TY - JOUR
T1 - First Sample of Hα+[O iii]λ5007 Line Emitters at z > 6 Through JWST/NIRCam Slitless Spectroscopy
T2 - Physical Properties and Line-luminosity Functions
AU - Sun, Fengwu
AU - Egami, Eiichi
AU - Pirzkal, Nor
AU - Rieke, Marcia
AU - Baum, Stefi
AU - Boyer, Martha
AU - Boyett, Kristan
AU - Bunker, Andrew J.
AU - Cameron, Alex J.
AU - Curti, Mirko
AU - Eisenstein, Daniel J.
AU - Gennaro, Mario
AU - Greene, Thomas P.
AU - Jaffe, Daniel
AU - Kelly, Doug
AU - Koekemoer, Anton M.
AU - Kumari, Nimisha
AU - Maiolino, Roberto
AU - Maseda, Michael
AU - Perna, Michele
AU - Rest, Armin
AU - Robertson, Brant E.
AU - Schlawin, Everett
AU - Smit, Renske
AU - Stansberry, John
AU - Sunnquist, Ben
AU - Tacchella, Sandro
AU - Williams, Christina C.
AU - Willmer, Christopher N.A.
N1 - Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/8/1
Y1 - 2023/8/1
N2 - We present a sample of four emission-line galaxies at z = 6.11-6.35 that were serendipitously discovered using the commissioning data for the James Webb Space Telescope (JWST)/NIRCam wide-field slitless spectroscopy mode. One of them (at z = 6.11) has been reported previously, while the others are new discoveries. These sources are selected by the secure detections of both [O iii] λ5007 and Hα lines with other fainter lines, which were tentatively detected in some cases (e.g., [O ii] λ3727, [O iii] λ4959). In the [O iii]/Hβ-[N ii]/Hα Baldwin-Phillips-Terlevich diagram, these galaxies occupy the same parameter space as that of z ∼ 2 star-forming galaxies, indicating that they have been enriched rapidly to subsolar metallicities (∼0.4 Z ⊙), similar to galaxies with comparable stellar masses at much lower redshifts. The detection of strong Hα lines suggests a higher ionizing photon production efficiency within galaxies in the early universe. We find brightening of the [O iii] λ5007 line-luminosity function (LF) from z = 3 to 6, and weak or no redshift evolution of the Hα line LF from z = 2 to 6. Both LFs are underpredicted at z ∼ 6 by a factor of ∼10 in certain cosmological simulations. This further indicates a global Lyα photon escape fraction of 7%-10% at z ∼ 6, which is slightly lower than previous estimates through the comparison of the UV-derived star formation rate density and Lyα luminosity density. Our sample recovers 66 − 44 + 128 % of z = 6.0-6.6 galaxies in the survey volume with stellar masses greater than 5 × 108 M ⊙, suggesting the ubiquity of strong Hα and [O iii] line emitters in the Epoch of Reionization, which will be further uncovered in the era of JWST.
AB - We present a sample of four emission-line galaxies at z = 6.11-6.35 that were serendipitously discovered using the commissioning data for the James Webb Space Telescope (JWST)/NIRCam wide-field slitless spectroscopy mode. One of them (at z = 6.11) has been reported previously, while the others are new discoveries. These sources are selected by the secure detections of both [O iii] λ5007 and Hα lines with other fainter lines, which were tentatively detected in some cases (e.g., [O ii] λ3727, [O iii] λ4959). In the [O iii]/Hβ-[N ii]/Hα Baldwin-Phillips-Terlevich diagram, these galaxies occupy the same parameter space as that of z ∼ 2 star-forming galaxies, indicating that they have been enriched rapidly to subsolar metallicities (∼0.4 Z ⊙), similar to galaxies with comparable stellar masses at much lower redshifts. The detection of strong Hα lines suggests a higher ionizing photon production efficiency within galaxies in the early universe. We find brightening of the [O iii] λ5007 line-luminosity function (LF) from z = 3 to 6, and weak or no redshift evolution of the Hα line LF from z = 2 to 6. Both LFs are underpredicted at z ∼ 6 by a factor of ∼10 in certain cosmological simulations. This further indicates a global Lyα photon escape fraction of 7%-10% at z ∼ 6, which is slightly lower than previous estimates through the comparison of the UV-derived star formation rate density and Lyα luminosity density. Our sample recovers 66 − 44 + 128 % of z = 6.0-6.6 galaxies in the survey volume with stellar masses greater than 5 × 108 M ⊙, suggesting the ubiquity of strong Hα and [O iii] line emitters in the Epoch of Reionization, which will be further uncovered in the era of JWST.
UR - https://www.scopus.com/pages/publications/85167347056
UR - https://www.scopus.com/pages/publications/85167347056#tab=citedBy
U2 - 10.3847/1538-4357/acd53c
DO - 10.3847/1538-4357/acd53c
M3 - Article
AN - SCOPUS:85167347056
SN - 0004-637X
VL - 953
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 53
ER -