We have performed a high sensitivity observation of the UFO/BAL quasar APM 08279+5255 at z = 3.912 with NOEMA at 3.2 mm, aimed at detecting fast moving molecular gas. We report the detection of blueshifted CO(4-3) with maximum velocity (v95%) of -1340 km s<SUP>-1</SUP>, with respect to the systemic peak emission, and a luminosity of L' = 9.9 × 10<SUP>9</SUP>μ<SUP>-1</SUP>K km s<SUP>-1</SUP>pc<SUP>-2</SUP>, where μ is the lensing magnification factor. We discuss various scenarios for the nature of this emission and conclude that this is the first detection of fast molecular gas at redshift >3. We derived a mass flow rate of molecular gas in the range Ṁ = 3-7.4 × 10<SUP>3</SUP>M<SUB>☉</SUB>/yr and momentum boost Ṗ<SUB>OF</SUB>/Ṗ<SUB>AGN</SUB>2-6, which is therefore consistent with a momentum conserving flow. For the largest Ṗ<SUB>OF</SUB>the scaling is also consistent with an energy conserving flow with an efficiency of 10-20%. The present data can hardly discriminate between the two expansion modes. The mass loading factor of the molecular outflow η = Ṁ<SUB>OF</SUB>/SFR is ≫ 1. We also detected a molecular emission line at a frequency of 94.83 GHz corresponding to a rest-frame frequency of 465.8 GHz; we tentatively identified this frequency with the cation molecule N<SUB>2</SUB>H<SUP>+</SUP>(5-4), which would be the first detection of this species at high redshift. We discuss the alternative possibility that this emission is due to a CO emission line from the, so far undetected, lens galaxy. Further observations of additional transitions of the same species with NOEMA can discriminate between the two scenarios. <P />This work is based on observations carried out under project numbers S15CW and E15AF with the IRAM NOEMA Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). The reduced spectrum (FITS file) is only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>(<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A30">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A30
On the discovery of fast molecular gas in the UFO/BAL quasar APM 08279+5255 at z = 3.912
Bischetti, M.;MENCI, Nicola;
2017-01-01
Abstract
We have performed a high sensitivity observation of the UFO/BAL quasar APM 08279+5255 at z = 3.912 with NOEMA at 3.2 mm, aimed at detecting fast moving molecular gas. We report the detection of blueshifted CO(4-3) with maximum velocity (v95%) of -1340 km s-1, with respect to the systemic peak emission, and a luminosity of L' = 9.9 × 109μ-1K km s-1pc-2, where μ is the lensing magnification factor. We discuss various scenarios for the nature of this emission and conclude that this is the first detection of fast molecular gas at redshift >3. We derived a mass flow rate of molecular gas in the range Ṁ = 3-7.4 × 103M☉/yr and momentum boost ṖOF/ṖAGN2-6, which is therefore consistent with a momentum conserving flow. For the largest ṖOFthe scaling is also consistent with an energy conserving flow with an efficiency of 10-20%. The present data can hardly discriminate between the two expansion modes. The mass loading factor of the molecular outflow η = ṀOF/SFR is ≫ 1. We also detected a molecular emission line at a frequency of 94.83 GHz corresponding to a rest-frame frequency of 465.8 GHz; we tentatively identified this frequency with the cation molecule N2H+(5-4), which would be the first detection of this species at high redshift. We discuss the alternative possibility that this emission is due to a CO emission line from the, so far undetected, lens galaxy. Further observations of additional transitions of the same species with NOEMA can discriminate between the two scenarios. This work is based on observations carried out under project numbers S15CW and E15AF with the IRAM NOEMA Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). The reduced spectrum (FITS file) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr(http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A30Pubblicazioni consigliate
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