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Mem. S.A.It. Vol. 83, 401

SAIt 2012 c

Memoriedella

Concluding remarks

G.S. Bisnovatyi-Kogan

1,2

1

Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow, Russia

2

National Research Nuclear University MEPhI, Kashirskoye Sh. 31, 115409 Moscow, Russia, e-mail: gkogan@iki.rssi.ru

Abstract.

Short review of the conference

1. Introduction

The main topics of the conference are:

Cosmology.

X-ray sources.

Jets and GRBs.

Missions and Experiments.

Solar System.

Cosmology.

2. Cosmology

S. Colafrancesco: observations of SZ effect may solve most problems in cosmology.

R. Rebolo: CMB polarization as indicator of primordial gravtational waves

M.Regis: CMB in inhomogeneous universe acceleration of expansion without DE. Is spec- trum remains Planckian in such universe?

K. Maeda: SN1a too many parameters for a good standard candle in cosmology

3. X-ray sources

P. Blay: discovery of supergiant fast X ray transient SFXT in the Integral observations clumps in the stellar wind

Send offprint requests to: G.S. Bisnovatyi-Kogan

M. Nowak: review on Cyg X1, discussion on origin of the soft-hard (high-low) states – 3 models. In this connection I would like to remind our old paper with S. I. Blinnikov

”A hot corona around a black-hole accretion disk as a model for Cygnus X-1”, published in Sov.Astron.Lett. 2, 191-193 (Sep.-Oct. 1976) (see also astro-ph /0003275). The main conclu- sions of this paper are:

”For L ≈ 0.1L

c

, when acoustic heating pre- dominates, the rise in ˙ M may cause some de- crease in the heating of the corona and in the amount of hard radiation. At the same time the flux in the soft range is determined by the radi- ation of the disk photosphere and will increase with ˙ M.

Even if a corona with T ≈ 10

9

K is present

in the disk accretion model, radiation cannot

be formed at hν = 200 − 2000 keV. Electrons

with T

e

= 10

10

K or fast nonthermal electrons

would be needed for that purpose. There are in

fact two ways to form such fast electrons. Both

would require the presence of a magnetic field

in the disk. A magnetic field could exist in the

disk either through twisting of the lines of force

by differential rotation, or through infall onto

the black hole of magnetized material having a

small angular momentum. In the latter case a

poloidal magnetic field would be generated.

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402 Bisnovatyi-Kogan: Concluding remarks ... mechanism for producing fast particles

is analogous to the pulsar process. If magne- tized matter with low angular momentum falls into the black hole (in addition to the disk ac- cretion), a strong poloidal magnetic field will arise. By analogy to pulsars, rotation will gen- erate an electric field of strength E ≈ (v/c)B in which electrons are accelerated to energies ε ≈ R(v/c)Be ≈ 3 · 10

4

[B/(10

7

Gauss)] Mev where v/c ≈ 0.1, and R ≈ 10

7

cm, is the char- acteristic scale. In a field B ≈ 10

7

Gauss, such electrons will generate synchrotron radiation with energies up to ≈ 105 keV. Just as in pul- sars, it would be possible here for e

+

e

pairs to be formed and to participate in the synchrotron radiation.”

4. Jets and GRBs

J. Beall: Jet heating by the two stream instabil- ity. Heating by the transformation of the me- chanical energy of the jet into heat. It happens probably in heating of all kinds of jets.

No discussion about GRB central machine.

GRB statistics and correlation properties.

L.Amati: correlation between peak lumi- nosity and isotropic fluence in the local co- ordinate system. Correlation disappears in the observer system, what indicates to its physical meaning.

A. de Ugarte- Postigo, R. Salvaterra: prop- erties of farthest GRB, largest z=9.4.

D. Fragion: linear increase of the GRB lu- minosity with red shift poorly explained in the cosmological model.

Critical experiment: spectra and polariza- tion of the prompt optical emission, in the first one minute after trigger.

5. Missions and experiments N. Schartel: XMM-Newton.

P. Ubertini: Integral.

J. Ballet: Fermi.

K Ebisava: Suzaku, broad K-lines are not due to relativistic widening.

C. Pittori: Agile, best in the region ¡ 100 MeV.

N. Panagia: HST.

M. Tluczykont: H.E.S.S.

M* D. Rodrigies-Frias: Pierre Auger.

Particle acceleration Bottom-up and Top- down models.

P. Persi: Herschel. Star forming regions and Crab nebula in IR.

J.Tauber: Planck mission. 9 frequencies, minimal published results after 2 years.

J. Clavel: ESA plans. Cosmic vision 10 years after 2017.

6. Solar system

W. Kundt: doubts in the existence of termina-

tion shock

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