An Analysis of Gamma-Ray Burst Spectral Break Models

By Bing Zhang, P. Mészáros. 2002

232 citations recorded by the source corpus.

Typical γ-ray burst (GRB) spectra are characterized by a spectral break Ep, which for bright BATSE bursts is found to be narrowly clustered around 300 keV. Recently identified X-ray flashes, which may account for a significant portion of the whole GRB population, seem to extend the Ep distribution to a broader range below 40 keV. Positive correlations among Ep and some other observed parameters have been noticed. On the other hand, within the cosmological fireball model, the issues concerning the dominant energy ingredient of the fireball as well as the location of the GRB emission site are still unsettled, leading to several variants of the fireball model. Here we analyze these models within a unified framework and critically reexamine the Ep predictions in the various model variants. Attention is focused on the predictions of the narrowness of the Ep distribution in different models and the correlations among Ep and other measurable observables. These model properties can be tested against the current and upcoming GRB data, through which the nature of the fireball as well as the mechanism and site of the GRB emission will be identified. In view of the current data, various models are appraised through a simple Monte Carlo simulation, and a tentative discussion about the possible nature of X-ray flashes is presented.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/23f6be515e7d33389b318ae3347e464287d77708

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In Astronomy and Astrophysics

1. Bing Zhang
2. Pawan Kumar
3. B. Metzger
4. E. Liang
5. Binbin Zhang
6. E. Quataert
7. E. Berger
8. A. Pe’er

In Instrumentation

1. Bing Zhang
2. E. Liang
3. Pawan Kumar
4. Huirong Yan
5. L. Amati
6. Binbin Zhang
7. Federico Frontera
8. D. Burrows

Citations in the corpus

• EVIDENCE OF AN INITIALLY MAGNETICALLY DOMINATED OUTFLOW IN GRB 080916C (2009, background): “It has been suggested (Zhang & Mészáros 2002; Daigne & Mochkovitch 2002) that the photosphere thermal component can be much dimmer if the outflow is Poynting flux dominated.”
• Is Thermal Emission in Gamma-Ray Bursts Ubiquitous? (2005, background): “For the synchrotron, internal-shock model one expects E p ∝ Γ −2 L 1/2 t −1 v (e.g. Zhang & Mészáros (2002)), where t v is the typical variability time scale.”
• Swift Observations of GRB 070110: An Extraordinary X-Ray Afterglow Powered by the Central Engine (2007, background): “A long-lasting energy injection into the forward shock, due either to a late internal activity or to a radial distribution of Lorentz factors, has been invoked to interpret the shallower stage of the X-ray light curve (Rees & Meszaros 1998; Zhang & Mészáros 2002b; Granot & Kumar 2006).”
• The physics of gamma-ray bursts & relativistic jets (2014, methodology): “…2007) whereas sharper features in lightcurves might be due to energy injection from the central engine (Katz et al., 1998; Kumar and Piran, 2000b; Zhang and Mészáros, 2002c; Granot et al., 2003), angular fluctuations in energy per unit solid angle (Kumar and Piran, 2000a; Yamazaki et al.,…”
• The Ep,i–Eiso correlation in gamma-ray bursts: updated observational status, re-analysis and main implications (2006, background): “…which is currently the subject of many theoretical works, is that a substantial contribution to prompt radiation of GRBs comes from direct or Comptonized thermal emission from the photosphere of the fireball (Zhang & Mészáros 2002; Ryde 2005; Rees & Meśzaŕos 2005; Ramirez–Ruiz 2005).”
• THE INTERNAL-COLLISION-INDUCED MAGNETIC RECONNECTION AND TURBULENCE (ICMART) MODEL OF GAMMA-RAY BURSTS (2010, methodology): “(2), this suggests that GRBs all share a similar Lorentz factor regardless of their luminosities (Zhang and Mészáros 2002a).”
• Neutrinos from individual gamma-ray bursts in the BATSE catalog (2003, background): “In this case, the γ-ray luminosity of long duration bursts, and, therefore, the distance, can be estimated by assuming a relationship between the observed variability and the luminosity of a GRB (Lloyd-Ronning & Ramierz-Ruiz 2002; Zhang & Meszaros 2002; Kobayashi, Ryde & MacFadyen 2002).”
• Making a Short Gamma-Ray Burst from a Long One: Implications for the Nature of GRB 060614 (2006, background): “For example, in the internal shock synchrotron model, such a relation could be roughly reproduced if the Lorentz factors of various bursts do not vary significantly (e.g. Zhang & Mészáros 2002).”
• Gamma Ray Bursts in the Afterglow Era (2003, background): “A discussion on the possible interpretations of the above relation is given by Zhang and Mészáros (2002) within the internal and external shock scenario.”
• Physical Processes Shaping Gamma-Ray Burst X-Ray Afterglow Light Curves: Theoretical Implications from the Swift X-Ray Telescope Observations (2005, background): “Such an injection also happens if the central engine further ejects highshells that catch up with the decelerating blast wave (Zhang & Mészáros 2002a).”
• Measuring the cosmological parameters with the Ep,i–Eiso correlation of gamma-ray bursts (2008, methodology): “This value is also predicted by several theoretical models, involving in various forms synchrotron, inverse Compton, thermal and Comptonised thermal emissions; see, e.g., Zhang & Mészáros (2002); Thompson et al. (2007).”
• Model-independent Multivariable Gamma-Ray Burst Luminosity Indicator and Its Possible Cosmological Implications (2005, methodology): “…stars rotate more rapidly, and the GRBs they produce are more energetic and have more collimated jets, MacFadyen & Woosley 1999; Ramirez-Ruiz et al. 2002) or may be simply a manifestation of the viewing angle effect in a structuredjet scenario (Rossi et al. 2002; Zhang & Mészáros 2002b).”
• CONSTRAINING GAMMA-RAY BURST INITIAL LORENTZ FACTOR WITH THE AFTERGLOW ONSET FEATURE AND DISCOVERY OF A TIGHT Γ0–Eγ,iso CORRELATION (2009, methodology): “However, all the prompt GRB emission models predict Ep as a function of both Eγ,iso (or Lγ,iso) and Γ0 (e.g. Table 1 of Zhang & Mészáros 2002).”
• Gamma-Ray Bursts in the Swift Era (2007, methodology): “…external shock related processes, such as refreshedshocks, density fluctuation, inhomogeneous jets, or multiple component jets (Panaitescu et al. 1998; Zhang & Mészáros 2002a; Lazzati et al. 2002; Heyl & Perna 2003; Nakar et al. 2003; Berger et al. 2003a; Granot et al. 2003; Ioka et al. 2005).”
• The Proto-Magnetar Model for Gamma-Ray Bursts (2010, background): “Although a slowlyevolving peak energy could in principle be recovered by invoking e.g. time-dependent microphysical parameters, fine tuning appears unavoidable (e.g. Zhang & Mészáros 2002). c© ????”
• DISCERNING THE PHYSICAL ORIGINS OF COSMOLOGICAL GAMMA-RAY BURSTS BASED ON MULTIPLE OBSERVATIONAL CRITERIA: THE CASES OF z = 6.7 GRB 080913, z = 8.2 GRB 090423, AND SOME SHORT/HARD GRBs (2009, methodology): “The spectral peak energy, Ep, can be related to the GRB emission model parameters more directly, although modeldependent (Zhang & Mészáros 2002a).”