Non-stationarity of maser radio sources in star formation regions

Title:

Non-stationarity of maser radio sources in star formation regions

Creator:

Rudnitskij, G. M.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:b887a128-83b8-462e-bca2-f5608e69d101
uuid:b887a128-83b8-462e-bca2-f5608e69d101

Subject:

astronomy, maser radio emission, and star formation regions

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Sources of maser radio emission in the water vapour spectral line at 1.35 cm are considered, which are situated in star formation regions, in tho vicinity of young stellar objects. The H2O emission of many maser sources in subject to strong variability; maser activity is thereby of a cyclic character with a period of a few years. On the basis of observational data, it is aassumed that the region of maser generation is located in a rotating gas-dust disc around a young stellar object. The author auggests three models explaining the masers´ cyclic non-stationarity. (1) The maser´s variability is connected with the variable luminosity of the central stellar object, due to non-stationary accretion onto it. (2) In the central cavity of a large circumstellar disc containing the H2O maser, a smaller disc is located, with its axis tilted to that of the larger disc. The stellar wind jet collimated by the small disc and flowing out from its poles impacts connecutively onto different parts of the large disc´s internal surface. This results in the time- and space-variable maser pump. (3) If the maser is unsaturated and amplifies the background continuum radiation, then strong maser flares may be connected with radio flares of the centra! object (due, e.g., to its magnetic activity) and the corresponding increase of the maser´s input intensity. Oboervational tests for the suggested models are discussed.

Language:

Czech

Rights:

http://creativecommons.org/publicdomain/mark/1.0/
policy:public

Coverage:

51-55

Source:

Publications of the Astronomical Institute of the Academy of Sciences of the Czech Republic | 1987 Volume:63-70 | Number:69

Harvested from:

CDK

Metadata only:

false