Bibcode
Laporte, N.; Pelló, R.; Schaerer, D.; Richard, J.; Boone, F.; Kneib, J.-P.; Egami, E.
Referencia bibliográfica
SF2A-2011: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics Eds.: G. Alecian, K. Belkacem, R. Samadi and D. Valls-Gabaud, pp.141-145
Advertised on:
12
2011
Número de citas
0
Número de citas referidas
0
Descripción
We have conducted a survey aimed at identifying a sample of z˜7-10
candidates accessible to detailed spectroscopic studies. The deep survey
on A2667 covers a large field of view with HAWK-I and FORS2 at ESO/VLT
between 0.8 and 2.5μm (typical depth m(AB)=27.5 at 3σ). 13
sources were identified based on the Lyman Break technique, namely 1
J-drop, 8 Y-drops and 4 z-drops over the ˜45 arcmin^2 field of
view. Optical and near-IR data were combined with Spitzer and Hubble
Space Telescope data, when available, in order to determine photometric
redshifts. Although the best-fit is always obtained for a high-z
solution, this sample shows a relatively high contamination level from
extreme mid-z interlopers which may also be present in other surveys.
This is demonstrated by the recent detection of two candidates by
Herschel and LABOCA, making the high-z identification unlikely. Waiting
for a complete spectroscopic follow up, we have used different criteria
to account for this contamination and to derive new constraints on the
bright end of the UV LF from z˜7 to 9, using a MC approach based
on the redshift probability distributions. Our results are consistent
with a significant evolution in the density of bright galaxies beyond
z˜8, whereas no clear evolution is observed between z˜7 and
8.