Astronomy and Astrophysics – Astrophysics
Scientific paper
1997-07-04
Astrophys.J.486:L71,1997
Astronomy and Astrophysics
Astrophysics
ApJ Lett. in press, very minor change just making clear that the predicted rate-density evolution is in a comoving sense. (Rec
Scientific paper
10.1086/310853
Evolution of the rate density of cosmological gamma-ray bursts (GRBs) is calculated and compared to the BATSE brightness distribution in the context of binary neutron-star mergers as the source of GRBs, taking account of the realistic star formation history in the universe and evolution of compact binary systems. We tried two models of the evolution of cosmic star formation rate (SFR): one is based on recent observations of SFRs at high redshifts, while the other is based on a galaxy evolution model of stellar population synthesis that reproduces the present-day colors of galaxies. It is shown that the binary merger scenario of GRBs naturally results in the comoving rate-density evolution of \propto (1+z)^{2-2.5} up to z ~ 1, that has been suggested independently from the compatibility between the number-brightness distribution and duration-brightness correlation. If the cosmic SFR has its peak at z ~ 1--2 as suggested by recent observations, the effective power-index of GRB photon spectrum, \alpha >~ 1.5$ is favored, that is softer than the recent observational determination of \alpha = 1.1 \pm 0.3. However, high redshift starbursts (z >~ 5) in elliptical galaxies, that have not yet been detected, can alleviate this discrepancy. The redshift of GRB970508 is likely about 2, just below the upper limit that is recently determined, and the absorption system at z = 0.835 seems not to be the site of the GRB.
No associations
LandOfFree
Cosmological Gamma-Ray Bursts and Evolution of Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Cosmological Gamma-Ray Bursts and Evolution of Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cosmological Gamma-Ray Bursts and Evolution of Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-294671