The LABOCA survey of the Extended Chandra Deep Field-South: clustering of submillimetre galaxies
Abstract
We present a measurement of the spatial clustering of submillimetre galaxies (SMGs) at z= 1-3. Using data from the 870 μm Large APEX Bolometer Camera (LABOCA) submillimetre survey of the Extended Chandra Deep Field-South, we employ a novel technique to measure the cross-correlation between SMGs and galaxies, accounting for the full probability distributions for photometric redshifts of the galaxies. From the observed projected two-point cross-correlation function we derive the linear bias and characteristic dark matter halo masses for the SMGs. We detect clustering in the cross-correlation between SMGs and galaxies at the >4σ level. Accounting for the clustering of galaxies from their autocorrelation function, we estimate an autocorrelation length for SMGs of ? Mpc assuming a power-law slope γ= 1.8, and derive a corresponding dark matter halo mass of ?. Based on the evolution of dark matter haloes derived from simulations, we show that that the z= 0 descendants of SMGs are typically massive (∼2-3L*) elliptical galaxies residing in moderate- to high-mass groups (?). From the observed clustering we estimate an SMG lifetime of ∼100 Myr, consistent with lifetimes derived from gas consumption times and star formation time-scales, although with considerable uncertainties. The clustering of SMGs at z∼ 2 is consistent with measurements for optically selected quasi-stellar objects (QSOs), supporting evolutionary scenarios in which powerful starbursts and QSOs occur in the same systems. Given that SMGs reside in haloes of characteristic mass ∼6 × 1012 h-1 M⊙, we demonstrate that the redshift distribution of SMGs can be described remarkably well by the combination of two effects: the cosmological growth of structure and the evolution of the molecular gas fraction in galaxies. We conclude that the powerful starbursts in SMGs likely represent a short-lived but universal phase in massive galaxy evolution, associated with the transition between cold gas-rich, star-forming galaxies and passively evolving systems.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- March 2012
- DOI:
- 10.1111/j.1365-2966.2011.20303.x
- arXiv:
- arXiv:1112.0321
- Bibcode:
- 2012MNRAS.421..284H
- Keywords:
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- galaxies: evolution;
- galaxies: high-redshift;
- galaxies: starburst;
- large-scale structure of Universe;
- submillimetre: galaxies;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 13 pages, 8 figures, 1 table