A study of the intrinsic $\gamma$-ray emission of Fermi/LAT-detected BL Lacs

Ye, X. H.; Zeng, Xiaopeng; Yang, Weiping; Huang, H. S.; Xuan, Yuan; Huang, J. W.; Zhang, Z.; Pei, Z. Y.; Yang, Jiang-He; Jiang, Fan

doi:10.1007/s10509-021-04018-1

Cited by 2 publications

(2 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A study of the optical properties for 350 nearby FR-Is, shows their absolute magnitudes (M B ) are distributed within a narrow interval around M B ∼ −21.3, suggesting that FR-Is are reliable standard candles (Magliocchetti et al 2002b). Based on the optical properties of FR-Is, we consider FR-Is as a standard candle and assume that the luminosity for FR-Is is a constant; therefore, the logarithm of the flux density ( f log ) will be expected to have a linear correlation with their logarithm of the luminosity distance (Fan & Xie 1996;Ye et al 2021). The correlations between the logarithm of the γ-ray flux densities ( f log g ) and the logarithm of the luminosity distances ( d log L ) for the 30 Fermi-LAT-detected FR-Is are plotted in Although the flux densities are correlated with their luminosity distances in the γ-ray band, the slope is not the same as the expected value of −2.…”

Section: Standard Candlesmentioning

confidence: 99%

The Beaming Effect for Fermi-LAT-detected FR-I Radio Galaxies

Ye¹,

Zeng²,

Huang³

et al. 2023

PASP

View full text Add to dashboard Cite

Our knowledge of Giga-electron volt (GeV) radio galaxies has been revolutionized by the Fermi-LAT Telescope, which provides an excellent opportunity to study the physical properties of GeV radio galaxies. According to the radio power and morphology, radio galaxies can be separated into Fanaroff–Riley Type I radio galaxies (FR-Is) and Type II radio galaxies (FR-IIs). In this paper, we consider the unification of FR-Is and BL Lacertae objects (BL Lacs), and assume FR-Is to be a standard candle to discuss the beaming effect for Fermi-LAT-detected FR-Is. Our main conclusions are as follows: (1) The estimated Doppler factors for 30 Fermi-LAT-detected FR-Is are in a range of δ I = 0.88 − 7.49. The average Doppler factor (〈δ I〉 = 2.56 ± 0.30) of the 30 FR-Is is smaller than that (〈δ BL〉 = 10.28 ± 2.03) of the 126 Fermi-LAT-detected BL Lacs, supporting the unification model that FR-Is are regarded as the misaligned BL Lacs with smaller Doppler factors; (2) We propose that different regions of FR-Is in the plot of the γ-ray luminosity against the photon spectral index ( log L γ – α ph ) may indicate the different beaming effects; (3) The average Doppler factor of the 6 TeV FR-Is is similar to that of the 24 non-TeV FR-Is, which implies that the difference between the TeV and GeV emissions is not driven by the beaming effect in the Fermi-LAT-detected FR-I samples.

show abstract

Section: Standard Candlesmentioning

confidence: 99%

The Beaming Effect for Fermi-LAT-detected FR-I Radio Galaxies

Ye¹,

Zeng²,

Huang³

et al. 2023

PASP

View full text Add to dashboard Cite

show abstract

“…Blazars are the most powerful active galactic nucleus (AGNs) with extreme observational properties, such as high luminosity, high and varible polarization, rapid variability from radio even up to TeV region, superluminal motions, coredominated nonthermal continuum, or strong γ-ray emissions etc. Those extreme properties are due to the relativistic jets pointing at a small viewing angle (<10°) toward the observer (Blandford & Rees 1978;Wills et al 1992; Urry & Padovani 1995;Chen & Shan 2011;Massaro et al 2011;Fan et al 2012Fan et al , 2016Padovani et al 2017;Xiao et al 2019;Abdollahi et al 2020;Zhang et al 2020;Fan et al 2021;Ye et al 2021;Zhang et al 2022a;Yang et al 2022b;Abdollahi et al 2022;Cai et al 2022;Pei et al 2022;Prandini & Ghisellini 2022;Xiao et al 2022;Zeng et al 2022). Based on the observational features, blazars can be grouped as two subclass: BL Lacertae objects (BL Lacs) and flat spectrum radio quasars (FSRQs).…”

Section: Introductionmentioning

confidence: 99%

Comparison Between TeV and Non-TeV Fermi-detected BL Lacertae Objects

Liang,

Zeng,

Chen

et al. 2023

PASP

View full text Add to dashboard Cite

In this paper, we compiled a sample of 410 Fermi-detected BL Lacs, including 42 TeV-detected BL Lacs (TBLs) and 368 non-TeV-detected BL Lacs (non-TBLs) with corresponding mid-infrared (mid-IR), TeV and Fermi γ-ray data, and calculated some important parameters including monochromatic luminosities (mid-IR, GeV and TeV bands) and mid-IR spectral indices. Based on those parameters, we discussed the relationship between the mid-IR and the TeV bands and that between the mid-IR and the GeV bands. Main conclusions are drawn as follows: (1) In the color–color and color–magnitude diagrams, our sample forms a WISE-Gamma Strip in the [3.4]–[4.6]–[12] μm color–color diagram, and TBLs occupy the brighter region than the non-TBLs for the similar color-index in the color-magnititue diagram; (2) The mid-IR luminosity of the TBLs is on average higher than that of non-TBLs, while the average mid-IR spectral index of TBLs is smaller than the non-TBLs, suggesting that TBLs are brighter and hold a more flat spectrum than do the non-TBLs in the mid-IR band. Besides, HBLs have a more flat mid-IR spectrum than LBLs and IBLs; (3) The mid-IR luminosity is positively correlated with the GeV luminosity and the intrinsic TeV luminosity. A positive correlation exists between the mid-IR spectral index and the observed TeV spectral index, which is consistent with the expectations of the synchrotron self-Compton mechanism. We suggest that the HBLs with extreme relativistic electrons might scatter the mid-IR photons up to the TeV band.

show abstract

A study of the intrinsic $\gamma$-ray emission of Fermi/LAT-detected BL Lacs

Cited by 2 publications

References 36 publications

The Beaming Effect for Fermi-LAT-detected FR-I Radio Galaxies

The Beaming Effect for Fermi-LAT-detected FR-I Radio Galaxies

Comparison Between TeV and Non-TeV Fermi-detected BL Lacertae Objects

Contact Info

Product

Resources

About