Index: /trunk/MagicSoft/GRB-Proposal/GRB_proposal_2005.tex =================================================================== --- /trunk/MagicSoft/GRB-Proposal/GRB_proposal_2005.tex (revision 6803) +++ /trunk/MagicSoft/GRB-Proposal/GRB_proposal_2005.tex (revision 6804) @@ -56,30 +56,35 @@ \title{Proposal for the Observation of Gamma-Ray Bursts with the MAGIC Telescope} % {\it \Large DRAFT 2.1 }} -\author{N. Galante\\ \texttt{}\\ - D. Bastieri\\ \texttt{}\\ - M. Garczarczyk\\ \texttt{}\\ - M. Gaug\\ \texttt{}\\ - S. Mizobuchi\\ \texttt{}\\ -} +\author{{PI: Nicola Galante, Universit\`a degli Studi di Siena}} +% \coauthor{{Co-I:} , {Denis Bastieri} , {Universit\`a degli Studi di Padova}}\\ +% & Luigi Peruzzo & Universit\`a degli Studi di Padova\\ +% & Riccardo Paoletti & Universit\`a degli Studi di Siena\\ +% & Markus Gaug & IFAE\\ +% & Markus Garczarczyk & MPI\\ +% & Satoko Mizobuchi & MPI\\ +% Co-Th: & Steve Shore & Universit\`a degli Studi di Pisa +%}\\ \date{March, 2005\\} -\TDAScode{MAGIC-TDAS 05-02\\ 050314/NGalante} +\TDAScode{MAGIC-TDAS 05-03\\ 050321/NGalante} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %% title %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \maketitle -%% abstract %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% Summary %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \begin{abstract} -We present a detailed strategy for the observation of Gamma Ray Bursts (GRBs) for the first -half year of 2005. Because of similarities, X-Ray Flashes (XRFs) and Soft Gamma Repeaters (SGR) -are also included in our proposal. -All observations will be mainly triggered by alerts from \sw. +We ask for observations of Gamma-Ray Bursts (GRBs) for the next six months of year 2005. +Therefore we present a detailed strategy for the observation of GRBs. +X-Ray Flashes (XRFs) and Soft Gamma Repeaters (SGR) +are also included in our proposal, given their similarities to GRB phenomena. +All observations will be mainly triggered by \sw. In addition, the \he and \ig satellites can contribute a small number of alerts. The \sw collaboration expects a total alert rate of about 15 per months -- -although with big uncertainties -- out of which 1--2 should be observable due to our +although with big uncertainties -- out of which 1--2 should be +observable by \ma due to our duty cycle. The overlap in sky converages between \sw and \ma seems to be favorable for \ma. -As it is still unknown how many alerts \sw will deliver exactly, and how its sky coverage matches -with the one of \ma, we cannot predict the alert frequency now to better than 100\% uncertainty. -This leads to an {\bf expected observation time of 5$\pm$5 hours per month}. +As it is still unknown how many alerts \sw will deliver exactly, +we cannot predict the alert frequency now to better than 100\% uncertainty. +This leads to an expected observation time of 5$\pm$5 hours per month. This number includes observation during the moon-time. We give a detailed description of the observation procedures in La Palma and @@ -90,9 +95,8 @@ %% contents %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \newpage - \thetableofcontents %% body %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\include{Introduction} +\include{ScientificCase} \include{Alerts} \include{Monitor} @@ -190,5 +194,5 @@ \bibitem{GRB030329} Spectra of the burst: http://space.mit.edu/HETE/Bursts/GRB030329/ \bibitem{ecl} Private communication with Lorenz E. - +\bibitem{JUAN} Private communication with Cortina J. %References used in Timing Index: /trunk/MagicSoft/GRB-Proposal/Monitor.tex =================================================================== --- /trunk/MagicSoft/GRB-Proposal/Monitor.tex (revision 6803) +++ /trunk/MagicSoft/GRB-Proposal/Monitor.tex (revision 6804) @@ -6,13 +6,13 @@ The Burst Alarm System {\it gspot} (Gamma -Sources Pointing Trigger) is installed and working in La Palma since last summer. +Sources Pointing Trigger) is installed and working in La Palma since last Summer. It performs a full-time survey of the {\it GRB Coordinates Network} (\g) alerts~\cite{GCN}. Different satellite experiments -send GRB coordinates to the \g which distributes +send GRB coordinates to the \g which in its turn broadcasts the alerts to registered users. The Burst Alarm System is composed of a core program which manages the monitoring of the \g and the communication with the Central Control (CC). It also handles three communication channels to notice the shifters -about an alert. It is a C based daemon running 24 +about an alert. It is a c-based daemon running 24 hours a day on the {\it www} machine, our external server, in a {\it stand alone} mode. It does not need to be operated and is @@ -27,10 +27,9 @@ This computer distributes the alerts from the satellite experiments through an internet socket connection. {\it gspot} -acts as a server while the client, running at the GSFC, -manages the communication of the data concerning the GRBs -and concerning the status of the connection. \\ - -The format of the data distributed through the \g differ between the individual satellites -and the kind of package. Currently three satellites participate in the GRB survey: +acts as a server, while the client, running at the GSFC, +manages the communication of the GRB data the status.\\ + +The format of the data distributed via \g depends on the broadcasting satellite +and on the kind of package. Currently three satellites participate in the GRB survey: HETE-2~\cite{HETE}, INTEGRAL~\cite{INTEGRAL} and SWIFT~\cite{SWIFT}. The alerts include the UTC, the GRB coordinates (not always), error on coordinates @@ -53,14 +52,30 @@ shining, the maximal zenith angle is reduced to 65$^\circ$. \item {\bf Position of Moon}: The angular -distance from the GRB to the Moon has to be at least 30$^\circ$. +distance from the GRB to the Moon has to be at least 30$^\circ$. This constant +value of 30$^\circ$ will change in the future as soon as the camera experts +will provide a plot of the safe distance from the Moon vs. Moon's phase. +Therefore such dynamical limit for this value will be used. \end{itemize} If one or more of these conditions fail, {\it gspot} enters into a -{\color[rgb]{0.9,0.75,0.}\bf Yellow Alarm State} (it means the GRB is not observable at the moment). In this case the program saves the alert in a list and calculates when the GRB will become observable for \ma. In the moment when the criteria listed above will be fulfilled for this burst, and the time intervall after the burst onset is smaller than 5 hours, {\it gspot} enters into \textcolor{red}{\bf Red Alarm State}. +{\color[rgb]{0.9,0.75,0.}\bf Yellow Alarm State} (it means the GRB is not observable at the moment). +In this case the program saves the alert in a list and calculates when the GRB will become observable for \ma. +At the moment when the criteria listed above are fulfilled for this burst, and the time intervall +after the burst onset is smaller than 5 hours, {\it gspot} enters into \textcolor{red}{\bf Red Alarm State}. If all the mentioned conditions are satisfied from the beginning, {\it gspot} enters into Red Alarm State immediately. -If more than one alert is recived and the burst can not be observed immediately, the alert information are saved in a list. The software is weightning the alerts in respect to the time when they will became observable, the delay after the onset and the strenght of the burst. The best candidate will be send to the CC when it will enter the Red Alarm state.\\ - -However, in both cases (\textcolor{red}{\bf RED} or {\color[rgb]{0.9,0.75,0.}\bf YELLOW} Alarm State), {\it gspot} establishes the communication with the CC and sends the GRB equatorial coordinates (RA/DEC J2000). -For the communication with CC the format defined in~\cite{CONTROL} is used. At the same time, the shifters and the GRB-MAGIC group are contacted. +If more than one alert is recived and the burst can not be observed immediately, the alert information are saved in a list. +The software weights the alerts according the total amount of time in which +the GRB will be observable, the delay of the onset of GRB's observability, +the intensisty of the burst and the mean GRB's zenith angle during its +period of observability. +The best candidate is sent to the CC as soon as {\it gspot} +enters the \textcolor{red}{\bf Red Alarm state}, i.e. as soon as such +candidate becomes observable.\\ + +However, in case of \textcolor{red}{\bf RED Alarm State}, +if the communication with the CC is available then {\it gspot} sends to it +the GRB's equatorial coordinates (RA/DEC J2000). +For the communication with CC the format defined in~\cite{CONTROL} is used. +At the same time, the shifters and the GRB-MAGIC group are contacted. \subsection{The Interface to the Central Control} @@ -69,22 +84,24 @@ When {\it gspot} is not in alarm state, standard packages are continuously exchanged between CC and {\it gspot}. These packages contain the main global status of the two subsystems. -In case of alert, {\it gspot} starts to send special alert packages to the CC, -containing information about the GRB and the ``color'' of the alert. +In case of \textcolor{red}{\bf RED alert}, {\it gspot} starts to send special alert packages to the CC +containing information about the GRB. The exchange of the alert packages continues until: \begin{itemize} \item {\it gspot} receives from the CC the confirmation -that the alert notice has been received. (The CC must send back the alert in order -to perform a cross-check of the relevant data.) -\item the alarm state expires after {\bf 5 hours} +that the alert notice has been received (the CC must send back the alert in order +to perform a cross-check of the relevant data); +\item the \textcolor{red}{\bf RED Alarm state} expires because of the +missing of one ore more of the needed criteria mentioned above; +\item the alarm state expires after {\bf 5 hours}. \end{itemize} -The CC informs the shift crew about the alert and undertakes -further steps only in case of a \textcolor{red}{\bf red alerts}. +The CC informs the shift crew about the alert +in case of a \textcolor{red}{\bf RED alert}. In this case, a pop-up window -appears with all the alert information received by the burst monitor. +appears with all the alert information received by the Burst Monitor. The operator has to confirm the notice by closing the pop-up window. He can decide whether to stop the current scheduled observation and to point the GRB. -A new button will be displayed in the CC allowing to point the telescope to +A new button is so displayed in the CC allowing to point the telescope to the GRB coordinates. @@ -94,15 +111,16 @@ information is translated into ``human language'' and stored in ASCII files. At the same time, an e-mail is sent to the MAGIC GRB-mailing list -{\it grb@mppmu.mpg.de}. +{\it magic\_grb@mppmu.mpg.de}. \subsection{The GRB Web Page} -The status of the GRB Alert System and relevant informations about the last -alert are displayed on a separate web page. The page is hosted at the web server in La Palma and can be accessed under:\\ +The status of the GRB Alert System and relevant informations about the +current and/or the last alert are displayed on a separate web page. +The page is hosted at the web server in La Palma and can be accessed under:\\ \qquad \qquad http://www.magic.iac.es/site/grbm/\\ The web page updates itself automatically every 10 seconds. In this way -the status of the Burst Alarm System can be checked by the shifters and from outside. +the status of the Burst Alarm System can be checked by the shifters and from outside too. \subsection{The Acoustic Alert} @@ -122,21 +140,32 @@ 21 contained GRB's coordinates. Time delays to the onset of the burst were of the order of several minutes to tens of minutes. The Burst Monitor can be considered stable -since November 2004. Since then we have received the following two significant alerts:\\ +since November 2004. Since then we have received the following four significant alerts:\\ \begin{tabular}{lllcccl} -19th & December & 2004 & 1:44 am & INTEGRAL & Zd $\sim 60^\circ$ & time delay 71 sec.\\ -28th & January & 2005 & 5:36 am & HETE-2 & Zd $\sim 65^\circ$ & time delay 73 min. \\ \\ +19th & December & 2004 & 1:44 am & INTEGRAL & Zd $\sim 60^\circ$ & time delay 71 sec. \\ +28th & January & 2005 & 5:36 am & HETE-2 & Zd $\sim 65^\circ$ & time delay 73 min. \\ +5th & March & 2005 & 8:42 pm & SWIFT & Zd $\sim 40^\circ$ & time delay 40 sec. \\ +5th & March & 2005 & 10:23 pm & SWIFT & Zd $\sim 70^\circ$ & time delay 80 sec. \\\\ \end{tabular} -In both cases the weather conditions at La Palma were bad. +In the first two cases the weather conditions at La Palma were bad. In the last two +a couple of GRBs were detected within two hours by SWIFT. They were observable since +their own onset and for all the following 5 hours. The weather was good, but unfortunately +the Telescope was off-service because of the exceptional events occured in La Palma +during the previous weeks. \subsection{Experience from SWIFT GRBs until now} -According to the \sw home page~\cite{SWIFT}, the satellite has detected 20 GRBs since mid-December last year. The first bursts were detected by chance during the commissioning phase. Since February 15$^{\mathrm{th}}$ the satellite sends burst allerts to the \g in real time. The current sample contains three bursts which could have been observed by \ma. The coordinates of the last burst from February 15$^{\mathrm{th}}$ were send via an alert within few seconds. Also in this cases the weather conditions did not allow any observation.\\ +According to the \sw home page~\cite{SWIFT}, the satellite has detected 20 GRBs since mid-December last year. +The bursts were detected by chance during the commissioning phase. Since February 15$^{\mathrm{th}}$ +the satellite sends burst allerts to the \g in real time. The current sample contains five bursts which could +have been observed by \ma. \\ \begin{tabular}{lllcc} 19th & December & 2004 & 1:42 am & Zd $\sim 65^\circ$ \\ 26th & December & 2004 & 8:34 pm & Zd $\sim 52^\circ$ \\ -15th & Februar & 2005 & 2:33 am & Zd $\sim 17^\circ$ \\ \\ +15th & Februar & 2005 & 2:33 am & Zd $\sim 17^\circ$ \\ +5th & March & 2005 & 8:42 pm & Zd $\sim 40^\circ$ \\ +5th & March & 2005 & 10:23 pm & Zd $\sim 70^\circ$ \\\\ \end{tabular} Index: /trunk/MagicSoft/GRB-Proposal/PreparatoryWork.tex =================================================================== --- /trunk/MagicSoft/GRB-Proposal/PreparatoryWork.tex (revision 6804) +++ /trunk/MagicSoft/GRB-Proposal/PreparatoryWork.tex (revision 6804) @@ -0,0 +1,1 @@ +\section{Preparatory Work} Index: /trunk/MagicSoft/GRB-Proposal/ScientificCase.tex =================================================================== --- /trunk/MagicSoft/GRB-Proposal/ScientificCase.tex (revision 6804) +++ /trunk/MagicSoft/GRB-Proposal/ScientificCase.tex (revision 6804) @@ -0,0 +1,93 @@ +%% Requested observation time +\section{Requested observation time} +We espect up to two alerts per month. Maximum time requested +for a single alert is 5h. + +\section{Scientific Case} + +\subsection{Observation of GRBs} + +The support structure and mirrors of the \ma telescope were designed to be exceptionally light in order to +react quickly to GRB alerts from satellites. The aim was to turn the telescope toward the burst position +within 30\,s~\cite{design,PETRY}, +in order to have a fair chance to detect a burst when the prompt $\gamma$--emission is still ongoing. +During the commissioning phase, it could be proven that the goal was achieved. +The telescope is able to turn $360^\circ$ in azimuth within 20\,s and $90^\circ$ in zenith within 10\,s.\\ + +Very high energy (VHE) GRB observations have the potential to constrain the current GRB models +on both the prompt and the extended phase of GRB emission~\cite{HARTMANN,MANNHEIM}. +Models based on either internal or external shocks predict VHE gamma-ray fluences comparable to, +or in certain situations stronger than, the keV-MeV radiation, +with durations ranging from shorter than the keV-MeV burst to extended TeV +afterglows~\cite{DERMER, PILLA, ZHANG1, RAZZAQUE}. + +\par + +Possible causes range from proton-synchrotron emission~\cite{TOTANI} to +photon-pion production~\cite{WAXMAN,BOETTCHER} and inverse-Compton scattering +in the burst environment~\cite{MESZAROS93,CHIANG,PILLA,ZHANG2,BELOBORODOV}. +A long-term high energy (HE) $\gamma$-emission can come from accelerated protons in the forward-shock, as predicted in~\cite{LI}. +This model predicts GeV inverse Compton emission up to one day after the burst. +Even considering pure electron-synchrotron radiation, measurable GeV-emission for a significant +fraction of GRBs is predicted~\cite{ZHANG2}. + +\par + +GeV-emission in GRBs is particularly sensitive to the Lorentz factor and the photon density of the emitting material -- and thus to the distance of the radiating shock from the source -- due to the $\gamma \gamma \rightarrow \textrm{e}^+\textrm{e}^-$ absorption in the emission region. Direct comparison of the prompt GRB flux at $\sim$\,10\,GeV and $\sim$\,100\,keV may allow to determine the magnetic field strength~\cite{ASAF2}.\\ + + +Several attempts were made in the past to observe GRBs in the GeV range, +each indicating some excess over background but without stringent evidence. +The only significant detections were performed by \eg, that was able to observe seven GRBs emitting HE photons with energies between 100\,MeV and 18\,GeV~\cite{EGRET, DINGUS1}. The data shows a HE spectral component presumably due to the ultra-relativistic acceleration of hadrons and producing a spectral index of $-1$ with no cut-off up to the TASC detector energy limit at 200\,MeV~\cite{DINGUS2, GONZALES}. 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}.\\ + +To estimate the observability of GRB by \ma, sources of the +third and fourth \ba catalogue were studied~\cite{ICRC,NICOLA}. Their spectra were extended to GeV +energies with a simple power-law and using the observed high-energy spectral index: the extrapolated fluxes +were at last compared with \ma sensitivities. Setting conservative cuts on observation times and significances, +and assuming an energy threshold of 15~GeV, a 5\,$\sigma$-signal rate of $0.5-2$ per year +was obtained for an assumed observation delay between 15 and 60\,s and a \ba trigger rate +($\sim$\,360/year). As the \sw alert rate is about a factor~2 lower, including even fainter bursts than +those observed by \ma, this number still have to be lowered. + +Taking into account the local rate of GRBs estimated in~\cite{GUETTA}, late afterglow emission from a +few tens of GRBs per year should be observable over the whole sky above our energy threshold. +The model of~\cite{ASAF2} predicts delayed GeV-emission that should be significantly detectable by \ma +in 100\,s. + +\subsection{Observation of XRFs} + +While the major energy from the prompt GRBs is emitted in $\gamma$-rays with a peak energy of 200\,keV, +X-ray flashes (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 suggested. +Some theories~\cite{DADO} suggest that XRFs are produced from GRBs observed ''off-axis''. +Alternatively, an increase of the baryon load within the fireball itself~\cite{HUANG} or low efficiency +shocks~\cite{BARRAUD} could produce XRFs. +If there is a connection between XRFs and GRBs, they should originate at rather low redshifts ($z < 0.6$) +because otherwise, the XRF energies would not fit into the observed correlation +between GRB peak energy and isotropic energy release~\cite{LEVAN}. + +\subsection{Observation of SGRs} + +Soft Gamma Repeaters (SGRs) are believed to be 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 within the same gamma jet model where the jet is observed at different +beam-angles and different times~\cite{FARGION}.\\ + +The BAT instrument on the SWIFT satellite triggered on an outburst from SGR1806-20 on January $30^{\mathrm{th}}$, 2005. +The fluence was about $10^{-5}\mathrm{erg}\cdot\mathrm{cm}^{-2}$ in the range between 15 and 350\,keV. +This event was five orders of magnitude smaller than the giant flare from this source on the December 27$^{\mathrm{th}}$, 2004~\cite{GCN3002}. +MAGIC has enough sensitivity for observing events with fluences bigger than $2.5 \times 10^{-2}\mathrm{erg}\cdot\mathrm{cm}^{-2}\mathrm{s}^{-1}$ at 100\,keV, when a spectral index of $-2.0$ and 100\,s of observation time are assumed. +Therefore if an SGR as the giant flare of SGR1806-20 occurs, MAGIC would be able to detect its $\gamma$-ray emission.\\ + +Gamma-ray satellites react in the same way to XRFs, SGRs 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. We include therefore the observation of XRFs and SGRs by \ma in our proposal. + + +%%% Local Variables: +%%% mode: latex +%%% TeX-master: "GRB_proposal_2005" +%%% End: