Astrophys. J., 795, 126 (2014/November-2)
A census of star-forming galaxies in the z ∼ 9-10 universe based on HST+Spitzer observations over 19 CLASH clusters: three candidate z ∼ 9-10 galaxies and improved constraints on the star formation rate density at z ∼ 9.2.
BOUWENS R.J., BRADLEY L., ZITRIN A., COE D., FRANX M., ZHENG W., SMIT R., HOST O., POSTMAN M., MOUSTAKAS L., LABBE I., CARRASCO M., MOLINO A., DONAHUE M., KELSON D.D., MENEGHETTI M., BENITEZ N., LEMZE D., UMETSU K., BROADHURST T., MOUSTAKAS J., ROSATI P., JOUVEL S., BARTELMANN M., FORD H., GRAVES G., GRILLO C., INFANTE L., JIMENEZ-TEJA Y., LAHAV O., MAOZ D., MEDEZINSKI E., MELCHIOR P., MERTEN J., NONINO M., OGAZ S. and SEITZ S.
Abstract (from CDS):
We utilize a two-color Lyman-break selection criterion to search for z ∼ 9-10 galaxies over the first 19 clusters in the CLASH program. A systematic search yields three z ∼ 9-10 candidates. While we have already reported the most robust of these candidates, MACS1149-JD, two additional z ∼ 9 candidates are also found and have H160-band magnitudes of ∼26.2-26.9. A careful assessment of various sources of contamination suggests ≲ 1 contaminants for our z ∼ 9-10 selection. To determine the implications of these search results for the luminosity function (LF) and star formation rate density at z ∼ 9, we introduce a new differential approach to deriving these quantities in lensing fields. Our procedure is to derive the evolution by comparing the number of z ∼ 9-10 galaxy candidates found in CLASH with the number of galaxies in a slightly lower-redshift sample (after correcting for the differences in selection volumes), here taken to be z ∼ 8. This procedure takes advantage of the fact that the relative volumes available for the z ∼ 8 and z ∼ 9-10 selections behind lensing clusters are not greatly dependent on the details of the lensing models. We find that the normalization of the UV LF at z ∼ 9 is just 0.28–0.20+0.39 x that at z ∼ 8, which is ∼1.4_-0.8+3.0 x lower than extrapolating z ∼ 4-8 LF results. While consistent with the evolution in the UV LF seen at z ∼ 4-8, these results marginally favor a more rapid evolution at z > 8. Compared to similar evolutionary findings from the HUDF, our result is less insensitive to large-scale structure uncertainties, given our many independent sightlines on the high-redshift universe.
galaxies: evolution - galaxies: high-redshift
Fig. 3, Table 2: [BBZ2014] MACSJHHMM-JD1 (Nos MACSJ1115-JD1, MACSJ1720-JD1). Table 5: [BBZ2014] JHHMMSS.ss+DDMMSS.s N=17, [BBZ2014] JHHMMSS.ss+DDMMSS.ss N=1.
View the reference in ADS
To bookmark this query, right click on this link: simbad:2014ApJ...795..126B and select 'bookmark this link' or equivalent in the popup menu