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Explaining the Origin of TeV Gamma Rays from M87 During High and Low States

Nibedita Mondal, Sandeep Kumar Mondal, Nayantara Gupta

Abstract

The detection of very high-energy gamma-rays from M87 can provide crucial insights into particle acceleration and radiation mechanisms in jets. The recent observations by the Large High Altitude Air Shower Observatory (LHAASO) detector extend the energy range of TeV gamma-ray astronomy, and also the variability study to the TeV energy domain. We have modelled the low state and flare state multi-wavelength spectral energy distributions of M87 within a time-dependent framework. In our model, the low state gamma-ray flux results from the emissions from the sub-parsec and the kilo-parsec scale jets of M87, whereas the flare state gamma-ray flux is mainly produced in the sub-parsec scale jet. We have shown that the spectral and temporal features of the TeV gamma-ray spectrum of M87 are consistent with this two-zone model, where the contribution from the sub-parsec scale jet significantly increases during the flare state.

Explaining the Origin of TeV Gamma Rays from M87 During High and Low States

Abstract

The detection of very high-energy gamma-rays from M87 can provide crucial insights into particle acceleration and radiation mechanisms in jets. The recent observations by the Large High Altitude Air Shower Observatory (LHAASO) detector extend the energy range of TeV gamma-ray astronomy, and also the variability study to the TeV energy domain. We have modelled the low state and flare state multi-wavelength spectral energy distributions of M87 within a time-dependent framework. In our model, the low state gamma-ray flux results from the emissions from the sub-parsec and the kilo-parsec scale jets of M87, whereas the flare state gamma-ray flux is mainly produced in the sub-parsec scale jet. We have shown that the spectral and temporal features of the TeV gamma-ray spectrum of M87 are consistent with this two-zone model, where the contribution from the sub-parsec scale jet significantly increases during the flare state.

Paper Structure

This paper contains 17 sections, 6 equations, 5 figures, 7 tables.

Table of Contents

  1. Introduction
  2. Multi-Wavelength Data ACCUMULATION
  3. Fermi-LAT Data Analysis
  4. Gamma-ray : Likelihood Test Using Different Spectral Model
  5. Gamma-ray Spectral Analysis Outcomes
  6. GeV flare in Fermi-LAT
  7. Swift XRT and UVOT Data Analysis
  8. Archival Data
  9. LHAASO Data
  10. MOJAVE Data
  11. MMDC Data
  12. SSDC Data
  13. Other Data Sources
  14. Multi-wavelength SED modelling:
  15. Result: Multi-wavelength Modelling
  16. ...and 2 more sections

Figures (5)

  • Figure 1: Gamma-ray light curves of M87 observed with Fermi-LAT at different binning at time periods.
  • Figure 3: Multi-wavelength SED plot for low state. Non-simultaneous data points are represented by markers with solid grey & grey-fill coloured edges, whereas simultaneous data points are represented by markers filled with one colour and outlined with black colour.
  • Figure 4: Multi-wavelength SED plot for flare state. The marker style and colour conventions are similar to Fig. \ref{['fig:lowstate_mwsed']}.
  • Figure 5: MW modelling of the low state of M87 with contributions from the sub-parsec and kiloparsec-scale jets. SSDC data and host galaxy emission are shown in solid grey colour. The red and blue dotted lines represent the synchrotron and SSC emission from the sub-pc jet, respectively. The brown, magenta, green, and cyan dashed lines indicate the synchrotron, IC/CMB, IC/Starlight, and IC/Dust components in kpc-jet. The sum of all of these components (total SED) is shown by the black solid line.
  • Figure 6: MW modelling of the flare state of M87 with contributions from the sub-parsec and kiloparsec-scale jets. The line styles are similar to Fig. \ref{['Fig:Low-state_GAMERA']}. SSDC data and host galaxy emission are shown in solid grey colour.