scholarly journals Constraints on the spectral index for the inflation models in the string landscape

2007 ◽  
Vol 76 (6) ◽  
Author(s):  
Qing-Guo Huang
1990 ◽  
Vol 137 (1) ◽  
pp. 21 ◽  
Author(s):  
M.S. Stern ◽  
P.C. Kendall ◽  
P.W.A. McLlroy

1989 ◽  
Vol 25 (2) ◽  
pp. 107 ◽  
Author(s):  
P.C. Kendall ◽  
P.W.A. Mcllroy ◽  
M.S. Stern

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Samuele Ronchini ◽  
Gor Oganesyan ◽  
Marica Branchesi ◽  
Stefano Ascenzi ◽  
Maria Grazia Bernardini ◽  
...  

Abstractγ-ray bursts (GRBs) are short-lived transients releasing a large amount of energy (1051 − 1053 erg) in the keV-MeV energy range. GRBs are thought to originate from internal dissipation of the energy carried by ultra-relativistic jets launched by the remnant of a massive star’s death or a compact binary coalescence. While thousands of GRBs have been observed over the last thirty years, we still have an incomplete understanding of where and how the radiation is generated in the jet. Here we show a relation between the spectral index and the flux found by investigating the X-ray tails of bright GRB pulses via time-resolved spectral analysis. This relation is incompatible with the long standing scenario which invokes the delayed arrival of photons from high-latitude parts of the jet. While the alternative scenarios cannot be firmly excluded, the adiabatic cooling of the emitting particles is the most plausible explanation for the discovered relation, suggesting a proton-synchrotron origin of the GRB emission.


2021 ◽  
Vol 184 ◽  
pp. 106088
Author(s):  
Jing Zhang ◽  
Haiqing Tian ◽  
Di Wang ◽  
Haijun Li ◽  
Abdul Mounem Mouazen

1986 ◽  
Vol 64 (4) ◽  
pp. 531-535 ◽  
Author(s):  
Nebojsa Duric ◽  
E. R. Seaquist

Very large array, radio-continuum observations of the edge-on spiral galaxy NGC 3079 are presented. The observations reveal that the nucleus has windlike properties and that the central region of the galaxy exhibits an unusual figure-eight morphology that shows evidence of severe depolarization and a flattening spectral index away from the nucleus. A qualitative description of a model is presented to account for the observed radio properties. It is shown that a wind-driven shock propagating away from the nucleus and focused by the ambient disk gas can give rise to the observed morphology.


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