Detection Forecasting for Blazars at MeV Energies with Fermi-LAT Swift-BAT Cross Match
Abstract
Over the past two decades, the lack of an MeV γ-ray all-sky instrument has left an observational gap in blazar broadband emission. Recently, a new suite of MeV γ-ray instruments with sensitivity in the 10−11 to 10−12 erg/cm2/s range has been proposed, with the potential to far surpass the capabilities of previous all-sky MeV instruments. In this work, we forecast the capabilities of future MeV γ-ray instruments including COSI, GRAMS, newASTROGAM, and AMEGO-X to observe blazars. We pair total source count estimates of blazar luminosity functions with SED-modeled flux estimates of 76 blazars selected from a sample of 115 blazars cross-matched between the latest Fermi-LAT and Swift-BAT catalogs. We forecast that an instrument with a sensitivity limit of 10−11 erg/cm2/s could detect 61 of the 76 SED-modeled blazars, and expect a total population of a few tens to a few hundreds of Flat-Spectrum Radio Quasars (FSRQs), as well as a few hundred BL Lacs (BLLs). An instrument with a sensitivity limit of 10−12 erg/cm2/s could detect all 76 of the SED-modeled blazars, and we expect a total population of a few hundred to one thousand FSRQs and roughly one thousand BLLs. As MeV blazars have been observed to be extremely luminous and MeV γ-rays are minimally attenuated by the extragalactic background light, we use luminosity functions to estimate that blazars could be detected out to z≈6. Lastly, we demonstrate detectability for blazars that have been proposed as neutrino-emitting candidates, as the MeV regime could provide a window into resolving lepto-hadronic degeneracies.
Related
- A Multi-Mission Detection Framework for High-Energy Transients: Application to a 13-year Fermi/GBM and Swift/BAT Sample
- FALCON (FERMI-ALMA Calibrator ObservatioN): Cross-matching ALMA Calibrators with Fermi-LAT Blazars
- Validating an X-ray-based method for identifying Fermi blazars
- Estimating redshift distributions of Fermi blazars with multiple machine-learning models
- Morphology-aware periodicity searches in Fermi-LAT blazars
BibTeX
@misc{wesslingresnick2026detection,
title = {{Detection Forecasting for Blazars at MeV Energies with Fermi-LAT Swift-BAT Cross Match}},
author = {Timothy Wessling-Resnick and Naomi Tsuji and Tsuguo Aramaki and Paolo Coppi and Manel Errando and Yoshiyuki Inoue and Reshmi Mukherjee and Svanik Tandon and Jiancheng Zeng},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26658},
eprint = {2610.26658},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26658},
}
RIS
TY - UNPB
TI - Detection Forecasting for Blazars at MeV Energies with Fermi-LAT Swift-BAT Cross Match
AU - Timothy Wessling-Resnick
AU - Naomi Tsuji
AU - Tsuguo Aramaki
AU - Paolo Coppi
AU - Manel Errando
AU - Yoshiyuki Inoue
AU - Reshmi Mukherjee
AU - Svanik Tandon
AU - Jiancheng Zeng
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26658
UR - https://arxiv.org/abs/2610.26658
AB - Over the past two decades, the lack of an MeV γ-ray all-sky instrument has left an observational gap in blazar broadband emission. Recently, a new suite of MeV γ-ray instruments with sensitivity in the 10^−11 to 10^−12 erg/cm^2/s range has been proposed, with the potential to far surpass the capabilities of previous all-sky MeV instruments. In this work, we forecast the capabilities of future MeV γ-ray instruments including COSI, GRAMS, newASTROGAM, and AMEGO-X to observe blazars. We pair total source count estimates of blazar luminosity functions with SED-modeled flux estimates of 76 blazars selected from a sample of 115 blazars cross-matched between the latest Fermi-LAT and Swift-BAT catalogs. We forecast that an instrument with a sensitivity limit of 10^−11 erg/cm^2/s could detect 61 of the 76 SED-modeled blazars, and expect a total population of a few tens to a few hundreds of Flat-Spectrum Radio Quasars (FSRQs), as well as a few hundred BL Lacs (BLLs). An instrument with a sensitivity limit of 10^−12 erg/cm^2/s could detect all 76 of the SED-modeled blazars, and we expect a total population of a few hundred to one thousand FSRQs and roughly one thousand BLLs. As MeV blazars have been observed to be extremely luminous and MeV γ-rays are minimally attenuated by the extragalactic background light, we use luminosity functions to estimate that blazars could be detected out to z≈6. Lastly, we demonstrate detectability for blazars that have been proposed as neutrino-emitting candidates, as the MeV regime could provide a window into resolving lepto-hadronic degeneracies.
ER -