English

Model-independent Redshift Estimation of BL Lac Objects through VHE Observations

High Energy Astrophysical Phenomena 2022-02-23 v1

Abstract

The very high energy (VHE) gamma-ray spectral indices of blazars show strong correlation with the source redshift. Absence of any such correlation in low energy gamma rays and X-rays indicate the presence of Extragalactic Background Light (EBL) induced absorption of VHE gamma rays. By employing a linear regression analysis, this observational feature of blazars is used to constrain the redshift of BL Lac objects which was unknown/uncertain earlier. Additionally, we also compare the observed VHE spectral index-redshift correlation with the ones predicted from commonly adopted EBL models. Our study highlights the deviation of the EBL model based predictions from the observation especially at high redshifts.

Keywords

Cite

@article{arxiv.2110.15953,
  title  = {Model-independent Redshift Estimation of BL Lac Objects through VHE Observations},
  author = {Malik Zahoor and Sunder Sahayanathan and Shah Zahir and Naseer Iqbal and Aaqib Manzoor and Nilay Bhatt},
  journal= {arXiv preprint arXiv:2110.15953},
  year   = {2022}
}

Comments

Accepted for publication in MNRAS

R2 v1 2026-06-24T07:18:18.733Z