J/A+A/680/A95ivo://CDS.VizieR/J/A+A/680/A95doi:10.26093/cds/vizier/bc-n8/ljfCDSYang C.Omont A.Martin S.Bisbas T.G.Cox P.Beelen A.,Gonzalez-Alfonso E.Gavazzi R.Aalto S.Andreani P.Ceccarelli C.,Gao Y.Gorski M.Guelin M.Fu H.Ivison R.J.Knudsen K.K.Lehnert M.,Messias H.Muller S.Neri R.Riechers D.van der Werf P.Zhang Z.-Y.2026-07-03T06:35:46Z2023-12-14T08:26:49ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesspectroscopyinterstellar-mediummillimeter-astronomysubmillimeter-astronomyUnderstanding the nature of high-redshift dusty galaxies requires a comprehensive view of their interstellar medium (ISM) and molecular complexity. However, the molecular ISM at high redshifts is commonly studied using only a few species beyond ^12^C^16^O, limiting our understanding. In this paper, we present the results of deep 3mm spectral line surveys using the NOrthern Extended Millimeter Array (NOEMA) targeting two strongly lensed dusty galaxies observed when the Universe was less than 1.8Gyr old: APM 08279+5255, a quasar at redshift z=3.911, and NCv1.143 (H-ATLAS J125632.7+233625), a z=3.565 starburst galaxy. The spectral line surveys cover rest-frame frequencies from about 330 to 550GHz for both galaxies. We report the detection of 38 and 25 emission lines in APM 08279+5255 and NCv1.143, respectively. These lines originate from 17 species, namely CO, ^13^CO, C^18^O, CN, CCH, HCN, HCO+, HNC, CS, C^34^S, H_2_O, H_3_O^+^, NO, N_2_H^+^, CH, c-C_3_H_2_, as well as the vibrationally excited HCN and neutral carbon. The spectra reveal the chemical richness and the complexity of the physical properties of the ISM. By comparing the spectra of the two sources and combining the analysis of the molecular gas excitation, we find that the physical properties and the chemical imprints of the ISM are different between them: the molecular gas is more excited in APM 08279+5255, exhibiting higher molecular gas temperatures and densities compared to NCv1.143; the molecular abundances in APM 08279+5255 are akin to the values of local active galactic nuclei (AGN), showing boosted relative abundances of the dense gas tracers that might be related to high-temperature chemistry and/or the X-ray-dominated regions, while NCv1.143 more closely resembles local starburst galaxies. The most significant differences between the two sources are found in H_2_O, where the 448GHz ortho-H_2_O(423-330) line is significantly brighter in APM 08279+5255, likely linked to the intense far-infrared radiation from the dust powered by AGN. Our astrochemical model suggests that, at such high column densities, FUV radiation is less important in regulating the ISM, while cosmic rays (and/or X-rays and shocks) are the key players in shaping the molecular abundances and the initial conditions of star formation. Both our observed CO isotopologues line ratios and the derived extreme ISM conditions (high gas temperature and density, high cosmic-ray ionization rate) suggest the presence of a top-heavy initial mass function. From the ~330-550GHz continuum, we also find evidence of non-thermal millimeter flux excess in APM 08279+5255 that might be related to the central supermassive black hole. Such deep spectral line surveys open a new window to study the physics and chemistry of the ISM and the radiation field of galaxies in the early Universe.2023A&A...680A..95Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/680/A95CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/680/A95https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/680/A95http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/680/A95https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/680/A95https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/680/A95http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/680/A95GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/680/A95/list (List of fits spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/680/A95/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/680/A95/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/680/A95/list?GETtext/xml+votable180.050000true127.923791752.75488890.0055555555555555566/7309 28115https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/680/A95?format=asciiMillimeterdefaultJ/A+A/680/A95/listList of fits spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintspShow the spectrummeta.ref.urlcharFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar