J/ApJ/820/L26 J=1-0 transitions of argonium (ArH+) (Bizzocchi+, 2016)
First laboratory measurement of the J=1-0 transitions of 36ArH+ and
38ArH+: new, improved rest frequencies for astronomical searches.
Bizzocchi L., Dore L., Degli Esposti C., Tamassia F.
<Astrophys. J., 820, L26 (2016)>
=2016ApJ...820L..26B 2016ApJ...820L..26B (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: ISM: molecules; methods: laboratory: molecular; molecular data;
techniques: spectroscopic
Abstract:
The recent detections of 36ArH+ and 38ArH+ in the interstellar
medium have triggered interest in argonium. This molecular cation has
proved to be widespread in our galaxy in the diffuse medium and may
serve as a very specific tracer of atomic gas and as a proxy for the
cosmic-ray ionization rate. Pure rotational transitions of the two
isotopologues detected in the ISM have never been recorded in the
laboratory until this work. Here, we report on the first detection of
the J=1←0 transition of both 36ArH+ and 38ArH+ produced in a
low-pressure glow discharge. All of the rotational and ro-vibrational
transition frequencies available have been analyzed in global
multi-isotopologues fit to give a comprehensive set of isotopic
independent spectroscopic parameters. These data allow us to compute
an improved set of rotational and ro-vibrational rest frequencies to
assist astronomical searches of ArH+.
Description:
The J=1-0 pure rotational transition of the argonium ion was
observed in absorption with a frequency-modulated millimeter-wave
spectrometer equipped with a negative glow discharge cell.
See section 2 for the experimental details.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 38 100 Predicted rotational and ro-vibrational
transitions for 36ArH+ and 38ArH+
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See also:
J/ApJ/783/L5 : Ro-vibration transitions of the protonated argon ion
(Cueto+, 2014)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1 I1 --- Type Transition type (1)
3- 16 F14.6 --- LP Line position
18- 25 F8.6 --- e_LP [0.0003/0.74] The 1σ uncertainty in LP
27- 32 A6 --- x_LP Units on LP (MHz or cm-1)
34- 38 A5 --- QN Quantum numbers (2)
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Note (1): Transition type as follows:
1 = 36ArH, v=0 rotational transitions.
2 = 38ArH, v=0 rotational transitions.
3 = 36ArH, v=1-0 band.
4 = 38ArH, v=1-0 band.
Note (2): Quantum numbers are indicated as J'-J for rotational transitions
and P(J),R(J) for infrared lines.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 02-Jun-2016