3,089 research outputs found
Magnetic Fields and Afterglows of BdHNe: Inferences from GRB 130427A, GRB 160509A, GRB 160625B, GRB 180728A and GRB 190114C
GRB 190114C is the first binary-driven hypernova (BdHN) fully observed from
the initial supernova appearance to the final emergence of the optical SN
signal. It offers an unprecedented testing ground for the BdHN theory and it is
here determined and further extended to additional gamma-ray bursts (GRBs).
BdHNe comprise two subclasses of long GRBs with progenitors a binary system
composed of a carbon-oxygen star (CO) and a neutron star (NS)
companion. The CO explodes as a SN leaving at its center a
newborn NS (NS). The SN ejecta hypercritically accretes both on the
NS and the NS companion. BdHNe I are the tightest binaries where the
accretion leads the companion NS to gravitational collapse into a black hole
(BH). In BdHN II the accretion onto the NS is lower, so there is no BH
formation. We observe the same structure of the afterglow for GRB 190114C and
other selected examples of BdHNe I (GRB 130427A, GRB 160509A, GRB 160625B) and
for BdHN II (GRB 180728A). In all the cases the explanation of the afterglow is
reached via the synchrotron emission powered by the NS: their magnetic
fields structures and their spin are determined. For BdHNe I, we discuss the
properties of the magnetic field embedding the newborn BH, inherited from the
collapsed NS and amplified during the gravitational collapse process, and
surrounded by the SN ejecta.Comment: 7 figures, 3 tables, submitted to Ap
Exponential inequalities for positive linear mappings
In this article, we present exponential-type inequalities for positive linear
mappings and Hilbert space operators, by means of convexity and the Mond-Pe\v
cari\'c method. The obtained results refine and generalize some known results.
As an application, we present extensions for operator-like geometric and
harmonic means
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