When cosmic quantum mechanics is applied to a double galaxy, the result is mass limits in order for the two galaxies to form a quantum binary system. For a non-relativistic theory (based on the Schrödinger wave equation), the mass limits are: (mg)max 1012M and (mg)min 1010M. One possible consequence appears to be a Newtonian gravitational constant that varies with cosmic time, with its value larger in the cosmic past. 相似文献
The expected equivalent widths of individual rotational lines of the most intense Q2 branch of the 0-0 band of the A2-X2i; system of S32H and S34H have been calculated in the umbral spectrum for five disk positions using Zwaan's (1974) sunspot model. Percentage abundance of S34 in the terrestrial case has been considered valid in our calculations.Strong lines of S32H and S34H of the A-X band system should be detectable in the sunspot spectrum. The molecule SH may play a possible role as a major opacity source in the ultraviolet spectrum of sunspots along with the molecule OH in the upper layers (up to
0.5m = 1.0) wherefrom most of the continuum arises. Study of this molecule in the umbral spectrum may also provide the solar isotopic abundance ratio N(S32)/N(S34). 相似文献
In 2003–2008, highly accurate photoelectric and CCD observations of the close binary system DI Her were performed in the V band. The light curves of three primary and three secondary eclipses were constructed. These observations, along with the highly accurate photoelectric observations of other authors obtained in different years from 1963 to 1986, have confirmed the difference between the observed (1.o3 ± 0.o1/100 yr) and theoretical (4.o3/100 yr) rates of apsidal motion. Our photometric data are indicative of a possible variability in the system with period P′ = 1.175 days and amplitude A′ = 0.m011, which is probably related to the pulsations of one of the components. There may be a third body in the system that produces in-phase variations in the times of primary and secondary minima with a period of 10.5 yr and an amplitude of 1.m5. 相似文献
The nucleus26Al(1/2 = 7.4 × 105 yr) has long been considered as a possible heat source during the formation of the solar system. Recent experimental work has found no evidence for26Al at the time of final solidification of the meteorites. Due to the short half-life these measurements do not rule out the possibility that26Al was a significant heat source a few million years prior to final solidification. For26Al to be an effective heat source in the early solar system it is necessary for the ratio26Al/Si to be 2×10–7 at the time of a solidification. The nucleosynthetic yields of26Al by silicon burning, carbon burning, and spallation are discussed. It is shown that26Al can be synthesized in carbon and/or silicon-burning supernovae. However, time scales in the early solar system make it more likely that26Al, if present in planets, was synthesized by a proton irradiation in the early solar system. An integrated proton flux >4×1018 cm–2 is shown to be necessary in order for26Al to be a significant heat source. No conclusive evidence has been observed for an irradiation of this magnitude. Therefore, unless such evidence is found, it should be assumed that26Alwas not involved in the formation of the solar system. In addition, the production of26Al in cosmic rays is discussed and it is shown that either resolution of the Al isotopes in the cosmic rays or accurate measurements of the variation with energy of the cosmic ray abundance ratios Al/Si and Mg/Si can be used to determine the age of the cosmic rays, C.R.. Current abundance data are extremely uncertain; however, the trend tends toward values of C.R. 106 yr.Supported in part by the National Science Foundation [GP-19887, GP-28027, GP-27304]. 相似文献
Results of evolutionary calculations for a close binary system with a central helium burning He-star filling its Roche lobe and an accreting white dwarf are presented. Values for the mass of the components and the degree of central helium exhaustion before the filling of the Roche lobe are varied. It is shown that in such a system the mass accretion rate will remain for a long time (2–4) Ö 10–8
yr–1 ifq<1 (q=MHe,2/MCO,1). The obtained results are discussed in connection with pre-supernova I phenomenon. 相似文献
We present the results of photometric observations of a bright cataclysmic variable TT Ari with an orbital period of 0.13755 days. CCD observations were carried out with the Russian-Turkish RTT 150 telescope in 2001 and 2004 (13 nights). Multi-color photoelectric observations of the system were obtained with the Zeiss 600 telescope of SAO RAS in 1994–1995 (6 nights). In 1994–1995, the photometric period of the system was smaller than the orbital one (0.d132 and 0.d134), whereas it exceeded the latter (0.d150 and 0.d148) in 2001, 2004. An additional period exceeding the orbital one (0.d144) is detected in 1995 modulations. We interpret it as indicating the elliptic disc precession in the direction of the orbital motion. In 1994, the variability in colors shows periods close to the orbital one (0.d136, b-v), as well as to the period indicating the elliptic disk precession (0.d146, w-b). We confirm that during the epochs characterized by photometric periods shorter than the orbital one, the quasi-periodic variability of TT Ari at time scales about 20 min is stronger than during epochs with long photometric periods. In general, the variability of the system can be described as a “red” noise with increased amplitudes of modulations at characteristic time scales of 10–40 min. 相似文献
Prentice (1978a) in his modern Laplacian theory of the origin of the solar system has established the scenario of the formation of the solar system on the basis of the usual laws of conservation of mass and angular momentum and the concept of supersonic turbulent convection that he has developed. In this, he finds the ratio of the orbital radii of successively disposed gaseous rings to be a constant - 1.69. This serves to provide a physical understanding of the Titius-Bode law of planetary distances. In an attempt to understand the law in an alternative way, Rawal (1984) starts with the concept of Roche limit. He assumes that during the collapse of the solar nebula, the halts at various radii are brought about by the supersonic turbulent convection developed by Prentice and arrives at the relation: Rp= Rap, where Rpare the radii of the solar nebula at various halts during the collapse, Rthe radius of the present Sun and a = 1.442. a is referred here as the Roche constant. In this context, it is shown here that Kepler's third law of planetary system assumes the form: Tp = T0(a3/2)p, where Tp are the orbital periods at the radii Rp, T0 - 0.1216d - 3 h, and a the Roche constant. We are inclined to interpret T0' to be the rotation period of the Sun at the time of its formation when it attained the present radius. It is also shown that the oribital periods Tpcorresponding to the radii Rpsubmit themselves to the Laplace's resonance relation. 相似文献
The estimates of the population of excited vibrational states of the CO2 molecule and of the rate of radiative cooling of the atmosphere in the 15-m CO2 band are given for the nighttime mesosphere and thermosphere of Mars. For the first time, these estimates are made (1) with allowance for the overlap of lines in the 15-m band; (2) for a wide set of vibrational states of seven isotopes of the CO2 molecule, which was used earlier in the solution of a similar terrestrial problem; and (3) using the rate constant for quenching of the CO2(0110) state in collisions with oxygen atoms, which has been recently measured for low temperatures by Khvorostovskaya et al. (2002). The main results are as follows. 1. The approximation of isolated lines provides a satisfactory accuracy of determining the radiative cooling rate and overestimates vibrational temperatures of the states of the 2 mode by no more than 3 K for the 12C16O2 molecule and by no more than 2 K for low-abundant isotopes of the CO2 molecule. 2. A reasonably high accuracy of estimating the cooling rate can be achieved by taking into account only fundamental vibrational transitions in 12C16O2, 13C16O2, 16O12C18O, and 16O12C17O molecules and the hot transitions 222 and 32 22 in the 12C16O2 molecule. 3. The vertical profile of the total rate of radiative cooling displays two peaks. The maximum near a height of 130 km is very sensitive to temperature and to the ratio of the mixture for oxygen in the atmosphere. 相似文献
We have analyzed the optical (U BV) and ultraviolet (λ1000–2700 Å) observations of the nuclear variability of the Seyfert galaxy NGC 4151 in the period 1987–2001 (the second cycle of activity). The fast (tens of days) and slow (～10 years) components of the nuclear variability, F and S, respectively, are shown to be completely different, but thermal in nature. We associate the S component with the formation and evolution of an accretion disk and the F component (flares) with instabilities in the accretion disk and their propagation over the disk in the form of a shock wave. The S component is present not only in the optical, but also in the ultraviolet range, with its amplitude being comparable over the entire range λ1000–5500 Å under study. The amplitude of the average flare (the F component) doubles as the wavelength decreases from 5500 to 1000 Å, while the rise time of the brightness to its maximum Δt (the variability time scale) decreases from
to 6d ± 2d. The brightness decline (flare decay) time decreases by a factor of 16. The extinction in the ultraviolet is shown to have been grossly underestimated: beginning from the first IUE data, only the extinction in our Galaxy,
leads to a large increase in the luminosity of the variable source in the nucleus of NGC 4151: L = (6–8) × 1046 erg s?1. The spectral energy distribution for the variable source (λ950–5500 Å) agrees well with two Planck distributions: Te = 65 000 (λmax = 450 Å) and 8000 K. The radiation with Te = 8000 K is the reprocessing of the bulk of the ultraviolet radiation by the accretion disk with a lag of 0.5–0.6 days in the V band. The lag in the U-B variability of the slow component revealed the existence of an extended broad line region (EBLR) at an effective distance of 1.5 lt-years, as confirmed by spectroscopic data obtained at the Crimean Astrophysical Observatory. This yields the following mass of the central object in NGC 4151: Mc = (1–3) × 109M⊙. The luminosity of the variable source then accounts for 50–60% of LEdd rather than 1–2%, as has been thought previously. In general, the pattern of ultraviolet and optical variability in NGC 4151 agrees excellently with the theory of disk accretion instability for a supermassive black hole suggested by N. Shakura and R. Sunyaev 30 years ago: the energy release is at a maximumin the ultraviolet (in the case under consideration, at λ450 Å), the luminosity is ～1047 erg s?1 for Mc ～ 109M⊙ (several tens of percent of LEdd), and the variability time scale ranges from several days to many years.
Some weak unidentified solar photospheric lines in the wavelength range: (3400–3465) Å may be due to PH lines of the (0, 0) band of the PH(A3i - X3-)system. These faint PH molecular lines have resulted an excitation temperature of the order of 4500 K. Using experimental lifetime data for PH in the A3istate, an absorption oscillator strength f00 = 0.0075 is derived for the 3410 Å band of the PH (A3i - X3-)system. Accurate line positions, oscillator strength and transition probability for the 4.4 fundamental rotation-vibration band of the PH molecule are obtained. A comparison of positions of some lines of the 4.4 band with those obtained on new tracings of high resolution solar spectra shows many coincidences with weak solar lines. 相似文献
The dependence of the spin frequency derivative \(\dot \nu \) of accreting neutron stars with a strongmagnetic field (X-ray pulsars) on the mass accretion rate (bolometric luminosity, Lbol) has been investigated for eight transient pulsars in binary systems with Be stars. Using data from the Fermi/GBM and Swift/BAT telescopes, we have shown that for seven of the eight systems the dependence \(\dot \nu \) (Lbol) can be fitted by the model of angular momentum transfer through an accretion disk, which predicts the relation \(\dot \nu \) ～ L6/7bol. Hysteresis in the dependence \(\dot \nu \) (Lbol) has been confirmed in the system V 0332+53 and has been detected for the first time in the systems KS 1947+300, GRO J1008-57, and 1A 0535+26. Estimates for the radius of the neutron star magnetosphere in all of the investigated systems have been obtained. We show that this quantity varies from pulsar to pulsar and depends strongly on the analytical model and the estimates for the neutron star and binary system parameters. 相似文献
In this paper the magnetic superstar model is used to discuss QSO luminosity and density evolution. Our main hypotheses are that (i) mass loss from old stars in massive galaxies cools and then falls into the centre to form a nuclear disc (Bailey, 1980); and (ii) magnetic superstars in galactic nuclei condense out of gaseous material at the centre of a supermassive-magnetised disc (Kundt, 1979). On this generalised model we find that the non-thermal (synchrotron) optical luminosity scales asLoptL3t–7/3, whereL is the total blue luminosity of old stars in the galaxy and t is cosmic time. In addition we show that QSO co-moving density follows the lawD(t)exp-(t/tEvol)16/15 with an evolution timescaletEvol = 1.95 × 109 yr. The model as a whole is in good agreement with observations. 相似文献
A plausible scenario for the formation of a stable supermassive star in the relativistic regime has been discussed. The onset of the negativity of the `distribution function' in the stable sequences of the star clusters [the stability of star clusters is assured by using the variational method (Chandrasekhar, 1964a,b) for equivalent gas spheres] described by Tolman's type VII solution with vanishing surface density has been regarded as an indication of the conversion of the cluster structure into a supermassive star. For the critical values of the `adiabatic index', (4/3) < crit (5/3) (forwhich a supermassive star represent neutrally stable system), the mass, and the size of this object comes out to be 6.87 × 107 M M 1.7 × 109M, and 2.74× 1014 cm a 1.43× 1015cm respectively, for the central temperature,T0 = 6× 107°K, which is sufficient for the release ofnuclear energy. The total energy released during their evolution rangesfrom 2.46× 1060 - 3.18× 1062 erg, which is sufficient to power these objects at least for a period of 106 - 107years. These figures agrees quite well with those cited for Quasi Stellar Objects (QSOs) in the literature. 相似文献
Prentice (1978a, b), in his modern Laplacian theory of the origin of the solar system, has established a scenario in which he finds the ratio of the orbital radii of successively disposed gaseous rings to be a constant 1.69. In an attempt to understand this law in an alternative way, Rawal (1984a) assumes that during the collapse of the solar nebula the halts at various radii are brought about by the supersonic turbulent convection and arrives at the relation of the formRp=Rap, whereR is the radius of the present Sun anda=1.422, is referred to, here, as the Roche constant. Kepler's third law assumes the form:Tp=T0(a3/2)p,T0 being the rotational period of the Sun at the time it attained its present radius.Rpsatisfy Laplace's resonance relation without any exception. The present paper investigates inter-relations among the concepts of supersonic turbulent convection, rotational instability, and Roche limit.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984. 相似文献
Energetic particle (0.1 to 100 MeV protons) acceleration is studied by using high resolution interplanetary magnetic field and plasma measurements at 1 AU (HEOS-2) and at 5 AU (Pioneer 10). Energy changes of a particle population are followed by computing test particle trajectories and the energy changes through the particle interaction with the time varying magnetic field. The results show that considerable particle acceleration takes place throughout the interplanetary medium, both in the corotating interaction regions (CIR) (5 AU), and in quiet regions (1 AU). Although shocks may contribute to acceleration we suggest statistical acceleration within the CIRs is sufficient to explain most energetic particle observations (e.g., McDonaldet al., 1975; Barnes and Simpson, 1976).The first and second order statistical acceleration coefficients which include transit time damping and Alfvén resonance interactions, are found to be well represented byDT8.5×10–6T0.5 MeV s–1 andDTT4×10–6T1.5 MeV2 s–1 at 5 AU.By comparison, Fisk's estimates (1976), based on quasi-linear theory for transit-time damping, gaveDTT5×10–7T MeV2 s–1 at 1 AU. 相似文献
This paper aims to investigate what kind of density perturbations did lead to elliptical galaxies and what kind to spiral galaxies, in the context of a CDM scenario. Previous work by HP (Heavens and Peacock, 1988) is reviewed and extended; more particularly: (i) a theoreticalJM relation is derived for virialized configurations, with a slope increasing with the mass, in the range 5/3<<2, and compared with its counterpart deduced by HP for expanding configurations; (ii) an non-dimensional angular momentum =J/(G2M5tff)1/3; withtfffree-fall time at turnaround, is calculated explicitly and compared with the usual spin parameter =J(–E)1/2/(GM5/2), in the special case of polytropic spheres and for different peak heights; (iii) a model is built up where the ellipsoidal density perturbations described by HP are approximated as spherical density perturbations with the same mass and the same rate of acquisition of angular momentum, and the contribution of the latter to the expansion is also taken into account. The calculations are limited to the special case of Einstein-de Sitter universes (of dust only), in the whole range of HP distributions of angular momenta. If a massM=1012m is typical for galaxies, the results are consistent with both an inferred difference roughly in a factor of six times between angular momenta of ellipticals and spirals, and a continuous transition from the former to the latter, for each peak height. It is argued that star formation together with angular momentum, instead of peak height alone, makes the fate of a given proto-object; more specifically, if star formation is high enough and/or angular momentum is low enough, the system will be frozen as an elliptical galaxy; if, on the other hand, the rate of star formation is low enough, and/or angular momentum is high enough, the system will be frozen as a spiral galaxy. In addition, the results lead to an obvious trend: more ellipticals are associated with higher peak heights and more spirals with lower peak heights. 相似文献
We report the results of our optical speckle interferometric observations of the nearby triple system GJ 795 performed with the 6 m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences with diffraction-limited angular resolution. The three components of the system were optically resolved for the first time. Position measurements allowed us to determine the elements of the inner orbit of the triple system. We use the measured magnitude differences to estimate the absolute magnitudes and spectral types of the components of the triple: MVAa=7.31±0.08, MVAb=8.66±0.10, MVB=8.42±0.10, SpAa≈K5, SpAb≈K9, SpB≈K8. The total mass of the system is equal to ΣMAB=1.69±0.27M⊙. We show GJ795 to be a hierarchical triple system which satisfies the empirical stability criteria. 相似文献
A two-stage model of the propagation of 1–50 MeV solar-flare cosmic rays is presented. The first stage consists of a thin spherical shell of radius ra near the Sun which feeds particles into interplanetary space (the second stage) where they propagate along the Archimedean mean interplanetary magnetic field under the influences of anisotropic diffusion, convection, and energy changes. To calculate the time dependence at a fixed point in space, account is taken of the corotation of flux tubes past the observer.It is shown that the well-known east-west effect of the time-to-maximum cannot be obtained if the injection from the first stage is impulsive and thus a time and longitude dependent release for the second stage is essential. This is achieved by treating the first stage as a thin, spherical, diffusing shell of radius ra with diffusion coefficient
s, from which particles leak into interplanetary space at a rate determined by the leakage coefficient .With this model we are able to reproduce simultaneously four principal features of solar events observed at r = 1 AU: (i) the east-west effect, i.e. the time-to-maximum as a function of flare longitude; (ii) the three phases of the anisotropy vector variation; (iii) the time-to-convective-phase as a function of flare longitude; and (iv) the longitudinal distribution of the differential intensity. Our best estimates of the parameters of the near-Sun propagation are that 0.01 hr–1s/r
a2
0.02 hr–1 and 1/15 hr–1 1/10 hr–1. For the interplanetary propagation we estimate /V - 1.2AU with , the effective cosmic-ray diffusion coefficient and V, the solar-wind speed. 相似文献
A small particle moves in the vicinity of two masses, forming a close binary, in orbit about a distant mass. Unique, uniformly valid solutions of this four-body problem are found for motion near both equilateral triangle points of the binary system in terms of a small parameter , where the primaries move in accordance with a uniformly-valid three-body solution. Accuracy is maintained within a constant errorO(8), and the solutions are uniformly valid as tends to zero for time intervalsO(–3). Orbital position errors nearL4 andL5 of the Earth-Moon system are found to be less than 5% when numerically-generated periodic solutions are used as a standard of comparison. 相似文献
