Accepted for publication in Reviews of Modern Physics
astro-ph/0405503
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THE PHYSICS OF GAMMA-RAY BURSTS
Tsvi Piran *
Racah Institute for
Physics,
The Hebrew University, Jerusalem, 91904, Israel
tsvi@phys.huji.ac.il
Abstract.
Gamma-Ray Bursts (GRBs), short and intense pulses of low energy
-rays, have
fascinated astronomers and astrophysicists since their
unexpected discovery in the late sixties. During the last decade,
several space missions: BATSE (Burst and Transient Source
Experiment) on Compton Gamma-Ray Observatory, BeppoSAX and now
HETE II (High-Energy Transient Explorer), together with ground
optical, infrared and radio observatories have revolutionized our
understanding of GRBs showing that they are cosmological, that
they are accompanied by long lasting afterglows and that they are
associated with core collapse Supernovae. At the same time a
theoretical understanding has emerged in the form of the fireball
internal-external shocks model. According to this model GRBs are
produced when the kinetic energy of an ultra-relativistic flow is
dissipated in internal collisions. The afterglow arises when the
flow is slowed down by shocks with the surrounding circum-burst
matter. This model has numerous successful predictions like the
prediction of the afterglow itself, the prediction of jet breaks
in the afterglow light curve and of an optical flash that
accompanies the GRBs themselves. In this review I focus on
theoretical aspects and on physical processes believed to take
place in GRBs.
Table of Contents
INTRODUCTION
- OBSERVATIONS
- Prompt Emission
- The Afterglow
- Hosts and Distribution
- Energetics
- THE GLOBAL PICTURE - GENERALLY ACCEPTED INGREDIENTS
- RELATIVISTIC EFFECTS
- Compactness and relativistic motion
- Relativistic time effects
- Relativistic Beaming and the Patchy Shell Model
- PHYSICAL PROCESSES
- Relativistic Shocks
- Particle Acceleration
- Synchrotron
- Inverse Compton
- Quasi-Thermal Comptonization
- Polarization from Relativistically Moving Sources
- THE GRB AND THE PROMPT EMISSION
- Internal vs. External Shocks
- Internal Shocks
- External Shocks
- The Transition from Internal Shocks to External
Shocks
- Prompt Polarization
- THE AFTERGLOW
- Relativistic Blast Waves and the Blandford-McKee
solution
- Light Curves for the "Standard" Adiabatic Synchrotron
Model
- Light Curves for the early radiative phase
- Light Curve During the Newtonian transition
- Generalizations: I. Winds
- Generalizations: II. Energy injection and refreshed
shocks
- Generalizations: III. Inhomogeneous density
profiles
- Generalizations: IV. Jets
- Generalizations: V. Angular Dependent Jets and the
Structured Jet Model
- Afterglow Polarization - a tool that distinguished
between the different jet models
- Orphan Afterglows
- Generalizations: VI. Additional Physical
Processes
- ADDITIONAL EMISSION FROM GRBs
- TeV -rays
- Neutrinos
- Cosmic Rays and Ultra High Energy Cosmic Rays
- Gravitational Radiation
- MODELS OF INNER ENGINES
- Black hole accretion
- The Pulsar Model
- Rotating black holes and the Blandford Znajek
mechanism
- The Collapsar Model
- The Supranova Model
- Merging neutron stars
- OPEN QUESTIONS AND FUTURE PROSPECTS
- REFERENCES
* Electronic address:
tsvi@phys.huji.ac.il
