1,342 research outputs found
Neutrinos from Gamma Ray Bursts in the IceCube and ARA Era
In this review I discuss the ultra-high energy neutrinos (UHEN) originated
from Cosmic-Rays propogation (GZK neutrinos) and from Gamma Ray Bursts (GRBs),
and discuss their detectability in kilometers scale detectors like ARA and
IceCube.
While GZK neutrinos are expected from cosmic ray interactions on the CMB, the
GRB neutrinos depend on the physics inside the sources. GRBs are predicted to
emit UHEN in the prompt and in the later 'after-glow' phase.
I discuss the constraints on the hadronic component of GRBs derived from the
search of four years of IceCube data for a prompt neutrino fux from gamma-ray
bursts (GRBs) and more in general I present the results of the search for
high-energy neutrinos interacting within the IceCube detector between 2010 and
2013.Comment: Accepted for publication in Journal of High Energy Astrophysics.
arXiv admin note: text overlap with arXiv:1407.015
The rate and luminosity function of Short GRBs
We compare the luminosity function and rate inferred from the BATSE short
hard bursts (SHBs) peak flux distribution with the redshift and luminosity
distributions of SHBs observed by Swift/HETE II. The Swift/HETE II SHB sample
is incompatible with SHB population that follows the star formation rate.
However, it is compatible with a distribution of delay times after the SFR.
This would be the case if SHBs are associated with binary neutron star mergers.
The implied SHB rates that we find range from \sim 8 to \sim
30h_{70}^3Gpc^{-3}yr^{-1}. This rate is a much higher than what was previously
estimated and, when beaming is taken into account, it is comparable to the rate
of neutron star mergers estimated from statistics of binary pulsars. If GRBs
are produced in mergers the implied rate practically guarantees detection by
LIGO II and possibly even by LIGO I, if we are lucky. Our analysis, which is
based on observed short hard burst is limited to bursts with luminosities above
10^{49}erg/sec. Weaker bursts may exist but if so they are hardly detected by
BATSE or Swift and hence their rate is very weakly constrained by current
observations. Thus the rate of mergers that lead to a detection of a
gravitational radiation signal might be even higher.Comment: Proceedings of the conference on "Gamma Ray Bursts in the Swift Era",
November 29,-December 2, Washington, D
Wide Angle X-ray Sky Monitoring for Corroborating non-Electromagnetic Cosmic Transients
Gravitational waves (GW) can be emitted from coalescing neutron star (NS) and
black hole-neutron star (BH-NS) binaries, which are thought to be the sources
of short hard gamma ray bursts (SHBs). The gamma ray fireballs seem to be
beamed into a small solid angle and therefore only a fraction of detectable GW
events is expected to be observationally coincident with SHBs. Similarly
ultrahigh energy (UHE) neutrino signals associated with gamma ray bursts (GRBs)
could fail to be corroborated by prompt gamma-ray emission if the latter is
beamed in a narrower cone than the neutrinos. Alternative ways to corroborate
non-electromagnetic signals from coalescing neutron stars are therefore all the
more desirable. It is noted here that the extended X-ray tails (XRT) of SHBs
are similar to X-ray flashes (XRFs), and that both can be attributed to an
off-axis line of sight and thus span a larger solid angle than the hard
emission. It is proposed that a higher fraction of detectable GW events may be
coincident with XRF/XRT than with hard gamma-rays, thereby enhancing the
possibility to detect it as a GW or neutrino source. Scattered gamma-rays,
which may subtend a much larger solid angle that the primary gamma ray jet, are
also candidates for corroborating non-electromagnetic signals.Comment: 13 pages, accepted for publication in Astrophysical Journal Letter
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