Changeset 6236 for trunk/MagicSoft
- Timestamp:
- 02/03/05 13:49:33 (20 years ago)
- Location:
- trunk/MagicSoft/GRB-Proposal
- Files:
-
- 3 edited
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trunk/MagicSoft/GRB-Proposal/GRB_proposal_2005.tex
r6228 r6236 169 169 \bibitem{GUETTA} The Luminosity and Angular Distributions of Logn-Duration GRBs, 170 170 Guetta D., Piran T., Waxman E., astroph/0311488, 2003. 171 \bibitem{DADO} Dado S. et al, A\&A, 422, 381 (2004) 172 \bibitem{HUANG} Huang Y.F., Dai Z. G., Lu T., MNRAS, 332, 735 (2002) 173 \bibitem{BARRAUD} Barraud C. et al, A\&A, 400, 1021 (2003) 174 \bibitem{LEVAN} Levan A. et al, astro-ph/0410560 (2004) 175 \bibitem{FARGION} Fargion D. astro-ph/0011403 (2000) 176 \bibitem{CORBEL} Corbel S. and Eikenberry S. S. astro-ph/0311313 (2003) 171 177 172 178 %References used in chapter 2: Burst Alert System -
trunk/MagicSoft/GRB-Proposal/Introduction.tex
r6224 r6236 71 71 by peak energies below 50~keV and a dominant X-ray fluence. Because of similar properties, a connection 72 72 between XRFs and GRBs is suggested. 73 The most popular theories suggest that XRFs are produced from GRBs observed ''off-axis''. 74 Alternatively, an increase of the baryon load within the fireball itself or low efficiency shocks could 75 produce XRFs. 76 If there is a connection between XRFs and GRBs, 77 they should originate at rather low redshifts (z $<$ 0.6).\\ 73 The most popular theories ~\cite{DADO} suggest that XRFs are produced from GRBs observed ''off-axis''. 74 Alternatively, an increase of the baryon load within the fireball itself ~\cite{HUANG} or low efficiency shocks ~\cite{BARRAUD} could produce XRFs. 75 If there is a connection between XRFs and GRBs, they should originate at rather low redshifts (z $<$ 0.6). Because If XRFs lie at large distances, their energies would not fit the observed correlation between GRB peak energy and isotropic energy release~\cite{LEVAN}. \\ 78 76 79 77 Gamma-ray satellites react in the same way to XRFs and GRBs. … … 91 89 SGR0526-66, SGR1806-20, SGR1900+14, SGR1627-41. 92 90 GRBs and SGRs can be explained within one same gamma jet model where the jet is observed at different 93 beam-angles and at different ages .\\91 beam-angles and at different ages~\cite{FARGION}.\\ 94 92 95 93 The BAT instrument on the SWIFT satellite triggered on an outburst from SGR1806-20 on 30. January 2005. 96 94 The fluence was about $10^{-5}$\,erg/cm$^2$ in the range between 15 and 350\,keV. 97 95 This event was five orders of magnitude smaller than the giant flare from this source on the 98 December 27$^{th}$, 2004. 99 If a giant flare from SGR occurs as SGR1806-20, MAGIC would be able to detect the $\gamma$-ray 100 emission from the source with 100\,sec. observationes time. 96 December 27$^{th}$, 2004~\cite{GCN3002}. MAGIC have a enough sensitivity for observing the event which have a fluence more than 4.0 $\times$ 10 $^{-1}$ erg/cm$^{2} sec$ at SWIFT observable energy range, when power law index of -2.2 and 100 sec. observation time are assumpted. Therefore if a giant flare from SGR occurs as SGR1806-20, MAGIC would be able to detect the $\gamma$-ray emission from these source. 101 97 102 98 -
trunk/MagicSoft/GRB-Proposal/Timing.tex
r6201 r6236 10 10 \begin{itemize} 11 11 12 \item Taking into account the fireball model~\cite{REES1,REES2} there are two efficient mechanisms for the generation of VHE photons~\cite{DERISHEV} in GRBs. (1) The prompt emission of $\sim$100\,GeV photons is expected before and during the keV-MeV peak. This emission should have their highest luminosity together with the main GRB peak. (2) UHE photons generated due to inverse Compton (IC) scattering in relativistic shocks are strongly absorbed by infrared background radiation and cannot be observed from source at cosmological distances. With the presence of an dense ambient medium close to the GRB, the VHE photons will be reprocessed into a softer spectral range. This would lead to VHE emission delayed by few minutes to hours with respect to the beginning of GRB. The timeline including both prozesses is illustrated in figure~\ref{fig:timeline}.12 \item Taking into account the fireball model~\cite{REES1,REES2} there are two efficient mechanisms for the generation of VHE photons~\cite{DERISHEV} in GRBs. (1) The prompt emission of $\sim$100\,GeV photons is expected before and during the keV-MeV peak. This emission should have their highest luminosity together with the main GRB peak. (2) VHE photons generated due to inverse Compton (IC) scattering in relativistic shocks are strongly absorbed by infrared background radiation and cannot be observed from source at cosmological distances. With the presence of an dense ambient medium close to the GRB, the UHE photons will be reprocessed into a softer spectral range. This would lead to VHE emission delayed by few minutes to hours with respect to the beginning of GRB. The timeline including both prozesses is illustrated in figure~\ref{fig:timeline}. 13 13 14 14 \item In~\cite{DERMER} two peaks in the GeV light curve are calculated. The first is coincident with the keV-MeV peak, some seconds after the burst onset. The second maximum is peaking at between $\approx$ 1.5 hours up to $\approx$ 25 hours after the burst onset. … … 25 25 \end{figure} 26 26 27 Based on the model in~\cite{DERISHEV}, only the (2) component is promising to be detectable by \ma and other ground based $\gamma$-ray detectors. 27 Based on the model in~\cite{DERISHEV}, three different components of VHE emission exists in an GRB. This components are illustrated in figure~\ref{fig:timeline}. (a) There is the prompt 100\,GeV peak before and during the first keV-MeV peak, (b) the VHE emission due to inverse Compton scattering lasting for the whole duration of the GRB pulse and (c) the reprocessed inverse Compton emission which may last up to hours after the GRB onset. 28 (b) and (c) are the components which may be detectable by \ma and other ground based $\gamma$-ray detectors. 28 29 29 30 \par 30 31 31 For reprocessing of UHE photons below 1\,TeV where radiation can reach the Earth without interaction with the IBL the minimal magnetic field B$_{min}$ is necessary:32 To achive significant emission due to inverse Comton scattering of the sub-MeV radiation, a minimal magnetic field $B_{min}$ is necessary: 32 33 33 34 \begin{equation} … … 38 39 \end{equation} 39 40 40 When the magnetic field is much stronger than B$_{min}$, the delay of reprocessed VHE emission maybe calculated via the following asymptotic expression:41 When the magnetic field is much stronger than $B_{min}$, the delay of reprocessed photons may become observable. For this perpendicular case it can be calculated via the following asymptotic expression: 41 42 42 43 \begin{equation} … … 49 50 Observation of the delayed VHE emission and the time correlation will give informations about the density of the surrounding interstellar gas, the magnetic field and the Lorentz factor of the GRB shell.\\ 50 51 51 It is not easy to fix a reasonable observation time of a GRB based on the described models. Every bust has its own characteristic and time profile. Hovewer, obseration of the GRB coordinates for/ orwithin 5 hours after the alert may put constraints on model parameters of GRB sources.\\52 It is not easy to fix a reasonable observation time of a GRB based on the described models. Every bust has its own characteristic and time profile. Hovewer, obseration of the GRB coordinates for/within 5 hours after the alert may put constraints on model parameters of GRB sources.\\ 52 53 53 54 In case of an \textcolor{red}{\bf Red Alarm}, we propose to take data for {\bf 5 hours}.
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