Changeset 6176 for trunk/MagicSoft/GRB-Proposal/Introduction.tex

Timestamp:

02/01/05 16:54:17 (20 years ago)

Author:

garcz

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• trunk/MagicSoft/GRB-Proposal/Introduction.tex (modified) (4 diffs)

trunk/MagicSoft/GRB-Proposal/Introduction.tex

@@ -12 +12 @@
 
 Very high energy (VHE) GRB observations have the potential to constrain the current GRB models
-on both the prompt and extended phases of GRB emission~\cite{HARTMANN,MANNHEIM,SALOMON}. 
-Models based on both internal and external shocks predicts VHE fluence comparable to, 
-or in certain situations stronger than, the keV-MeV radiation, 
+on both the prompt and extended phases of GRB emission~\cite{HARTMANN,MANNHEIM,SALOMON}.
+Models based on both internal and external shocks predicts VHE fluence comparable to,
+or in certain situations stronger than, the keV-MeV radiation,
 with duration ranging from shorter than the keV-MeV burst to extended TeV afterglows~\cite{DERMER, PILLA, ZHANG1}.
 
 \par
 
-In many publications, the possibility that more energetic $\gamma$-rays come along with the 
-(low-energy) GRB, have been explored. Proton-synchrotron emission~\cite{TOTANI} have been suggested 
+In many publications, the possibility that more energetic $\gamma$-rays come along with the
+(low-energy) GRB, have been explored. Proton-synchrotron emission~\cite{TOTANI} have been suggested
 as well as photon-pion production~\cite{WAXMAN,BAHCALL,BOETTCHER} and inverse-Compton scattering
 in the burst environment~\cite{MESZAROS93,CHIANG,PILLA,ZHANG2}.
-Long-term HE $\gamma$ emission from accelerated protons in the forward-shock has been predicted in~\cite{LI}. 
-This model predicts GeV inverse Compton emission even one day after the burst.
-Even considering pure electron-synchrotron radiation predicts measurable GeV emission for a significant fraction of GRBs~\cite{ZHANG2}.\\
+Long-term HE $\gamma$ emission from accelerated protons in the forward-shock has been predicted in~\cite{LI}. This model predicts GeV inverse Compton emission even one day after the burst.
+Even considering pure electron-synchrotron radiation predicts measurable GeV emission for a significant fraction of GRBs~\cite{ZHANG2}. In order to be able to describe prompt synchrotron optical flashes (like observed in GRB990123 by ROTSE), GeV--TeV emission by inverse Compton scattering of the MeV photons should be produced at the same time~\cite{BELOBORODOV}.\\
 
 GeV emission in GRBs is particularly sensitive to the Lorentz factor and the photon density of the emitting material -
@@ -37 +36 @@
 The only significant detection was performed by \eg which detected seven GRBs emitting high energy (HE)
 photons in the 100\,MeV to 18\,GeV range~\cite{EGRET}. The data shows no evidence of a HE cut-off
-in the GRB spectrum~\cite{DINGUS}. Recent results indicate that the spectrum of some GRBs contains a very hard,
-luminous, long-duration component~\cite{GONZALES}.
+in the GRB spectrum~\cite{DINGUS}. Recent results indicate that the spectrum of some GRBs contains a very hard, luminous, long-duration component~\cite{GONZALES}.
 There have been results suggesting gamma rays beyond the GeV range from the TIBET air shower array
-in coincidence with BATSE bursts~\cite{AMENOMORI}, rapid follow-up observations by the 
-Whipple Air Cherenkov Telescope~\cite{CONNAUGHTON1}, and coincident and monitoring studies by HEGRA-AIROBICC~\cite{PADILLA}, 
-Whipple~\cite{CONNAUGHTON2} and the Milagro prototype Milagrito~\cite{MILAGRO}.
-The GRAND array has reported some excess of observed muons during seven BATSE bursts~\cite{GRAND}. 
-In this context, especially the publication from the TASC detector on \eg is important~\cite{GONZALES}, 
-finding a HE spectral component presumably due to ultra-relativistic acceleration
-of hadrons and producing a spectral index of $-1$ with no cut-off up to the detector energy limit (200\,MeV).\\
+in coincidence with BATSE bursts~\cite{AMENOMORI}, rapid follow-up observations by the
+Whipple Air Cherenkov Telescope~\cite{CONNAUGHTON1}, and coincident and monitoring studies by HEGRA-AIROBICC~\cite{PADILLA}, Whipple~\cite{CONNAUGHTON2} and the Milagro prototype Milagrito~\cite{MILAGRO}. The GRAND array has reported some excess of observed muons during seven BATSE bursts~\cite{GRAND}. In this context, especially the publication from the TASC detector on \eg is important~\cite{GONZALES}, finding a HE spectral component presumably due to ultra-relativistic acceleration of hadrons and producing a spectral index of $-1$ with no cut-off up to the detector energy limit (200\,MeV).\\
 
 Concerning estimates about the \ma observability of GRBs, a very detailed study of GRB spectra obtained from the
@@ -55 +48 @@
 
 Taking into account the local rate of GRBs estimated in~\cite{GUETTA}, late afterglow emission from few tens of GRBs per year
-should be observable above our energy threshold. The model of~\cite{ASAF2} predict delayed GeV emission that 
-should be significantly detectable by MAGIC in 100\,seconds.
+should be observable above our energy threshold. The model of~\cite{ASAF2} predict delayed GeV emission that should be significantly detectable by MAGIC in 100\,seconds.
 
 \subsection{Observation of XRFs}
 
 While the major energy from the prompt GRBs is emitted in $\gamma$-rays ($E_p \sim$ 200~keV), XRFs are characterized
-by peak energies below 50~keV and a dominant X-ray fluence. Because of similar properties a connection between XRFs and GRBs is 
+by peak energies below 50~keV and a dominant X-ray fluence. Because of similar properties a connection between XRFs and GRBs is
 suggested. The most popular theories say that XRFs are produced from GRBs observed ''off-axis''.
-Alternatively, an increase of the baryon load within the fireball itself or low efficiency shocks can produce XRFs. 
+Alternatively, an increase of the baryon load within the fireball itself or low efficiency shocks can produce XRFs.
 If there is a connection between the XRFs and GRBs, they should originate at rather low redshifts (z $<$ 0.6).\\
 
-Gamma-ray satellites react in the same way to XRFs and GRBs. In case of a detection the coordinates are distributed 
+Gamma-ray satellites react in the same way to XRFs and GRBs. In case of a detection the coordinates are distributed
 to other observatories (see section 2.1). Only from later analysis the difference can be established.
 
@@ -73 +65 @@
 In this case we include also the observation of XRFs by MAGIC in our proposal.
 
+\subsection{Observation of SGRs}
 
+Soft Gamma Repeaters (SGRs) are extremely rare strong magnetic neutron stars that periodically emit $\gamma$-rays. Only four identified SGRs were discovered in the last 20 years: SGR0526-66, SGR1806-20, SGR1900+14, SGR1627-41. GRBs and SGRs can be explained with an unique processing gamma jet model observed at different beam-angle and at different ages.\\
 
-\subsection{Observation of SGRs}
-A stronger magnetic neutron star, a so-called ``Soft Gamma Repeaters (SGRs)'' periodically emit gamma-ray, and are extremely rare stars. Only four identified 
-SGRs are discovered in the last 20 years: SGR0526-66, SGR1806-20, SGR1900+14, SGR1627-41. GRBs and SGRs can be explained with an unique processing gamma jet model observed at different beam-angle and at different ages.\\
-\par
-The BAT instrument on the SWIFT satellite triggered on an outburst from SGR1806-20 on 30 Jan 05. The fluence is $\sim$ 1$\times$10$^{-5}$erg/cm$^2$(15-350keV). This event have five orders of magnitude smaller than the giant flare from this source on 27 Dec 04. If a giant flare from SGR occurs as SGR1806-20, MAGIC has enough sensitivity for 100 second observation time.\\
-\par
-MAGIC and Gamma-ray satellites react in the same way for also SGRs. 
-
-
-
-
-
-
-
-
-
+The BAT instrument on the SWIFT satellite triggered on an outburst from SGR1806-20 on 30. January 2005. The fluence was $\sim$ 1$\times$10$^{-5}$erg/cm$^2$(15-350keV). This event was five orders of magnitude smaller than the giant flare from this source on the 27. December 2004. If a giant flare from SGR occurs as SGR1806-20, MAGIC would be able to detect the 100\,seconds delayed $\gamma$-emission from the source.