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+.
Bizzocchi, L., Dore, L., Claudio Degli Esposti, ., Tamassia, F. (2016). FIRST LABORATORY MEASUREMENT OF THE J-0 TRANSITIONS OF 36ArH+ AND 38ArH+: NEW, IMPROVED REST FREQUENCIES FOR ASTRONOMICAL SEARCHES. THE ASTROPHYSICAL JOURNAL LETTERS, 820, 26-31 [10.3847/2041-8205/820/2/L26].
FIRST LABORATORY MEASUREMENT OF THE J-0 TRANSITIONS OF 36ArH+ AND 38ArH+: NEW, IMPROVED REST FREQUENCIES FOR ASTRONOMICAL SEARCHES
DORE, LUCA;DEGLI ESPOSTI, CLAUDIO;TAMASSIA, FILIPPO
2016
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+.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
