2010A&A...524A..28C


Query : 2010A&A...524A..28C

2010A&A...524A..28C - Astronomy and Astrophysics, volume 524, A28-28 (2010/12-1)

The bright end of the z ∼ 7 UV luminosity function from a wide and deep HAWK-I survey.

CASTELLANO M., FONTANA A., PARIS D., GRAZIAN A., PENTERICCI L., BOUTSIA K., SANTINI P., TESTA V., DICKINSON M., GIAVALISCO M., BOUWENS R., CUBY J.-G., MANNUCCI F., CLEMENT B., CRISTIANI S., FIORE F., GALLOZZI S., GIALLONGO E., MAIOLINO R., MENCI N., MOORWOOD A., NONINO M., RENZINI A., ROSATI P., SALIMBENI S. and VANZELLA E.

Abstract (from CDS):

We perform a deep search for galaxies in the redshift range 6.5≤z≤7.5 to measure the evolution of the number density of luminous galaxies in this redshift range and derive useful constraints on the evolution of their luminosity function. We present here the second half of an ESO Large Programme, which exploits the unique combination of area and sensitivity provided in the near-IR by the camera Hawk-I at the VLT. We have obtained ∼30 observing hours with Hawk-I in the Y-band of two high galactic latitude fields. We combined the Y-band data with deep J and K Hawk-I observations, as well as FORS1/FORS2 U, B, V, R, I, and Z observations to select z-drop galaxies with Z-Y>1, no optical detection, and flat Y-J and Y-K colour terms. We detect eight high-quality candidates in the magnitude range Y=25.5-26.5 that we add to the z-drop candidates selected in two Hawk-I pointings over the GOODS-South field. We use this full sample of 15 objects found in ∼161 arcmin2 of our survey to constrain the average physical properties and the evolution of the number density of z∼7 LBGs. A stacking analysis yields a best-fit SED with photometric redshift z=6.85+0.20–0.15 and an E(B-V)=0.05+0.15–0.05. We compute a binned estimate of the z∼7 LF and explore the effects of photometric scatter and model uncertainties on the statistical constraints. After accounting for the expected incompleteness through MonteCarlo simulations, we strengthen our previous finding that a Schechter luminosity function constant from z=6 to z=7 is ruled out at a > 99% confidence level, even including the effects of cosmic variance. For galaxies brighter than M1500=-19.0, we derive a luminosity density ρUV=1.5+2.1–0.8x1025erg/s/Hz/Mpc3, implying a decrease by a factor 3.5 from z=6 to z≃6.8. We find that under standard assumptions, the emission rate of ionizing photons coming from UV bright galaxies is lower by at least a factor of two than the value required for reionization. Finally, we exploit deep Hawk-I J and K band observations to derive an upper limit on the number density of M1500≲-22.0 LBGs at z∼8 (Y-dropouts).

Abstract Copyright:

Journal keyword(s): galaxies: distances and redshifts - galaxies: high-redshift - galaxies: luminosity function, mass function - galaxies: evolution

Nomenclature: Fig. 3, Table 3: [CFP2010] BDF NNNN (Nos 521, 3299, 5905), [CFP2010] NTTDF NNNN N=5 among (Nos 1479-6543).

Simbad objects: 11

goto Full paper

goto View the references in ADS

Number of rows : 11
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
#notes
1 NAME GOODS Southern Field reg 03 32 28.0 -27 48 30           ~ 1361 1
2 NAME Hubble Ultra Deep Field reg 03 32 39.0 -27 47 29           ~ 1685 0
3 NAME NTTDF reg 12 05 -07.5           ~ 21 0
4 [CFP2010] NTTDF 1917 G 12 05 17.1 -07 41 16           ~ 3 0
5 [CFP2010] NTTDF 1479 G 12 05 22.3 -07 40 53           ~ 3 0
6 [CFP2010] NTTDF 6543 G 12 05 32.0 -07 45 34           ~ 3 0
7 [CFP2010] NTTDF 1632 G 12 05 32.6 -07 41 01           ~ 4 0
8 [CFP2010] NTTDF 6345 G 12 05 36.9 -07 45 22           ~ 17 0
9 [CFP2010] BDF 521 G 22 27 46.7 -35 07 08           ~ 24 0
10 [CFP2010] BDF 5905 G 22 28 05.5 -35 12 34           ~ 1 0
11 [CFP2010] BDF 3299 G 22 28 12.3 -35 09 59           ~ 44 0

To bookmark this query, right click on this link: simbad:objects in 2010A&A...524A..28C and select 'bookmark this link' or equivalent in the popup menu