Bright X-ray flares from Sgr A*

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F17%3A00483412" target="_blank" >RIV/67985815:_____/17:00483412 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1093/mnras/stx2312" target="_blank" >http://dx.doi.org/10.1093/mnras/stx2312</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stx2312" target="_blank" >10.1093/mnras/stx2312</a>

Result language

angličtina

Original language name

Bright X-ray flares from Sgr A*

Original language description

We address a question whether the observed light curves of X-ray flares originating deep in galactic cores can give us independent constraints on the mass of the central supermassive black hole. To this end, we study four brightest flares which have been recorded from Sagittarius A*. They all exhibit an asymmetric shape consistent with a combination of two intrinsically separate peaks which occur at a certain time delay with respect to each other, and are characterized by their mutual flux ratio and the profile of raising/declining parts. Such asymmetric shapes arise naturally in the scenario of a temporary flash from a source orbiting near a supermassive black hole, at a radius of only similar to 10-20 gravitational radii. An interplay of relativistic effects is responsible for the modulation of the observed light curves: Doppler boosting, gravitational redshift, light focusing and light-travel time delays. We find the flare properties to be in agreement with the simulations (our ray-tracing code SIM5LIB). The inferred mass for each of the flares comes out in agreement with previous estimates based on orbits of stars, the latter have been observed at radii and over time-scales two orders of magnitude larger than those typical for the X-ray flares, so the two methods are genuinely different. We test the reliability of the method by applying it to another object, namely, the Seyfert I galaxy RE J1034+396.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

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

Name of the periodical

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

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Volume of the periodical

472

Issue of the periodical within the volume

4

Country of publishing house

GB - UNITED KINGDOM

Number of pages

12

Pages from-to

4422-4433

UT code for WoS article

000415652500050

EID of the result in the Scopus database

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