Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userSwifts GRB GRB071010B : outlier of the $rm E^{src}_{peak} - E_{gamma}$ and ${rm E_{iso}-E^{src}_{peak}-t^{src}_{jet}}$ correlations
439
0
0.0
(
0
)
Authors
Yuji Urata
Ask ChatGPT about the research
No Arabic abstract
We present multi-band results for GRB071010B based on Swift, Suzaku, and ground-based optical observations. This burst is an ideal target to evaluate the robustness of the ${rm E^{src}_{peak}-E_{iso}}$ and ${rm E^{src}_{peak}-E_{gamma}}$ relations, whose studies have been in stagnation due to the lack of the combined estimation of $rm E^{src}_{peak}$ and long term optical monitoring. The joint prompt spectral fitting using Swift/Burst Alert Telescope and Suzaku/Wide-band All sky Monitor data yielded the spectral peak energy as E$^{src}_{peak}$ of $86.5^{+6.4}_{-6.3}$ keV and E$_{iso}$ of $2.25^{+0.19}_{-0.16}times10^{52}$ erg with $z=0.947$. The optical afterglow light curve is well fitted by a simple power law with temporal index $alpha=-0.60pm0.02$. The lower limit of temporal break in the optical light curve is 9.8 days. Our multi-wavelength analysis reveals that GRB071010B follows ${rm E^{src}_{peak}-E_{iso}}$ but violates the ${rm E^{src}_{peak}-E_{gamma}}$ and ${rm E_{iso}-E^{src}_{peak}-t^{src}_{jet}}$ at more than the 3$sigma$ level.
rate research
Read More
The comprehensive statistical analysis of Swift X-ray light-curves, collecting data from six years of operation, revealed the existence of a universal scaling among the isotropic energy emitted in the rest frame 10-10^4 keV energy band during the prompt emission (E_{gamma,iso}), the peak of the prompt emission energy spectrum (E_{pk}), and the X-ray energy emitted in the 0.3-10 keV observed energy band (E_{X,iso}). In this paper we show that this three-parameter correlation is robust and does not depend on our definition of E_{X,iso}. It is shared by long, short, and low-energetic GRBs, differently from the well-known E_{gamma,iso}-E_{pk} correlation. We speculate that the ultimate physical property that regulates the GRB properties is the outflow Lorentz factor.
The grand unified group $E_6$~is a predictive scheme for physics beyond the standard model (SM). It offers the possibility of extra $Z$ bosons, new vector-like fermions, sterile neutrinos, and neutral scalars in addition to the SM Higgs boson. Some previous discussions of these features are updated and extended. Their relevance to present searches at the CERN Large Hadron Collider and in patterns of neutrino masses is noted. Addition of a small set of scalar bosons at the TeV scale permits gauge unification near a scale of $10^{16}$ GeV, and leads to bounds on masses of particles beyond those in the standard model.
We present a new measurement of $E_{rm G}$, which combines measurements of weak gravitational lensing, real-space galaxy clustering and redshift space distortions. This statistic was proposed as a consistency test of General Relativity (GR) that is insensitive to linear, deterministic galaxy bias and the matter clustering amplitude. We combine deep imaging data from KiDS with overlapping spectroscopy from 2dFLenS, BOSS DR12 and GAMA and find $E_{rm G}(overline{z}=0.267)=0.43 pm 0.13$ (GAMA), $E_{rm G}(overline{z}=0.305)=0.27 pm 0.08$ (LOWZ+2dFLOZ) and $E_{rm G}(overline{z}=0.554)=0.26 pm 0.07$ (CMASS+2dFHIZ). We demonstrate that the existing tension in the value of the matter density parameter hinders the robustness of this statistic as solely a test of GR. We find that our $E_{rm G}$ measurements, as well as existing ones in the literature, favour a lower matter density cosmology than the Cosmic Microwave Background. For a flat $Lambda$CDM Universe and assuming GR, we find $Omega_{rm m}(z=0)=0.25pm0.03$. With this paper we publicly release the 2dFLenS dataset at: url{http://2dflens.swin.edu.au}.
We report new measurements of the neutron charge form factor at low momentum transfer using quasielastic electrodisintegration of the deuteron. Longitudinally polarized electrons at an energy of 850 MeV were scattered from an isotopically pure, highly polarized deuterium gas target. The scattered electrons and coincident neutrons were measured by the Bates Large Acceptance Spectrometer Toroid (BLAST) detector. The neutron form factor ratio $G^{n}_{E}/G^{n}_{M}$ was extracted from the beam-target vector asymmetry $A_{ed}^{V}$ at four-momentum transfers $Q^{2}=0.14$, 0.20, 0.29 and 0.42 (GeV/c)$^{2}$.
We examine the two-point correlation function of local maxima in temperature fluctuations at the last scattering surface when this stochastic field is modified by the additional fluctuations produced by straight cosmic strings via the Kaiser-Stebbins effect. We demonstrate that one can detect the imprint of cosmic strings with tension $Gmu gtrsim 1.2 times 10^{-8}$ on noiseless $1^prime$ resolution cosmic microwave background (CMB) maps at 95% confidence interval. Including the effects of foregrounds and anticipated systematic errors increases the lower bound to $Gmu gtrsim 9.0times 10^{-8}$ at $2sigma$ confidence level. Smearing by beams of order 4 degrades the bound further to $Gmu gtrsim 1.6 times 10^{-7}$. Our results indicate that two-point statistics are more powerful than 1-point statistics (e.g. number counts) for identifying the non-Gaussianity in the CMB due to straight cosmic strings.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
