Journal or Publication Title:

Բյուրականի աստղադիտարանի հաղորդումներ: Երևանի աստղադիտարանի բյուլետեն = Сообщения Бюраканской обсерватории. Бюллетень ереванской Астрономической обсерватории = Contributions from the Burakan observatory. Bulletin of the Erevan astronomical observatory

Date of publication:

2026

Volume:

73

Number:

1

ISSN:

2579-2276

Coverage:

1-7

Abstract:

The paper presents new results on the patterns of evolution of spectral lines formed in absorbing and scattering media under the influence of non-stationary energy sources. When describing the time evolution of radiation diffusion, both possible causes of time consumption are taken into account: the time spent in the absorbed state and the time taken to travel the path between two successive scattering events. Mathematically, this is expressed as a convolution of the probability distributions of these two quantities. Proof is provided of the existence of a relationship between two time averages characterising the process of spectral lines radiation diffusion. It follows that the description of the evolution of a spectral line becomes a mathematically single-parameter problem, with the ratio of the mentioned two temporal values as a parameter. The value of the ratio for a given spectral line is determined by the number-density of emitting or absorbing atoms/ions (dependent on spectrum) and their thermal velocity. The fact that the dependence on the numberdensity far exceeds that on thermal velocity significantly simplifies the determination of the chemical composition of the object under study.

Format:

pdf

Identifier:

oai:arar.sci.am:439332

General note:

Communications of the Byurakan Astrophysical Observatory (ComBAO) is a peer-reviewed scientific journal, which publishes research in observational and theoretical astronomy/astrophysics and presents recent advances in these fields. It is being published by the NAS RA V. Ambartsumian Byurakan Astrophysical Observatory (BAO) in English in electronic form. The journal publishes original papers, review papers, brief reports, book reviews, special communications, observational and theoretical results in various fields of astronomy and related sciences, and some editorial notes, including anniversaries and obituaries. Under the heading “Legacy”, the renewed magazine will republish some old articles of high value in English. The heading “Guest articles” will bring to the attention of readers the articles of researchers who are not employees of BAO. ComBAO was founded in 1946 and regularly published in 1946-1990. However, the publication was interrupted because of the economic situation after the disintegration of the Soviet Union in 1991.

Location of original object:

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