The halo masses and galaxy environments of hyperluminous QSOs at z~2.7 in the Keck Baryonic Structure Survey

Details The halo masses and galaxy environments of hyperluminous QSOs at z~2.7 in the Keck Baryonic Structure Survey The halo masses and galaxy environments of hyperluminous QSOs at z~2.7 in the Keck Baryonic Structure Survey

2012-04-16

arxiv.org/abs/1204.3636v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

15 pages, 6 figures. Accepted for publication in ApJ

Scientific paper

We present an analysis of the galaxy distribution surrounding 15 of the most luminous (>10^{14} L_sun; M_1450 ~ -30) QSOs in the sky with z~2.7. Our data are drawn from the Keck Baryonic Structure Survey (KBSS). In this work, we use the positions and spectroscopic redshifts of 1558 galaxies that lie within ~3', (4.2 h^{-1} comoving Mpc; cMpc) of the hyperluminous QSO (HLQSO) sightline in one of 15 independent survey fields, together with new measurements of the HLQSO systemic redshifts. We measure the galaxy-HLQSO cross-correlation function, the galaxy-galaxy autocorrelation function, and the characteristic scale of galaxy overdensities surrounding the sites of exceedingly rare, extremely rapid, black hole accretion. On average, the HLQSOs lie within significant galaxy overdensities, characterized by a velocity dispersion sigma_v ~ 200 km s^{-1} and a transverse angular scale of ~25", (~200 physical kpc). We argue that such scales are expected for small groups with log(M_h/M_sun)~13. The galaxy-HLQSO cross-correlation function has a best-fit correlation length r_0_GQ = (7.3 \pm 1.3) h^{-1} cMpc, while the galaxy autocorrelation measured from the spectroscopic galaxy sample in the same fields has r_0_GG = (6.0 \pm 0.5) h^{-1} cMpc. Based on a comparison with simulations evaluated at z ~ 2.6, these values imply that a typical galaxy lives in a host halo with log(M_h/M_sun) = 11.9\pm0.1, while HLQSOs inhabit host halos of log(M_h/M_sun) = 12.3\pm0.5. In spite of the extremely large black hole masses implied by their observed luminosities [log(M_BH/M_sun) > 9.7], it appears that HLQSOs do not require environments very different from their much less luminous QSO counterparts. Evidently, the exceedingly low space density of HLQSOs (< 10^{-9} cMpc^{-3}) results from a one-in-a-million event on scales << 1 Mpc, and not from being hosted by rare dark matter halos.

Affiliated with

Also associated with

No associations

Rating

The halo masses and galaxy environments of hyperluminous QSOs at z~2.7 in the Keck Baryonic Structure Survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The halo masses and galaxy environments of hyperluminous QSOs at z~2.7 in the Keck Baryonic Structure Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The halo masses and galaxy environments of hyperluminous QSOs at z~2.7 in the Keck Baryonic Structure Survey will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-288431