TY - JOUR
T1 - An ALMA Multiline Survey of the Interstellar Medium of the Redshift 7.5 Quasar Host Galaxy J1342+0928
AU - Novak, Mladen
AU - Banados, Eduardo
AU - Decarli, Roberto
AU - Walter, Fabian
AU - Venemans, Bram
AU - Neeleman, Marcel
AU - Farina, Emanuele Paolo
AU - Mazzucchelli, Chiara
AU - Carilli, Chris
AU - Fan, Xiaohui
AU - Rix, Hans Walter
AU - Wang, Feige
N1 - Publisher Copyright:
© 2019. The American Astronomical Society. All rights reserved.
PY - 2019/8/10
Y1 - 2019/8/10
N2 - We use Atacama Large Millimeter Array observations of the host galaxy of the quasar ULAS J1342+0928 at z = 7.54, to study the dust continuum and far-infrared lines emitted from its interstellar medium (ISM). The Rayleigh-Jeans tail of the dust continuum is well sampled with eight different spectral setups, and from a modified blackbody fit we obtain an emissivity coefficient of β = 1.85 ±0.3. Assuming a standard dust temperature of 47 K we derive a dust mass of M dust = 0.35 ×108 M and a star formation rate of . We have >4σ detections of the , , and atomic fine structure lines and limits on the , , and emission. We also report multiple limits of CO rotational lines with J up ≥ 7, as well as a tentative 3.3σ detection of the stack of four CO lines (J up = 11, 10, 8, and 7). We find line deficits that are in agreement with local ultra-luminous infrared galaxies. Comparison of the and lines indicates that the emission arises predominantly from the neutral medium, and we estimate that the photodisassociation regions in J1342+0928 have densities ≲5 ×104 cm-3. The data suggest that ∼16% of hydrogen is in ionized form and that the H ii regions have high electron densities of n e > 180 cm-3. Our observations favor a low gas-to-dust ratio of <100, and a metallicity of the ISM comparable to the solar value. All the measurements presented here suggest that the host galaxy of J1342+0928 is highly enriched in metal and dust, despite being observed just 680 Myr after the big bang.
AB - We use Atacama Large Millimeter Array observations of the host galaxy of the quasar ULAS J1342+0928 at z = 7.54, to study the dust continuum and far-infrared lines emitted from its interstellar medium (ISM). The Rayleigh-Jeans tail of the dust continuum is well sampled with eight different spectral setups, and from a modified blackbody fit we obtain an emissivity coefficient of β = 1.85 ±0.3. Assuming a standard dust temperature of 47 K we derive a dust mass of M dust = 0.35 ×108 M and a star formation rate of . We have >4σ detections of the , , and atomic fine structure lines and limits on the , , and emission. We also report multiple limits of CO rotational lines with J up ≥ 7, as well as a tentative 3.3σ detection of the stack of four CO lines (J up = 11, 10, 8, and 7). We find line deficits that are in agreement with local ultra-luminous infrared galaxies. Comparison of the and lines indicates that the emission arises predominantly from the neutral medium, and we estimate that the photodisassociation regions in J1342+0928 have densities ≲5 ×104 cm-3. The data suggest that ∼16% of hydrogen is in ionized form and that the H ii regions have high electron densities of n e > 180 cm-3. Our observations favor a low gas-to-dust ratio of <100, and a metallicity of the ISM comparable to the solar value. All the measurements presented here suggest that the host galaxy of J1342+0928 is highly enriched in metal and dust, despite being observed just 680 Myr after the big bang.
KW - cosmology: observations
KW - galaxies: ISM
KW - galaxies: high-redshift
KW - galaxies: individual (ULAS J1342+0928)
KW - quasars: emission lines
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U2 - 10.3847/1538-4357/ab2beb
DO - 10.3847/1538-4357/ab2beb
M3 - Article
AN - SCOPUS:85071986614
SN - 0004-637X
VL - 881
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 63
ER -