Evolution of the optical and hard X-ray activity of AM Her in a season dominated by the high states

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F16%3A00463124" target="_blank" >RIV/67985815:_____/16:00463124 - isvavai.cz</a>

Alternative codes found

RIV/68407700:21230/16:00301738

Result on the web

<a href="http://dx.doi.org/10.1007/s10509-016-2825-x" target="_blank" >http://dx.doi.org/10.1007/s10509-016-2825-x</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10509-016-2825-x" target="_blank" >10.1007/s10509-016-2825-x</a>

Result language

angličtina

Original language name

Evolution of the optical and hard X-ray activity of AM Her in a season dominated by the high states

Original language description

The long-term activity of AM Her, the prototype of polars, consists of interchanging high and low states. This analysis uses the data from the BAT/Swift, MAXI/ISS, and AAVSO data archives (including long CCD V-band night series) for investigating the relation of the time evolution of intensities in the hard X-ray, medium/hard X-ray, and the optical bands on super-orbital timescale in a season dominated by the long high-state episodes. The observations mapped the relation of the cyclotron and bremsstrahlung luminosities in such episodes. Although an increase of intensity of the cyclotron emission is generally accompanied by a brightening of the bremsstrahlung component, this relation differs for the individual high-state episodes. These variations were accompanied by the large changes of the optical modulation. In my view, all of these variations suggest variations of the dimensions and structure of the cyclotron emitting region(s), not only the changes of the mass accretion rate. The activity during a decline (much less steep than the state transition) from an initial very bright peak can be explained by a gradual evolution of the conditions in stratified shock regions in a single high state episode. The observed behavior in the neighboring high-state episodes is also important for explaining the mechanisms which cause the low state between them. In the interpretation, some low-state episodes cause that AM Her develops a different accretion mode than the one before entering the low state. Each high-state episode is a complex phenomenon in the history of accretion in this system.

Czech name

—

Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

BN - Astronomy and celestial mechanics, astrophysics

OECD FORD branch

—

Project

<a href="/en/project/GC13-39464J" target="_blank" >GC13-39464J: Digitizing Astronomical Plate Archives and Investigation of Celestial Sources in Digitized Plate Archives</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysics and Space Science

ISSN

0004-640X

e-ISSN

—

Volume of the periodical

361

Issue of the periodical within the volume

7

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

8

Pages from-to

"235/1"-"235/8"

UT code for WoS article

000379003700031

EID of the result in the Scopus database

2-s2.0-84975818603