Научен семинар – 29.06.2015

НАУЧЕН СЕМИНАР

Редовната сбирка на семинара на Института по Астрономия ще се проведе на 29 юни от 13:30 часа в зала 301 на Института по Електроника на БАН, Цариградско Шосе 72, София.

Тема: “Ultraluminous X-ray sources”

Докладва: prof. DSc Sergei Fabrika, Head of the Laboratory of Stellar Physics at the

Special Astrophysical Observatory of the Russian Academy of Sciences

Поканени са всички интересуващи се.

От ръководството на семинара

Абстракт:

The origin of Ultraluminous X-ray sources (ULXs) in external

galaxies whose X-ray luminosities exceed those of the brightest black

holes in our Galaxy by hundreds and thousands of times is mysterious. The

most popular models for the ULXs involve either intermediate mass black

holes (IMBH, ~1000 solar masses) with standard accretion disks or

stellar-mass black holes (10 solar masses) accreting at super-Eddington

rates. We find that all ever spectrally observed ULX counterparts have the

same optical spectra and they are very similar to that of SS 433, the only

known supercritical accretor in Milky Way. We study ULXs in two classical

galactic mergings Antennae and NGC3256. All the ULXs are located nearby

(in 200 pc) or inside extremely young (< 5 Myrs) massive stellar clusters,

and this association is not occasional. The ULX progenitor mass is bigger

than 40-50 solar masses. Probably, these close binary systems were ejected

from the interior of massive-star clusters during the cluster formation.