High-Energy Spectral Components in Gamma-Ray Burst Afterglows

By Bing Zhang, P. Mészáros. 2001

195 citations recorded by the source corpus.

We investigate two high-energy radiation mechanisms, the proton-synchrotron and the electron inverse Compton emission, and explore their possible signatures in the broadband spectra and in the keV-GeV light curves of gamma-ray burst afterglows. We develop a simple analytical approach, also allowing for the effects of photon-photon pair production, and explore the conditions under which one or the other of these components dominates. We identify three parameter-space regions in which different spectral components dominate: (1) a region where the proton-synchrotron and other hadron-related emission components dominate, which is small; (2) a region in which the electron inverse Compton component dominates, which is substantial; and (3) a third substantial region in which electron-synchrotron emission dominates. We discuss the prospects and astrophysical implications of directly detecting the inverse Compton and the proton high-energy components in various bands, in particular, in the GeV band, with future missions such as the Gamma-Ray Large Area Space Telescope (GLAST) and in the X-ray band with Chandra. We find that regime II parameter space is the most favorable regime for high-energy emission. The inverse Compton component is detectable by GLAST within hours for bursts at typical cosmological distances and by Chandra within days if the ambient density is high.

Subfields: Astronomy and Astrophysics, Pulmonary and Respiratory Medicine

View Paper: https://www.semanticscholar.org/paper/743bba3d11d49206b1e1046ed562d405a4951668

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In Astronomy and Astrophysics

1. Bing Zhang
2. Pawan Kumar
3. E. Liang
4. A. Pe’er
5. E. Nakar
6. Binbin Zhang
7. Xuefeng Wu
8. P. Mészáros

In Pulmonary and Respiratory Medicine

1. E. Nakar
2. Bing Zhang
3. Pawan Kumar
4. P. Mészáros
5. Xuefeng Wu
6. He Gao
7. F. Ryde
8. A. Pe’er

Citations in the corpus

• An Analysis of Gamma-Ray Burst Spectral Break Models (2002, background): “First, ǫB/ǫe ≪ 1 is generally required to achieve a prominent IC component (Zhang & Mészáros 2001 and references therein).”
• On the generation of high-energy photons detected by the Fermi Satellite from gamma-ray bursts (2009, background): “…or of an external origin e.g. Meszaros & Rees (1994), Pilla & Loeb (1998), Dermer et al. (2000), Sari & Esin (2001), Wang et al. (2001a, 2001b), Zhang & Meszaros (2001), Granot & Guetta (2003), Guetta & Granot (2003), Piran et al. (2004), Beloborodov (2005), Fan et al. (2005 & 2008), Fan &…”
• Gamma-Ray Bursts in the Swift Era (2007, methodology): “Such a possibility is valid for thecentral engines invoking a spinning-down pulsar (Dai & Lu 1998a, b; Zhang & Mészáros 2001a) or a long-lasting BH-torus system (MacFadyen et al. 2001).”
• FERMI OBSERVATIONS OF GRB 090510: A SHORT–HARD GAMMA-RAY BURST WITH AN ADDITIONAL, HARD POWER-LAW COMPONENT FROM 10 keV TO GeV ENERGIES (2010, background): “The SSC component is stronger for a large ratio of nonthermal electron to magnetic-field energy density, as expressed by the condition ǫe ≫ ǫB (Sari & Esin 2001; Zhang & Mészáros 2001), and also when the GRB has a lower bulk Lorentz factor for an external shock origin.”
• Theories of Gamma-Ray Bursts (2001, background): “Other ways to get a lightcurve bump after ∼ days is through microlensing (Garnavich, Loeb & Stanek 2000), late injection (Zhang & Mészáros 2001a), or inverse Compton effects (Zhang & Mészáros 2001b,Harrison et al. 2001).”
• Short-hard gamma-ray bursts (2007, methodology): “…radiation also upscatter synchrotron photons by the inverse Compton process (synchrotron self-Compton - SSC; e.g., Mészáros, Rees & Papathanassiou 1994; Waxman 1997c; Wei & Lu 1998, 2000; Panaitescu & Kumar 2000; Dermer, Chiang & Mitman 2000; Sari & Esin 2001; Zhang & Mészáros 2001b).”
• A COMPREHENSIVE ANALYSIS OF FERMI GAMMA-RAY BURST DATA. I. SPECTRAL COMPONENTS AND THE POSSIBLE PHYSICAL ORIGINS OF LAT/GBM GRBs (2010, background): “…afterglow parameters, the GeV afterglow is initially dominated by the synchrotron self-Compton component (Mészáros & Rees 1994; Dermer et al. 2000; Zhang & Mészáros 2001; Wei & Fan 2007; Gou & Mészáros 2007; Galli & Piro 2007; Yu et al. 2007; Fan et al. 2008), or by other IC processes…”
• A complete reference of the analytical synchrotron external shock models of gamma-ray bursts (2013, methodology): “The energy injection effect becomes significant when Einj > Eimp, where Eimp is the impulsively injected energy during the prompt emission phase (Zhang and Mészáros, 2001a).”
• The physics of gamma-ray bursts & relativistic jets (2014, background): “Two types of widely discussed central engines satisfy these requirements: a hyper-accreting stellar-mass black hole (Woosley, 1993; Popham et al., 1999; Lee et al., 2000; Narayan et al., 2001; Di Matteo et al., 2002; Wang et al., 2002; McKinney, 2005; Uzdensky and MacFadyen, 2006; Chen and Beloborod”