Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune (India)
Eureka Scientific, Oakland, CA (United States)
Korea Astronomy and Space Science Institute (KASI), Daejeon (Korea, Republic of); Kyoto Univ. (Japan)
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford Univ., CA (United States). Kavli Institute for Particle Astrophysics & Cosmology
Kyoto Univ. (Japan)
Tel Aviv Univ., Tel Aviv (Israel)
Pontifica Universidad Catolica de Chile, Santiago (Chile)
Univ. Diego Portales (Chile); Peking Univ., Beijing (China); George Mason Univ., Fairfax, VA (United States)
California Institute of Technology (CalTech), Pasadena, CA (United States)
We derive the most up-to-date Swift-Burst Alert Telescope (BAT) blazar luminosity function in the 14–195 keV range, making use of a clean sample of 118 blazars detected in the BAT 105 month survey catalog, with newly obtained redshifts from the BAT Active Galatic Nucleus Spectroscopic Survey. We determine the best-fit X-ray luminosity function for the whole blazar population, as well as for flat-spectrum radio quasars (FSRQs) alone. The main results are: (1) at any redshift, BAT detects the most luminous blazars, above any possible break in their luminosity distribution, which means we cannot differentiate between density and luminosity evolution; (2) the whole blazar population, dominated by FSRQs, evolves positively up to redshift z ~ 4.3, confirming earlier results and implying lower number densities of blazars at higher redshifts than previously estimated. The contribution of this source class to the cosmic X-ray background at 14–195 keV can range from 5%–18%, while possibly accounting for 100% of the MeV background. We also derived the average 14 keV–10 GeV spectral energy distribution for BAT blazars, which allows us to predict the number counts of sources in the MeV range, as well as the expected number of high-energy (>100 TeV) neutrinos. A mission like COSI will detect 40 MeV blazars, of which two may have coincident neutrino detections. Finally, taking into account beaming selection effects, the distribution and properties of the parent population of these extragalactic jets are derived. We find that the distribution of viewing angles is quite narrow, with most sources aligned within <5° of the line of sight. Moreover, the average Lorentz factor, $$\langle$$Γ$$\rangle$$ = 8–12, is lower than previously suggested for these powerful sources.
Marcotulli, L., et al. "BASS. XXXIII. Swift-BAT Blazars and Their Jets through Cosmic Time." The Astrophysical Journal, vol. 940, no. 1, Nov. 2022. https://doi.org/10.3847/1538-4357/ac937f
Marcotulli, L., Ajello, M., Urry, C. M., Paliya, V. S., Koss, M., Oh, K., Madejski, G., Ueda, Y., Baloković, M., Trakhtenbrot, B., Ricci, F., Ricci, C., Stern, D., Harrison, F., & Powell, M. C. (2022). BASS. XXXIII. Swift-BAT Blazars and Their Jets through Cosmic Time. The Astrophysical Journal, 940(1). https://doi.org/10.3847/1538-4357/ac937f
Marcotulli, L., Ajello, M., Urry, C. M., et al., "BASS. XXXIII. Swift-BAT Blazars and Their Jets through Cosmic Time," The Astrophysical Journal 940, no. 1 (2022), https://doi.org/10.3847/1538-4357/ac937f
@article{osti_1991578,
author = {Marcotulli, L. and Ajello, M. and Urry, C. M. and Paliya, V. S. and Koss, M. and Oh, K. and Madejski, G. and Ueda, Y. and Baloković, M. and Trakhtenbrot, B. and others},
title = {BASS. XXXIII. Swift-BAT Blazars and Their Jets through Cosmic Time},
annote = {We derive the most up-to-date Swift-Burst Alert Telescope (BAT) blazar luminosity function in the 14–195 keV range, making use of a clean sample of 118 blazars detected in the BAT 105 month survey catalog, with newly obtained redshifts from the BAT Active Galatic Nucleus Spectroscopic Survey. We determine the best-fit X-ray luminosity function for the whole blazar population, as well as for flat-spectrum radio quasars (FSRQs) alone. The main results are: (1) at any redshift, BAT detects the most luminous blazars, above any possible break in their luminosity distribution, which means we cannot differentiate between density and luminosity evolution; (2) the whole blazar population, dominated by FSRQs, evolves positively up to redshift z ~ 4.3, confirming earlier results and implying lower number densities of blazars at higher redshifts than previously estimated. The contribution of this source class to the cosmic X-ray background at 14–195 keV can range from 5%–18%, while possibly accounting for 100% of the MeV background. We also derived the average 14 keV–10 GeV spectral energy distribution for BAT blazars, which allows us to predict the number counts of sources in the MeV range, as well as the expected number of high-energy (>100 TeV) neutrinos. A mission like COSI will detect 40 MeV blazars, of which two may have coincident neutrino detections. Finally, taking into account beaming selection effects, the distribution and properties of the parent population of these extragalactic jets are derived. We find that the distribution of viewing angles is quite narrow, with most sources aligned within <5° of the line of sight. Moreover, the average Lorentz factor, $\langle$Γ$\rangle$ = 8–12, is lower than previously suggested for these powerful sources.},
doi = {10.3847/1538-4357/ac937f},
url = {https://www.osti.gov/biblio/1991578},
journal = {The Astrophysical Journal},
issn = {ISSN 0004-637X},
number = {1},
volume = {940},
place = {United States},
publisher = {IOP Publishing},
year = {2022},
month = {11}}