SIERRA NEGRA Observatory

H. Salazar, C. Alvarez, O.Martinez,T. Murrieta, G.Perez, L.Villasenor, Facultad de Ciencias

Físico Matemáticas BUAP

CABAÑA

ALT: 4560N 18° 59’ 03.9’’W 97° 18’ 44.7’’

ALT: 4558N 18° 59’ 04.6’’W 97° 18’ 45.4’’ CENTRO

ALT: 4557N 18° 59’ 03.7’’W 97° 18’ 45.5’’

ALT: 4557N 18° 59’ 04’’W 97° 18’ 46.4’’

ALT: 4558N 18° 59’ 02.9’’W 97° 18’ 45.2’’

ARENA

RAMPA

NORTESUR

Array distribution

Stability of the detectors: Left one day. Rigth 8 hoursBelow 1hr.

Vertical Muon signals

Calibration with the Crab Nebula•Flux: 2.68x10-7 fotons/m2/s E>TeV•4 hours observation/day (+-30o) =14400 s•Area=500 m2

•Flux/day = 1 fotón/day

Measured Flux at la Sierra Negra300 Showers/min95% protones rejected, 50% photons Direction accuracy +/- 2o=16 minShowers in the field of view N~240 , sigma~155 sigma = 75 means 150 days of detection of the Crab.