Search for Gamma Rays

with SPASE/AMANDA

Data

• How to get raw data:
  • Raw data is located at /acs/amanda2002/raw/ at Zeuthan
  • dccp /acs/amanda2002/raw/run56XX/5668/ab_2002_112_5668_00X.data.mu.to_tape_2.gz.tar /tmp
• How to get AMANDA dead time:
  • Live- and dead-time analysis
• How to extract the following information from the raw data:
  • Want T_trig, X, Y, θ, and φ from SPASE, and T_trig and nch from AMANDA
  • Need Reader to read the binary data
  • Use extr.pl

  Probability

  Cuts

  Cut level	R	Cylsize	S30
  1	< 180	< 1.0	> 5

  • R: core distance from SPASE center at surface
  • Cylsize: cylinder size
  • S30: shower size at 30 m

  SPASE triggered AMANDA events (No AMANDA multiplicity trigger here)

  • 50,000 proton showers were generated in fixed zenith angle region of 0^o to 32^o and azimuth angle region of 205^o to 290^o.
    
    • Red lines: before cuts
    • Green lines: after cuts
    • Blue lines: additional nch cut
    • Black lines: ratios of green lines to blue lines

    

  • Nch >=10
    
  • Nch >= 30
    
  • Nch >= 50
    
  • Nch >= 100
    
  • Nch >= 10 after the same cuts exept for S30 cut.
    Low energy hadronic showers may not be able to pass nch cut even though they are
    heading to the center of AMANDA. So, S30 cut is needed to obtain 100 % efficiency.
    

  Dead-times

  • AMANDA Monitoring Monitoring page
  • Live- and Dead-time Analysis by Christian Walck
  • Trigger times for every events are stored at /data/exp/AMANDA/$YEAR/trigger-time/$RUN/.

  ab_2002_017_4464_000.data.mu.to_tape_1.gz

  

  Geometry

  • SPASE2 center = (-144.67 ,-346.12 ,1727.91 )

    

  • Unit cylinder size: H=2*175 m and R=100 m centered at AMANDA center

    

  References

  • "Limits on the TeV flux of diffuse gamma rays as measured with the HEGRA air shower array", Astroparticle Physics, Volume 17, Issue 4, p. 459-475.