Main spectral features of meteors studied using a terawatt-class high-power laser

¹ J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
e-mail: martin.ferus@jh-inst.cas.cz
² Charles University in Prague, Faculty of Science, Department of Physical and Macromolecular Chemistry, Albertov 2030, 12840 Prague 2, Czech Republic
³ Valašské Meziříčí Observatory, Vsetínská 78, 75701 Valašské, Meziříčí, Czech Republic
⁴ Department of Radiation and Chemical Physics, Institute of Physics, Czech Academy of Sciences, Na Slovance 1999/2, 18221 Prague 8, Czech Republic
⁵ Institute of Plasma Physics, Czech Academy of Sciences, Za Slovankou 1782/3, 182 00 Prague 8, Czech Republic
e-mail: krus@ipp.cas.cz
⁶ National Technical University of Athens, School of Mining and Metallurgical Engineering, 9 Heroon Polytechneiou str., 15780, Zografou Athens, Greece
⁷ Czech Technical University in Prague, Jugoslávských partyzánů 1580/3, 160 00 Prague 6, Czech Republic

Received: 1 May 2019
Accepted: 17 August 2019

Abstract

Context. Meteor spectra are commonly interpreted using data from databases and tables. Several studies have demonstrated very sophisticated calculations of elemental compositions of meteoroid bodies based on the computation of synthetic meteor spectra or on the spectral analysis of airglow plasma containing evaporated, atomized, and ionized meteoroid matter. However, considering accuracy, reliability of computations, lack of laboratory experimental data in this field, as well as the complicated physical structure of meteor plasma, such qualitative assignment or quantitative calculations are still extensively discussed in the scientific community. Even on the laboratory level, many studies have shown the high complexity of the acquisition and interpretation of the data that are recorded with techniques of emission spectroscopy that are in fashion and philosophy similar to the spectral analysis of meteor plasma, that is, detection and quantification of the elements that are ablated from complicated multicomponent matrices.

Aims. The current study is focused on the application of terawatt-class laser-induced breakdown spectroscopy (TC-LIBS) of real samples of chondritic meteorites. We recorded emission spectra with high resolution and high precision that contain spectral lines that are typical for real meteoric spectra. Experimental data were compiled in a form that is convenient for the meteoric spectra interpretation and calibration.

Methods. TC-LIBS was carried out by a high-power terawatt-class laser facility, the Prague Asterix Laser System (PALS). The spectra were simultaneously recorded by an echelle high-resolution spectrograph in the UV/VIS spectral ranges and by a low-resolution spectrograph that was used for real observation of meteor spectra. We also present calculated synthetic spectra based on data from the NIST atomic spectra database.

Results. We assembled etalon qualitative tables of major meteoric spectral features that can be used both for the spectral wavelength calibration of low-resolution observational instruments and for the exact interpretation of meteor spectra. The data are compared with real meteor spectra.