Observations of A0535+26 transient X-ray source

Observations of the transient X-ray A0535+26 source with the SIGNE-2MP instrument on-board the Soviet “Prognoz-6” and “Prognoz-7” satellites are considered in the paper.     

Phobos-Grunt: Russian sample return mission

As an important milestone in the exploration of Mars and small bodies, a new generation space vehicle “Phobos-Grunt” is planned to be launched by the Russian Aviation and Space Agency. The project is optimized around a Phobos sample return mission and follow up missions targeted to study some main asteroid belt bodies, NEOs and short period comets. The principal constraint is use of the “Soyuz-Fregat” rather than the “Proton” launcher to accomplish these challenging goals. The vehicle design incorporates innovative SEP technology involving electrojet engines that allowed us to increase significantly the mission's energetic capabilities, as well as highly autonomous on-board systems. Basic criteria underlining the “Phobos-Grunt” mission scenario, scientific objectives and rationale including Mars observations during the vehicle's insertion into Mars orbit and Phobos approach maneuvers, are discussed and an opportunity for international cooperation is suggested.     

Experimental investigations of quasistable radiation belts formed after solar proton events in September–October 1989 and March 1991 based on measurements made by “Liulin” dosimeter-radiometer on board the “MIR” space station

Since 1988 high sensitivity dosimeter-radiometer “Liulin” has been installed on board the MIR space station. Device measured absorbed dose rate and flux of penetrating particles. Results of measurements showed that after powerful solar proton events (SPE) September–October, 1989 and March, 1991 additional quasistable radiation belts were formed in the near earth space within the interval L=1.8−3.0. These “new” belts were observed as an additional maximums in flux (and sometimes dose) channels when crossing the SAA region. “New” belts were quasi stable and existed at least several months, decaying slightly after SPE. Dose to flux ratio analysis showed that major components of these belts were energetic electrons and protons arising in connection with preceding SPEs.     

Remote sensing of the ring current using energetic neutral atoms

Energetic neutral atom (ENA) images of the storm-time ring current obtained from the ISEE-1 spacecraft provide information for a “zero-order” global model of the energetic ion distribution. With the assumption of isotropic pressure and magnetostatic, non-convective pressure balance, the global system of electrical currents driven by the ion pressure can be calculated using Euler potentials for the divergenceless current density. Radial pressure gradients drive azimuthal currents, and azimuthal pressure gradients drive radial currents. The radial currents cause current lines in the inner magnetosphere to close in the ionosphere, forming a “partial” ring current. The intensities and locations of these field-aligned currents driven into and out of the ionosphere resemble those of the observed Region 2 current system, but not all observed properties of the Region 2 system are reproduced by the “zero-order” model.     

Collection of cometary dust

Rendezvous Missions to Comets lead to low velocities at the nucleus of the comet. The resulting impact velocity of the cometary dust on a target will range between 10 and 400 m/s. The dust particle which impacts on a target can be collected for a subsequent in-situ analysis.

The collection efficiency of a target depends in addition to obvious geometrical conditions upon the surface of the target. The surface characteristics can be divided into two groups:

• “dirty” surfaces, covered with silicate or hydrocarbon compounds (for example vacuum grease),

• “clean” surfaces, like gold (with additional sputtering).

This paper deals with the experimental and theoretical investigation of the collection efficiency of “clean” targets. Laboratory experiments are described which were conducted at the Technische Universität München, Lehrstuhl für Raumfahrttechnik, and the Max-Planck-Institut für Kernphysik, Heidelberg. In both experiments an electromagnetic accelerator is used to accelerate different types of dust in vacuum to velocities between 10 and 400 m/s.

The target is then examined under the microscope and a secondary ion mass spectrometer (which is a model of the laboratory carried on board of the spacecraft for “in situ” analysis). The adhesion of the dust grains at the target is evaluated experimentally in an ultracentrifuge.     

Acceleration and transport of energeticparticles at CME-driven shocks

Historically, solar energetic particle (SEP) events are classified in two classes as “impulsive” and “gradual”. Whether there is a clear distinction between the two classes is still a matter of debate, but it is now commonly accepted that in large “gradual” SEP events, Fermi acceleration, also known as diffusive shock acceleration, is the underlying acceleration mechanism. At shock waves driven by coronal mass ejections (CMEs), particles are accelerated diffusively at the shock and often reach > MeV energies (and perhaps up to GeV energies). As a CME-driven shock propagates, expands and weakens, the accelerated particles can escape ahead of the shock into the interplanetary medium. These escaping energized particles then propagate along the interplanetary magnetic field, experiencing only weak scattering from fluctuations in the interplanetary magnetic field (IMF). In this paper, we use a Monte-Carlo approach to study the transport of energetic particles escaping from a CME-driven shock. We present particle spectra observed at 1 AU. We also discuss the particle “crossing number” at 1AU and its implication to particle anisotropy. Based on previous models of particle acceleration at CME-driven shocks, our simulation allows us to investigate various characteristics of energetic particles arriving at various distances from the sun. This provides us an excellent basis for understanding the observations of high-energy particles made at 1 AU by ACE and WIND.     

Energetic neutron and gamma-ray spectra under the earth radiation belts according to “SALUTE-7”-“KOSMOS-1686” orbital complex and “CORONAS-i” satellite data

The spectra of neutrons >10 MeV and gamma-rays 1.5–100 MeV under the Earth Radiation Belts, restored from the data, obtained onboard orbital complex “SALUTE-7”-“KOSMOS-1686”, are presented. The spectra shapes are similar to those for albedo neutrons and gamma-rays, but absolute values of their fluxes (0.2 cm⁻² s⁻¹ for neutrons, 0.8 cm⁻² s⁻¹ for gamma-rays at the equator and 1.2 cm⁻² s⁻¹, 1.9 cm⁻² s⁻¹, accordingly, at L=1.9) are several times as large. It is possibly explained by the fact that most of the detected particles were produced by the cosmic ray interactions with the orbital complex matter. Neutron and gamma-ray fluxes obtained from “CORONAS-I” data are near those for albedo particles.     

On the non-occurrence of Type I X-ray bursts from the black hole candidates

It has been justifiably questioned if the black hole candidates (BHCs) have “hard surface” why Type I X-ray bursts are not seen from them [Narayan, R., Black holes in astrophysics, New J. Phys, 7, 199–218, 2005]. It is pointed out that a “physical surface” need not always be “hard” and could be “gaseous” in case the compact object is sufficiently hot [Mitra, A., The day of the reckoning: the value of the integration constant in the vacuum Schwarzschild solution, physics/0504076, p1–p6, 2005; Mitra, A., BHs or ECOs: A review of 90 years of misconceptions, in: Focus on Black Holes Research, Nova Science Pub., NY, p1–p94, 2005]. Even if a “hard surface” would be there, presence of strong intrinsic magnetic field could inhibit Type I X-ray burst from a compact object as is the case for Her X-1. Thus, non-occurrence of Type I bursts actually rules out those alternatives of BHs which are either non-magnetized or cold and, hence, is no evidence for existence of Event Horizons (EHs). On the other hand, from the first principle, we again show that the BHCs being uncharged and having finite masses cannot be BHs, because uncharged BHs have a unique mass M = 0. Thus the previous results that the so-called BHCs are actually extremely hot, ultramagnetized, Magnetospheric Eternally Collapsing Objects (ECOs) [Robertson, S., Leiter, D., Evidence for intrinsic magnetic moment in black hole candidates, Astrophys. J., 565, 447–451, (astro-ph/0102381), 2002 ; Robertson, S., Leiter, D., MECO model of galactic black hole candidates and active galactic nuclei, in: New Developments in Black Hole Research, Nova Science Pub., NY, p1–p44, astro-ph/0602453, 2005] rather than anything else get reconfirmed by non-occurrence of Type I X-ray bursts in BHCs.     

Sunspot numbers during 1736–1739 revisited

Some periods in the sunspot number reconstruction composed by Hoyt and Schatten [Hoyt, D.V., Schatten, K.H. Group Sunspot Numbers: a new solar activity reconstruction. Sol. Phys. 179, 189–219, 1998. Reprinted with figures in Sol. Phys. 181, 491–512, 1998], are based on very few records. For example, there are only a few solar observations during the years 1736–1739. In this paper we intend to improve the reliability of the sunspot numbers reconstruction developed by Hoyt and Schatten for this 4-years period based on information about solar activity published in three journals of that epoch: “Philosophical Transactions”, “Histoire de l’Académie Royale des Sciences”, and “Nova Acta Eruditorum”. We were able to identify 42 papers with solar observations, including 30 with relevant information on sunspots. Based upon this new outlook, a reconstruction of the monthly solar activity for these years is proposed.     

Mercury: can any ice exist at subpolar regions?

The heat transfer in a regolith subsurface layer of thickness 20 m has been theoretically simulated for the areas near Mercury's north pole aiming at the clarification of the possible existence of subsurface ice formations of different form. The paper considers different models of the icy regolith structure and composition: pure uniform amorphous ice; a porous dispersive system with ice-filled pores and voids; permafrost. For comparison the heat transfer in dry iceless regolith has been considered as well. It has been shown that the line of maximum distribution of subsurface icy formations depends on the icy regolith model, but for any one in the “hot” regions it does not go below 70°. For the “cool” regions this line has been shown to go from 5° to 10° southward than that for the “hot” ones. The possible thickness of icy regolith near the pole has been estimated for different models assuming an interior heat flow of 15 mW m⁻². It has been shown that the maximum thickness of this layer takes place at the pole and is equal to 10 km for any model.     

Analysis of the nucleus and circumnuclear area of comet Halley with the “I.K.S.” infrared sounder from the “Vega” flyby probes

The “Vega” Soviet flyby probes to comet Halley will carry a French infrared sounder, called “I.K.S.”. In order to assess its observing capabilities, a theoretical model of the comet infrared emission was constructed. We show how the experiment results will be used to derive the nucleus size and radiative properties, and to study the distribution of gas and dust in the inner coma and circumnuclear area. A preliminary discussion is made of the relevance of the data in instances where the cometary phenomena would be more complex than assumed in the model.     

Mini-belt as a fine spatial structure of the outer radiation belt in quiet and disturbed conditions

Electron flux data from LANL geostationary spacecrafts were statistically treated and ordered in a special magnetic coordinate system (effective L-coordinate and MLT). The data treating procedure allowed to obtain the dynamics of quasi-trapped electrons of different energies on effective L-shells ranging from 6.6 to 7.0. It was found that in quiet conditions a stable fine spatial structure of quasi-trapped electrons exists with maximum of fluxes near L = 6.78 and MLT=12. This structure may be looked at as an asymmetrical “mini-belt”. The position of the maximum depends on electron energy and changes with magnetic activity. The dynamics of this mini-belt for both quiet and disturbed periods is illustrated and discussed. During isolated magnetic storms the mini-belt maximum shifts in a regular manner outward and inward; a diffusion wave of quasi-trapped particles propagates from outside of the geostationary orbit and serves as a source of new particles for the mini-belt. The azimuthal geometry of this diffusion wave extracted from experimental data is illustrated. The possible role of the “mini-belt” is discussed in relation with well-known “anomalous” dynamics of the inner radiation belt.     

Free librations of the two-layer Moon and the possibilities of their detection

Based on the forthcoming second stage of the Japanese Lunar mission ILOM (2013), when an optical telescope will be set on the surface near one of the Lunar poles, the possibility to detect free Lunar modes (Chandler-like wobble and free-core nutation) is considered. The difference between the Lunar Eulerian and Chandler-like wobble is explained. The terms “arbitrary libration” and “free libration” are discussed. The geometrical and physical interpretations of the free polar motion over the Lunar surface are considered from the viewpoints of Lunar surface-based observations and the Lunar Navigation Almanac. The dependencies of the free libration period on the core’s radius, density, and ellipticity are modelled and discussed.     

Type I supernovae origin: “Dualistic” hypothesis

Stars that explode as Type I Supernovae (SNI) are white dwarfs with masses practically equal to the Chandrasekhar limit M_ch. These white dwarfs forme either as a result of gas overflow onto a degenerate component in a binary system or due to the evolution of nuclei of the stars whose mass, on the main sequence, was 3 to 7 M_o. The masses of their nuclei are quite close to M_ch. It is convenient to consider three types of stellar evolution 1) “hyperbolic”: masses of nuclei formed as a result of evolution are > M_ch; such evolution ends in a Type II Supernova (SNII) outburst; 2) “parabolic” - masses of nuclei ≈ M_ch, with the evolution ending in an SNI outburst; 3) “elliptical” with nuclei masses < M_ch. The latter type of evolution leads to the formation of planetary nebulae and white dwarfs. A new hypothesis is suggested that explains more frequent occurrence of SNI in irregular galaxies by flashes of star formation.     

Updated TUS space fluorescence detector for study of UHECR

The TUS (Tracking Ultra-violet Set up) space fluorescence detector has to be launched in 2010 as a separated platform in Foton (Bion) mission prepared by the Samara enterprise. This detector was designed for another satellite and the updated variant of the TUS detector for a new platform is presented. The data on UV glow of the atmosphere obtained in operation of one pixel of the TUS detector on board the Moscow State University “Universitetsky-Tatiana” satellite was taken into account in design of the updated TUS detector. The data on UV transient flashes registered in “Universitetsky-Tatiana” mission are of special interest. Electronics of the TUS detector able to select and register different types of UV events in the atmosphere is presented.     

Results of cosmic radiation dose field measurements aboard the “Salyut-6” orbital station

During the 3rd main expedition on board the “Salyut-6” orbital station in 1979 the integral characteristics of cosmic radiation were measured in various positions inside the manned modules (experiment “Integral”). Measurements were performed with thermoluminescent dosimeters, photographic films and solid state plastic detectors supplied for the experiment by specialists of the USSR, Bulgaria, Hungary, GDR and Romania. The dose gradient inside the manned modules of the station amounted to 70 % for long intervals of time. During the experimental period the dose rate inside the station was 15 to 30 mrad per day. The mean flux of particles with z 6 and LET 200 keV/μm was found to be 0.22 cm⁻² day⁻¹.     

Space radiation quality factor investigations with “NAUSICAA”-device on board the “MIR” space station

The estimation of radiation quality factor in space flights is a serious problem of space dosimetry. The solution of this problem is based on LET-spectra measurements. The “NAUSICAA”-device installed on the “MIR” station has a detector with a large geometric factor, that gives the possibility of measuring LET-spectra with sufficient statistic in relatively short time interval and hence the corresponding Q. LET-spectra are accumulated through 24 hour periods and equivalent dose (H), absorbed dose (D), quality factor and flux (F) are measured every 10 minutes. The obtained data permit the estimate of the diurnal Q and Q in South Atlantic Anomaly. These values vary in the range of 1.4 – 2.2. The analysis of these values including their comparison with the calculated results is given in this paper.     

Energy deposition in the upper atmosphere in the EXCEDE III experiment

The EXCEDE III sounding rocket flight of April 27, 1990 used a 18 Ampere 2.5 keV electron beam to produce an artificial aurora in the region 90 to 115 km. A “daughter” sensor payload remotely monitored the low-energy X-ray spectrum while scanning photometers measured the spatial profile of prompt emissions of N₂⁺ (1N) and N₂ (2P) transitions (3914Å and 3805Å, respectively). Two Ebert-Fastie spectrometers measured the spectral region from 1800 to 8000Å. On the “mother” accelerator payload, the return current electron differential energy spectra were monitored by an electrostatic analyzer (up to 10 keV) and by a retarding potential analyzer (0 eV to 100 eV). We present an overview of the results from this experiment.     

Energetic ion observations during comet Giacobini-Zinner encounter

The Energetic Particle Anisotropy Spectrometer (EPAS) on the ICE spacecraft observed large fluxes of energetic ions (E > 65-keV) for a period of one day prior to encounter with comet Giacobini-Zinner to several days afterwards. These observations permit the study of the way in which cometary atoms and molecules are “picked-up” and accelerated by the solar wind flow, such that the flow becomes mass-loaded and slowed in the vicinity of the comet. The ion bulk flow within the mass-loaded region can also be studied together with the nature of the boundary between this region and the outer “pick-up” region. Finally it is also possible to study ion motion close to, and within, the induced magnetotail of the comet.     

The X-ray properties of accreting black holes

Accreting black holes in binary systems exhibit two properties that distinguish them from the vast majority of binary X-ray sources: (1) rapid ≤ 1 s variability and (2) bi-modal spectral behaviour. These findings are based primarily on the observed properties of Cyg X-1 where an estimate of the X-ray source mass from radial velocity studies indicates a mass of 10 M. The recently suggested black hole candidacy of LMC X-3 is based on a similar mass estimate. The X-ray properties are similar to those of Cyg X-1 in its “high state”. The unique spectral properties of these systems are used to search for other similar systems, and new “possible” candidates are suggested, that include several transient sources. A possible spectral connection between these systems and their more massive counterparts in AGN is discussed.