Analysis Crab Nebula Dec 2022 w IRF interpolation Priyadarshi

Crab Nebula December 2022

General information

• Name of the source: Crab Nebula
• Brief description of the source:
  • Pulsar Wind Nebula
  • z = 0
  • RA: 5 34 31.94 (hh mm ss), Dec: +22 0 52.2 (dd mm ss)
  • RA, Dec in deg (ICRS): 83.63308333, 22.015

• Analysis by Chaitanya Priyadarshi ((IFAE - cpriyadarshi@ifae.es)

Data-taking information

• Dates of data-taking: 20221219, 20221221, 20221222, 20221223

• • 20221219 (3.55 h)
    • ZD range (deg): [7.11, 48.99]
    • AZ range (deg): [94.06, 218.3]
    • Runs: 11486 - 11494, 11510 - 11512
    • Joint observations with MAGIC? : No

• • 20221221 (0.91 h)
    • ZD range (deg): [21.10, 31.71]
    • AZ range (deg): [257.13, 265.27]
    • Runs: 11560 - 11563
    • Joint observations with MAGIC? : No

• • 20221222 (1.28 h)
    • ZD range (deg): [6.99, 15.91]
    • AZ range (deg): [110.59, 199.80]
    • Runs: 11575 - 11579
    • Joint observations with MAGIC? : No

• • 20221223 (1.12 h)
    • ZD range (deg): [20.25, 33.88]
    • AZ range (deg): [256.10, 266.70]
    • Runs: 11603 - 11606
    • Joint observations with MAGIC? : Yes

Monte Carlo information

For getting a closer data-MC comparison, we produce MC data along various sky positions (nodes) as a preliminary method to facilitate a better Random Forest model for the reconstruction and to interpolate IRFs from various sky positions to the target position of each Observation Run.

DL1 data

This includes whether you use LSTOSA, specific versions of lstchain, dllab scripts, cleaning levels, and calibration information.

DL1a files produced by LSTOSA (lstchain v0.9)

• original real DL1a data

/fefs/aswg/data/real/DL1/{Date}/v0.9/tailcut84/

• lstchain v0.9 tailcut8-4 (with cleaning based on pedestal RMS, dynamical cleaning)

 /fefs/aswg/data/real/DL1/20221219/v0.9/tailcut84/log/lstchain_config_v0.9.4_from2022onwards_heuristic.json

• MC nodes: tailcut8-4 (with cleaning based on pedestal RMS), dynamic cleaning, NSB tuning

 /fefs/aswg/data/mc/DL1/AllSky/20220518_allsky_dec2276_tuned/{Testing, Training}Dataset/

Random forest

Here we use the TrainingDataset nodes, selected along the declination path (or closer to) of the selected source (BL Lac here). The "dec2276" part in the production ID refers to the declination angle of +22.76 deg. In this new RF model production, we include zenith and azimuth pointing parameters as well.

• lstchain v0.9.13dev source-independent, dynamic cleaning, NSB tuning

 /fefs/aswg/data/models/AllSky/20220518_allsky_dec2276_tuned/

For IRF interpolation

Here we create an almost uniform grid of nodes of sky positions for TestingDataset MC, so as to facilitate IRF interpolation in the parameter space of cos zenith and the sin of angle (delta) between the geomagnetic field and the particle shower direction. IRF interpolation is performed using pyirf v0.7.

• Link to MC DL2 files used:

/fefs/aswg/data/mc/DL2/AllSky/20220518_allsky_dec2276_tuned/TestingDataset/

• Particle types: ring-wobble gamma (offset range = [0.3999, 0.4001] deg)

DL2 data

The DL2 files of the real data are stored here - /fefs/aswg/workspace/chaitanya.priyadarshi/real_data/AGN/Crab/v09x/tailcut84/DL2/real/src_indep/20220518_dec2276_nsb_tuned/{Date}

DL3 data selection

For energy-dependent cuts

Information about your DL3 data selection.

• intensity > 50
• r: [0, 1]
• wl: [0.01, 1]
• leakage_intensity_width_2: [0, 1]

• source-independent
  • gh_efficiency: 0.8
  • theta_containment: 0.8

• Energy-dependent Gammaness and Theta cut distribution

High-level analysis

• lstchain Tools to generate source-independent IRF and DL3
• Science Tool: gammapy 1.0
• point-like IRF, 1D analysis

For DL3 data reduction to DL4 dataset,

• OFF regions selected - 2 Wobble
• Excluded region: RGB J0521+212, circular region with radius 0.5 deg
• Safe Energy mask for systematics - Yes
• Energy axes -
  • True: 10 GeV to 100 TeV with 5 bins per decade
  • Reco: 10 GeV to 100 TeV with 5 bins per decade

For spectral analysis,

• Model used - Log Parabola + EBL (Dominguez)
• Reference energy used by calculating the decorrelation energy with a Power Law fit, 508 GeV
• Spectral Fit energy range - 39.8 GeV to 100 TeV with 5 bins per decade
• Spectral fit with gammapy default optimization - minuit

For LC,

• E_min = 100 Gev

Analysis Results

Theta2 plot

• 5 bins per decade in energy

Spectral results

For energy-dependent cuts

• Total dataset

Preliminary LC and SED