Changeset 6830

Timestamp:

03/16/05 13:55:41 (20 years ago)

Author:

wittek

Message:

*** empty log message ***

Location:

trunk/MagicSoft/GC-Proposal

Files:

• GC.tex (modified) (6 diffs)
• GCregion14largeW.eps (added)
• GCregionOFF1.eps (added)

trunk/MagicSoft/GC-Proposal/GC.tex

@@ -341 +341 @@
 %\end{figure}
 
-Preliminary conclusion : ??????????????????
+The results of the preliminary analysis can be summarized as follows. After the gamma/hadron separation, the ALPHA distributions of the ON data show excess signals of 121 and 32 events, with significances of 5.2 and 3.7 $\sigma$, for SIZE values above 300 p.e. and 800 p.e., respectively. If the SIZE cut at 300 p.e. corresponds to an energy threshold of 1.9 TeV and if the effective collection area is assumed to be 1.e5 m$^2$ the observed excess is by a factor of 10 higher than that expected on the basis of the HESS flux.
+
+Studies are going on concerning appropriate OFF data, the false-source plot and better estimates of the energy threshold and the effective collection area.
+
 
 
@@ -348 +351 @@
 
 \subsection{Expected gamma-ray fluxes}
-The HESS collaboration has observed the GC for 16.5 hours, at zenith angles around 20 degrees, with energy thresholds between 165 and 255 GeV. The total number of excess events amounts to $\sim$300, and the differential gamma flux is measured as \cite{GC_hess}:
+The HESS collaboration has observed the GC for 16.5 hours, at zenith angles around 20 degrees, with energy thresholds between 165 and 255 GeV. The total number of excess events amounts to $\sim$300. The differential gamma flux as determined in the energy region from 200 GeV to 10 TeV is \cite{GC_hess}:
 
 \begin{equation}
@@ -411 +414 @@
 \subsection{Verification of the MAGIC analysis at high zenith angles}
 In order to verify the correct performance of the MAGIC analysis at high ZA it is proposed to take Crab data in the interesting ZA range from 58$^{\circ}$ to 70$^{\circ}$, to reconstruct the gamma energy spectrum and to compare it with existing measurements. Like for the GC, either dedicated OFF data should be taken or observations should be made in the wobble mode.
+
+???? Propose suitable OFF regions ???
 
 
@@ -461 +466 @@
 %\end{table}
 
+The star field around the GC, including stars up to a magnitude of 14, is depicted in Figure \ref{fig:GC_starfield}. Within a distance of 1$^{\circ}$ from the GC there are no stars brighter than mag = 8.4, and there are 16 stars with $8<$ mag $<9$. At distances between 1$^{\circ}$ and 1.75$^{\circ}$ from the GC the total number of stars with  $4<$ mag $<9$ is 26. The brightest ones are Sgr 3 with mag = 4.5, GSC 6836-0644 with mag = 6.4 and GSC 6839-0196 with mag = 7.2.
+
 \subsection{Wobble mode}
-The star field around the GC, including stars up to a magnitude of 14, is depicted in Figure \ref{fig:GC_starfield}. One can see that the star field is roughly uniform except for the left lower part (RA$\;>\;$RA$_{GC}+4.7$ min), where the field is significantly brighter. The sky directions (WGC1, WGC2) to be tracked in the wobble mode should be chosen such that in the camera the sky field relative to the source position (GC) is similar to the sky field relative to the mirror source position (anti-source position). For this reason the prefered directions for the wobble mode are WGC1 = (RA$_{GC}$, dec$_{GC}$+0.4$^{\circ}$) and WGC2 = (RA$_{GC}$, dec$_{GC}$-0.4$^{\circ}$. During one night, 50\% of the data should be taken at WGC1 and 50\% at WGC2, switching between the 2 directions every 30 minutes.
+
+As can be seen from Figure \ref{fig:GC_starfield} the star field around the GC is roughly uniform except for the left lower part (RA$\;>\;$RA$_{GC}+4.7$ min), from the GC 1$^{\circ}$ to the left, where the field is significantly brighter. The sky directions (WGC1, WGC2) to be tracked in the wobble mode should be chosen such that in the camera the sky field relative to the source position (GC) is similar to the sky field relative to the mirror source position (anti-source position). For this reason the prefered directions for the wobble mode are WGC1 = (RA$_{GC}$, dec$_{GC}$+0.4$^{\circ}$) and WGC2 = (RA$_{GC}$, dec$_{GC}$-0.4$^{\circ}$. During one night, 50\% of the data should be taken at WGC1 and 50\% at WGC2, switching between the 2 directions every 30 minutes. 
+
+A larger sky area than in Fig.\ref{fig:GC_starfield} is shown in Figs. \ref{fig:GC_starfield_largeW} and \ref{fig:GC_starfield_OFF1}. The circles in the center indicate the region around the GC. The positions of WGC1 and WGC2 are indicated as full circles.
 
 \begin{figure}[h!]
@@ -468 +478 @@
 \includegraphics[totalheight=16cm]{GCregion14.eps}
 \end{center}
-\caption[Star field around the GC.]{Star field around the GC. Stars up to a magnitude of 14 are plotted. The 2 big circles correspond to distances of 1$^{\circ}$ and 1.75$^{\circ}$ from the GC, respectively. The x axis is pointing into the direction of decreasing RA, the y axis into the direction of increasing declination. The grid spacing in the declination is 20 arc minutes.
+\caption[Star field around the GC.]{Star field around the GC. Stars up to a magnitude of 14 are plotted. The 2 big circles correspond to distances of 1$^{\circ}$ and 1.75$^{\circ}$ from the GC, respectively. The x axis is pointing into the direction of decreasing RA, the y axis into the direction of increasing declination. The grid spacing in the declination is 20 arc minutes. The Galactic Plane is given by the dotted line.
 } \label{fig:GC_starfield}
 \end{figure}
@@ -474 +484 @@
 \begin{figure}[h!]
 \begin{center}
-\includegraphics[totalheight=16cm]{GCregion14large.eps}
-\end{center}
-\caption[Star field around the GC.]{Star field around the GC. Stars up to a magnitude of 14 are plotted. The 2 big circles correspond to distances of 1$^{\circ}$ and 1.75$^{\circ}$ from the GC, respectively. The x axis is pointing into the direction of decreasing RA, the y axis into the direction of increasing declination. The grid spacing in the declination is 1 degree.
-} \label{fig:GC_starfield_large}
-\end{figure}
-
-\begin{figure}[h!]
-\begin{center}
-\includegraphics[totalheight=16cm]{GCregionOFF.eps}
-\end{center}
-\caption[Star field around the GC.]{Star field around the GC. Stars up to a magnitude of 12 are plotted. The ON region is indicated by the bigger circle in the center. A possible OFF region is shown by the bigger circle in the left upper part of the figure. The x axis is pointing into the direction of decreasing RA, the y axis into the direction of increasing declination. The grid spacing in the declination is 1 degree.
-} \label{fig:GC_starfield_OFF}
+\includegraphics[totalheight=16cm]{GCregion14largeW.eps}
+\end{center}
+\caption[Star field around the GC.]{Star field around the GC. Stars up to a magnitude of 14 are plotted. The 2 big circles correspond to distances of 1$^{\circ}$ and 1.75$^{\circ}$ from the GC, respectively. The wobble positions WGC1 and WGC2 are given by the full circles. The x axis is pointing into the direction of decreasing RA, the y axis into the direction of increasing declination. The grid spacing in the declination is 1 degree.
+} \label{fig:GC_starfield_largeW}
+\end{figure}
+
+\begin{figure}[h!]
+\begin{center}
+\includegraphics[totalheight=16cm]{GCregionOFF1.eps}
+\end{center}
+\caption[Star field around the GC.]{Star field around the GC. Stars up to a magnitude of 14 are plotted. The ON region is indicated by the bigger circle in the center. A possible OFF region is shown by the bigger circle in the left upper part of the figure. The x axis is pointing into the direction of decreasing RA, the y axis into the direction of increasing declination. The grid spacing in the declination is 1 degree.
+} \label{fig:GC_starfield_OFF1}
 \end{figure}
 
 \subsection{ON/OFF mode}
 
-A larger sky area than in Fig.\ref{fig:GC_starfield} is shown in Figs. \ref{fig:GC_starfield_large} and \ref{fig:GC_starfield_OFF}. The bigger circle in the center indicates the ON region around the GC. An appropriate OFF region, with a sky field similar to that of the ON region,  would be the one marked by the bigger circle in the upper left part of Fig.\ref{fig:GC_starfield_OFF} . It is centered at the Galactic Plane, contains the bright star Sgr 3 (at (RA, dec) = $(17^h47^m34^s,\;-27^{\circ}49'51"$) ) in its outer part and has the coordinates GC$_{OFF}$ = (RA, dec) = $(17^h52^m00^s,\;-26^{\circ}39'06")$. The difference in RA between the GC and GC$_{OFF}$ corresponds to about 7 minutes.
+The bigger circle in the center of Fig. \ref{fig:GC_starfield_OFF1}
+indicates the ON region around the GC. 
+An appropriate OFF region, with a sky field similar to that of the ON region,  would be the one marked by the bigger circle in the upper left part of Fig.\ref{fig:GC_starfield_OFF1} . Like the ON region, the OFF region is centered at the Galactic Plane and contains the bright star Sgr 3 (at (RA, dec) = $(17^h47^m34^s,\;-27^{\circ}49'51"$) ) in its outer part. The center of the OFF region has the coordinates GC$_{OFF}$ = (RA, dec) = $(17^h51^m12^s,\;-26^{\circ}52'00")$. The difference in RA between the GC and GC$_{OFF}$ corresponds is 6 minutes. Thus GC$_{OFF}$ culminates 6 minutes later than the GC.
 
 %In order to have the most appropriate OFF data we propose to