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    r5967 r5968  
    5454%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    5555\title{Proposal for the Observation of Gamma-Ray Bursts with the MAGIC Telescope \\
    56      {\it \Large DRAFT 0.0 }}
     56     {\it \Large DRAFT 1.0 }}
    5757\author{  N. Galante\\ \texttt{<nicola.galante@pd.infn.it>}\\
    5858  M. Garczarczyk\\ \texttt{<garcz@mppmu.mpg.de>}\\
     
    6161}
    6262 
    63 \date{December, 2003\\}
    64 \TDAScode{MAGIC-TDAS 02-??\\ 0312??/NGalante}
     63\date{January, 2005\\}
     64\TDAScode{MAGIC-TDAS 05-??\\ 0312??/NGalante}
    6565%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    6666%% title %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     
    7070\begin{abstract}
    7171We give a detailed plan for the observation of Gamma Ray Bursts for the year
    72 2004. All observations will be triggered by alerts of the satellites \he, \ig, 
    73 \sw or by other circulars by the \g. Based on \he experience from the year 2002,
    74 we expect an alert rate of a total of about 50 per year out of which only about 20 will
    75 be followed by a position.
    76 %FIXME
    77 {\it \bf THIS HAS STILL TO BE UPDATED FOR 2003 !!}
    78 The majority of these alerts will be based on ground analysis and
    79 arrive with a delay of about an hour or more.
     722005. All observations will be triggered mainly by alerts of the satellites \he, \ig   
     73and above all \sw. we expect an alert rate of a total of about
     74\par
     75\ldots HOW MANY??? \ldots
     76\par
     77per year out of which only about
     78\par
     79\ldots HOW MANY??? \ldots
     80\par
     81will be followed by a position.
     82We give a detailed description of the observation procedures in La Palma and
     83propose to review the situation in half a year from now.
    8084\end{abstract}
    8185
    8286%% contents %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    83 %\thetableofcontents
     87\thetableofcontents
    8488
    8589\newpage
    8690
    8791%% body %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     92\include{Introduction}
     93\include{Alerts}
     94\include{Monitor}
     95\include{Strategies}
     96\include{Timing}
     97\include{Requirements}
     98
    8899
    89100%------------------------------------------------------------
    90 \section{Introduction}
    91 The MAGIC telescope has been designed especially light with a special focus on
    92 being able to react fastly to GRB alerts from the satellites.
    93 In \cite{design} and~\cite{PETRY},
    94 the objective was set to turn the telescope to the burst position in 10-30~s
    95 in order to have a fair chance of detecting a burst with the MAGIC telescope.
    96 The current possible value is 20 sec. for full turn-around
    97 %FIXME
    98 {\it \bf THIS HAS TO BE CHECKED FROM THOMAS B. !!}
    99 \par
    100 Several attempts have been made in the past to observe GRBs at energies
    101 from the GeV range upwards each indicating some excess over background but
    102 without stringent evidence. The only secured detection was performed by EGRET
    103 which detected seven GRBs emitting high energy photons in the
    104 100~MeV to 18~GeV range~\cite{EGRET}. There have been
    105 results suggesting gamma rays beyond the GeV range from the TIBET array~\cite{TIBET} and
    106 from HEGRA-AIROBICC~\cite{HEGRA}. Evidence for TeV emission of one burst was claimed by
    107 the MILAGRITO experiment~\cite{MILAGRO}. Recently, the GRAND array has reported some
    108 excess of observed muons during seven BATSE bursts~\cite{GRAND}. In this context, note
    109 especially a recent publication from the TASC detector on \eg~\cite{TASC},
    110 finding a high-energy spectral
    111 component presumably due to ultra-relativistic acceleration of hadrons and
    112 producing a spectral index of $-1$ with no cut-off up to the detector limit (200 MeV).
    113 \par
    114 The nowadays most widely accepted model for gamma emission from GRB suggests a bursts
    115 environment involving collisions of an ultra-relativistic e$^+$-e$^-$
    116 plasma fireball~\cite{PAZCYNSKI,GOODMAN,SARI}. These fireballs may produce
    117 low-energy gamma rays either by ``internal'' collisions of multiple
    118 shocks~\cite{XU,REES} or by ``external'' collisions of a single shock
    119 with the ambient circum burst medium (CBM)~\cite{MESZAROS94}.
    120 \par
    121 In many publications,
    122 the possibility that more energetic gamma-rays come along with the (low-energy) gamma-ray
    123 burst, have been explored.
    124 Proton-synchrotron emission~\cite{TOTANI} have
    125 been suggested as well as photo-pion production~\cite{WAXMAN,BAHCALL,BOETTCHER}
    126 and inverse-Comption
    127 scattering in the burst environment~\cite{MESZAROS93,CHIANG,PILLA,ZHANG}.
    128 Long-term high-energy gamma emission from accelerated protons in forward-shock
    129 has been predicted in~\cite{LI}.
    130 Even considering pure electron-synchrotron radiation predicts measurable GeV emission for a
    131 significant fraction of GRBs~\cite{ZHANG}.
    132 Implications of the observation of a high-energy gamma-ray component on
    133 distance scale, energy production in the GRB and distinction between internal and
    134 external shock models have been treated in~\cite{HARTMANN,MANNHEIM,SALOMON,PRIMACK}.
    135 \par
    136 In the year 2004, mainly three satellites will produce the bulk of the GRB alerts: The \he
    137 satellite, launched in October 2000, the \ig satellite, launched October 2002 and the
    138 \sw satellite, scheduled for launch in May, 2004.
    139 \par
    140 % HERE
    141 We will give an overview of the types of alarms, we expect from the three satellites
    142 and add then our proposal for observation strategies. Note that while there is already some
    143 experience accumulated from the \he and \ig alarms, we do not know yet how \sw will perform
    144 since it is still not launched. Because the observation of GRBs will differ
    145 from conventional observations in several aspects, we also propose a detailed plan to test
    146  and calibrate the system in order to meet our purposes.
    147 \par
    148 {\ldots \it \bf THIS IS TO BE CHECKED BY NICOLA G. !! \ldots \\}
    149 \par
    150 Concerning estimates about the MAGIC observability of GRBs, a very detailed study
    151 of GRB spectra obtained from the third and fourth \ba catalogue has been made
    152 in~\cite{ICRC,NICOLA}. The spectra were extrapolated to \ma energies with a simple continuation
    153 of the observed high-energy power law behaviour and the calculated fluxes compared
    154 with \ma sensitivities. Setting conservative cuts on observation times and significances,
    155 and assuming an energy threshold of 15~GeV, a GRB detection rate of $0.5--2$ per year
    156 was obtained for an assumed observation delay of 15~sec. and the \sw GRB trigger rate ($\sim 100/year$).
    157 
    158 
    159 \section{\he Alarms}
    160 
    161 {\it \bf THIS HAS TO BE UPDATED TO 2003 !!}
    162 
    163 The HETE mission has three instruments on board which can generate burst triggers:
    164 Fregate, the WXM, and the SXC.
    165 Fregate data are examined in two broad energy channels:
    166 5-80 keV and 30-400 keV.
    167 The WXM data are from 2-30 keV,
    168 and the SXC data are from 1.5 to 12 keV.
    169 \par
    170 The Fregate data are searched for counts excesses on four different timescales:
    171 20 ms, 160 ms, 1.3 s, and 5.2 s.
    172 The threshold for a count excess to be considered significant is generally around 5 sigma.
    173 Such an excess must be seen in two of the four Fregate detectors on the same timescale
    174 for a burst to be considered real.
    175 \par
    176 The WXM data are examined on multiple timescales between 80 ms and 10 s.
    177 The thresholds are all near 5 sigma. This analysis is done on one of the on-board transputers.
    178 \par
    179 Fregate data are also analyzed on multiple timescales in a manner identical
    180 to that for the WXM data on the same transputer the WXM data are analyzed by.
    181 \par
    182 SXC data can be used to create a continuous series of cross-correlation maps using a dedicated DSP,
    183 and a burst is registered when the peak of the cross-correlation map exceeds a threshold.
    184 Because of the difficulties with the SXC hardware, SXC triggering is currently not operating.
    185 \par
    186 When a burst is detected, the real-time spacecraft notification will distribute
    187 \begin{itemize}
    188 \item the energy range of the burst (1.5-12 keV, 2-30 keV, 5-80 keV, or 30-400 keV)
    189 \item the timescale of the trigger (from 20 ms to over 10 s)
    190 \item the S/N or the peak count rate of the burst
    191 \end{itemize}
    192 \par
    193 
    194 In the year 2002, about 630 internal \he triggers occurred, out of which about 75 were
    195 considered as GRBs or possible GRBs by the ground analysis. About 50 of these bursts
    196 were subsequently considered as real\cite{HETE-SUM}. Note that about 40 of
    197 another species of bursts called ``X-ray bursts'' (XRB) were detected, mainly while the
    198 satellite was looking towards the Galactic center.
    199 \par
    200 
    201 The real-time alerts sent to the \g by \he have the following signature~\cite{HETE}:
    202 \begin{description}
    203 \item[ALERT] If the burst is detected using photons in the 5-80 keV or 30-400 keV bands,
    204 regardless whether a position has been determined or not. This type of alert has occurred
    205 about 170 times in 2002.
    206 \item[UPDATE] If a position is determined on board and it is considered significant enough,
    207 the RA and declination of the burst will be distributed in this type to the \g.
    208  Each additional position determined on board
    209 (each with higher significance than all determined before)
    210 will result in a new Notice of type UPDATE. In 2002, about 10 UPDATE's were sent to
    211 the \g, two third of which had a position error of about 1 arcmin, one third with about
    212 half an arcmin.
    213 \item[LAST] Once the on-board processing of data near the time of the trigger is complete,
    214 there will be no more immediate results from the spacecraft,
    215 a summary Notice this type is distributed. In 2002, about 120 LAST's were sent out to the \g,
    216 containing about 20 positions of bursts.
    217 \end{description}
    218 The quality of the real-time positions are assured by making a cut on the lightcurve S/N and the
    219 image S/N in a way that with $>$90\% the real-time position is correct.
    220 As a result, HETE positions distributed in real time from the spacecraft are in one of two categories:
    221 \begin{itemize}
    222 \item Category I:
    223 The image and lightcurve S/N all exceed 3.0,
    224 so the position is distributed with a 90\% error radius of 12-14 arcminutes.
    225 \item Category II:
    226 Not all of the image and lightcurve S/N exceeds 3.0,
    227 but the quadrature sum of the image S/N from the WXM X and Y detectors is > 3.7,
    228 and neither the X nor the Y incident angle exceeds 30 degrees,
    229 so the position is distributed with a 90\% error radius of 30 arcminutes.
    230 \end{itemize}
    231 
    232 In order to accommodate those observers who would like to make their own estimate
    233 of the quality of a real-time burst localization, also included in the \g message are:
    234 \begin{itemize}
    235 \item The image S/N from the X and Y modules of the WXM
    236 \item The lightcurve S/N from the X and Y modules of the WXM
    237 \item The longitude of the HETE spacecraft at the time of the trigger.
    238 \end{itemize}
    239 The higher the image and lightcurve S/N,
    240 the more reliable the localization will be.
    241 Low values of image and lightcurve S/N are typically associated with events
    242 localized at the edge of the instrument FOV.
    243 \par
    244 This method of distribution of \g Notices results in a few common situations:
    245 \begin{itemize}
    246 \item If there is no significant position calculated in real time on board,
    247 there will be no burst coordinates in any \g Notice.
    248 If ground analysis reveals a position,
    249 it will be sent out as a type GND\_ANALYSIS Notice.
    250 \item Because the Burst Alert Station coverage is not always 100\%,
    251 there can be gaps in the reception of burst data from the spacecraft.
    252 If the flight analysis of a burst is over before a Burst Alert Station is seen,
    253 the full analysis of the burst will be sent in two Notices,
    254 one of type ALERT and the other of type LAST.
    255 This means that a Notice of type ALERT could, in principle,
    256 contain the coordinates of the burst.
    257 \end{itemize}
    258 Both the WXM and SXC search data from seconds before the burst trigger to minutes after,
    259 looking for the image of the burst. The WXM software matches the shadow pattern on the detector
    260 with template patterns, looking for a best fit; the SXC looks for peaks in the cross-correlation map.
    261 In either case, if a significant position is found in either instrument,
    262 its location is sent to the ground in real time.
    263 Once the positions and their significances are received on the ground,
    264 the RA and declination of the image are calculated and,
    265 if the significances are high enough, transmitted to the \g.
    266 At present, SXC positions are not sent to the \g automatically,
    267 but rather only after ground analysis.
    268 
    269 \par
    270 Ground analysis of a burst begins as soon as the full burst data reach MIT after a
    271 Primary Ground Station contact (from a few minutes to over an hour after the burst).
    272 Automated software performs standard analyses of the downlinked data,
    273 and a human is notified to make the final decisions.
    274 A followup \g Notice, of type GND\_ANALYSIS,
    275 will be distributed under the following circumstances:
    276 \begin{itemize}
    277 \item There was no position calculated on board, but ground analyses reveal a significant position.
    278 \item There was a position calculated on board and ground analyses can improve the coordinates
    279 and/or reduce the error box size.
    280 \item There was a position calculated on board, but there is actually no significant position in the data.
    281 \end{itemize}
    282 In general, if there is a position in a real-time \g Notice,
    283 it should be considered accurate.
    284 If there is no position in a real-time \g Notice,
    285 a position may be forthcoming within an hour or so of the original Notice.
    286 If a burst position was distributed and it is wrong because of software or operator error,
    287 a GND\_ANALYSIS message will be distributed;
    288 if no position was distributed, no GND\_ANALYSIS message will be sent.
    289 In 2002, about 25 ground analyses contained positions of GRB's and 5 further of XRB's.
    290 \par
    291 
    292 From the 30 bursts with position sent to the \g in 2002, \ma would have had 7 in its FOV
    293 which are  listed in the following table:
    294 \begin{table}[h]
    295 \label{tab:heteoverlap}
    296 \begin{center}
    297 {\small
    298 \begin{tabular}{|c|c|c|c|c|c|c|c|c|c|}
    299 \hline
    300 \hline
    301 GRB &    date & UTC & RA & dec. & error     & $\theta$ & $\phi$ & flag  & comments\\
    302 name & (dd.mm)&     &    &      & arc.      & MA- & MA- & providing & \\
    303      &        &     &    &      & min.      & GIC & GIC & position & \\
    304 \hline
    305 --   & 27.11. & 1:20:39 & 53.78 & -15.84 & 60 & 48 & 198 & UPDATE & probable GRB \\
    306      &        &         &       &        &    &    &     &  & moon at:\\
    307      &        &         &       &        &    &    &     &  & $\theta= 77^\circ, \phi=77^\circ$\\
    308 \hline
    309 GRB021113 & 13.11. & 06:38:57 & 23.47 & 40.4 & 28 & 85 & 314 & GND & no moon \\
    310 \hline
    311 GRB021112 & 12.11. & 03:28:16 & 39.22 & 48.8 & 54 & 40 & 313 & GND & no moon \\
    312 \hline
    313 GRB020813 & 13.08. & 02:44:19 & 296.66 & -19.6 & 28 & 67 & 229 & ALERT &  no moon \\
    314 \hline
    315 --   & 28.07. & 21:44:58 & 273.67 & -12.13 & 28 & 45 & 153 & UPDATE & probable GRB\\
    316      &        &         &       &        &    &    &     &  & no moon \\
    317 \hline
    318 GRB020531 & 31.05. & 00:26:18 & 228.69 & -19.36 & 77 & 49 & 191 & GND & 
    319 moon at: \\
    320      &        &         &       &        &    &    &     &  & $\theta= 87^\circ, \phi=118^\circ$ \\
    321 \hline
    322 GRB020127 & 27.01. & 20:57:24 & 123.77 & 36.74 & 240 & 51 & 64 & UPDATE &
    323 moon at: \\
    324      &        &         &       &        &    &    &     &  & $\theta= 47^\circ, \phi=83^\circ$ \\
    325 \hline
    326 \hline
    327 \end{tabular}
    328 }
    329 \end{center}
    330 \caption{\he bursts, which would have been in principle visible from the \ma telescope site at
    331 night. No burst durations, alert delays, weather conditions, etc. are displayed. For more
    332 detailed information on single bursts, see~\cite{NICOLAGRB}.}
    333 \end{table}
    334 
    335 As one can see from table~\ref{tab:heteoverlap}, more overlap bursts
    336 than expected from randomly superimposed fields of view ($\sim$1--2 bursts only),
    337 have been found. As expected from the increase of covered solid angle at high
    338 zenith angles, all bursts had rather larger zenith angles ($\theta \geq 40^\circ$)
    339 culminating and cover the whole range of azimuths.
    340 \par
    341 Additionally, five bursts occurred during the day, but would have moved into the \ma FOV in a
    342 delay of less than six hours (see table~\ref{tab:hetelongoverlap}):
    343 \begin{table}[h]
    344 \label{tab:hetelongoverlap}
    345 \begin{center}
    346 {\small
    347 \begin{tabular}{|c|c|c|c|c|c|c|c|c|c|}
    348 \hline
    349 \hline
    350 GRB &    date & UTC & RA & dec. & error     & $\theta$ & $\phi$ & flag  & comments\\
    351 name & (dd.mm)&     &    &      & arc.      & MA- & MA- & providing & \\
    352      &        &     &    &      & min.      & GIC & GIC & position & \\
    353 \hline
    354 --   & 15.07. & 18:45:40 & 273.7 & -12.1 & 2.0 & 51 & 138 & UPDATE & XRB \\
    355      &        &         &       &        &    &    &     &  & $\theta$ and $\phi$ at 21:43:00 UTC \\
    356      &        &         &       &        &    &    &     &  & moon at:\\
    357      &        &         &       &        &    &    &     &  & $\theta= 69^\circ, \phi=252^\circ$\\
    358 \hline
    359 --   & 09.06. & 20:45:37 & 275.9 & -30.4 & 1.4 & 88 & 126 & LAST & possible GRB \\
    360      &        &         &       &        &    &    &     &  & $\theta$ and $\phi$ at 21:43:00 UTC \\
    361      &        &         &       &        &    &    &     &  & no moon \\
    362 \hline
    363 --   & 08.06. & 16:02:39 & 275.9 & -30.4 & 2.2 & 89 & 125 & GND & XRB \\
    364      &        &         &       &        &    &    &     &  & $\theta$ and $\phi$ at 21:43:00 UTC \\
    365      &        &         &       &        &    &    &     &  & no moon \\
    366 \hline
    367 GRB020331 & 31.03. & 16:32:28 & 199.1 & -17.9 & 20 & 86 & 113 & GND & $\theta$ and $\phi$ at 21:49:00 UTC \\
    368      &        &         &       &        &    &    &     &  & no moon \\
    369 \hline
    370 GRB020317 & 17.03. & 18:15:31 & 155.8 & 12.7 & 36 & 46 & 101 & GND & $\theta$ and $\phi$ at 21:40:00 UTC \\
    371      &        &         &       &        &    &    &     &  & moon at:\\
    372      &        &         &       &        &    &    &     &  & $\theta= 19^\circ, \phi=271^\circ$\\
    373 \hline
    374 \hline
    375 \end{tabular}
    376 }
    377 \end{center}
    378 \caption{\he bursts, which would have been in principle visible from the \ma telescope site occurring
    379 during the day but moving into the \ma FOV in less than six hours.
    380 No burst durations, alert delays, weather conditions, etc. are displayed. For more
    381 detailed information on single bursts, see~\cite{NICOLAGRB,GCNARCHIVE}. Two bursts are marked
    382 as XRB (X-ray bursts) a phenomenon seen regularly by the \he WXM while looking into the Galactic Center.}
    383 \end{table}
    384 
    385 The \he field of view spans roughly 75$^\circ$ in DEC and and 5 hrs in RA.
    386 Because \he is anti-solar pointing, its field-of view drifts along the ecliptic
    387 at a rate of about one degree per day. Its maximum declination reaches 60$^\circ$ with the lower
    388  border of its field of view at about -15$^\circ$. Its minimum declination reaches -60$^\circ$
    389 with the upper border at about +15$^\circ$~\cite{HETE}.
    390 The best overlap between \ma and \he fields of view
    391 is thus in the winter, between October and March.
    392 
    393 \section{\ig Alarms}
    394 
    395 {\ldots \it \bf THIS IS TO BE UPDATED TO 2003 !! \ldots \\}
    396 \par
    397 The \ig satellite was successfully commissioned in March 2003.
    398 The use of INTEGRAL is planned for 2 years with a possible extension for up to 5 years.
    399 
    400 \par
    401 The satellite contains four main instruments:
    402 \begin{description}
    403 \item[IBIS:\xspace] The imager IBIS (Imager on Board the INTEGRAL Satellite)
    404 will achieve an angular resolution of 12 arcmin over an energy range between 15 keV and 10 MeV.
    405 \item[SPI:\xspace] The spectrometer SPI (SPectrometer on INTEGRAL)
    406 will provide spectral analysis of gamma-ray point sources
    407 as well as extended sources over an energy range between 20 keV and 8 MeV.
    408 \item[JEM-X:\xspace]
    409 Two identical X-ray monitors, JEM-X (Joint European X-ray Monitor) will work
    410 simultaneously with the other instruments in the energy range between 3 and 35 keV
    411 and with an angular resolution of one arcmin.
    412 \item[OMC:\xspace]
    413 The optical monitoring camera, OMC, covers a field of 17.6 x 17.6 arcsec.
    414 The total field of view of the OMC camera will be of 5 x 5 degrees.
    415 \end{description}
    416 
    417 \par
    418 Alerts with the coordinates of GRBs will be distributed via internet
    419 with a small delay with respect to the GRB occurrence.
    420 It is expected that this delay will be smaller than a few minutes. The alerts as
    421 such can be delivered to the recipient within 1 second.
    422 The expected rate of GRBs that will be localized with an accuracy of a few arcminutes
    423 is of the order of 1-2 per month~\cite{GOTZ}.
    424 \par
    425 The IBAS alerts are sent via internet, using the UDP transport protocol. The Client Software
    426 made available by \ig together with the first real alerts are currently being tested in Barcelona.
    427 Five Alert Types have been defined so far~\cite{IBAS}:
    428 \begin{description}
    429 \item[POINTDIR] Gives the \ig pointing direction (e.g. to obtain reference images of the pre-GRB sky). No
    430 alert is attached with this type.
    431 \item[SPIACS]
    432 SPIACS alert packets will be sent after positive triggers detected with the
    433 SPI Anti-Coincidence Shield (ACS). No position information will be available,
    434 unless the same GRB also triggers some of the imaging instruments
    435 and in such a case the position will come through other packet types.
    436 \item[WAKEUP]
    437 WAKEUP packets are generated only once for each GRB
    438 and only if the GRB position information is available.
    439 They contain the preliminary position derived for the GRB.
    440 These are the alerts with the shortest time delay.
    441 Any (potential) GRB will generate only one WAKEUP packet.
    442 \item[REFINED]
    443 REFINED packets provide refined information on a GRB event.
    444 Zero to several REFINED packets can be generated for a given GRB.
    445 \item[OFFLINE]
    446 OFFLINE packets are generated manually after interactive analysis of the data has been performed
    447 offline by a Duty Scientist.
    448 The time delay might be from one to a few hours (or even longer in some cases).
    449 \end{description}
    450 
    451 One \ig burst was delivered to the GCN up to now. It would have been visible
    452 by \ma with a delay of about 1.5 hours (see table~\ref{tab:integraloverlap}).
    453 
    454 \begin{table}[ht]
    455 \begin{center}
    456 {\small
    457 \begin{tabular}{|c|c|c|c|c|c|c|c|c|c|}
    458 \hline
    459 \hline
    460 GRB &    date & UTC & RA & dec. & error     & $\theta$ & $\phi$ & flag  & comments\\
    461 name & (dd.mm)&     &    &      & arc.      & MA- & MA- & providing & \\
    462      &        &     &    &      & min.      & GIC & GIC & position & \\
    463 \hline
    464 GRB021125 & 25.11. & 17:58:30 & 19.78 & 28.1 & 30 & 51 & 280 & --- & no moon \\
    465      &        &         &       &        &    &    &     &  & $\theta$ and $\phi$ at 19:37:00 UTC \\
    466 \hline
    467 \hline
    468 \end{tabular}
    469 }
    470 \end{center}
    471 \label{tab:integraloverlap}
    472 \caption{\ig bursts, which would have been in principle visible from the \ma telescope site at
    473 night. No burst durations, alert delays, weather conditions, etc. are displayed. For more
    474 detailed information on single bursts, see~\cite{NICOLAGRB,GCNARCHIVE}.}
    475 \end{table}
    476 
    477 The period of the INTEGRAL orbit is 3 sideral days,
    478 so that the perigee occurs always above the same geographical point on Earth.
    479 
    480 %It is a highly eccentric orbit,
    481 %with a perigee height of 10'000 km and
    482 %an apogee height of 152'600 km
    483 %with an inclination of 51.6 degrees with respect to the equatorial plane.
    484 
    485 
    486 \section{\sw Alarms}
    487 
    488 {\ldots \it \bf THIS IS TO BE UPDATED !! \ldots \\}
    489 
    490 The \sw satellite~\cite{SWIFT} is scheduled for launch in May, 2004 for a nominal two-years mission.
    491 \par
    492 It contains three instruments:
    493 \begin{description}
    494 \item[BAT:\xspace] The BAT has an large field of view (1.4~sr) in an energy range of 15-150~keV.
    495 It has an angular resolution of 22 arcmin. and is itself able to determine GRB source locations (of
    496 5$\sigma$ or higher) to a resolution of 4 arcmin. It is predicted to locate more than 100 sources
    497 per year.
    498 \item[XRT:\xspace] The X-Ray Telescope on \sw provides afterglow positions of 5 arcsec. accuracy within
    499 100 sec. of the burst alert from BAT in an energy range of 0.2-10~keV.
    500 \item[UVOT:\xspace]
    501 The UVOT is designed for optical images of the GRB field 20-60 sec. after the GRB alert and
    502 in a wavelength range between 170 and 650~nm.
    503 \end{description}
    504 
    505 1--4 arcmin. position estimates of the GRB coordinates are predicted to arrive at ground within
    506 15 seconds~\cite{SWIFT2}.
    507 \par
    508 \sw autonomously sends preliminary information to the GCN, including a crude optical finding chart
    509 populated with postage stamp images around detected stars in UVOT, and BAT and XRT source positions
    510 and spectra. Within hours of the next ground pass, the Swift Science Data Center (SDC)
    511 initiates autonomous pipeline processing of the telemetry and serves it immediately
    512 to the community on its Quick-Look area, available to the community (FITS-files).
    513 
    514 \section{Further Possible Alarms}
    515 
    516 \subsection{IPN position notices}
    517 
    518 These notices are sent out by the GCN itself with GRB positions obtained
    519 after triangulation of at least three satellites
    520 using the individual arrival times and positions of the spacecrafts \he, \ig,
    521 KONUS, NEAR, MARS and ULYSSES.
    522 Usually, these messages arrive
    523 after previous alerts by the satellites themselves and refine the GRB position determination.
    524 
    525 There are two types of messages:
    526 \begin{description}
    527 \item[IPN\_SEG:\xspace]
    528 These Notices use the data from two different spacecrafts.
    529 Triangulation
    530 yields an annulus for possible GRB positions.
    531 The annulii segments are long (2-10deg) and narrow (2-30armin).
    532 %yielding an error box area of 4 sq.arcmin to 5 sq.deg.
    533 %The range of time delays is on average 24 to 48 hours (with the shortest being 11 hours to date).
    534 These message will not be considered further here
    535 because their position uncertainties are too large.
    536 \item[IPN\_POS:\xspace]
    537 For IPN\_POS Notices, the error boxes will be in the several arcmin and above range.
    538 For about 55\% of the Notices there will be only a single error box,
    539 but because 3 sources yield only 2 unique annuli and these 2 annuli cross in 2 locations,
    540 there can be 2 error boxes reports (~25\% of the cases).
    541 Depending on the relative timing of the GRB and the data dumps through the DSN,
    542 the wait can be 1-25 hours (more on the weekends).
    543 In 2002, 22 such messages were sent out with errors in the range of usually
    544 5--30 arcmin. There were no messages before the May 5$^{th}$, however.
    545 \end{description}
    546 
    547 Only one burst would have been announced by an IPN\_POS in less than 12 hours after the burst
    548 (see table~\ref{tab:ipnoverlap}).
    549 
    550 \begin{table}[ht]
    551 \label{tab:ipnoverlap}
    552 \begin{center}
    553 {\small
    554 \begin{tabular}{|c|c|c|c|c|c|c|c|c|c|}
    555 \hline
    556 \hline
    557 GRB &    date & UTC & RA & dec. & error     & $\theta$ & $\phi$ & flag  & comments\\
    558 name & (dd.mm)&     &    &      & arc.      & MA- & MA- & providing & \\
    559      &        &     &    &      & min.      & GIC & GIC & position & \\
    560 \hline
    561 GRB021016 & 16.10. & 10:29:00 & 8.43 & 46.8 & 22 & 61 & 43 & IPN\_POS &
    562 $\theta$ and $\phi$ at 22:06:48 UTC \\
    563      &        &         &       &        &    &    &     &  & moon at: \\
    564      &        &         &       &        &    &    &     &  & $\theta= 87^\circ, \phi=118^\circ$ \\
    565 \hline
    566 \hline
    567 \end{tabular}
    568 }
    569 \end{center}
    570 \caption{\ip bursts, which would have been in principle visible from the \ma telescope site at
    571 night. Only bursts which have been announced with less than 12 hours are taken into account.
    572 No burst durations, weather conditions, etc. are displayed. For more
    573 detailed information on single bursts, see~\cite{NICOLAGRB,GCNARCHIVE}.}
    574 \end{table}
    575 
    576 \section{Proposed Observation Strategies}
    577 
    578 {\ldots \it \bf THIS IS TO BE UPDATED !! \ldots \\}
    579 \par
    580 One can see from tables~\ref{tab:heteoverlap},~\ref{tab:hetelongoverlap},~\ref{tab:integraloverlap}
    581 and~\ref{tab:ipnoverlap} that observing GRBs
    582 at moon periods will significantly increase the chance to observe some.
    583 Three out of the seven bursts from table~\ref{tab:heteoverlap}
    584 would have occurred in astronomical twilight
    585 or very close to the start or end of observation
    586 (GRB021113 half an hour after usual closing of the telescope and
    587 GRB020127 and the one on 28.7. each three quarters of an hour after usual
    588 start). If we want to have a realistic chance to observe bursts, it is therefore
    589 important to use all available time {\it including moon periods, periods of astronomical
    590 twilight and putting the telescope as soon as possible in GRB-alert position}.
    591 
    592 \subsection{What to do at alerts without position (yet)}
    593 
    594 {\ldots \it \bf THIS IS TO BE REWRITTEN !! \ldots \\}
    595 
    596 \begin{verbatim}
    597 suggestion email Martin Kestel: \\
    598 \\
    599 When you put the telescope in Alt=90 degrees (zenith) and Az=90 degrees east,
    600 you have at most 90 degrees to move in either
    601 axis in order to reach any position on the sky, either in normal tracking mode
    602 or in reverse tracking mode. The actual speed will most probably be different
    603 in the two axes and the elevation will probably be slower, as it has only one
    604 motor attached. Now, the maximum elevation movement from zenith will
    605 correspond to the maximum zenith angle you want your GRB to have, so,
    606 this number will be certainly smaller than 90 degrees.
    607 \end{verbatim}
    608 
    609 \subsection{What to do at alerts with position}
    610 
    611 
    612 \section{Timing considerations}
    613 
    614 {\ldots \it \bf HAS TO BE UPDATED AND COMPLETED!! \ldots \\}
    615 {\it Here, all possible models should go in with reasonning why certain time
    616 or flux estimates are proposed.  We have now only estimates on extrapolations
    617 of the \eg power-laws. Maybe we should include: IC (in many possible combinations),
    618 hadronic emission models (see~\cite{TASC}), Cannonball model. }
    619 \par
    620 
    621 The EGRET~\cite{EGRET} instrument on the CGRO
    622 has detected GeV emission of GRB940217 promptly and 90 sec. after
    623 the burst onset.
    624 \\
    625 \par
    626 In~\cite{DERMER}, two peaks in the GeV light curve are calculated. An early maximum coincident
    627 with the MeV eak is the high-eneryg extension of the synchrotron component, some seconds
    628 after the burst onset. The second maximum peaking at $\approx$ 1.5 hours is due primarily to
    629 SSC radiation with significant emission of up to $10^5$ sec. ($\approx 25$ hours) after the burst.
    630 \\
    631 \par
    632 Li, Dai and Lu~\cite{LI} suggest GeV emission after pion production and some thermalization of the
    633 UHE component with radiation maxima of up to one day or even one week (accompanied by long-term
    634 neutrino emission).
     101
     102
    635103
    636104\subsection{Determine a reasonable upper time delay limit for the onset of an observation}
     
    670138
    671139{\ldots \it \bf STILL TO BE WRITTEN  \ldots \\}
    672 
    673 \subsection{Observing neutrino events below the horizon}
    674 
    675 {\ldots \it \bf CAN BE MAYBE GO INTO A SEPARATE PROPOSAL  \ldots \\}
    676140
    677141\subsection{Observing XRFs}
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