Changeset 6784
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- 03/08/05 12:53:09 (20 years ago)
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trunk/MagicSoft/GC-Proposal/GC.tex (modified) (10 diffs)
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trunk/MagicSoft/GC-Proposal/GC.tex
r6782 r6784 278 278 279 279 Figure \ref{fig:exclusion_lmits} shows exclusion limits for MAGIC (solid straight lines) for the four most promising sources, 280 in the plane $N_{\gamma}(E_{\gamma}>E_{\mathrm{thresh}})\langle \sigma v \rangle$ vs. $m_{\chi}$. Due to its proximity the GC yields the largest expected flux from particle dark matter annihilation. Nevertheless, this minimum measurable flux is more than one order of magnitude above the highest fluxes predicted by SUSY models. Also the flux measured by the HESS experiment is far above the theoretical expectation.280 in the plane $N_{\gamma}(E_{\gamma}>E_{\mathrm{thresh}})\langle \sigma v \rangle$ vs. $m_{\chi}$. The energy threshold $E_th$ has been assumed to be 100 GeV. Due to its proximity the GC yields the largest expected flux from particle dark matter annihilation and thus the lowest exclusion limit. Nevertheless, this minimum measurable flux is more than one order of magnitude above the highest fluxes predicted by SUSY models (full circles). Also the flux measured by the HESS experiment is far above the theoretical expectation. 281 281 282 282 … … 285 285 \includegraphics[totalheight=6cm]{plot_DM_exclusion.eps}%{Dark_exclusion_limits.eps} 286 286 \end{center} 287 \caption[DM exclusion limits.]{Exclusion limits (solid straight lines) for the four most promising sources of dark matter annihilation radiation. The GC is expected to give the largest flux from all sources. For energies above 700 GeV, the flux from the GC as observed by the HESS experiment (dotted line) is within the reach of MAGIC. The solid points represent flux predictions from some typical SUSY models. -- Figure to be updated --} \label{fig:exclusion_lmits}287 \caption[DM exclusion limits.]{Exclusion limits (solid straight lines) for the four most promising sources of dark matter annihilation radiation. The GC is expected to give the largest flux from all sources. For energies above 700 GeV, the flux from the GC as observed by the HESS experiment (dotted line) is within the reach of MAGIC. The full circles represent flux predictions from some typical SUSY models. -- Figure to be updated --} \label{fig:exclusion_lmits} 288 288 \end{figure} 289 289 … … 300 300 still being analyzed. Preliminary results were presented at the MAGIC 301 301 collaboration meeting in Berlin, 21-25th February 2005.\\ 302 Up to now there is only 2.9 hours of ON data available at a very large zenith 303 angle range. Some details of the data set are shown in Table \ref{table:GC_dataset}.\\ 302 Up to now only 2.9 hours of ON data are available, at zenith angles between 60.3 and 67.8 degrees. Some details of the data set are shown in Table \ref{table:GC_dataset}.\\ 304 303 305 304 \begin{table}[!ht]{ … … 321 320 ZA (65$^\circ$ ZA and 205$^\circ$ Az) Monte Carlo gammas were generated, 322 321 99500 events in all, with energies between 200 323 and 30,000 GeV. The slope of the generated spectrum is $-2.6$, conforming the 324 energy spectrum of the Crab nebula... 325 326 The MC sample is divided into training 327 and test sample. Since there is no dedicated OFF data available, we used a 328 subsample of Sgr A$^*$ ON data for the Random Forest training. As training 322 and 30,000 GeV. The differential spectral index of the generated spectrum is $-2.6$, conforming with the energy spectrum of the Crab nebula. 323 324 The MC sample was divided into a training 325 and a test sample. Since no dedicated OFF data were available, we used a 326 subsample of Sgr A$^*$ ON data to represent the hadronic background in the Random Forest training. As training 329 327 parameters we used SIZE, DIST, WIDTH, LENGTH, CONC, and M3Long... 330 328 … … 348 346 349 347 350 The observed differential gamma fluxby the HESS collaboration is given by \cite{GC_hess}:348 The differential gamma flux observed by the HESS collaboration is given by \cite{GC_hess}: 351 349 352 350 \begin{equation} … … 375 373 376 374 377 Thus the expectedintegral fluxes above 700 GeV based on the HESS and Cangaroo data agree within errors.375 Thus the integral fluxes above 700 GeV based on the HESS and Cangaroo data agree within errors. 378 376 379 377 Using MC simulations \cite{MC-Camera} for small zenith angles we conservatively estimate MAGICs sensitivity \cite{MC-Sensitivity} to the integral flux to be: … … 383 381 \end{equation} 384 382 385 Assuming this sensitivity MAGIC shall be able to get an excess at the 5 386 $\sigma$ significance level in $1.8 \pm 0.5$ h observation time for both the 387 Cangaroo and HESS spectrum. The observed Cangaroo and HESS spectra differ 383 Assuming this sensitivity and using the integrated flux of $3.2\cdot 10^{-12} cm^{-2}s^{-1}$ MAGIC will obtain an excess at the 5 384 $\sigma$ significance level in $1.8 \pm 0.5$ h observation time. 385 386 The observed Cangaroo and HESS spectra differ 388 387 substantially in the spectral index. While the Cangaroo spectrum only extends 389 to about 2 TeV, the recently published HESS spectrum goes up to about 9 TeV. Figure \ref{fig:MAGIC_flux_limits} shows the HESS and Cangaroo observed fluxes together with the mimimum detectable flux withMAGIC in 20 hours observation time.388 to about 2 TeV, the recently published HESS spectrum goes up to about 9 TeV. Figure \ref{fig:MAGIC_flux_limits} shows the HESS and Cangaroo observed fluxes together with the mimimum flux detectable by MAGIC in 20 hours observation time. 390 389 391 390 MAGIC will be able to solve the obvious discrepancy between the observed fluxes. Due to the observation under high zenith angle of about 60 deg MAGIC will be able to extend the source spectrum to higher energies. … … 396 395 \includegraphics[totalheight=8cm]{MAGIC_flux_limits.eps} 397 396 \end{center} 398 \caption[Flux limits.]{Observed gamma spectra of the HESS and Cangaroo experiments compared to the minimum detectable flux withthe MAGIC telescope in 20 hours observation time.} \label{fig:MAGIC_flux_limits}397 \caption[Flux limits.]{Observed gamma spectra of the HESS and Cangaroo experiments compared to the minimum flux detectable by the MAGIC telescope in 20 hours observation time.} \label{fig:MAGIC_flux_limits} 399 398 \end{figure} 400 399 … … 423 422 Based on the above estimations a 5 $\sigma$ excess is expected to be observed in about 2 hours assuming the HESS flux. To acquire a comparable data set to the other experiments at least 20 hours of good ON data and 20 hours of good dedicated OFF data are needed. 424 423 425 To get the lowest possible threshold all data shall be taken underthe424 To get the lowest possible threshold all data shall be taken at the 426 425 smallest possible zenith angles between culmination at about 58 deg and 60 427 426 deg. This limits the data taking interval to about 1 hour per night between … … 435 434 436 435 In order to take part in exploring the exciting physics of the GC 437 we propose to start taking data as soon as possible beginning in April. In this way first results may be presented inthe summer conferences 2005.436 we propose to start taking data as soon as possible, beginning in April. In this way first results may be presented at the summer conferences 2005. 438 437 439 438
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