8249851
On Hawking/Unruh Process: Where does the Radiation Come from?
The energy source of the radiation in Unruh/Hawking process is investigated with emphasis on the particle number definition based on conservation laws. It has been shown that the particle radiation is not the result of pair creation by the gravitational force, but the result of difference in the conservation laws to define the particle number. The origin of the radiated energy in the distant future corresponds to the zero point oscillations with infinitely large wave numbers. This result implies the need of reconsideration on the scenario of black hole evaporation.
55094258
Three Views of a Secret in Relativistic Thermodynamics
It has been shown three different views in relativistic thermodynamics can be derived from the basic formulation proposed by van Kampen and Israel. The way to decompose energy-momentum into work and heat is not uniquely determined; the different choices result in different views. Also the definition of three dimensional volume causes ambiguity of thermodynamical quantities. The present paper shows various theories are obtained depending on the choice of these two factors. Subject Index: 070
15956163
Factor Two Discrepancy of Hawking Radiation Temperature
The possibility of an alternative way to formulate the Hawking radiation in a static Schwarzschild spacetime has been explored. To calculate the Hawking radiation, there can be two possible choices of the spacetime wedge pairs in the Krucal-Szekeres coordinates. One is the wedge pair consists of exterior spacetime of a black hole and the exterior spacetime of a white hole, and the other is that of exterior and interior spacetimes of one black hole. The radiation from the former is the Hawking's original one. Though the the latter has been often regarded as the same phenomena as the former, the result here suggests it is not; its radiation has a temperature twice as high as the Hawking temperature.
119269714
LUMINOUS SUPERNOVA-LIKE UV/OPTICAL/INFRARED TRANSIENTS ASSOCIATED WITH ULTRA-LONG GAMMA-RAY BURSTS FROM METAL-POOR BLUE SUPERGIANTS
Metal-poor massive stars typically end their lives as blue supergiants (BSGs). Gamma-ray bursts (GRBs) from such progenitors could have an ultra-long duration of relativistic jets. For example, Population III (Pop III) GRBs at z {approx} 10-20 might be observable as X-ray-rich events with a typical duration of T{sub 90} {approx} 10{sup 4}(1 + z) s. The recent GRB111209A at z = 0.677 has an ultra-long duration of T{sub 90} {approx} 2.5 Multiplication-Sign 10{sup 4} s and it has been suggested that its progenitor might have been a metal-poor BSG in the local universe. Here, we suggest that luminous UV/optical/infrared emission is associated with this new class of GRBs from metal-poor BSGs. Before the jet head breaks out of the progenitor envelope, the energy injected by the jet is stored in a hot plasma cocoon, which finally emerges and expands as a baryon-loaded fireball. We show that the photospheric emissions from the cocoon fireball could be intrinsically very bright (L{sub peak} {approx} 10{sup 42}-10{sup 44} erg s{sup -1}) in UV/optical bands ({epsilon}{sub peak} {approx} 10 eV) with a typical duration of {approx}100 days in the rest frame. Such cocoon emissions from Pop III GRBs might be detectable in infrared bands atmore » {approx}years after Pop III GRBs at up to z {approx} 15 by upcoming facilities such as the James Webb Space Telescope. We also suggest that GRB111209A might have been rebrightening in UV/optical bands up to an AB magnitude of {approx}< 26. The cocoon emission from local metal-poor BSGs might have been observed previously as luminous supernovae without GRBs since they can be seen from the off-axis direction of the jet.« less
126088861
Tail Emission of Prompt Gamma-Ray Burst Jets
Tail emission of the prompt gamma‐ray burst is discussed using a multiple emitting sub‐shell (inhomogeneous jet, sub‐jets) model. The tail is a superposition of a number of smooth, long‐duration, dim, and soft pulses emitted by segments located far from the line of sight. We find that the behavior of the tail is not so much affected by the local inhomogeneity but affected by the global sub‐jet distribution. Some observed tails may disfavor the power‐law jets.
118117830
Coalescence of binary neutron stars and gravitational radiation.
13196246
A Possible Origin of Lognormal Distributions in Gamma-Ray Bursts
We show that if the intrinsic break energy of gamma-ray bursts (GRBs) is determined by the product of more than three random variables, the observed break energy distribution becomes almost lognormal including the redshift effect because of the central limit theorem. The excess from the lognormal distribution at the low break energy is possibly due to the high-redshift GRBs. The same argument may also apply to the pulse duration, the interval between pulses, and so on.