Identification of 3.55 KeV line in the framework of standard physics

Identification of the X-ray 3.55 KeV line as a recombination line of $\pi^-$ tritium mesoatom is proposed. It has been shown that in principle it is possible to form such an atom under standard laboratory conditions, without bringing in new physics

What is the manifestation of a "quasar" at z > 10^{10} ?

The process of forming an image of a cosmological point source (CPS) in condition of high optical depth is considered accounting for all types of interactions. It is shown that the energy conservation law causes the size of this image which is keeping constant over all redshifts of the CPSs. This effect must be taken into account for the consideration of the angular power spectrum of the CMBR. In particular, distant point sources and small scale fluctuations which were damping before recombination will contribute their energy in the region of angular scale \theta_0 \approx 20'.Comment: 3 pages, submitted to Astron. Let

The beginning of nonlinear stage of evolution of protostars at $ z=20

The results of the EDGES (Experiment to Detect the Global EoR Signature) experiment (Bowman et al., 2018) is interpreted as the beginning of compression stage of primary density fluctuations in a mini halo. Estimates of the mass of these objects are given

Cosmological dinosaurs

The hypothesis of existence of primordial black holes with large masses (\geq 10^6 M\odot), formed at the earliest stages of the Universe evolution, is considered in the paper. The possibility does not contradict some theories, see e.g. Barkana & Loeb (2001), and may match new observational data. In particular, this scenario of evolution could describe some peculiarities in distant galaxies and quasars. Calculations of evolution of central body mass in protogalaxies for different initial conditions are presented. It is shown that the sufficient rate of BH mass growth is not achieved in the standard scheme without complex additional assumptions. Moreover, the appearance of a primordial black hole in the epoch of primordial nucleosynthesis could significantly change the chemical composition around it. This can lead to different exotic stars with low mass and nonstandart metals enrichment. The proposed scheme is not considered as universal. On the other hand, if only tiny part of existed objects have the considered nature, it gives a unique possibility to study extremal stages of matter and fields evolution in our Universe.Comment: 5 pages, 3 figures; revised version with updated ref

Propagation of the burst of radiation in expanding and recombining Universe: Thomson scattering

Within the framework of a flat cosmological model a propagation of an instantaneous burst of nonpolarized isotropic radiation is considered from the moment of its beginning at some initial redshift z0 to the moment of its registration now (at z=0). Thomson (Rayleigh) scattering by free electrons is considered as the only source of opacity. Spatial distributions of the mean (over directions) radiation intensity are calculated as well as angular distributions of radiation intensity and polarization at some different distances from the center of the burst. It is shown that for redshifts z0 large enough (z0 > 1400) the profile of the mean intensity normalized to the total number of photons emitted during the burst weakly depends on initial conditions (say the moment z0 of the burst, the width and shape of initial radiation distribution in space). As regards angular distributions of intensity and polarization they turn to be rather narrow (3 - 5 arcmin) while polarization can reach 70%. On the average an expected polarization can be about 15%.Comment: 14 pages, 7 figure

Local bursts model of primordial CMB temperature fluctuations: scattering in hydrogen lines

Within the framework of a flat cosmological model a propagation of an instantaneous burst of isotropic radiation is considered from the moment of its beginning at some initial redshift z0 to the moment of its registration now (at z=0). Thomson scattering by free electrons and scattering in primordial hydrogen lines Ha, Hb, Pa and Pb are considered as the sources of opacity and when calculating an albedo of a single scattering in the lines we take into account deactivation of the upper levels of transitions by background blackbody radiation. Profiles for these lines in a burst spectrum are calculated for different distances from the center of the burst and different values of z0. In the first approximation these profiles do not depend on spectrum and intensity of a burst radiation. It is shown that lines are in absorption at sufficiently large distance but emission components may appear as a distance decreases and it becomes stronger while absorption component weakens with a further distance decrease. For the sum of Ha and Hb lines the depth of absorption can reach 2e-4 while for the sum of Pa and Pb lines the maximum absorption is about 7e-6. So that the relative magnitude of temperature fluctuations lies between 1e-7 and 1e-9. The calculations were fulfiled for bursts with different initial sizes. For the same z0 the profiles of hydrogen lines are practically coinside for burst sizes lower than someone and for greater ones the lines weaken as the burst size grows.Comment: 20 pages, 8 figure

CO molecules in the shells of quasars 1556+3517 and 0840+3633

New class of low- ionization BAL quasars (Becker et al. 1997), represented by QSO 1556+3517, 0840+3633 and 0059-2735, is considered. Their optical spectra are completely dominated by absorption features, whereas emission lines are weak or absent. Possibility to explain these exclusive features of their spectra by existence of molecular shells, responsible for the absorption is discussed. In particular, it is suggested to identify line at lambda = 2063 A, attributed to CrII, as a line of Cameron band of CO molecule. Estimation of the expected optical depth value in rotational radio lines of this molecule is made. It is suggested to carry out radio observations of quasars 1556+3517 and 0840+3633 to check the molecular hypotheses.Comment: 6 pages, Late

EIT phenomenon for the three-level hydrogen atoms and its application to the era of the cosmological recombination

The electromagnetically induced transparency (EIT) phenomenon in earlier universe is considered. We evaluated the elementary processes of the single scattering of photon on the hydrogen atom with the purpose of their use in the tasks of the radiation transfer theory. The additional function $f$, which depends on external conditions, is found. This function can be considered as an adjustment of the optical depth that leads to the necessity of modernization of the escape probability $p_{ij}(\tau_S)\rightarrow p_{ij}(\tau_S(1+f))$. The numerical values of $f$ for the different schemes of atom in three-level approximation are given. It is found that the magnitude of function $f$ could influence significantly on the formation of CMB in some partial cases.Comment: 19 pages, 2 figures, 7 table

Dynamics of the Primordial Hydrogen and Helium (HeI) Recombination in the Universe

The dependences on z of fractional number densities of H+ and He+ ions are calculated with a proper allowance for two-photon decays of upper levels of hydrogen and parahelium and radiative transfer in intercombination line 2 3P_1 --> 1 1S_0 of helium. It is shown that for hydrogen this gives corrections for a degree of ionization in no more than a few percents but for helium this leads to a significant acceleration of recombination compared to the recent papers by Seager et al. (1999; 2000) where these effects were ignored.Comment: 10 pages, 2 figures, accepted for publication in Astronomy Letter

Local Bursts Model of CMB Temperature Fluctuations: Scattering in Resonance Lines of Primordial Hydrogen and Helium

Within the framework of a flat cosmological model a propagation of an instantaneous burst of isotropic radiation is considered from the moment of its beginning at some initial redshift z0 to the moment of its registration now (at z=0). We take into account Thomson scattering by free electrons and scattering in La and Lb lines of primordial hydrogen and in lines 1s2 - 1s2p, 1s3p (1S-1P*) of HeI. It is shown that relative amplitude of spectrum distortions caused by scattering in these lines may be from 1000 to 10000 times greater than maximum possible amplitude due to scattering in subordinate lines considered in our previous paper (Dubrovich, Grachev, 2015). In a linear approximation on the optical thickness in the lines the profiles of distortions in resonance lines turn out to be purely in absorption and do not depend on both direction and distance to the burst center in contradistinction to the profiles in subordinate lines. The profiles contain jumps on frequencies corresponding to appearance of a source (burst) at a given redshift z=z0. For z0=5000 the jumps in hydrogen La and Lb lines are on frequencies 493 and 584 GHz respectively and jumps in two HeI lines are on 855 and 930 GHz for z0=6000. Relative magnitude of jumps amounts to 1e-4 - 3e-3.Comment: 15 pages, 7figures. Submitted to Astronomy Letter