SAO researchers have discovered that supercritical accretion disks eject
hot gas with a velocity of a few thousand kilometers per second.
The supercritical regime of accretion onto black holes is very important
for astrophysics.
In the first half-billion years just after our Universe was born,
supermassive black holes (quasars) began to appear and grow in centers
of young galaxies.
In such a "short" period they accumulated a huge mass of a few billion
masses of the Sun. This is possible only in the supercritical accretion
regime. So far, nobody was able to observe the process of fast quasar
growth, because it ejects such a huge mass of gas and dust that it is
not possible to see the quasar itself. However, there is a micro-copy
of those young quasars in our Milky Way Galaxy - SS433. That is why it
is very important to study this unique object.
Gas falling onto a black hole (accretion) is not a frequent phenomenon
in our Galaxy. Gas falling onto a black hole in the supercritical regime
is even rarer. A supercritical accretion disk appears. SS433 is the only
object of this kind in the Galaxy, and therefore it is unique. It is a
binary system consisting of two close stars; the first one is a black
hole of about 10 solar masses, the second is a donor-star, which
literally drowns the black hole in its material.
Many groups all over the world have studied SS433. Recently in SAO we
have succeeded in discovering a new property of SS433 - the super-broad
lines in its spectrum (Fig. 1). The gas falls onto the black hole, but
the black hole can not accept all this gas (the supercritical regime),
and most of the matter is thrown back with a velocity of about 4000
kilometers per second. We developed for the first time a computer
model of the supercritical-disk wind (Fig. 2), which explains all
the main observational data. The supercritical disk in SS433 possesses
the most powerful wind in the Galaxy.
Published:
P.S.Medvedev, S.N.Fabrika, V.V.Vasiliev, V.P.Goranskij, E.A.Barsukova
Astronomy Letters, v.39, p.826 (2013)
Contact - S.N.Fabrika
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Fig.1.
The spectra of SS433 were obtained with the 6-meter BTA telescope (Russia)
and the 8-meter Subaru telescope (Hawaii)
Fig.2.
The first computer model of the supercritical-disk wind
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