NGC1068 LST1 analysis Cycle I DanielMorcuende

Analysis of LST-1 NGC 1068 data from observation cycle I

General information

• Name of the source: NGC 1068
• Brief description of the source:
  • Object type : AGN, Seyfert II galaxy
  • Redshift (z) : 0.0037
  • Other relevant information: neutrino excess found by IceCube (https://doi.org/10.1126/science.abg3395)
  • RA, Dec in deg (ICRS): 40.66962153, -0.0132943

• Analysis by Name (Institute - email)
  • Daniel Morcuende (IAA-CSIC, dmorcuende@iaa.es)
  • José Manuel Gavilán (IAA-CSIC)

Data-taking information

There are a total of 124 runs from 2023-08-19 to 2024-02-10

• Dates of data-taking:
  • Date (time of observation h)
    • ZD range (deg): 25-65

Dataset after good quality selection

Number of runs (% is w.r.t. those in Sky region & zenith range):

    In the requested Sky region and range of dates:	 128
  + zenith in requested range:				 127
  + NSB in requested range:				 127 (100.0%) 

  + FF and pedestal interleaved events are present:	 125 (98.4%)
  + Stable pointing:					 123 (96.9%)
  + dR/dI fit P-value ok:				 123 (96.9%)
  + dR/dI LS periodogram ok:				 118 (92.9%)
  + dR/dI index ok:					 94 (74.0%)
  + dR/dI rate ok:					 60 (47.2%)
  + intensity threshold ok:				 60 (47.2%)
Total observation time: 15.46 h

Total number of runs: 60 (in 16 nights)
Total observation time: 15.46 hours 

'2023-09-22': [14696, 14697, 14698, 14699],
'2023-10-06': [14927, 14929],
'2023-11-03': [15256, 15257, 15258, 15259],
'2023-11-04': [15263],
'2023-11-10': [15387, 15388, 15389],
'2023-11-12': [15474, 15475, 15476, 15477],
'2023-11-16': [15615, 15616, 15618],
'2023-11-17': [15656, 15657, 15658, 15659, 15672, 15673, 15674, 15675],
'2023-11-18': [15706, 15707, 15708, 15709, 15710, 15713],
'2023-12-08': [15883, 15884, 15886, 15887, 15888],
'2023-12-09': [15917, 15918, 15919, 15920],
'2023-12-14': [16085, 16086, 16087],
'2023-12-17': [16195, 16198],
'2024-01-29': [16427, 16428, 16429],
'2024-01-31': [16445, 16446, 16447, 16448],
'2024-02-10': [16660, 16661, 16662, 16663],

Analysis information

• lstchain v0.10
• source-independent analysis
• Gammapy v1.1

Monte Carlo information

Closest declination line towards La Palma latitude (28.8 deg)

20240131_allsky_v0.10.5_all_dec_base/dec_931

DL1 data

Standard DL1b files produced by LSTOSA (lstchain v0.10, tailcut 8-4 with cleaning based on pedestal RMS, dynamic cleaning)

/fefs/aswg/data/real/DL1/YYYYMMDD/v0.10/tailcut84/dl1_LST-1.Run?????.h5

Random forest

Models:

/fefs/aswg/data/models/AllSky/20240131_allsky_v0.10.5_all_dec_base/dec_931

DL2

Files:

/fefs/aswg/workspace/daniel.morcuende/data/real/DL2/NGC1068

DL3 data selection

Files:

/fefs/aswg/workspace/daniel.morcuende/data/real/DL3/NGC1068/20240131_allsky_v0.10.5_all_dec_base/dec_931/gh_eff_0.7_th_cont_0.7

• intensity > 50 p.e.
• gammaness energy-dependent cuts with 70% efficiency
• theta energy-dependent cuts 70% efficiency

High-level analysis

• Science Tool: Gammapy 1.1
• point-like IRF, 1D analysis

Analysis Results

Theta2 plot

No detection

Energy range: 0.0 - 0.2 TeV
Excess: -5324.0; Off: 450085
Gamma rate: -6.0 events / minute
Off rate: 510.9 events / minute
alpha (backg normalization): 1.00
Li & Ma Significance: 0.0 standard deviations

Energy range: 0.2 - 1000000.0 TeV
Excess: 14.0; Off: 3798
Gamma rate: 0.0 events / minute
Off rate: 4.3 events / minute
alpha (backg normalization): 0.33
Li & Ma Significance: 0.3 standard deviations

Spectral results

• Fermi-LAT 3FHL and 3FGL SED shown.
  • Spectral model plotted corresponds to the Fermi-LAT data, extended to VHE.
• For comparison 125-h long MAGIC results (V. A. Acciari et al 2019 ApJ 883 135)

Light curve