TY - JOUR
T1 - Investigating the physical properties of galaxies in the Epoch of Reionization with MIRI/JWST spectroscopy
AU - Alvarez-Marquez, J.
AU - Colina, Luis
AU - Marques-Chaves, R.
AU - Ceverino , D.
AU - Alonso-Herrero, A.
AU - Caputi, K.
AU - Garcia-Marin, M.
AU - Labiano, A.
AU - Le Fevre, O.
AU - Nørgaard-Nielsen, H. U.
AU - Ostlin, G.
AU - Perez-Gonzalez, P. G.
AU - Pye, J. P.
AU - Tikkanen, T. V.
AU - van der Werf, P. P.
AU - Walter, F.
AU - Wright, G. S.
PY - 2019
Y1 - 2019
N2 - The James Webb Space Telescope (JWST) will provide deep imaging
and spectroscopy for sources at redshifts above 6, covering the entire
Epoch of Reionization (EoR, 6 < z < 10), and enabling the
detailed exploration of the nature of the different sources during the
first 1 Gyr of the history of the Universe. The Medium Resolution
Spectrograph (MRS) of the mid-IR Instrument (MIRI) will be the only
instrument on board JWST able to observe the brightest optical emission
lines Hα and [OIII]0.5007 μm at redshifts above 7 and 9,
respectively, providing key insights into the physical properties of
sources during the early phases of the EoR. This paper presents a study
of the Hα fluxes predicted by state-of-the-art FIRSTLIGHT
cosmological simulations for galaxies at redshifts of 6.5–10.5, and its
detectability with MIRI. Deep (40 ks) spectroscopic integrations with
MRS will be able to detect (signal-to-noise ratio > 5) EoR sources at
redshifts above 7 with intrinsic star formation rates (SFR) of more
than 2 M⊙ yr−1, and stellar masses above 4–9 × 107 M⊙.
These limits cover the upper end of the SFR and stellar mass
distribution at those redshifts, representing ∼6% and ∼1% of the
predicted FIRSTLIGHT population at the 6.5–7.5 and 7.5–8.5 redshift
ranges, respectively. In addition, the paper presents realistic MRS
simulated observations of the expected rest-frame optical and
near-infrared spectra for some spectroscopically confirmed EoR sources
recently detected by ALMA as [OIII]88 μm emitters. The MRS simulated spectra cover a wide range of low metallicities from about 0.2–0.02 Z⊙, and different [OIII]88 μm/[OIII]0.5007 μm line ratios. The simulated 10 ks MRS spectra show S/N in the range of 5–90 for Hβ, [OIII]0.4959,0.5007 μm, Hα and HeI1.083 μm
emission lines of the currently highest spectroscopically confirmed EoR
(lensed) source MACS1149-JD1 at a redshift of 9.11, independent of
metallicity. In addition, deep 40 ksec simulated spectra of the luminous
merger candidate B14-65666 at 7.15 shows the MRS capabilities of
detecting, or putting strong upper limits on, the weak [NII]0.6584 μm, [SII]0.6717,0.6731 μm, and [SIII]0.9069,0.9532 μm
emission lines. These observations will provide the opportunity of
deriving accurate metallicities in bright EoR sources using the full
range of rest-frame optical emission lines up to 1 μm. In
summary, MRS will enable the detailed study of key physical properties
such as internal extinction, instantaneous star formation, hardness of
the ionizing continuum, and metallicity in bright (intrinsic or lensed)
EoR sources.
AB - The James Webb Space Telescope (JWST) will provide deep imaging
and spectroscopy for sources at redshifts above 6, covering the entire
Epoch of Reionization (EoR, 6 < z < 10), and enabling the
detailed exploration of the nature of the different sources during the
first 1 Gyr of the history of the Universe. The Medium Resolution
Spectrograph (MRS) of the mid-IR Instrument (MIRI) will be the only
instrument on board JWST able to observe the brightest optical emission
lines Hα and [OIII]0.5007 μm at redshifts above 7 and 9,
respectively, providing key insights into the physical properties of
sources during the early phases of the EoR. This paper presents a study
of the Hα fluxes predicted by state-of-the-art FIRSTLIGHT
cosmological simulations for galaxies at redshifts of 6.5–10.5, and its
detectability with MIRI. Deep (40 ks) spectroscopic integrations with
MRS will be able to detect (signal-to-noise ratio > 5) EoR sources at
redshifts above 7 with intrinsic star formation rates (SFR) of more
than 2 M⊙ yr−1, and stellar masses above 4–9 × 107 M⊙.
These limits cover the upper end of the SFR and stellar mass
distribution at those redshifts, representing ∼6% and ∼1% of the
predicted FIRSTLIGHT population at the 6.5–7.5 and 7.5–8.5 redshift
ranges, respectively. In addition, the paper presents realistic MRS
simulated observations of the expected rest-frame optical and
near-infrared spectra for some spectroscopically confirmed EoR sources
recently detected by ALMA as [OIII]88 μm emitters. The MRS simulated spectra cover a wide range of low metallicities from about 0.2–0.02 Z⊙, and different [OIII]88 μm/[OIII]0.5007 μm line ratios. The simulated 10 ks MRS spectra show S/N in the range of 5–90 for Hβ, [OIII]0.4959,0.5007 μm, Hα and HeI1.083 μm
emission lines of the currently highest spectroscopically confirmed EoR
(lensed) source MACS1149-JD1 at a redshift of 9.11, independent of
metallicity. In addition, deep 40 ksec simulated spectra of the luminous
merger candidate B14-65666 at 7.15 shows the MRS capabilities of
detecting, or putting strong upper limits on, the weak [NII]0.6584 μm, [SII]0.6717,0.6731 μm, and [SIII]0.9069,0.9532 μm
emission lines. These observations will provide the opportunity of
deriving accurate metallicities in bright EoR sources using the full
range of rest-frame optical emission lines up to 1 μm. In
summary, MRS will enable the detailed study of key physical properties
such as internal extinction, instantaneous star formation, hardness of
the ionizing continuum, and metallicity in bright (intrinsic or lensed)
EoR sources.
KW - Galaxies: high-redshift
KW - Galaxies: formation
KW - Galaxies: evolution
KW - Infrared: galaxies
KW - Telescopes
U2 - 10.1051/0004-6361/201935594
DO - 10.1051/0004-6361/201935594
M3 - Journal article
SN - 0004-6361
VL - 629
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A9
ER -