GRB Afterglows with Energy Injection from a spinning down NS

Details GRB Afterglows with Energy Injection from a spinning down NS GRB Afterglows with Energy Injection from a spinning down NS

2010-04-16

arxiv.org/abs/1004.2788v1

Astronomy and Astrophysics

Astrophysics

High Energy Astrophysical Phenomena

7 pages, 2 figures, submitted to Astronomy & Astrophysics - referee's comments included

Scientific paper

We investigate a model for the shallow decay phases of Gamma-ray Burst (GRB) afterglows discovered by Swift/XRT in the first hours following a GRB event. In the context of the fireball scenario, we consider the possibility that long-lived energy injection from a millisecond spinning, ultramagnetic neutron star (magnetar) powers afterglow emission during this phase. We consider the energy evolution in a relativistic shock subject to both radiative losses and energy injection from a spinning down magnetar in spherical symmetry. We model the energy injection term through magnetic dipole losses and discuss an approximate treatment for the dynamical evolution of the blastwave. We obtain an analytic solution for the energy evolution in the shock and associated lightcurves. To fully illustrate the potential of our solution we calculate lightcurves for a few selected X-ray afterglows observed by Swift and fit them using our theoretical lightcurves. Our solution naturally describes in a single picture the properties of the shallow decay phase and the transition to the so-called normal decay phase. In particular, we obtain remarkably good fits to X-ray afterglows for plausible parameters of the magnetar. Even though approximate, our treatment provides a step forward with respect to previously adopted approximations and provides additional support to the idea that a millisecond spinning (1-3 ms), ultramagnetic (B$\sim 10^{14}-10^{15}$ G) neutron star loosing spin energy through magnetic dipole radiation can explain the luminosity, durations and shapes of X-ray GRB afterglows.

Affiliated with

Also associated with

No associations

Rating

GRB Afterglows with Energy Injection from a spinning down NS 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 GRB Afterglows with Energy Injection from a spinning down NS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and GRB Afterglows with Energy Injection from a spinning down NS will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-623726