COSMOS2020: UV-selected galaxies at z >= 7.5
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COSMOS2020 : UV-selected galaxies at z >= 7.5. / Kauffmann, O. B.; Ilbert, O.; Weaver, J. R.; McCracken, H. J.; Milvang-Jensen, B.; Brammer, G.; Davidzon, I.; Le Fevre, O.; Liu, D.; Mobasher, B.; Moneti, A.; Shuntov, M.; Toft, S.; Casey, C. M.; Dunlop, J. S.; Kartaltepe, J. S.; Koekemoer, A. M.; Sanders, D. B.; Tresse, L.
In: Astronomy & Astrophysics, Vol. 667, A65, 07.11.2022.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - COSMOS2020
T2 - UV-selected galaxies at z >= 7.5
AU - Kauffmann, O. B.
AU - Ilbert, O.
AU - Weaver, J. R.
AU - McCracken, H. J.
AU - Milvang-Jensen, B.
AU - Brammer, G.
AU - Davidzon, I.
AU - Le Fevre, O.
AU - Liu, D.
AU - Mobasher, B.
AU - Moneti, A.
AU - Shuntov, M.
AU - Toft, S.
AU - Casey, C. M.
AU - Dunlop, J. S.
AU - Kartaltepe, J. S.
AU - Koekemoer, A. M.
AU - Sanders, D. B.
AU - Tresse, L.
PY - 2022/11/7
Y1 - 2022/11/7
N2 - This paper presents a new search for z >= 7.5 galaxies using the COSMOS2020 photometric catalogues. Finding galaxies at the reionisation epoch through deep imaging surveys remains observationally challenging. The larger area covered by ground-based surveys such as COSMOS enables the discovery of the brightest galaxies at these high redshifts. Covering 1.4 deg(2), our COSMOS catalogues were constructed from the latest UltraVISTA data release (DR4) combined with the final Spitzer/IRAC COSMOS images and the Hyper-Suprime-Cam Subaru Strategic Program DR2 release. We identified 17 new 7.5 < z < 10 candidate sources, and confirm 15 previously published candidates. Using deblended photometry extracted by fitting surface brightness models on multi-band images, we selected four candidates which would be rejected using fixed aperture photometry. We tested the robustness of all our candidates by comparing six different photometric redshift estimates. Finally, we computed the galaxy UV luminosity function in three redshift bins centred at z = 8, 9, 10. We find no clear evolution of the number density of the brightest galaxies M-UV < 21 .5, in agreement with previous works. Rapid changes in the quenching efficiency or attenuation by dust could explain such a lack of evolution between z similar to 8 and z similar to 9. A spectroscopic confirmation of the redshifts, already planned with JWST and the Keck telescopes, will be essential to confirm our results.
AB - This paper presents a new search for z >= 7.5 galaxies using the COSMOS2020 photometric catalogues. Finding galaxies at the reionisation epoch through deep imaging surveys remains observationally challenging. The larger area covered by ground-based surveys such as COSMOS enables the discovery of the brightest galaxies at these high redshifts. Covering 1.4 deg(2), our COSMOS catalogues were constructed from the latest UltraVISTA data release (DR4) combined with the final Spitzer/IRAC COSMOS images and the Hyper-Suprime-Cam Subaru Strategic Program DR2 release. We identified 17 new 7.5 < z < 10 candidate sources, and confirm 15 previously published candidates. Using deblended photometry extracted by fitting surface brightness models on multi-band images, we selected four candidates which would be rejected using fixed aperture photometry. We tested the robustness of all our candidates by comparing six different photometric redshift estimates. Finally, we computed the galaxy UV luminosity function in three redshift bins centred at z = 8, 9, 10. We find no clear evolution of the number density of the brightest galaxies M-UV < 21 .5, in agreement with previous works. Rapid changes in the quenching efficiency or attenuation by dust could explain such a lack of evolution between z similar to 8 and z similar to 9. A spectroscopic confirmation of the redshifts, already planned with JWST and the Keck telescopes, will be essential to confirm our results.
KW - galaxies: luminosity function, mass function
KW - galaxies: evolution
KW - galaxies: formation
KW - galaxies: high-redshift
KW - galaxies: photometry
KW - galaxies: statistics
KW - STELLAR POPULATION SYNTHESIS
KW - EVOLUTION SURVEY COSMOS
KW - HUBBLE FRONTIER FIELDS
KW - DIGITAL SKY SURVEY
KW - LUMINOSITY FUNCTION
KW - HIGH-REDSHIFT
KW - BRIGHT END
KW - BLACK-HOLES
KW - DEEP SURVEY
KW - LY-ALPHA
U2 - 10.1051/0004-6361/202243088
DO - 10.1051/0004-6361/202243088
M3 - Journal article
VL - 667
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
SN - 0004-6361
M1 - A65
ER -
ID: 326627677