118437731
Growth and replication of red rain cells at 121°C and their red fluorescence
We have shown that the red cells found in the Red Rain (which fell on Kerala, India, in 2001) survive and grow after incubation for periods of up to two hours at 121°C . Under these conditions daughter cells appear within the original mother cells and the number of cells in the samples increases with length of exposure to 121°C. No such increase in cells occurs at room temperature, suggesting that the increase in daughter cells is brought about by exposure of the Red Rain cells to high temperatures. This is an independent confirmation of results reported earlier by two of the present authors, claiming that the cells can replicate under high pressure at temperatures upto 300°C. The flourescence behaviour of the red cells is shown to be in remarkable correspondence with the extended red emission observed in the Red Rectagle planetary nebula and other galactic and extragalactic dust clouds, suggesting, though not proving an extraterrestrial origin.
83809193
New biology of red rain extremophiles prove cometary panspermia
This paper reports the extraordinary biology of the microorganisms from the mysterious red rain of Kerala, India. These chemosynthetic organisms grow optimally at an extreme high temperature of 300 degrees C in hydrothermal conditions and can metabolize inorganic and organic compounds including hydrocarbons. Stages found in their life cycle show reproduction by a special multiple fission process and the red cells found in the red rain are identified as the resting spores of these microbes. While these extreme hyperthermophiles contain proteins, our study shows the absence of DNA in these organisms, indicating a new primitive domain of life with alternate thermostable genetics. This new biology proves our earlier hypothesis that these microbes are of extraterrestrial origin and also supports our earlier argument that the mysterious red rain of Kerala is due to the cometary delivery of the red spores into the stratosphere above Kerala.
16519092
Analytic Light Curves of Gamma-Ray Burst Afterglows: Homogeneous versus Wind External Media
Assuming an adiabatic evolution of a gamma-ray burst (GRB) remnant interacting with an external medium, we calculate the injection, cooling, and absorption break frequencies and the afterglow flux for plausible orderings of the break and observing frequencies. The analytical calculations are restricted to a relativistic remnant and, in the case of collimated ejecta, to the phase where there is an insignificant lateral expansion. Results are given for both a homogeneous external medium and a wind ejected by the GRB progenitor. We compare the afterglow emission at different observing frequencies, for each type of external medium. It is found that observations at submillimeter frequencies during the first day provide the best way of discriminating between the two models. By taking into account the effect of inverse Compton (IC) scatterings on the electron cooling, a new possible time dependence of the cooling break is identified. The signature of the upscattering losses could be seen in the optical synchrotron emission from a GRB remnant interacting with a preejected wind, as a temporary mild flattening of the afterglow decay. The upscattered radiation itself should be detected in the soft X-ray emission from GRB remnants running into denser external media, starting a few hours after the main event.
73714687
Charged Hadron Multiplicity Distribution at Relativistic Heavy-Ion Colliders
The present paper reviews facts and problems concerning charge hadron production in high energy collisions. Main emphasis is laid on the qualitative and quantitative description of general characteristics and properties observed for charged hadrons produced in such high energy collisions. Various features of available experimental data, for example, the variations of charged hadron multiplicity and pseudorapidity density with the mass number of colliding nuclei, center-of-mass energies, and the collision centrality obtained from heavy-ion collider experiments, are interpreted in the context of various theoretical concepts and their implications. Finally, several important scaling features observed in the measurements mainly at RHIC and LHC experiments are highlighted in the view of these models to draw some insight regarding the particle production mechanism in heavy-ion collisions.
120551696
alpha-particle emission as a probe of dynamical deformations
We have measured alpha-particle spectra at different laboratory angles from the fusion reaction Si-28+V-51 at 140 MeV. These spectra deviate at higher energies from the statistical model calculations using rotating liquid drop model values of the moment of inertia. In order to explain the experimental spectra, changes were required in the moments of inertia corresponding to deformation, which suggests dynamical effects on the deexcitation process for charged-particle emission. The comparison of decay times with formation times implies that light charged particles are preferentially emitted prior to the full relaxation of the compound nucleus. Statistical models and dynamical calculations have been employed in an attempt to interpret the experimental data. The results were compared with the Si-28+Al-27 system studied earlier in order to understand the symmetric and asymmetric entrance channel effects in the formation of the compound system.
123993434
Theoretical interpretation of the systematics of effective single-particle level densities from (n,p) reactions at 14.8 MeV energy
The universal experimental data for the energy-integrated angular distribution and the angle-integrated energy spectra for protons emitted from the (n,p) reactions at 14.8 MeV incident energy were analyzed earlier using the computer code PRECO-D2, developed on the basis of Kalbach’s semiempirical model for the preequilibrium reactions. The results of the analysis provided the semiempirical systematics of the single-particle level densities gR(exp) (effective in the residual nuclei) and gc(exp) (effective in the composite system). In order to interpret these results, we have carried out the theoretical calculations with Shlomo’s theory developed on the basis of the Green’s function approach. The theoretical values based on Shlomo’s theory for g Th (eRn )a ndg Th Rp (eRp) for the residual nucleus and g Th cn (ecn )a ndg Th cp (ecp ) for the composite systems, respectively, were calculated at various excitation energies by using a reasonable single-particle nuclear potential strength V0 ,a vailable from systematics in literature. Here, eRn and eRp are the single-particle excitation energies for single-particle level densities for the residual nucleus, and ecn and ecp are the single-particle excitation energies of effective single-particle level densities for the composite system for neutrons and protons, respectively. The Coulomb interaction potential Vc was included for protons over and above the nuclear potential V0. The total theoretical values were taken as g TTh (eR) = g Th Rn(eRn) + g Th Rp (eRp) for residual nuclei and g TTh c (ec) = g Th cn (ecn) + g TTh cp (ecp ) for the composite system. eR is the Fermi energy of the total effective single-particle level density for residual nuclei, and ec is the excitation energy of the effective single-particle level density of the composite system. Careful comparison of theoretical and experimental results shows that gR(exp) matches with g TTh R (ef )f orV i 0 = 45 MeV where (ef ) is the Fermi energy. The theoretical values g TTh (ef ) also nearly agree with the previously reported values by various groups, obtained through different approaches for a large number of cases. The values of gc(exp) always are found to be greater than gR(exp) and match with g TTh c (ec) at effective excitation energies ec, which are found to be invariably much higher than the respective ef and are positive and follow the nuclear shell model structure when plotted against A. This supports the concept that the values of effective gc(exp) are decided mainly by dominant transition, which occurs during initial stages of the multistep statistical direct preequilibrium process that involves unbound states. The values of gR(exp), on the other hand, are found to correspond to the effective eR around the Fermi energies of the bound states of residual nuclei involved in the decay processes. The ratios of gc(exp)/gR(exp) are found to follow the ( � e c� � ef � ) 1/2 f description and to match Shlomo’s theory.
118602066
On the smoothness of multi center coplanar black hole and membrane horizons
We study the differentiability of the metric and other fields at any of the horizons of multi center Reissner-Nordstrom black hole solutions in $d \ge 5$ and of multi center $M2$ brane solutions. The centers are distributed in a plane in transverse space, hence termed coplanar. We construct the Gaussian null co-ordinate system for the neighborhood of a horizon by solving the geodesic equations in expansions of (appropriate powers of) the affine parameter. Organizing the harmonic functions that appear in the solution in terms of what can be called generalized Gegenbauer polynomials is key to obtaining the solution to the geodesic equations in a compact and manageable form. We then compute the metric and other fields in the Gaussian null co-ordinate system and find that the differentiability of the coplanar solution is \emph{identical to} the differentiability of the collinear solution (centers distributed on a line in transverse space). The results of this paper thus run counter to a suggestion in the literature that posits reduction in the degree of smoothness to accompany reduction in symmetries. We end the paper with a conjecture on the degree of smoothness of the most general multi center solution, the one with centers distributed arbitrarily and hence possessing no transverse spatial isometries.