Changeset 6236 for trunk/MagicSoft


Ignore:
Timestamp:
02/03/05 13:49:33 (20 years ago)
Author:
satoko
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*** empty log message ***
Location:
trunk/MagicSoft/GRB-Proposal
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3 edited

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  • trunk/MagicSoft/GRB-Proposal/GRB_proposal_2005.tex

    r6228 r6236  
    169169\bibitem{GUETTA} The Luminosity and Angular Distributions of Logn-Duration GRBs,
    170170Guetta 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)
    171177
    172178%References used in chapter 2: Burst Alert System
  • trunk/MagicSoft/GRB-Proposal/Introduction.tex

    r6224 r6236  
    7171by peak energies below 50~keV and a dominant X-ray fluence. Because of similar properties, a connection
    7272between 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).\\
     73The most popular theories ~\cite{DADO} suggest that XRFs are produced from GRBs observed ''off-axis''.
     74Alternatively, an increase of the baryon load within the fireball itself ~\cite{HUANG} or low efficiency shocks ~\cite{BARRAUD} could produce XRFs.
     75If 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}. \\
    7876
    7977Gamma-ray satellites react in the same way to XRFs and GRBs.
     
    9189SGR0526-66, SGR1806-20, SGR1900+14, SGR1627-41.
    9290GRBs 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.\\
     91beam-angles and at different ages~\cite{FARGION}.\\
    9492
    9593The BAT instrument on the SWIFT satellite triggered on an outburst from SGR1806-20 on 30. January 2005.
    9694The fluence was about $10^{-5}$\,erg/cm$^2$ in the range between 15 and 350\,keV.
    9795This 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.
     96December 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.
    10197
    10298
  • trunk/MagicSoft/GRB-Proposal/Timing.tex

    r6201 r6236  
    1010\begin{itemize}
    1111
    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}.
    1313
    1414\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.
     
    2525\end{figure}
    2626
    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.
     27Based 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.
    2829
    2930\par
    3031
    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:
     32To achive significant emission due to inverse Comton scattering of the sub-MeV radiation, a minimal magnetic field $B_{min}$ is necessary:
    3233
    3334\begin{equation}
     
    3839\end{equation}
    3940
    40 When the magnetic field is much stronger than B$_{min}$, the delay of reprocessed VHE emission may be calculated via the following asymptotic expression:
     41When 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:
    4142
    4243\begin{equation}
     
    4950Observation 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.\\
    5051
    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/or within 5 hours after the alert may put constraints on model parameters of GRB sources.\\
     52It 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.\\
    5253
    5354In case of an \textcolor{red}{\bf Red Alarm}, we propose to take data for {\bf 5 hours}.
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