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  • An ALMA Multiline Survey of...
    Novak, Mladen; Bañados, Eduardo; Decarli, Roberto; Walter, Fabian; Venemans, Bram; Neeleman, Marcel; Farina, Emanuele Paolo; Mazzucchelli, Chiara; Carilli, Chris; Fan, Xiaohui; Rix, Hans-Walter; Wang, Feige

    Astrophysical journal/˜The œAstrophysical journal, 08/2019, Letnik: 881, Številka: 1
    Journal Article

    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 Mdust = 0.35 × 108 M☉ and a star formation rate of . We have >4 detections of the , , and atomic fine structure lines and limits on the , , and emission. We also report multiple limits of CO rotational lines with Jup ≥ 7, as well as a tentative 3.3 detection of the stack of four CO lines (Jup = 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 ne > 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.