2007ApJ...669...32K


Query : 2007ApJ...669...32K

2007ApJ...669...32K - Astrophys. J., 669, 32-44 (2007/November-1)

Black hole masses and enrichment of z ∼ 6 SDSS quasars.

KURK J.D., WALTER F., FAN X., JIANG L., RIECHERS D.A., RIX H.-W., PENTERICCI L., STRAUSS M.A., CARILLI C. and WAGNER S.

Abstract (from CDS):

We present sensitive near-infrared spectroscopic observations for a sample of five z∼6 quasars. These quasars are among the most distant, currently known quasars in the universe. The spectra have been obtained using ISAAC at the VLT and include the C IV, Mg II, and Fe II lines. We measure the Fe II/Mg II line ratio, as an observational proxy for the Fe/α-element ratio. We derive a ratio of 2.7±0.8 for our sample, which is similar to that found for lower redshift quasars; i.e., we provide additional evidence for the lack of evolution in the Fe II/Mg II line ratio of quasars up to the highest redshifts. This result demonstrates that star formation must have commenced at z≥8 in the quasar hosts. The line widths of the Mg II and C IV lines give two estimates for the black hole masses. A third estimate is given by assuming that the quasars emit at their Eddington luminosity. The derived masses using these three methods agree well, implying that the quasars are not likely to be strongly lensed. We derive central black hole masses of (0.3-5.2)x109 M. We use the difference between the redshift of Mg II (a proxy for the systemic redshift of the quasar) and the onset of the Gunn-Peterson trough to derive the extent of the ionized Strömgren spheres around our target quasars. The derived physical radii are about 5 Mpc. Using a simple ionization model, the emission of the central quasars would need of order 106-108 yr to create these cavities. As the e-folding timescale for the central accreting black hole is on the order of a few times 107 yr, it can grow by one e-folding or less within this time span.

Abstract Copyright:

Journal keyword(s): Galaxies: Evolution - Galaxies: Formation - Galaxies: Fundamental Parameters - Galaxies: High-Redshift - quasars: individual (J000552.34-000655.8) - quasars: individual (J083643.85+005453.3) - quasars: individual (J103027.10+052455.0) - quasars: individual (J130608.26+035626.3) - quasars: individual (J141111.29+121737.4)

Simbad objects: 6

goto Full paper

goto View the references in ADS

Number of rows : 6
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 SDSS J000552.33-000655.6 QSO 00 05 52.333 -00 06 55.65   26.37 25.36     ~ 73 0
2 Mrk 1502 Sy1 00 53 34.9331107632 +12 41 35.929269132   14.41 14.03     ~ 1128 1
3 SDSS J103027.09+052455.0 QSO 10 30 27.092 +05 24 55.02   26.15 25.44     ~ 251 0
4 SDSS J114816.64+525150.3 QSO 11 48 16.647 +52 51 50.31   25.73 25.04     ~ 436 0
5 SDSS J130608.25+035626.3 QSO 13 06 08.259 +03 56 26.19   25.59 24.81     ~ 149 0
6 SDSS J141111.27+121737.3 QSO 14 11 11.277 +12 17 37.31   24.79 23.82     ~ 70 0

To bookmark this query, right click on this link: simbad:objects in 2007ApJ...669...32K and select 'bookmark this link' or equivalent in the popup menu


2023.03.30-23:35:26

© Université de Strasbourg/CNRS

    • Contact