TY - JOUR
T1 - On the evolution of clustering of 24-μm-selected galaxies
AU - Magliocchetti, M.
AU - Cirasuolo, M.
AU - McLure, R. J.
AU - Dunlop, James
AU - Almaini, O.
AU - Foucaud, S.
AU - de Zotti, G.
AU - Simpson, C.
AU - Sekiguchi, K.
PY - 2008/1/1
Y1 - 2008/1/1
N2 - This paper investigates the clustering properties of a complete sample
of 1041 24-μm-selected sources brighter than F24μm =
400μJy in the overlapping region between the Spitzer Wide-Area
Infrared Extragalactic (SWIRE) and UKIRT Infrared Deep Sky Survey
(UKIDSS) Ultra Deep Survey (UDS) surveys. With the help of photometric
redshift determinations we have concentrated on the two interval ranges
z = [0.6-1.2] (low-z sample) and z >= 1.6 (high-z sample) as it is in
these regions were we expect the mid-infrared (IR) population to be
dominated by intense dust-enshrouded activity such as star formation and
black hole accretion. Investigations of the angular correlation function
produce an amplitude A ~ 0.010 for the high-z sample and A ~ 0.0055 for
the low-z one. The corresponding correlation lengths are r0 =
15.9+2.9-3.4 and
8.5+1.5-1.8Mpc, showing that the high-z population
is more strongly clustered. Comparisons with physical models for the
formation and evolution of large-scale structure reveal that the high-z
sources are exclusively associated with very massive (M >~
1013Msolar) haloes, comparable to those which
locally host groups-to-clusters of galaxies and are very common within
such (rare) structures. Conversely, lower z galaxies are found to reside
in smaller haloes (Mmin ~ 1012Msolar)
and to be very rare in such systems. On the other hand, mid-IR
photometry shows that the low-z and high-z samples include similar
objects and probe a similar mixture of active galactic nucleus (AGN) and
star-forming galaxies. While recent studies have determined a strong
evolution of the 24-μm luminosity function between z ~ 2 and 0, they
cannot provide information on the physical nature of such an evolution.
Our clustering results instead indicate that this is due to the presence
of different populations of objects inhabiting different structures, as
active systems at z
AB - This paper investigates the clustering properties of a complete sample
of 1041 24-μm-selected sources brighter than F24μm =
400μJy in the overlapping region between the Spitzer Wide-Area
Infrared Extragalactic (SWIRE) and UKIRT Infrared Deep Sky Survey
(UKIDSS) Ultra Deep Survey (UDS) surveys. With the help of photometric
redshift determinations we have concentrated on the two interval ranges
z = [0.6-1.2] (low-z sample) and z >= 1.6 (high-z sample) as it is in
these regions were we expect the mid-infrared (IR) population to be
dominated by intense dust-enshrouded activity such as star formation and
black hole accretion. Investigations of the angular correlation function
produce an amplitude A ~ 0.010 for the high-z sample and A ~ 0.0055 for
the low-z one. The corresponding correlation lengths are r0 =
15.9+2.9-3.4 and
8.5+1.5-1.8Mpc, showing that the high-z population
is more strongly clustered. Comparisons with physical models for the
formation and evolution of large-scale structure reveal that the high-z
sources are exclusively associated with very massive (M >~
1013Msolar) haloes, comparable to those which
locally host groups-to-clusters of galaxies and are very common within
such (rare) structures. Conversely, lower z galaxies are found to reside
in smaller haloes (Mmin ~ 1012Msolar)
and to be very rare in such systems. On the other hand, mid-IR
photometry shows that the low-z and high-z samples include similar
objects and probe a similar mixture of active galactic nucleus (AGN) and
star-forming galaxies. While recent studies have determined a strong
evolution of the 24-μm luminosity function between z ~ 2 and 0, they
cannot provide information on the physical nature of such an evolution.
Our clustering results instead indicate that this is due to the presence
of different populations of objects inhabiting different structures, as
active systems at z
UR - http://www.scopus.com/inward/record.url?scp=38949101944&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2007.12605.x
DO - 10.1111/j.1365-2966.2007.12605.x
M3 - Article
VL - 383
SP - 1131
EP - 1142
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
ER -