


Том 61, № 4 (2017)
- Год: 2017
- Статей: 18
- URL: https://journals.rcsi.science/1063-7729/issue/view/11944
Article
Iosif Samuilovich Shklovskii
Аннотация
July 1, 2016 was the 100th anniversary of the birthday of the eminent Russian astrophysicist Iosif Samuilovich Shklovskii (1916–1985), who was a corresponding member of the USSR Academy of Sciences, a recipient of the Lenin Prize, and a member of the National Academy of Sciences of the USA, the Royal Astronomical Society, and many other academies. Iosif Samuilovich made important and fundamental contributions in many areas of modern astrophysics, and is the author of nine books and more than 300 scientific publications. The Russian Academy of Science, Astro Space Center of the Lebedev Physical Institute, Space Research Institute of the Russian Academy of Sciences, the Sternberg Astronomical Institute of Moscow State University, and the Astronomical Society held the international conference “All-Wave Astronomy. Shklovskii-100” to commemorate this anniversary. This issue of Astronomy Reports presents papers based on selected talks at this conference.






Black holes in close binary systems and galactic nuclei
Аннотация
After 50 years of observational studies of black holes, great progress has been achieved in this branch of astrophysics. Several dozen stellar-mass black holes have been discovered in X-ray binaries, and several hundred supermassive black holes in galactic nuclei. The remarkable recent discovery of gravitational waves from merging black holes in a binary system by LIGO marks the beginning of a new stage in black-hole research. It is quite possible that gravitational-wave studies will provide definitive evidence for the existence of event horizons in black holes in the near future. On the other hand, the development of methods for space and ground-based radio-interferometry observations provides hope that it will be possible to obtain images of “shadows” of supermassive black holes in galactic nuclei, and to observe directly processes occurring in the vicinities of the event horizons of supermassive black holes. This is important for tests of general relativity in extremely strong gravitational fields.



Early formation of (super)massive black holes and gravitational waves from their coalescence
Аннотация
Astronomical observations of last few years have presented a surprising evidence that the Universe at redshift of order 10 is densely populated by supermassive black holes (quasars), supernovae, and contains very large amount of dust. All these data are in conflict with the canonical theory of quasar and supernova formation. A model is discussed which in a simple and natural way solves all these problem. In addition it explains an existence of supermassive black holes in each large galaxy and even in small ones. An inverted picture of galaxy formation is suggested when primordial black holes serve as seeds of galaxy formation. Simultaneously the origin and properties of black hole binaries, sources of gravitational waves registered by LIGO are explained. As a by-product the model may lead to abundant cosmological antimatter even in the Galaxy.



Inspiring the next generation of scientists with their observations of quasars, black holes, Jupiter, and SETI with the Goldstone Apple Valley Radio Telescope, GAVRT
Аннотация
This paper describes a radio astronomy programfor schools, the Goldstone-AppleValley Radio Telescope,GAVRT. The GAVRT program is designed to bring the inspiration and enthusiasm to a younger generation of teachers and children who learn about science by doing real science, just as Iosif Shklovsky brought to an older generation.



Square Kilometre Array: The radio telescope of the XXI century
Аннотация
The Square Kilometre Array (SKA) will be the world’s largest and most sensitive radio telescope. It will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of theUniverse, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. This project envisages the construction of 133 15-m antennas in South Africa and 131072 log-periodic antennas in Australia, together with the associated infrastructure in the two desert sites. In addition, the SKA is an exemplar Big Data project, with data rates of over 10 Tbps being transported from the telescope to HPC/HTC facilities.






VLBI of supernovae and gamma-ray bursts
Аннотация
Supernovae and gamma-ray bursts (GRBs) are among the brightest events in the universe. Excluding Type Ia supernovae and short GRBs, they are the result of the core collapse of a massive star with material being ejectedwith speeds of several 1000 km/s to nearly the speed of light, and with a neutron star or a black hole left over as the compact remnant of the explosion. Synchrotron radiation in the radio is generated in a shell when the ejecta interact with the surrounding medium and possibly also in the central region near the compact remnant itself. VLBI has allowed resolving some of these sources and monitoring their expansion in detail, thereby revealing characteristics of the dying star, the explosion, the expanding shock front, and the expected compact remnant. We report on updates of some of the most interesting results that have been obtained with VLBI so far. Movies of supernovae are available from our website. They show the evolution from shortly after the explosion to decades thereafter, in one case revealing an emerging compact central source, which may be associated with shock interaction near the explosion center or with the stellar corpse itself, a neutron star or a black hole.



Limits on panspermia
Аннотация
Problems related to the origin of life and the role of migration of the dust component in the Galaxy and between galaxies in the spreading life are discussed. Limits on possible distances between points of action of panspermia are derived.



RadioAstron and millimetron space observatories: Multiverse models and the search for life
Аннотация
The transition from the radio to the millimeter and submillimeter ranges is very promising for studies of galactic nuclei, as well as detailed studies of processes related to supermassive black holes, wormholes, and possible manifestations of multi-element Universe (Multiverse) models. This is shown by observations with the largest interferometer available—RadioAstron observatory—that will be used for the scientific program forMillimetron observatory. Observations have also shown the promise of this range for studies of the formation and evolution of planetary systems and searches for manifestations of intelligent life. This is caused by the requirements to use a large amount of condensedmatter and energy in large-scale technological activities. This range can also be used efficiently in the organisation of optimal channels for the transmission of information.



Progress in low-frequency radio astronomy and I.S. Shklovskii’s contribution to its development
Аннотация
Radio astronomy at decameter wavelengths is currently undergoing very active development. Large-scale, new generation low-frequency radio telescopes are being constructed and already used in many countries around the world. As before, the largest, most sensitive, and most versatile telescope at decameter wavelengths is the Ukrainian UTR-2 radio telescope operating at 8–32 MHz, which has an effective area of more than 105 m2 and an angular resolution of about 0.5◦, as well as the URAN interferometric system based on the UTF-2. Many studies that have been carried out on these facilities have been based on important results and far-sighted predictions of Shklovskii. These include, in particular, studies of dynamical spectra and the brightness distributions of the sporadic and quiescent decameter radio emission of the hot solar corona, complex, broadband radio spectroscopy of the interstellar medium, and multi-frequency monitoring of secular decreases in the flux densities of supernova remnants. The coordinated use of highly effective existing and newly constructed radio telescopes joined into ground networks, as well as specialized space missions, are opening new prospects for low-frequency radio astronomy.



Searches for extraterrestrial life in the solar system: Status and perspectives
Аннотация
The results of space studies of the Moon and Mars are considered from the perspective of questions related to the appearance and evolution of life, as presented in the monograph of I.S. Shklovskii “Universe, Life and Razum” (Vselennaya, Zhizn’, Razum [in Russian]).






Collective supernova outbursts and the growth of supershells: Observational manifestations
Аннотация
Numerous supernova outbursts that are correlated in time and space are the main mechanism for the formation of powerful galactic winds and supershells of ionized hydrogen. Information about the dynamics and thermal properties of the gas in shells (bubbles) can be obtained from spectral observations, including those of optical recombination lines. The emission properties of the Hα and Hβ recombination lines and the velocity dispersion of the gas in bubbles formed by numerous supernova outbursts are studied. The appearance of the intensity vs. velocity dispersion (I(Hα)−σ) diagram depends on the supernova rate and the age of the bubble. The temperature dependence of the I(Hα)/I(Hβ) line-intensity ratio (the Balmer decrement) can be used to obtain additional constraints on the evolutionary status of a collective remnant formed by numerous supernova outbursts.



The influence of variations of the elemental composition on the thermal properties of gas behind shock fronts
Аннотация
The homogenization of inhomogeneities in the elemental composition of the interstellar medium due to stellar evolution and weak mixing are inevitably related to the action of shocks. This paper considers the influence of variations in the elemental composition on the thermal and ionizational evolution of a collisional gas with the solar metallicity that is cooled behind a shock front with a velocity of 50–120 km/s. The intensities of lines of heavy elements in plasma cooling behind a shock front depend not only on variations in the elemental composition, but also on the shock velocity, due to the different values of the critical density for the transition to the equilibrium level populations in atoms and ions of heavy elements. This circumstance can be used to determine the elemental composition of cool and warm gas of the interstellar medium, as well as the thermal history of the gas.



Some properties of the companions of KIC 8462852 (based on KEPLER data)
Аннотация
The properties of the object KIC 8462852 or its exoplanets, discovered in the KEPLERmission, remain unexplained. The hypotheses that the object is a swarm of cometary bodies, wreckage from a catastrophic collision of asteroids, or an exoplanet KIC 8462852b encounter serious difficulties, and even contradictions with Kepler’s laws, if the eclipsing object is taken to be a physical body revolving around the central star. The hypothetical orbit of KIC 8462852b does not correspond to the expectations for a Dyson sphere in terms of energetic and other requirements. The mass characteristics of the eclipsing object remain unknown. Material from Boyajian et al. (2015) and subsequent publications on this topic are used.



Circumstellar activity around the Herbig Ae/Be stars MWC 361, MWC 614, AB Aur
Аннотация
A study of the optical spectra of three Herbig Ae/Be stars is presented: MWC 361,MWC 614, AB Aur. Variations of the equivalent widths, radial velocities, and profiles of spectral lines formed in different regions of the circumstellar environments of these stars are analyzed. The most active spectral variations are observed in the Hα, Hβ, and He I 5876 lines. Other emission lines, such as Si II λλ6347, 6371 Åand [O I] λλ6300, 6363 Å, also display variations, but these are much smaller. Interstellar DIBs at λλ5780 and 5797 ˚A were detected for the stars MWC 361 and MWC 614 for the first time. The active processes that are underway in the circumstellar environments of these systems can also reach more distant, outer parts of their circumstellar disks.



Infra-low-frequency gravitational wave signals in the electric and magnetic fields of the earth
Аннотация
Signals with infra-low frequencies corresponding to the frequencies of gravitational-wave radiation from known binary star systems have been detected in the electric and magnetic fields of the Earth. The use of a eigenvector and signal-component analyzer has proved effective in detecting energetically not dominant components in time series of the electric and geomagnetic fields. The amplitude and probability characteristics of these signals are estimated.


