Rates and Radiative Efficiencies of the Highest Redshift Quasars","url":"http://arxiv.org/abs/1611.00772","abstract":"We estimate the accretion rates onto the super-massive black holes powering 20 of the highest-redshift quasars, at z\\textgreater5.8, including the quasar with the highest redshift known to date – ULAS J1120 at z=7.09. The analysis is based on the observed (rest-frame) optical luminosities and reliable \"virial\" estimates of the BH masses (M_BH) of the sources, and utilizing scaling relations derived from thin accretion disk theory. The mass accretion rates through the postulated disks cover a wide range, dM_disk/dt\\textasciitilde4-190 Msol/yr, with most of the objects (80%) having dM_disk/dt\\textasciitilde10-65 Msol/yr. By combining our estimates of dM_disk/dt with conservative estimates of the bolometric luminosities of the quasars in our sample, we investigate which alternative values of \\textbackslasheta\\textbackslash best account for all the available data. We find that the vast majority of quasars (\\textasciitilde85%) can be explained with radiative efficiencies in the range \\textbackslasheta\\textasciitilde0.03-0.3. In particular, we find conservative estimates of \\textbackslasheta\\textgreater0.14 for ULAS J1120 and SDSS J0100 (at z=6.3), and of \\textgreater0.19 for SDSS J1148 (at z=6.41). The implied accretion timescales are generally in the range t_acc=M_BH / dM_BH/dt \\textasciitilde0.1-1 Gyr, and suggest that most quasars had enough time for \\textasciitilde1-10 mass e-foldings since BH seed formation. Our analysis suggests that the available luminosities and masses for the highest-redshift quasars can be explained self-consistently within the thin, radiatively efficient accretion disk paradigm, without invoking radiatively inefficient accretion flows, at the observed epoch. Such episodes of radiatively inefficient, \"super-critical\" accretion, may have occurred at significantly earlier epochs (i.e., z\\textasciitilde10).","urldate":"2016-12-19","journal":"arXiv:1611.00772 [astro-ph]","author":[{"propositions":[],"lastnames":["Trakhtenbrot"],"firstnames":["Benny"],"suffixes":[]},{"propositions":[],"lastnames":["Volonteri"],"firstnames":["Marta"],"suffixes":[]},{"propositions":[],"lastnames":["Natarajan"],"firstnames":["Priyamvada"],"suffixes":[]}],"month":"November","year":"2016","note":"arXiv: 1611.00772","keywords":"Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics","bibtex":"@article{trakhtenbrot_accretion_2016,\n\ttitle = {On the {Accretion} {Rates} and {Radiative} {Efficiencies} of the {Highest} {Redshift} {Quasars}},\n\turl = {http://arxiv.org/abs/1611.00772},\n\tabstract = {We estimate the accretion rates onto the super-massive black holes powering 20 of the highest-redshift quasars, at z{\\textgreater}5.8, including the quasar with the highest redshift known to date -- ULAS J1120 at z=7.09. The analysis is based on the observed (rest-frame) optical luminosities and reliable \"virial\" estimates of the BH masses (M\\_BH) of the sources, and utilizing scaling relations derived from thin accretion disk theory. The mass accretion rates through the postulated disks cover a wide range, dM\\_disk/dt{\\textasciitilde}4-190 Msol/yr, with most of the objects (80\\%) having dM\\_disk/dt{\\textasciitilde}10-65 Msol/yr. By combining our estimates of dM\\_disk/dt with conservative estimates of the bolometric luminosities of the quasars in our sample, we investigate which alternative values of {\\textbackslash}eta{\\textbackslash} best account for all the available data. We find that the vast majority of quasars ({\\textasciitilde}85\\%) can be explained with radiative efficiencies in the range {\\textbackslash}eta{\\textasciitilde}0.03-0.3. In particular, we find conservative estimates of {\\textbackslash}eta{\\textgreater}0.14 for ULAS J1120 and SDSS J0100 (at z=6.3), and of {\\textgreater}0.19 for SDSS J1148 (at z=6.41). The implied accretion timescales are generally in the range t\\_acc=M\\_BH / dM\\_BH/dt {\\textasciitilde}0.1-1 Gyr, and suggest that most quasars had enough time for {\\textasciitilde}1-10 mass e-foldings since BH seed formation. Our analysis suggests that the available luminosities and masses for the highest-redshift quasars can be explained self-consistently within the thin, radiatively efficient accretion disk paradigm, without invoking radiatively inefficient accretion flows, at the observed epoch. Such episodes of radiatively inefficient, \"super-critical\" accretion, may have occurred at significantly earlier epochs (i.e., z{\\textasciitilde}10).},\n\turldate = {2016-12-19},\n\tjournal = {arXiv:1611.00772 [astro-ph]},\n\tauthor = {Trakhtenbrot, Benny and Volonteri, Marta and Natarajan, Priyamvada},\n\tmonth = nov,\n\tyear = {2016},\n\tnote = {arXiv: 1611.00772},\n\tkeywords = {Astrophysics - Astrophysics of Galaxies, Astrophysics - Cosmology and Nongalactic Astrophysics},\n}\n\n","author_short":["Trakhtenbrot, B.","Volonteri, M.","Natarajan, P."],"key":"trakhtenbrot_accretion_2016","id":"trakhtenbrot_accretion_2016","bibbaseid":"trakhtenbrot-volonteri-natarajan-ontheaccretionratesandradiativeefficienciesofthehighestredshiftquasars-2016","role":"author","urls":{"Paper":"http://arxiv.org/abs/1611.00772"},"keyword":["Astrophysics - Astrophysics of Galaxies","Astrophysics - Cosmology and Nongalactic Astrophysics"],"metadata":{"authorlinks":{}}},"bibtype":"article","biburl":"https://bibbase.org/zotero/polyphant","dataSources":["7gvjSdWrEu7z5vjjj"],"keywords":["astrophysics - astrophysics of galaxies","astrophysics - cosmology and nongalactic astrophysics"],"search_terms":["accretion","rates","radiative","efficiencies","highest","redshift","quasars","trakhtenbrot","volonteri","natarajan"],"title":"On the Accretion Rates and Radiative Efficiencies of the Highest Redshift Quasars","year":2016}