Bibcode
Laporte, N.; Pelló, R.; Hayes, M.; Schaerer, D.; Boone, F.; Richard, J.; Le Borgne, J. F.; Kneib, J. P.; Combes, F.
Bibliographical reference
Astronomy and Astrophysics, Volume 542, id.L31, 4 pp.
Advertised on:
6
2012
Journal
Citations
15
Refereed citations
15
Description
Context. We present additional constraints on the galaxy luminosity
function at z ~ 9 based on observations carried out with ESO/VLT FORS2,
HAWK-I, and X-Shooter around the lensing cluster A2667, as part of our
project designed to select z ~ 7-10 candidates accessible to
spectroscopy. We find that only one selected J-dropout source in this
field fulfills the color and magnitude criteria. This source was
recently confirmed as a mid-z interloper based on X-Shooter
spectroscopy. Aims: Owing to the considerable depth and area
covered by our survey, we are able to set strong constraints on the
bright end of the galaxy luminosity function and hence on the star
formation history at very high redshift. Methods: We used our
non-detection of reliable J-dropout sources over the ~36
arcmin2 field of view towards A2667 to carefully determine
the lens-corrected effective volume and the corresponding upper limit to
the density of sources. Results: Our strongest limit is obtained
for Φ(M1500 = -21.4 ± 0.50) < 6.70 ×
10-6 Mpc-3 mag-1 at z ~ 9. A
maximum-likelihood fit of the luminosity function to all available data
points including the present new result yields M⋆ >
-19.7 with fixed α = -1.74 and Φ⋆ = 1.10
× 10-3 Mpc-3. The corresponding
star-formation rate density should be ρSFR < 5.97
× 10-3 M⊙ yr-1
Mpc3 at z ~ 9. These results are in good agreement with the
most recent estimates already published for this range of redshift and
luminosity domain. Conclusions: This new result confirms
previously measured decreases in the density of luminous galaxies at
very high redshift, hence provides strong constraints on the design of
future surveys aiming to explore the very high-redshift Universe.
Based on observations collected at The European Southern Observatory,
Paranal, Chile, as part of the ESO 082.A-0163 and 087.A-0118.