Speaker
Isabel Tanarro
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/I4.011.pdf
USING RADIOASTRONOMY TECHNIQUES AND COLD PLASMAS
TO STUDY TRANSIENT AND STABLE MOLECULAR SPECIES OF
ASTROPHYSICAL INTEREST: A PROOF OF CONCEPT
I. Tanarro1, B. Alemán2, E. Moreno2, R. J. Peláez1, J. L. Doménech1, V. J. Herrero1,
P. de Vicente3, J. D. Gallego3, K. Lauwaet2, G. Santoro2, J. A. Martín-Gago2,
J. R. Pardo2, J. Cernicharo2
1
IEM-CSIC. C/Serrano 123, 28006 Madrid, Spain.
2
ICMM-CSIC. C/ Sor Juana Inés de la Cruz 3. Cantoblanco,28049 Madrid. Spain
3
CNTRAG-IGN, Observatorio Astronómico de Yebes, Spain
The development of new powerful radiotelescopes is enhancing tremendously the
detection of stable and transient species in the interstellar space at mm and sub-mm wave
wavelengths, and is improving the understanding of the kinetic processes involved.
Evaluation of these data can take great advantage of the information obtained in laboratory
cold plasmas.
In this work we describe the proof of concept of the joint use of standard radio
astronomical receivers and low pressure cold plasmas for emission spectroscopic studies of
different precursors and products. The goal is to obtain in the laboratory valuable information
on rotational emissions of molecular species of astrophysical interest at high spectral
resolution. An inductively coupled RF discharge has been used to generate the plasma. Gas
pressures 10-30 Pa allow stable plasma operation and produce column densities similar to
those of interstellar clouds. The experiment is performed in the 40 m radio-telescope of the
Observatory of Yebes (Spain), using its 41-49 GHz band receiver. The beam of the antenna
pointing towards the zenith is used as cold emission background. The RF discharge doesn’t
induce any electromagnetic spurious signals in the receiver, and astronomical detection of a
SiO maser in the AGB star TX Cam is unaffected by the presence of the plasma. OCS is
selected for preliminary gas detection in this emission band. OCS and CS2 are chosen as
plasma precursors of the CS radical, which emits also in this region. O2 discharges applied
after sulphur deposition on the reactor walls by the previous OCS and CS2 plasmas lead to the
detection of SO2 produced by surface reactions.
In conclusion, these experiments confirm the viability of using standard
radioastronomy receivers to detect molecular and short lived species in gas simulation
chambers based on plasma reactors.
