Recent Advances in our Understanding of GRB emission mechanism. Pawan Kumar. Constraints on radiation mechanisms
|
|
- Deirdre Kennedy
- 5 years ago
- Views:
Transcription
1 Recent Advances in our Understanding of GRB emission mechanism Outline Pawan Kumar Constraints on radiation mechanisms High energy emission from GRBs and our understanding of Fermi data. My goal is to generate a good discussion of this topic May 6, 2013
2 Understanding the radiation mechanism for ~10keV 10 MeV band is one of the most challenging problems in GRBs. Emission in this band lasts for <10 2 s, however it carries a good fraction of the total energy release in GRBs. And it offers the best link to the GRB central engine. Jet energy dissipation and γ-ray generation relativistic outflow central engine External shock radiation central engine jet -rays
3 Conversion of jet energy to thermal energy Internal/external shocks, magnetic reconnection etc. Piran et al. ; Rees & Meszaros; Dermer; Thompson; Lyubarsky; Blandford, Lyutikov; Spruit Radiation mechanism (sub-mev photons) Synchrotron, SSC, IC of external photon field, thermal radiation, jitter radiation Papathanassiou & Meszaros, 1996; Sari, Narayan & Piran, 1996 Liang et al. 1996; Ghisellini et al. 2000; Thompson (1994); Lazzati et al. (2000); Medvedev (2000); Meszaros & Rees Totani 1998; Paczynski & Xu 1994; Zhang & Meszaros 2001
4 GRB: current paradigm (internal shock model) Gehrels et al. (2002); Scientific American This paradigm has several problems. We don t know what replaces it though
5 GRB B: x-ray & optical LCs Distance (R s ) of γ-ray source from the center of explosion 1. Steep decline of flux at end of GRB prompt phase suggests: R s 2c 2 δt ~ cm (Lyutikov; Lazzati & Begelman; Kumar et al.) (R s can be smaller if the steep decline is due to central engine activity) 2. Prompt bright optical flash from GRBs: R s > cm (GRB B Zou, Piran & Sari 2009)) ~ t -5 (Too steep to be RS) (RS) Kumar & Panaitescu, 09 Prompt -ray emission from GRB B also suggests R s > ~ cm; Kumar & Narayan; Racusin et al Shen & Zhang (2009) provide a limit on R s from prompt optical for a number of GRBs.
6 3. Detection of high energy -ray photons by Fermi/LAT (GRB C, ) 10 3 R s = 2cΓ 2 δt cm Abdo et al. 2009; Greiner et al. 2009; Kumar & Barniol-Duran 2009 (R s is close to the deceleration radius for such a high ) > ~ > ~ R s > ~ cm is larger than expected for internal shocks ( cm) Large R s is a problem for the internal shock model; internal shocks are less efficient at larger distances. Large R s is expected for a poynting jet: Lyutikov & Blandford
7 Radiation mechanism Synchrotron, IC or SSC in internal shocks, RS or FS, or hadronic collision or photo-pion process... Meszaros & Rees 1994; Pilla & Loeb 1996; Dermer et al Wang et al & 06; Zhang & Meszaros 2001; Sari & Esin 01 Granot & Guetta 2003; Piran et al. 2004; Fan et al & 08 Beloborodov 2005; Fan & Piran 2006; Galli & Guetta 2008 Pe er et al. 06; Granot et al. 08; Bošnjak, Daigne & Dubus 09 Katz 1994; Derishev et al. 1999; Bahcall & Meszaros 2000 Dermer & Atoyan 2004; Razzaque & Meszaros 2006 Fan & Piran 2008; Gupta & Zhang 2008; Granot et al. 08; Daigne, Bošnjak & Dubus 2011
8 Let us turn to γ-ray radiation mechanism 1. Synchrotron Synchrotron peak at ~10 2 kev B i2 ~ 2x10 13 Electron cooling 6m e c(1+z) t cool = ~ (7x10 7 s) 3 i3 2 «t ~ 0.1s T B 2 i f 1/2 (or α = 1.5) which holds for only a small fraction of GRBs This is basically Ghisellini et al. (2000) argument; Sari & Piran 1997 Note: 1. Synchrotron solutions with α = 2/3 can be found for R s >10 17 cm; IC cooling in KN regime (Nakar, Ando & Sari, 2009; Bosnjak et al.) helps but not enough.. 2. It an be shown that for the Jitter process Y»10 3 ; recent PIC simulation of Sironi & Spitkovsky (2009) casts doubt on Jitter 3. Small pitch angle radiation ( < i -1 ) can give f +ve (Lloyd & Petrosian, 2000); but shock accelerations don t produce small distribution. angle between e - momentum and B
9 Continuous acceleration of electrons can fix the low energy spectral index problem. Recently Uhm & Zhang (2013) suggested an interesting idea that the magnetic field downstream of the shock front decays with distance and that can prevent synchrotron cooling and flatten the emergent spectrum to α ~ 1. The field should decay on a length scale of order ct`cool = 2x10 6 cm γ 3 i3 Γ 2 2 << R/Γ for the mechanism to work. This requires some degree of fine tuning However, if γ i ~10 5 then ct`cool ~ R/Γ, and no fine tuning is needed. This is in fact the value of γ i Uhm & Zhang considered in their work. The question then is how do you get such a large γ i in internal shocks? If 1 in 10 2 electrons are accelerated in shocks, then there should be a large population of electrons with γ e ~ 10 2 which would radiate in the optical band and produce a bright flash (~10 mag).
10 2. Synchrotron-self-Compton solutions It can be shown that for SSC solutions E e α R 3 and E B α R 4 emission must be produced within a narrow range of R (factor ~2) and that seems unlikely -- especially for the IS model. sharp minimum of E e + E B ; Kumar & Narayan (2009) There is another problem with the SSC solution: A lack of an excess in the Fermi/LAT band (100 MeV to 100 GeV), and absence of a bright optical flash severely constrains the SSC mode (e.g. Piran, Sari and Zou, 2009).
11 3. Thermal radiation + IC (for prompt -rays) Thompson (1994 & 06); Liang et al. 1997; Ghisellini & Celloti 1999; Meszaros & Rees (2001); Daigne & Mochkovitch (2002); Pe er et al. (2006), Beloborodov (2009) Observational constraints Photospheric radius ~ cm 3 3 L j53 ; so the IC of thermal radiation is expected to take place at a much smaller radius than R s ~ cm we are finding. GRB C for which there was excellent data from 8keV to ~20 GeV showed no thermal component Zhang and Pe er (2009) and that provides a severe constraint on this mechanism & baryonic jet model. Low energy spectrum should be f ν ν ν 2 which is rarely seen. The presence of a thermal component in GRB prompt emission is unclear Ryde (2004, 05) finds evidence for thermal spectrum, but Ghirlanda et al. (2007) do not. Recent work of Burgess et al. (arxiv: ) claims to see a thermal component for 5 out of 8 Fermi GRBs they analyzed.
12 Since GRB spectra are largely non-thermal, there are many different proposals as to how to modify the photospheric radiation so that the emergent spectrum is non-thermal. The basic idea behind all these proposals is to dissipate a fraction of the energy of GRB relativistic outflow & produce non-thermal seed photons, and mildly relativistic electrons (or e ± ). Seed photons are IC scattered by e ± multiple times, at the photosphere, to produce the observed non-thermal spectrum. The dissipation below the photosphere could be a result of magnetic reconnection (Meszaros & Rees) or n-p collisions (Beloborodov 2010, 2011; Meszaros & Rees, 2011).
13 Vrum, Lyubarsky and Piran (2013) derive general constraints that should be satisfied by photospheric models for GRB prompt radiation. They find that a large fraction of jet energy should be dissipated at a radius of cm and jet LF at this radius should be order a few 10s, i.e. the dissipation should take place at a high optical depth. We will consider one particular photosphere model n-p collision in some detail.
14 Photospheric model involving collisions between n & p Consider a baryonic jet consisting of n & p +. Neutrons accelerate with the fireball expansion as long as they collide frequently with protons. However, as the fireball expands p + density decreases as R 2 & the collision between n & p + becomes less frequent. Eventually at some radius (R np ) n & p + decouple & hereafter n are no longer accelerated whereas p + Lorentz factor could continue to increase with R as long as Γ(R np ) < η. The resulting differential velocity between n & p + result in their collision and conversion of a fraction of jet KE to thermal energy below the photosphere.
15 n p decoupling radius is given by ' t np R c 4R 2 npm p c 2 0 L R np c or R np 0 L 4m p c 3 2 For n p to develop differential velocity: R np < R s = R 0 η 0 L 4m p c 3 R / 485 L 4 1/ 4 51 R 0,7 Thus, GRB jets consisting of n & p & terminal Lorentz factor > 400 will undergo n p collisions below the Thomson photosphere & convert a fraction of jet kinetic energy to radiation & e ± thermal energy (Beloborodov 2010; Vurm et al & Meszaros & Rees 2011)
16 n p differential motion can also arise in internal shocks Beloborodov, 2010
17 Radius where internal collisions occur: R col = c Γ 2 δt And the radius where the probability of n-p collisions drop below 0.5 is: R np α Γ -3 R col /R np α Γ 5 For an efficient conversion of outflow kinetic energy to thermal energy via n p collisions these radii should be approximately equal, and that requires: 50 < Γ < 10 2 Which does not appear to be consistent with GRB data.
18 Meszaro & Rees (2011) added a new element to this picture n p collisions within the core of the jet, they claim, produces γ- rays of 20 MeV (higher energy γ-rays are converted to e ± since the hadronic collisions take place below the Thomson photosphere). Neutrons from the outer part of the jet which is moving more slowly diffuse inside the core region on a longer time scale, i.e. at a larger radius, and collide with protons. These collisions produce e ± which in turn produces >10 2 MeV photons. According to this picture the few second delay we see between MeV & GeV photons is due to GeV photons being produced at a larger radius.
19 Poynting jet dissipation and relativistic turbulence Meszaros & Rees 97; Lyutikov & Blandford 03 ; Narayan & Kumar 09 ; Lazar, Nakar & Piran 09; Zhang and Yan (2011) The acceleration of magnetic jets is very different from a thermal fireball: Γ α r 1/3 for Poynting jets when acceleration is driven by magnetic dissipation and also for adiabatic expansion of a short magnetic pulse, e.g. Contopoulos (1995), Drenkhahn (2002), Drenkhahn and Spruit (2002), Granot et al. (2011). While inside the star: Γ α r a/4 (p α r a ) These results are easy to understand using flux conservation, causality & pressure equilibrium
20 Example: Γ α r a/4 due to jet collimation by star (p α r a ) Consider the jet transverse radius to increase with r as R t (r). The transverse and radial components of the magnetic field, in the rest frame of the star scale as: B ϕ α R -1 t & B r α R -2 t respectively. In jet comoving frame: B ϕ α B ϕ /Γ, B r = B r & B ϕ ~ B r (to avoid magnetic pinching) Γ α R t Pressure equilibrium: B r 2 α Γ -4 α p Γ α r a/4 The fraction of magnetic energy converted to jet kinetic energy, and the fraction into radiation are still highly uncertain In magnetic dissipation/reconnection jet acceleration and radiation production are approximately equal and proceed together: γ-ray emission peaks at a radius ~ R BH σ 02 /ε; where σ 0 is jet initial magnetization parameter, and ε ~ 10 2 is the speed at which reconnection proceeds (in terms of the Alfven speed). For a Poynting jet undergoing adiabatic expansion, the radiation is produced by either reconnection, if conditions are appropriate, or by internal shocks after σ drops below unity.
21 ICMART (Internal Collision-induced Magnetic Reconnection and Turbulence) model of Zhang & Yan (2011) suggests that jet magnetic fields get increasingly more twisted in internal collisions and eventually reconnection is triggered. Relativistic turbulence is likely produced in the ICMART model, which can give rise to short time variability even at large radius from the central engine as shown by Lyutikov & Blandford 03 ; Narayan & Kumar 09 ; Lazar, Nakar & Piran 09. 1/ R s t Line of Sight Variability time = R s (1+z) (2c 2 ) t 2 Consistent solutions for -ray emission is found & R s ~ cm or larger as suggested by observations.
22 Fermi 8 KeV to 300 GeV 6/11/2008 High energy γ-rays One of the goals for Fermi is to understand γ-ray burst prompt radiation mechanism by observing high energy photons from GRBs.
23 Abdo et al >10 2 MeV photons lag <10MeV photons (2-5s) 2. >100 MeV radiation lasts for ~10 3 s whereas emission below 10 MeV lasts for ~30s or less!
24 high energy photons (>100 MeV) for t > ~ 10s are produced in the External-shock via synchrotron Gehrels, Piro & Leonard: Scientific American, Dec 2002
25 Long lived lightcurve for >10 2 MeV (Abdo et al. 2009) (GRB C) Abdo et al. 2009
26 Kumar & Barniol Duran (2009) Long lived lightcurve for >10 2 MeV (Abdo et al. 2009) >10 2 MeV data expected ES flux in the X-ray and optical band (GRB C) Abdo et al. 2009, Greiner et al. 2009, Evans et al We can then compare it with the available X-ray and optical data.
27 Or we can go in the reverse direction Kumar & Barniol Duran (2009) Assuming that the late (>1day) X-ray and optical flux are from ES, calculate the expected flux at 100 MeV at early times > 100MeV keV Optical X-ray Abdo et al. 2009, Greiner et al. 2009, Evans et al And that compares well with the available Fermi data.
28 Summary SSC is highly constrained by optical + Fermi data. Synchrotron process is very likely to contribute to the GRB prompt radiation. There are stringent limits on a thermal component for prompt γ- ray emission for some GRBs whereas at least several GRBs seem to have non-zero thermal radiation (even for these we probably need synchrotron to account for low energy index). Gamma-rays of >10 2 MeV energy, after the prompt phase, are produced in the external shock via the synchrotron process. However, their origin during the prompt phase is disputed.
High-energy emission from Gamma-Ray Bursts. Frédéric Daigne Institut d Astrophysique de Paris, Université Pierre et Marie Curie
High-energy emission from Gamma-Ray Bursts Frédéric Daigne Institut d Astrophysique de Paris, Université Pierre et Marie Curie HEPRO III High Energy Phenomena in Relativistic Outflows Barcelona, June 27
More informationAcceleration of Particles in Gamma-Ray Bursts
Acceleration of Particles in Gamma-Ray Bursts Bing Zhang Department of Physics and Astronomy University of Nevada, Las Vegas Sep. 29, 2009 In Nonlinear Processes in Astrophysical Plasma: Particle Acceleration,
More informationON GRB PHYSICS REVEALED BY FERMI/LAT
Proceedings of the 3rd Galileo Xu Guangqi Meeting International Journal of Modern Physics: Conference Series Vol. 23 (2013) 223 227 c World Scientific Publishing Company DOI: 10.1142/S2010194513011343
More informationOutline. Spectra of Fermi/LAT GRBs? Physical Origins of GeV emission? Summary
Outline Spectra of Fermi/LAT GRBs? Physical Origins of GeV emission? Summary Prompt GRB Spectra : Clear Observations for >20 years 1991-2000 BATSE Power Law Breaks (Schaefer 1992) Band function (1993)
More informationTheory of the prompt emission of Gamma-Ray Bursts
Theory of the prompt emission of Gamma-Ray Bursts Department of Physics, NC State University, Raleigh, NC 27695-8202 E-mail: davide_lazzati@ncsu.edu Since their discovery more than 40 years ago the origin
More informationSingle- and Two-Component GRB Spectra in the Fermi GBM-LAT Energy Range
Single- and Two-Component GRB Spectra in the Fermi GBM-LAT Energy Range Péter Veres and Péter Mészáros Dept. of Astronomy & Astrophysics, Dept. of Physics and Center for Particle Astrophysics Pennsylvania
More informationLecture 2 Relativistic Shocks in GRBs 2
Lecture 2 Relativistic Shocks in GRBs 2 Shiho Kobayashi (Liverpool JMU) We have discussed a blast wave. the dynamics: simple: single parameter E /" Blast wave model: applicable to any central engine model
More informationGamma-Ray Burst Afterglow
Gamma-Ray Burst Afterglow Bing Zhang Department of Physics and Astronomy University of Nevada Las Vegas May 29, 2009, KIAA-PKU Lecture series GRB overview Very general overview of the GRB field to general
More informationarxiv:astro-ph/ v1 7 Jul 1999
Gamma-ray Burst Energetics Pawan Kumar Institute for Advanced Study, Princeton, NJ 08540 Abstract arxiv:astro-ph/9907096v1 7 Jul 1999 We estimate the fraction of the total energy in a Gamma-Ray Burst (GRB)
More informationGammaray burst spectral evolution in the internal shock model: comparison with the observations
Gammaray burst spectral evolution in the internal shock model: comparison with the observations Ž. Bošnjak, F. Daigne, and G. Dubus Citation: AIP Conference Proceedings 1358, 59 (2011); doi: 10.1063/1.3621737
More informationRadiative processes in GRB (prompt) emission. Asaf Pe er (STScI)
Radiative processes in GRB (prompt) emission Asaf Pe er (STScI) May 2009 Outline Historical approach Synchrotron: pro s and co s Compton scattering in prompt emission (and why it is different than in afterglow)
More informationAfterglows Theory Re em Sari - Caltech
Π= Π m /3 Afterglows Theory Re em Sari - Caltech 30s 2h t -2 30m t +1/2 t Rising -1 spectrum ν 1/3 1d t -2.2 100d t -1.5 Gamma-Ray Burst: 4 Stages 1) Compact Source, E>10 51 erg 2) Relativistic Kinetic
More informationarxiv: v3 [astro-ph.he] 29 Jan 2013
Constraining the Bulk Lorentz Factor of GRB Outflow in the Magnetic-dominated Jet Model Zhe Chang 1,2,, Hai-Nan Lin 1,, Yunguo Jiang 1,2, arxiv:1205.3572v3 [astro-ph.he] 29 Jan 2013 1 Institute of High
More informationGRB emission models and multiwavelength properties
GRB emission models and multiwavelength properties Gabriele Ghisellini INAF-Osservatorio Astronomico di Brera - Italy with the help of: Z. Bosniak, D. Burlon, A. Celotti, C. Firmani, G. Ghirlanda, D. Lazzati,
More informationThe connection between thermal and non-thermal emission in gamma-ray bursts: general considerations and GRB B as a case study
Mon. Not. R. Astron. Soc. 420, 468 482 (2012) doi:10.1111/j.1365-2966.2011.20052.x The connection between thermal and non-thermal emission in gamma-ray bursts: general considerations and GRB 090902B as
More informationGRB : Modeling of Multiwavelength Data
GRB 090510: Modeling of Multiwavelength Data Soeb Razzaque NRC-NRL, Washington, DC Gamma Ray Bursts Workshop, Nov 8-12, GSFC Detection of GRB 090510 Fermi GBM and LAT observations Trigger on 2009 May 10
More informationarxiv: v1 [astro-ph.he] 11 Mar 2015
Shedding light on the prompt high efficiency paradox - self consistent modeling of GRB afterglows Paz Beniamini 1a, Lara Nava 1b, Rodolfo Barniol Duran 2c & Tsvi Piran 1d (a) paz.beniamini@mail.huji.ac.il;
More informationParticle acceleration at relativistic shock waves and gamma-ray bursts
Particle acceleration at relativistic shock waves and gamma-ray bursts Martin Lemoine Institut d Astrophysique de Paris CNRS, Université Pierre & Marie Curie Outline: 1. Particle acceleration and relativistic
More informationMikhail V. Medvedev (KU)
Students (at KU): Sarah Reynolds, Sriharsha Pothapragada Mikhail V. Medvedev (KU) Collaborators: Anatoly Spitkovsky (Princeton) Luis Silva and the Plasma Simulation Group (Portugal) Ken-Ichi Nishikawa
More informationarxiv: v1 [astro-ph.he] 1 Jun 2016
Mon. Not. R. Astron. Soc. 000, 1?? 00) Printed 1 November 018 MN LATEX style file v.) arxiv:1606.00311v1 [astro-ph.he] 1 Jun 016 A Revised Analysis of Gamma Ray Bursts prompt efficiencies Paz Beniamini,
More informationX-ray & γ-ray. Polarization in Gamma-Ray Bursts. Jonathan Granot. Institute for Advanced Study, Princeton
X-ray & γ-ray olarization in Gamma-Ray ursts Jonathan Granot Institute for Advanced Study, rinceton X-ray olarimetry Workshop KIAC, February 10, 2004 Outline of the Talk: Short Overview of GRs Why is GR
More informationTsvi Piran The Hebrew University
Some new (old) ideas about particle acceleration and other topics Tsvi Piran The Hebrew University Evgeny Derishev, Daniel Kagan, Ehud Nakar, Glennys Farrar Paris Sept 13-16, 2016 Outline Shock Acceleration
More informationarxiv: v1 [astro-ph.he] 18 Jun 2012 Accepted; Received; in original form 2011 December 22
Mon Not R Astron Soc 000, 000 000 (2012) Printed 20 June 2012 (MN LATEX style file v22) Inverse Compton cooling in Klein-Nishina regime and GRB prompt spectrum R Barniol Duran 1, Ž Bošnjak 2 and P Kumar
More informationGamma-ray burst prompt emission variability in synchrotron and synchrotron self-compton light curves
Mon. Not. R. Astron. Soc. 426, 1385 1395 2012) doi:10.1111/j.1365-2966.2012.21531.x Gamma-ray burst prompt emission variability in synchrotron and synchrotron self-compton light curves Lekshmi Resmi 1,2
More informationarxiv:astro-ph/ v2 26 Aug 2004
Mon. Not. R. Astron. Soc. 000, 000 000 (0000) Printed February 008 (MN LATEX style file v.) Gamma-ray burst internal shocks with magnetization arxiv:astro-ph/040758v 6 Aug 004 Y. Z. Fan,, D. M. Wei, and
More informationarxiv: v2 [astro-ph.he] 5 Jan 2016
Mon. Not. R. Astron. Soc. 000, 1?? (2002) Printed 6 January 2016 (MN LATEX style file v2.2) arxiv:1510.03873v2 [astro-ph.he] 5 Jan 2016 X-ray flares in GRBs: general considerations and photospheric origin
More informationarxiv:astro-ph/ v1 7 Apr 2001
The Inverse Compton Emission Spectra in the Very Early Afterglows of Gamma-Ray Bursts X. Y. Wang, Z. G. Dai and T. Lu Department of Astronomy, Nanjing University, Nanjing 210093, P.R.China email:xywang@nju.edu.cn;
More informationTesting an unifying view of Gamma Ray Burst afterglows
Marco Nardini Testing an unifying view of Gamma Ray Burst afterglows Gabriele Ghisellini In collaboration with Giancarlo Ghirlanda Annalisa Celotti 44th Rencontres de Moriond La Thuile (Val d'aosta, Italy)
More informationEmission Model And GRB Simulations
Emission Model And GRB Simulations Nicola Omodei (University of Siena, INFN Pisa) 1 ISSS-L Aquila 2001 N. Omodei Spectral Properties? Data collected Range (γ) 10 KeV 10 GeV In the BATSE energy range: (25
More informationarxiv: v1 [astro-ph] 17 Oct 2008
Mon. Not. R. Astron. Soc. 000, 000 000 (0000) Printed 1 November 2018 (MN LATEX style file v2.2) GeV Emission from neutron-rich internal shocks of some long Gamma-ray Bursts arxiv:0810.3130v1 [astro-ph]
More informationarxiv: v1 [astro-ph.he] 16 Jan 2013
DRAFT VERSION NOVEMBER, 018 Preprint typeset using LATEX style emulateapj v. 0/0/08 PHOTOSPHERIC EMISSION AS THE DOMINANT RADIATION MECHANISM IN LONG-DURATION GAMMA-RAY BURSTS DAVIDE LAZZATI 1, BRIAN J.
More informationarxiv:astro-ph/ v2 27 Mar 2000
The Synchrotron Spectrum of Fast Cooling Electrons Revisited Jonathan Granot 1 Tsvi Piran 1 and Re em Sari 2 jgranot@nikki.fiz.huji.ac.il tsvi@nikki.fiz.huji.ac.il sari@tapir.caltech.edu arxiv:astro-ph/0001160v2
More informationPawan Kumar Bibliography (published in peer reviewed journals)
Pawan Kumar Bibliography (published in peer reviewed journals) 1. Probing Massive Stars Around Gamma-Ray Burst Progenitors, Lu, W., Kumar, P., Smoot, G.F., accepted for publication in MNRAS 2. External
More informationTEMPORAL DECOMPOSITION STUDIES OF GRB LIGHTCURVES arxiv: v2 [astro-ph.he] 18 Feb 2013 Narayana P. Bhat 1
Title : will be set by the publisher Editors : will be set by the publisher EAS Publications Series, Vol.?, 2018 TEMPORAL DECOMPOSITION STUDIES OF GRB LIGHTCURVES arxiv:1301.4180v2 [astro-ph.he] 18 Feb
More informationHydrodynamic Evolution of GRB Afterglow
Chin. J. Astron. Astrophys. Vol. 1, No. 4, (2001) 349 356 ( http: /www.chjaa.org or http: /chjaa.bao.ac.cn ) Chinese Journal of Astronomy and Astrophysics Hydrodynamic Evolution of GRB Afterglow Ji-Rong
More informationRosalba Perna. (Stony Brook University)
Rosalba Perna (Stony Brook University) Swift observations opened a new window Pre-Swift Pre-Swift Pre-Swift belief belief. of surprises.with PLATEAUS & FLARES [figure courtesy of R. Mockovitch] PLATEAUS
More informationVariability in GRBs - A Clue
arxiv:astro-ph/9701002v1 1 Jan 1997 Variability in GRBs - A Clue Re em Sari Tsvi Piran August 10, 2018 Abstract We show that external shocks cannot produce a variable GRB, unless they are produced by an
More informationPulsar Winds. John Kirk. Max-Planck-Institut für Kernphysik Heidelberg, Germany. < > p.1/18
Pulsar Winds John Kirk Max-Planck-Institut für Kernphysik Heidelberg, Germany < > p.1/18 About 50 years after... The Crab Nebula Central star is source of particles and magnetic field (Piddington 1957)
More informationarxiv:astro-ph/ v3 9 Jul 2001
Afterglow Emission from Highly Collimated Jets with Flat Electron Spectra: Application to the GRB 010222 Case? arxiv:astro-ph/0105055v3 9 Jul 2001 Z. G. Dai 1 and K. S. Cheng 2 1 Department of Astronomy,
More informationHard X-ray emission from Novae
Hard X-ray emission from Novae Indrek Vurm (Columbia University) in collaboration with: Brian D. Metzger, Andrei M. Beloborodov (Columbia) Koji Mukai (NASA) Shocks and Particle Acceleration in Novae and
More informationTheories of multiwavelength emission from Gamma-Ray Bursts: Prompt to afterglow
Theories of multiwavelength emission from Gamma-Ray Bursts: Prompt to afterglow Dept. of Physics, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa E-mail: srazzaque@uj.ac.za Gamma-Ray
More informationEARLY OPTICAL AFTERGLOW LIGHT CURVES OF NEUTRON-FED GAMMA-RAY BURSTS
The Astrophysical Journal, 628:298 314, 2005 July 20 # 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A. EARLY OPTICAL AFTERGLOW LIGHT CURVES OF NEUTRON-FED GAMMA-RAY BURSTS
More informationGamma Ray Burst Jets: Predictions and Observations. James E. Rhoads Space Telescope Science Institute
Gamma Ray Burst Jets: Predictions and Observations James E. Rhoads Space Telescope Science Institute Motivation Burst energy requirements and event rates scale linearly with collimation solid angle. With
More informationObserving GRB afterglows with SIMBOL-X
Observing GRB afterglows with SIMBOL-X Frédéric Daigne (daigne@iap.fr) (Institut d Astrophysique de Paris - Université Paris 6) Gamma-ray bursts : prompt emission Highly variable time profile Non-thermal
More informationRosalba Perna. (University of
Rosalba Perna (University of Colorado@Boulder) Swift observations opened a new window Pre-Swift Pre-Swift Pre-Swift belief belief belief [figure courtesy of R. Mockovitch]. of surprises.with PLATEAUS &
More information1. GAMMA-RAY BURSTS & 2. FAST RADIO BURSTS
1. GAMMA-RAY BURSTS & 2. FAST RADIO BURSTS WITH TAM, Pak Hin (Sun Yat-sen University/ICRR) GAMMA-RAY BURST OBSERVATIONS WITH CTA LESSONS LEARNT FROM FERMI/LAT TAM, Pak Hin (Sun Yat-sen University/ICRR,
More informationDistribution of Gamma-ray Burst Ejecta Energy with Lorentz Factor
Distribution of Gamma-ray Burst Ejecta Energy with Lorentz Factor Jonathan Granot KIPAC, P.O. Box 20450, Mail Stop 29, Stanford, CA 94309 Pawan Kumar Department of Astronomy, University of Texas, Austin,
More informationarxiv: v2 [astro-ph.he] 19 Jul 2016
Draft version July 21, 216 Preprint typeset using L A TEX style emulateapj v. 5/2/11 MONTE CARLO RADIATION TRANSFER SIMULATIONS OF PHOTOSPHERIC EMISSION IN LONG-DURATION GAMMA-RAY BURSTS Davide Lazzati
More informationarxiv:astro-ph/ v1 6 Jun 1996
Submitted to Ap.J.(Lett.), 5/31/96 OPTICAL AND LONG WAVELENGTH AFTERGLOW FROM GAMMA-RAY BURSTS arxiv:astro-ph/9606043v1 6 Jun 1996 P. Mészáros 1 525 Davey Laboratory, Pennsylvania State University, University
More informationDiversity of Multi-wavelength Behavior of Relativistic Jet in 3C 279 Discovered During the Fermi Era
Diversity of Multi-wavelength Behavior of Relativistic Jet in 3C 279 Discovered During the Fermi Era Rapid Variability of Blazar 3C 279 during Flaring States in 2013-2014 with Joint Fermi-LAT, NuSTAR,
More informationShallow Decay of X-ray Afterglows in Short GRBs: Energy Injection from a Millisecond Magnetar?
Chin. J. Astron. Astrophys. Vol. 7 2007), No. 5, 669 674 http://www.chjaa.org) Chinese Journal of Astronomy and Astrophysics Shallow Decay of X-ray Afterglows in Short GRBs: Energy Injection from a Millisecond
More informationarxiv:astro-ph/ v1 1 Mar 1999
A Possible Explanation for the Radio Flare in the Early Afterglow of GRB990123 Xiangdong Shi and Geza Gyuk arxiv:astro-ph/9903023v1 1 Mar 1999 Department of Physics, University of California, San Diego,
More informationOn (shock. shock) acceleration. Martin Lemoine. Institut d Astrophysique d. CNRS, Université Pierre & Marie Curie
On (shock ( shock) acceleration of ultrahigh energy cosmic rays Martin Lemoine Institut d Astrophysique d de Paris CNRS, Université Pierre & Marie Curie 1 Acceleration Hillas criterion log 10 (B/1 G) 15
More informationarxiv:astro-ph/ v2 2 Sep 2006
Mechanical Model for Relativistic Blast Waves Andrei M. Beloborodov, 1 Zuhngwhi Lucas Uhm Physics Department and Columbia Astrophysics Laboratory, Columbia University, 538 West 10th Street, New York, NY
More informationParticle acceleration at relativistic shock waves
Particle acceleration at relativistic shock waves Martin Lemoine Institut d Astrophysique de Paris CNRS, Université Pierre & Marie Curie Introduction Why relativistic Fermi acceleration? Relativistic outflows
More informationMagnetic dissipation in pulsar winds
Magnetic dissipation in pulsar winds Benoît Cerutti, CNRS & Univ. Grenoble Alpes, France. In collaboration with Sasha Philippov, UC Berkeley, USA. Cerutti & Philippov, A&A (2017) Third Purdue Workshop
More informationMagnetically-dominated relativistic jets.
Magnetically-dominated relativistic jets. Serguei Komissarov University of Leeds UK N.Vlahakis, Y.Granot, A.Konigl, A.Spitkovsky, M.Barkov, J.McKinney, Y.Lyubarsky, M.Lyutikov, N.Bucciantini Plan 1. Astrophysical
More informationHigh-energy afterglow emission from gamma-ray bursts
Mon. Not. R. Astron. Soc. 384, 1483 1501 (2008) doi:10.1111/j.1365-2966.2007.12765.x High-energy afterglow emission from gamma-ray bursts Yi-Zhong Fan, 1,2,3 Tsvi Piran, 1 Ramesh Narayan 4 and Da-Ming
More informationarxiv: v1 [astro-ph.he] 1 Nov 2018
Draft version November 6, 2018 Typeset using LATEX default style in AASTeX62 Estimates of Reverse Shock Emission from Short Gamma-ray Bursts Nicole M. Lloyd-Ronning 1, 2 1 Center for Theoretical Astrophysics
More informationarxiv:astro-ph/ v1 31 Oct 2002
Astronomy & Astrophysics manuscript no. draft 15 March 11, 2008 (DOI: will be inserted by hand later) Extremely hard GRB spectra prune down the forest of emission models Giancarlo Ghirlanda 1, Annalisa
More informationNews from Fermi LAT on the observation of GRBs at high energies
News from Fermi LAT on the observation of GRBs at high energies Nicola Omodei* on behalf of the Fermi LAT collaboration *Stanford University The Fermi observatory LAT : Pair conversion telescope Trigger,
More informationThe Discovery of Gamma-Ray Bursts
The Discovery of Gamma-Ray Bursts The serendipitous discovery of Gamma-Ray Bursts (GRBs) in the late sixties puzzled astronomers for several decades: GRBs are pulses of gamma-ray radiation (typically lasting
More informationSynchrotron Radiation from Ultra-High Energy Protons and the Fermi Observations of GRB C
150 The Open Astronomy Journal, 010, 3, 150-155 Open Access Synchrotron Radiation from Ultra-High Energy Protons and the Fermi Observations of GRB 080916C Soebur Razzaque 1,,*, Charles D. Dermer 1,* and
More informationGAMMA-RAY BURST PROMPT EMISSION
International Journal of Modern Physics D Vol. 23, No. 2 (2014) 1430002 (18 pages) c World Scientific Publishing Company DOI: 10.1142/S021827181430002X GAMMA-RAY BURST PROMPT EMISSION BING ZHANG Department
More informationOn the GCR/EGCR transition and UHECR origin
UHECR 2014 13 15 October 2014 / Springdale (Utah; USA) On the GCR/EGCR transition and UHECR origin Etienne Parizot 1, Noémie Globus 2 & Denis Allard 1 1. APC Université Paris Diderot France 2. Tel Aviv
More informationPHOTOSPHERIC THERMAL RADIATION FROM GRB COLLAPSAR JETS
High Energy Phenomena in Relativistic Outflows III (HEPRO III) International Journal of Modern Physics: Conference Series Vol. 8 (2012) 225 230 c World Scientific Publishing Company DOI: 10.1142/S2010194512004631
More informationTESTING THE CURVATURE EFFECT AND INTERNAL ORIGIN OF GAMMA-RAY BURST PROMPT EMISSIONS AND X-RAY FLARES WITH SWIFT DATA
The Astrophysical Journal, 646:351 357, 2006 July 20 # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. A TESTING THE CURVATURE EFFECT AND INTERNAL ORIGIN OF GAMMA-RAY BURST
More informationCosmological implications of Gamma Ray Bursts
Mem. S.A.It. Vol. 78, 779 c SAIt 2007 Memorie della Cosmological implications of Gamma Ray Bursts Gabriele Ghisellini Istituto Nazionale di Astrofisica Oss. Astron. di Brera, Via Bianchi, 46 I 23806 Merate,
More informationLight Curves and Inner Engines Tsvi Piran HU, Jerusalem
Light Curves and Inner Engines Tsvi Piran HU, Jerusalem Theory and observations of Light curves Ehud Naker Implication of accretion theory P. Kumar & R. Narayan counts/sec 4.5 4 3.5 3.5 1.5 1 x 10 4 0
More informationGamma Ray Bursts and Their Afterglows
Gamma Ray Bursts and Their Afterglows Re em Sari Theoretical Astrophysics, Caltech 130-33, Pasadena, CA 91125; sari@tapir.caltech.edu Abstract. Gamma-Ray Bursts are extreme astrophysical events, which
More informationarxiv:astro-ph/ v2 1 Sep 2004
Submitted to ApJL Preprint typeset using L A TEX style emulateapj v. 11/12/01 arxiv:astro-ph/0408009v2 1 Sep 2004 LATE-TIME RADIO RE-BRIGHTENING OF GAMMA-RAY BURST AFTERGLOWS: EVIDENCE FOR DOUBLE-SIDED
More informationSimulations of relativistic reconnection in pulsar wind nebulae and pulsar winds
Simulations of relativistic reconnection in pulsar wind nebulae and pulsar winds Benoît Cerutti Lyman Spitzer Jr. Fellow Princeton University, Dept. of Astrophysical Sciences Collaborators @ Colorado :
More informationPLASMOIDS IN RELATIVISTIC RECONNECTION: THE BLOBS OF BLAZAR EMISSION? Maria Petropoulou Purdue University
PLASMOIDS IN RELATIVISTIC RECONNECTION: THE BLOBS OF BLAZAR EMISSION? Maria Petropoulou Purdue University in collaboration with Dimitrios Giannios (Purdue) Lorenzo Sironi(Columbia) October 19, 2016 Einstein
More informationPhoton Emission in a Cascade from Relativistic Protons Initiated by Residual Thermal Photons in Gamma-Ray Bursts
PASJ: Publ. Astron. Soc. Japan 55, 433 444, 2003 April 25 c 2003. Astronomical Society of Japan. Photon Emission in a Cascade from Relativistic Protons Initiated by Residual Thermal Photons in Gamma-Ray
More informationCitation PHYSICAL REVIEW LETTERS (2006), 97( RightCopyright 2006 American Physical So
Title High energy neutrino flashes from f flares in gamma-ray bursts Author(s) Murase, K; Nagataki, S Citation PHYSICAL REVIEW LETTERS (2006), 97( Issue Date 2006-08-04 URL http://hdl.handle.net/2433/50481
More informationCentral Engines and Jets of long GRB
Central Engines and Jets of long GRB Peter Mészáros, Pennsylvania State University Yukawa Inst. Workshop Kyoto, Nov. 2013 GRB: standard paradigm Bimodal distribution of t γ duration Short (t g < 2 s) Long
More informationGamma-rays from black-hole binaries (?)
Gamma-rays from black-hole binaries (?) Valentí Bosch-Ramon Dublin Institute for Advanced Studies Accretion and Outflow in Black Hole Systems IAU Symposium 275: Jets at all Scales Kathmandu, Nepal 13/10/2010
More informationRelativistic reconnection at the origin of the Crab gamma-ray flares
Relativistic reconnection at the origin of the Crab gamma-ray flares Benoît Cerutti Center for Integrated Plasma Studies University of Colorado, Boulder, USA Collaborators: Gregory Werner (CIPS), Dmitri
More informationGRB Spectra and their Evolution: - prompt GRB spectra in the γ-regime
GRB Spectra and their Evolution: - prompt GRB spectra in the γ-regime Andreas von Kienlin MPE -Gamma 14. November 2003 1 Outline Time averaged GRB spectra Example spectra Instrumental response Band function
More informationGamma-Ray Bursts in Pulsar Wind Bubbles: Putting the Pieces Together
Gamma-Ray Bursts in Pulsar Wind Bubbles: Putting the Pieces Together Jonathan Granot 1 and Dafne Guetta 2 ABSTRACT arxiv:astro-ph/0211136v1 7 Nov 2002 We present the main observational features expected
More informationGamma-Ray Bursts and their Afterglows
Seminar Ib Gamma-Ray Bursts and their Afterglows Mentor: Izr. prof. dr. Andreja Gomboc Author: Katja Bricman Ljubljana, May 2015 Abstract Gamma ray bursts (GRBs) are short flashes of gamma rays, that can
More informationGamma Ray Bursts. Progress & Prospects. Resmi Lekshmi. Indian Institute of Space Science & Technology Trivandrum
Gamma Ray Bursts Progress & Prospects Resmi Lekshmi Indian Institute of Space Science & Technology Trivandrum Why study GRBs? to study GRBs end stages of massive star evolution jet launching, collimation
More informationThe expected thermal precursors of gamma-ray bursts in the internal shock model
Mon. Not. R. Astron. Soc. 336, 171 180 (00) The expected thermal precursors of gamma-ray bursts in the internal shock model Frédéric Daigne 1, and Robert Mochkovitch 3 1 Max-Planck-Institut für Astrophysik,
More informationT ang. F ν (T )= 1 2D 2. r 2 dr. los
Modeling Fluctuations in the GRB-Afterglow Light Curves E. Nakar & T. Piran Racah Institute for Physics, The Hebrew University, Jerusalem 9194, ISRAEL ABSTRACT The fluctuations observed in the light curves
More informationarxiv: v1 [astro-ph.he] 20 Feb 2013
Preprint typeset using L A TEX style emulateapj v. 5//11 GRB 117A: LONG-LASTING, ENERGETIC X-RAY FLARES AND CLUES TO RADIATION MECHANISM AND PROGENITOR STAR Fang-kun Peng 1, You-Dong Hu 1, Shao-Qiang Xi
More informationarxiv:astro-ph/ v3 27 Jul 2000
Draft version February 1, 2008 Preprint typeset using L A TEX style emulateapj v. 04/03/99 PRECURSORS OF GAMMA-RAY BURSTS: A CLUE TO THE BURSTER S NATURE Maxim Lyutikov Canadian Institute for Theoretical
More informationarxiv: v2 [astro-ph.co] 25 Jun 2012
DRAFT VERSION NOVEMBER 6, 8 Preprint typeset using LATEX style emulateapj v. 5// THEORY OF PHOTOSPHERIC EMISSION FROM RELATIVISTIC OUTFLOWS R. RUFFINI, I. A. SIUTSOU AND G. V. VERESHCHAGIN ICRANet, 65,
More informationarxiv: v2 [astro-ph.he] 26 Sep 2017
Extremely bright GRB 6625B with multi-episodes emission: Evidences for Long-Term Ejecta Evolution arxiv:72.382v2 [astro-ph.he] 26 Sep 27 Hou-Jun Lü, Jing Lü, Shu-Qing Zhong, Xiao-Li Huang, Hai-Ming Zhang,
More informationarxiv:astro-ph/ v2 21 Nov 2001
Annu. Rev. Astron. Astrophys. 2002 40 Preprint astro-ph/0111170 Theories of Gamma-Ray Bursts arxiv:astro-ph/0111170 v2 21 Nov 2001 P. Mészáros Dept. of Astronomy & Astrophysics, 525 Davey Laboratory, Pennsylvania
More informationarxiv: v2 [astro-ph.he] 6 Nov 2010
DRAFT VERSION NOVEMBER 9, 00 Preprint typeset using LATEX style emulateapj v. /0/09 THE BULK LORENTZ FACTORS OF FERMI-LAT GRBS XIAO-HONG ZHAO,4, ZHUO LI,, JIN-MING BAI,4 Draft version November 9, 00 arxiv:005.59v
More informationMulti-messenger light curves from gamma-ray bursts
Multi-messenger light curves from gamma-ray bursts 1409.2874, 1606.02325 Mauricio Bustamante Center for Cosmology and AstroParticle Physics (CCAPP) The Ohio State University 8th Huntsville Gamma-Ray Burst
More informationFUNDAMENTAL PHYSICAL PARAMETERS OF COLLIMATED GAMMA-RAY BURST AFTERGLOWS A. Panaitescu. and P. Kumar
The Astrophysical Journal, 560:L49 L53, 001 October 10 001. The American Astronomical Society. All rights reserved. Printed in U.S.A. FUNDAMENTAL PHYSICAL PARAMETERS OF COLLIMATED GAMMA-RAY BURST AFTERGLOWS
More informationarxiv: v2 [astro-ph.he] 10 Jul 2018
Astronomy & Astrophysics manuscript no. paper c ESO 8 July, 8 Characterization of Gamma-Ray Burst prompt emission spectra down to soft X-rays G. Oganesyan, L. Nava,,, G. Ghirlanda, and A. Celotti arxiv:7.98v
More informationSpatial Profile of the Emission from Pulsar Wind Nebulae with steady-state 1D Modeling
Spatial Profile of the Emission from Pulsar Wind Nebulae with steady-state 1D Modeling Wataru Ishizaki ( Department of Physics, Graduate School of Science, The University of Tokyo ) Abstract The pulsar
More informationThe Fermi Zoo : GRB prompt spectra. Michael S. Briggs (Univ. Alabama in Huntsville) for the Fermi GBM & LAT Teams
The Fermi Zoo : GRB prompt spectra Michael S. Briggs (Univ. Alabama in Huntsville) for the Fermi GBM & LAT Teams Multi-Messenger Workshop KIAA 2013 1 Multi-Messenger Workshop KIAA 2013 2 Before Fermi:
More informationarxiv: v1 [astro-ph.he] 28 Jun 2012
Astronomy & Astrophysics manuscript no. Tolstov00 September 7, 08 (DOI: will be inserted by hand later) The influence of jet geometry on light curves and spectra of GRB afterglows arxiv:06.6807v [astro-ph.he]
More informationarxiv: v1 [astro-ph.he] 21 Jan 2019
Preprint January 23, 219 Compiled using MNRAS LATEX style file v3. Testing a model for subphotospheric dissipation in GRBs: fits to Fermi data constrain the dissipation scenario Björn Ahlgren 1, Josefin
More informationGamma-ray burst afterglows and evolution of postburst fireballs with energy injection from strongly magnetic millisecond pulsars
1 A&A manuscript no. (will be inserted by hand later) Your thesaurus codes are: (08.14.1; 08.16.6; 13.07.1) ASTRONOMY AND ASTROPHYSICS 27.10.1998 Gamma-ray burst afterglows and evolution of postburst fireballs
More informationarxiv: v1 [astro-ph.he] 28 Sep 2018
Draft version October, 8 Preprint typeset using L A TEX style emulateapj v. /6/ arxiv:8.v [astro-ph.he] 8 Sep 8 THE PROMPT EMISSION OF GAMMA-RAY BURSTS FROM THE WIND OF NEWBORN MILLISECOND MAGNETARS: A
More informationTHE EVOLUTION OF A STRUCTURED RELATIVISTIC JET AND GAMMA-RAY BURST AFTERGLOW LIGHT CURVES Pawan Kumar. and Jonathan Granot
The Astrophysical Journal, 591:175 185, 23 July 1 # 23. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE EVOLUTION OF A STRUCTURED RELATIVISTIC JET AND GAMMA-RAY BURST AFTERGLOW
More information