J/A+A/595/A128 PKS 1830-211 OH+ and H2O+ spectra (Muller+, 2016)
OH+ and H2O+ absorption toward PKS 1830-211.
Muller S., Mueller H.S.P., Black J.H., Beelen A., Combes F., Curran S.,
Gerin M., Guelin M., Henkel C., Martin S., Aalto S., Falgarone E.,
Menten K.M., Schilke P., Wiklind T., Zwaan M.A.
<Astron. Astrophys. 595, A128 (2016)>
=2016A&A...595A.128M 2016A&A...595A.128M (SIMBAD/NED BibCode)
ADC_Keywords: QSOs ; Spectroscopy
Keywords: quasars: absorption lines - quasars: individual: PKS 1830-211 -
galaxies: abundances - radio lines: galaxies - galaxies: ISM -
ISM: molecules
Abstract:
We report the detection of OH+ and H2O+ in the z=0.89 absorber
toward the lensed quasar PKS 1830-211. The abundance ratio of OH+
and H2O+ is used to quantify the molecular hydrogen fraction (fH2)
and the cosmic-ray ionization rate of atomic hydrogen ({dzeta}H)
along two lines of sight, located at ∼2kpc and ∼kpc to either side of
the absorber's center. The molecular fraction decreases outwards,
from ∼0.04 to ∼0.02, comparable to values measured in the Milky Way at
similar galactocentric radii. For {dzeta}H, we find values of
∼2x10-14s-1 and ∼3x10-15s-1, respectively, which are slightly
higher than in the Milky Way at comparable galactocentric radii,
possibly due to a higher average star formation activity in the z=0.89
absorber. The ALMA observations of OH+, H2O+, and other hydrides
toward PKS 1830-211 reveal the multi-phase composition of the
absorbing gas. Taking the column density ratios along the southwest
and northeast lines of sight as a proxy of molecular fraction, we
classify the species ArH+, OH+, H2Cl+, H2O+, CH, and HF as
tracing gases increasingly more molecular. Incidentally, our data
allow us to improve the accuracy of H2O+ rest frequencies and thus
refine the spectroscopic parameters.
Description:
We observed the OH+ N=1-0 J=1-0 line (two hyperfine components
at a rest frequency near 909GHz) redshifted into ALMA band 8 and the
p-H2O+ JKa,Kc=11,0-10,1 transition (four fine-structure
components at rest frequencies 604, 607, 631, and 634GHz) redshifted
into band 7. We complement this dataset with contemporary observations
of some other hydrides, collected at several epochs in Cycles 1, 2,
and 3, between 2014 and 2016.
Objects:
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RA (2000) DE Designation(s)
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18 33 39.92 -21 03 39.9 PKS 1830-211 = QSO B1830-211
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
h2o_607.dat 37 1638 PKS 1830-211 H2O+ 607GHz transition spectrum
oh.dat 37 461 PKS 1830-211 OH+ spectrum
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See also:
J/A+A/535/A103 : 7mm spectral survey of PKS 1830-211 (Muller+, 2011)
J/A+A/574/A108 : Molecular absorption lines in PKS 1830-211 (Schulz+, 2015)
Byte-by-byte Description of file: h2o_607.dat oh.dat
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Bytes Format Units Label Explanations
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1- 14 F14.10 GHz Freq Observed frequency
21- 37 F17.15 --- Int Intensity, normalized to the total continuum
level
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Acknowledgements:
Sebastien Muller, sebastien.muller(at)chalmers.se
(End) Patricia Vannier [CDS] 15-Nov-2016