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Spectral energy distributions for TeV blazars 被引量:2
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作者 Chao Lin Jun-Hui Fan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第10期19-32,共14页
In this work, we collected a sample of 69 TeV blazars from TeVCat, obtained their multi-wavelength observations, and fitted their spectral energy distributions by using a second degree poly-nomial function. The struct... In this work, we collected a sample of 69 TeV blazars from TeVCat, obtained their multi-wavelength observations, and fitted their spectral energy distributions by using a second degree poly-nomial function. The structure parameters of synchrotron bumps for 68 blazars and those of inverse- Compton bumps for 56 blazars were derived. Then, we conducted statistical analysis on the parame-ters (curvature, peak frequency, peak luminosity, bolometric luminosity and X/γ-ray spectral indexes). From our analysis and discussions, we can conclude the following: (1) There is a clear positive correla-tion between the synchrotron peak frequency, log (Vp)^s, and the inverse-Compton peak frequency, log (Vp)^IC, and between the synchrotron peak luminosity, log (Vp)^sL(Vp)^s, and the inverse-Compton peak luminosity,log(Vp)^IC L(Vp)^IC. (2) The correlation between the peak frequency and the curvature of synchrotron bump is clearly different from that of the inverse-Compton bump, which further indicates that there are differ-ent emission mechanisms between them. (3) There is a correlation between log (Vp)^IC and γ-ray spectral index, αγ, for the TeV blazars: log (Vp)^IC = -(4.59 ± 0.30)αγ + (32.67 ±0.59), which is consistent with previous work. (4) An "L-shape" relation is found between log(Vp)^s Up and αx for both TeV blazars and Fermi blazars. A significant correlation between log(Vp)^s and X-ray photon index (αx) is found for the TeV blazars with high synchrotron peak frequency: log(Vp)^s = -(3.20 ± 0.34)αx + (24.33 ± 0.79), while the correlation is positive for low synchrotron peaked TeV sources. (5) In the αx -αγ diagram, there is also an "L-shape." The anti-correlation is consistent with results available in the literature, and we also find a positive correlation between them. (6) Inverse-Compton dominant sources have luminous bolometric luminosities. 展开更多
关键词 GALAXIES active - BL Lacertae objects general - quasars general - galaxies jets
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Accretion and jet power in active galactic nuclei 被引量:2
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作者 Luigi Foschini 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2011年第11期1266-1278,共13页
The classical diagrams of radio loudness and jet power as a function of mass and accretion rate of the central spacetime singularity in active galactic nuclei are reanalyzed by including the data of the recently disco... The classical diagrams of radio loudness and jet power as a function of mass and accretion rate of the central spacetime singularity in active galactic nuclei are reanalyzed by including the data of the recently discovered powerful relativistic jets in Narrow-Line Seyfert 1 Galaxies. The results are studied in the light of the known theories of relativistic jets, indicating that, although the Blandford-Znajek mechanism is sufficient to explain the power radiated by BL Lac Objects, it falls to completely account for the power from quasars and Narrow-Line Seyfert 1 Galaxies. This favors the scenario outlined by Cavaliere & D'Elia of a composite jet, with a magnetospheric core plus a hydromagnetic component emerging when the accretion power increases and the disk becomes radiation-pressure dominated. A comparison with Galactic compact objects is also made, finding some striking similarities, indicating that since neutron stars are low-mass jet systems analogous to black holes, Narrow-Line Seyfert 1 Galaxies are low-mass counterparts of blazars. 展开更多
关键词 GALAXIES jets-BL Lacertae objects general-quasars general-galaxies SEYFERT
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The LAMOST survey of background quasars in the vicinity of M31 and M33–Ⅲ.results from the 2013 regular survey
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作者 Zhi-Ying Huo Xiao-Wei Liu +7 位作者 Mao-Sheng Xiang Jian-Rong Shi Hai-Bo Yuan Yang Huang Yong Zhang Yong-Hui Hou Yue-Fei Wang Ming Yang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第8期1438-1448,共11页
In this work, we report new quasars discovered in fields in the vicinity of the Andromeda(M31) and Triangulum(M33) galaxies with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST, also called t... In this work, we report new quasars discovered in fields in the vicinity of the Andromeda(M31) and Triangulum(M33) galaxies with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST, also called the Guo Shou Jing Telescope) during the 2013 observational season, the second year of the regular survey. In total, 1330 new quasars are discovered in an area of ~133 deg2 around M31and M33. With i magnitudes ranging from 14.79 to 20.0 and redshifts from 0.08 to4.85, the 1330 new quasars represent a significant increase in the number of identified quasars in fields in the vicinity of M31 and M33. Up to now, there have been a total of 1870 quasars discovered by LAMOST in this area. The much enlarged sample of known quasars in this area can potentially be utilized to construct a precise astrometric reference frame for the measurement of minute proper motions of M31, M33 and their associated substructures, which are vital for understanding the formation and evolution of M31, M33 and the Local Group of galaxies. Moreover, in the sample,there are a total of 45, 98 and 225 quasars with i magnitudes brighter than 17.0, 17.5and 18.0 respectively. In the aforementioned brightness bins, 15, 35 and 84 quasars are reported here for the first time, and 6, 21 and 81 are reported in our pervious work. In addition, 0, 1 and 6 are from the Sloan Digital Sky Survey and 24, 41 and 54 are from the NED database. These bright quasars provide an invaluable sample to study the kinematics and chemistry of the interstellar/intergalactic medium of the Local Group. 展开更多
关键词 galaxies: individual(M31 M33)—quasars generalquasars emission lines
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Statistical Cluster-QSO Weak Lensing in the Sloan Digital Sky Survey
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作者 Zhong-Lue Wen Yan-Bin Yang +2 位作者 Xu Zhou Qi-Rong Yuan Jun Ma 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2006年第5期521-529,共9页
We investigate the cross-correlation between galaxy clusters and QSOs using Sloan Digital Sky Survey (SDSS) DR4 - 5000 deg^2 data. With photometric redshifts of galaxies, we select galaxy clusters based on the local... We investigate the cross-correlation between galaxy clusters and QSOs using Sloan Digital Sky Survey (SDSS) DR4 - 5000 deg^2 data. With photometric redshifts of galaxies, we select galaxy clusters based on the local projected densities of LRGs brighter than Mr′ = -22. The QSOs are from the main sample of SDSS QSO spectroscopic survey to i′ = 19. A significant positive correlation is found between the clusters and QSOs. Under the assumption that the signal is caused by gravitational lensing, we fit the signal with singular isothermal sphere (SIS) model and NFW profile halo model. The velocity dispersion σv = 766 km s^-1 is derived for the best-fit of SIS model. Best-fit for the NFW model requires the dark matter halo mass within 1.5 h^-1 Mpc to be 4.6 × 10^14 h^-1 M⊙. The mass parameter Ωcl of the cluster sample is deduced as 0.077 with the SIS model and 0.083 with the NFW model. Our results of Ωcl are smaller than those given by Croom & Shanks and by Myers et al. 展开更多
关键词 COSMOLOGY observations - galaxies clusters general - quasars general - gravitational lensing
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Broadband spectral fitting of blazars using XSPEC
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作者 Sunder Sahayanathan Atreyee Sinha Ranjeev Misra 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第3期105-120,共16页
The broadband spectral energy distribution(SED) of blazars is generally interpreted as radiation arising from synchrotron and inverse Compton mechanisms. Traditionally,the underlying source parameters responsible fo... The broadband spectral energy distribution(SED) of blazars is generally interpreted as radiation arising from synchrotron and inverse Compton mechanisms. Traditionally,the underlying source parameters responsible for these emission processes,like particle energy density,magnetic field,etc.,are obtained through simple visual reproduction of the observed fluxes. However,this procedure is incapable of providing confidence ranges for the estimated parameters. In this work,we propose an efficient algorithm to perform a statistical fit of the observed broadband spectrum of blazars using different emission models. Moreover,we use the observable quantities as the fit parameters,rather than the direct source parameters which govern the resultant SED. This significantly improves the convergence time and eliminates the uncertainty regarding initial guess parameters. This approach also has an added advantage of identifying the degenerate parameters,which can be removed by including more observable information and/or additional constraints. A computer code developed based on this algorithm is implemented as a user-defined routine in the standard X-ray spectral fitting package,XSPEC. Further,we demonstrate the efficacy of the algorithm by fitting the well sampled SED of blazar 3 C 279 during its gamma ray flare in 2014. 展开更多
关键词 GALAXIES active-BL Lacertae objects general - quasars individual (3C 279) - relativistic processes - radiation mechanisms NON-THERMAL
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A RELATION BETWEEN THE APPARENT VELOCITY AND THE SPECTRAL POWER OF SUPERLUMINAL RADIO SOURCES
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作者 吴盛殷 A.QUIRRENBACH A.WITZEL 《Science China Chemistry》 SCIE EI CAS 1992年第10期1254-1265,共12页
It is proved that the apparent transverse velocities β_(app) and the spectral powers at 10GHz P_(10) of the cores of known superluminal sources are correlated. An interpretation ofthis result within the framework of ... It is proved that the apparent transverse velocities β_(app) and the spectral powers at 10GHz P_(10) of the cores of known superluminal sources are correlated. An interpretation ofthis result within the framework of the relativistic jet model shows that the jet Lorentzfactor γ depends on the intrinsic luminosity of the sources. The probable existence of twosubpopulations of the superluminal sources is shown by a linear regression analysis. 'Small'sources f i.e. the sources without extended emission or with a distance from the core tothe outer edge of the lobe<20 kpc, show lower β_(app) than the 'large' objects; this can beinterpreted as an orientation effect. Since all BL Lac objects belong to the 'small' class,this result sheds new light on such a question as why these sources have lower apparent ve-locities than the 'classical' superluminal quasars. 展开更多
关键词 RADIO sources general-quasars jets BL Lacertae OBJECTS
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The Doppler Effect and Spectral Energy Distribution of Blazars 被引量:3
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作者 Guang-ZhongXie Ben-ZhongDai 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2001年第3期213-220,共8页
The relativistic beaming model is adopted to discuss quantitatively the observational differences between radio-selected BL Lac objects (RBLs) and X-ray- selected BL Lac objects (XBLs), and between BL Lac objects and ... The relativistic beaming model is adopted to discuss quantitatively the observational differences between radio-selected BL Lac objects (RBLs) and X-ray- selected BL Lac objects (XBLs), and between BL Lac objects and flat spectrum radio quasars (FSRQs). The main results are the following: (1) In the Doppler corrected color-color ( ) diagram, XBLs and FSRQs occupy separated regions, while RBLs bridge the gap between them. These properties suggest that similar intrinsic physical processes operate in all the objects under a range of intrinsic physical conditions. (2) Our results are consistent with the results of Sambruna, Maraschi and Urry (1996) from other methods. We show the ■xox introduced by Sambruna to be a good index for describing the energy distribution because it represents the intrinsic energy distribution and includes the Doppler correction. (3) The Doppler effect of relativistic beaming is the main mechanism, and the physical differences (such as magnetic fields, electron energies) are also important complementary factors for understanding the relation between XBLs and RBLs; 展开更多
关键词 Blazars: general - quasars:general - radiation mechanism: nonthermal
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Discovery of six high-redshift quasars with the Lijiang 2.4 m telescope and the Multiple Mirror Telescope 被引量:1
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作者 Xue-Bing Wu Wen-Wen Zuo +6 位作者 Qian Yang Wei-Min Yi Chen-Wei Yang Wen-Juan Liu Peng Jiang Xin-Wen Shu Hong-Yan Zhou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第9期1185-1190,共6页
Quasars with redshifts greater than 4 are rare, and can be used to probe the structure and evolution of the early universe. Here we report the discovery of six new quasars with i-band magnitudes brighter than 19.5 and... Quasars with redshifts greater than 4 are rare, and can be used to probe the structure and evolution of the early universe. Here we report the discovery of six new quasars with i-band magnitudes brighter than 19.5 and redshifts between 2.4 and 4.6 from spectroscopy with the Yunnan Faint Object Spectrograph and Camera (YFOSC) at the Lijiang 2.4 m telescope in February, 2012. These quasars are in the list of z > 3.6 quasar candidates selected by using our proposed J K/i Y criterion and the photometric redshift estimations from the SDSS optical and UKIDSS near-IR photometric data. Nine candidates were observed by YFOSC, and five among six new quasars were identified as z > 3.6 quasars. One of the other three objects was identified as a star and the other two were unidentified due to the lower signal-to-noise ratio of their spectra. This is the first time that z > 4 quasars have been discovered using a telescope in China. Thanks to the Chinese Telescope Access Program (TAP), the redshift of 4.6 for one of these quasars was confirmed by the Multiple Mirror Telescope (MMT) Red Channel spectroscopy. The continuum and emission line properties of these six quasars, as well as their central black hole masses and Eddington ratios, were obtained. 展开更多
关键词 quasars: general quasars: emission lines galaxies: active galax- ies: high-redshift
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What determines the observational differences of blazars? 被引量:1
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作者 Xu-Liang Fan Jin-Ming Bai Ji-Rong Mao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第11期61-70,共10页
We examine the scenario that the Doppler factor determines the observational differences of blazars. Significantly negative correlations are found between the observational synchrotron peak frequency and the Doppler f... We examine the scenario that the Doppler factor determines the observational differences of blazars. Significantly negative correlations are found between the observational synchrotron peak frequency and the Doppler factor. After correcting the Doppler boosting, the intrinsic peak frequency has a tight linear relation with the Doppler factor. It is interesting that this relation is consistent with the scenario that the black hole mass governs both the bulk Lorentz factor and the synchrotron peak frequency. In addition, the distinction between the kinetic jet powers of BL Lac objects and fiat spectrum radio quasars disappears after the boosting factor δ2 is considered. The negative correlation between the peak frequency and the observational isotropic luminosity, known as the blazar sequence, also disappears after the Doppler boosting is corrected. We also find that the correlation between the Compton dominance and the Doppler factor exists for all types of blazars. Therefore, this correlation is unsuitable for examining the external Compton emission dominance. 展开更多
关键词 galaxies: jets - BL Lacertae objects: general - quasars general - radiation mechanisms:non-thermal
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引力透镜与类星体─星系(星系团)成协 被引量:1
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作者 朱宗宏 袁启荣 何香涛 《天文学进展》 CSCD 北大核心 1997年第2期157-168,共12页
综述了背景光源(类星体)与前方天体(星系、星系团等)成协的观测和统计事例.详尽叙述了与成协问题相关的引力透镜理论.全面介绍了对各种成协事例进行引力透镜理论解释的方法、研究现状及存在的问题.还给出了一种计算成协样品中面... 综述了背景光源(类星体)与前方天体(星系、星系团等)成协的观测和统计事例.详尽叙述了与成协问题相关的引力透镜理论.全面介绍了对各种成协事例进行引力透镜理论解释的方法、研究现状及存在的问题.还给出了一种计算成协样品中面密度超出因子的改进方法. 展开更多
关键词 引力透镜 星系 星系团 类星体
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A very bright (i=16.44) quasar in the ‘redshift desert’ discovered by the Guoshoujing Telescope (LAMOST) 被引量:2
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作者 Xue-Bing Wu Zhao-Yu Chen +18 位作者 Zhen-Dong Jia Wen-Wen Zuo Yong-Heng Zhao A-Li Luo Zhong-Rui Bai Jian-Jun Chen Hao-Tong Zhang Hong-Liang Yan Juan-Juan Ren Shi-Wei Sun Hong Wu Yong Zhang Ye-Ping Li Qi-Shuai Lu You Wang Ji-Jun Ni Hai Wang Xu Kong Shi-Yin Shen 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2010年第8期737-744,共8页
The redshift range from 2.2 to 3 is known as the 'redshift desert' of quasars because quasars with redshifts in this range have similar optical colors as normal stars and are thus difficult to find in optical sky su... The redshift range from 2.2 to 3 is known as the 'redshift desert' of quasars because quasars with redshifts in this range have similar optical colors as normal stars and are thus difficult to find in optical sky surveys. A quasar candidate, SDSS J085543.40-001517.7, which was selected by a recently proposed criterion involving near-IR Y - K and optical g - z colors, was identified spectroscopically as a new quasar with a redshift of 2.427 by the Guoshoujing Telescope (LAMOST) commissioning observation in 2009 December and confirmed by the observation made with the NAOC/Xinglong 2.16 m telescope in 2010 March. This quasar was not identified in the SDSS spectroscopic survey. Comparing with other SDSS quasars, we found that this new quasar, with an i magnitude of 16.44, is apparently the brightest one in the redshift range from 2.3 to 2.7. From its spectral properties, we derived its central black hole mass to be (1.4 - 3.9) × 10^110 M⊙ and its bolometric luminosity to be 3.7 × 10^48 erg s^-1, which indicates that this new quasar is intrinsically very bright and belongs to the class of the most luminous quasars in the universe. Our identification supports the notion that quasars in the redshift desert can be found by the quasar selection criterion involving the near-IR colors. More missing quasars are expected to be uncovered by future LAMOST spectroscopic surveys, which is important to the study of the cosmological evolution of quasars at redshifts higher than 2.2. 展开更多
关键词 quasars general -- quasars emission lines -- galaxies active
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Eight new quasars discovered by the Guoshoujing Telescope (LAMOST) in one extragalactic field 被引量:1
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作者 Xue-Bing Wu Zhen-Dong Jia +18 位作者 Zhao-Yu Chen Wen-Wen Zuo Yong-Heng Zhao A-li Luo Zhong-Rui Bai Jian-Jun Chen Hao-Tong Zhang Hong-Liang Yan Juan-Juan Ren Shi-Wei Sun Hong Wu Yong Zhang Ye-Ping Li Qi-Shuai Lu You Wang Ji-Jun Ni Hai Wang Xu Kong Shi-Yin Shen 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2010年第8期745-752,共8页
We report the discovery of eight new quasars in one extragalactic field (a five-degree field centered at RA=08^h58^m08.2^s, Dec=01°32′29.7″) with the Guoshoujing Telescope (LAMOST) commissioning observation... We report the discovery of eight new quasars in one extragalactic field (a five-degree field centered at RA=08^h58^m08.2^s, Dec=01°32′29.7″) with the Guoshoujing Telescope (LAMOST) commissioning observations made on 2009 December 18. These quasars, with i magnitudes from 16.44 to 19.34 and redshifts from 0.898 to 2.773, were not identified in the SDSS spectroscopic survey, though six of them with redshifts less than 2.5 were selected as quasar targets in SDSS. Except for one source without near-IR Y-band data, seven of these eight new quasars satisfy a newly proposed quasar selection criterion involving both near-IR and optical colors. Two of them were found in the 'redshift desert' for quasars (z from 2.2 to 3), indicating that the new criterion is efficient for uncovering missing quasars with similar optical colors to stars. Although LAMOST encountered some problems during the commissioning observations, we were still able to identify 38 other known SDSS quasars in this field, with i magnitudes from 16.24 to 19.10 and redshifts from 0.297 to 4.512. Our identifications imply that a substantial fraction of quasars may be miss- ing in previous quasar surveys. The implication of our results to the future LAMOST quasar survey is discussed. 展开更多
关键词 quasars general -- quasars emission lines -- galaxies active
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New background quasars in the vicinity of the Andromeda Galaxy discovered with the Guoshoujing Telescope (LAMOST) 被引量:1
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作者 Zhi-Ying Huo Xiao-Wei Liu +17 位作者 Hai-Bo Yuan Hui-Hua Zhang Yong-Heng Zhao Jian-Jun Chen Zhong-Rui Bai Hao-Tong Zhang Hua-Wei Zhang Ruben Garcia-Benito Mao-Sheng Xiang Hong-Liang Yan Juan-Juan Ren Shi-Wei Sun Yong Zhang Ye-Ping Li Qi-Shuai Lu You Wang Ji-Jun Ni Hai Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2010年第7期612-620,共9页
We present preliminary analyses of spectra of quasar candidates in two Guoshoujing Telescope (GSJT, formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope - LAMOST) test fields near M 31 where ... We present preliminary analyses of spectra of quasar candidates in two Guoshoujing Telescope (GSJT, formerly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope - LAMOST) test fields near M 31 where one is close to the optical center of the disk and the other is towards the northeastern outskirts of the halo, obtained during the early stage of the GSJT commissioning in the last season of 2009. Both fields contain background low-redshift quasar candidates selected from the SDSS photometry. In total, 14 new quasars with redshifts up to 2 and i magnitudes between 16.7 and 19.2, are discovered, including 7 within the 2.5° central region of M 31. We briefly discuss the potential applications of these newly discovered bright quasars. 展开更多
关键词 GALAXIES individual (M31) -- quasars general -- quasars emission lines
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Extending the correlation of L_R-L_X to gamma-ray bursts 被引量:1
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作者 Jing L Jing-Wen Xing +3 位作者 Yuan-Chuan Zou Wei-Hua Lei Qing-Wen Wu Ding-Xiong Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第5期617-622,共6页
The well-known correlation between radio luminosity (LR) and X-ray luminosity (Lx), LR/LX 10^-5, holds for a variety of objects, such as active galactic nuclei, Galactic black holes, solar flares and cool stars.... The well-known correlation between radio luminosity (LR) and X-ray luminosity (Lx), LR/LX 10^-5, holds for a variety of objects, such as active galactic nuclei, Galactic black holes, solar flares and cool stars. Here we extend the relation to gamma-ray bursts (GRBs) and find that the GRBs also obey a similar LR - LX relation, with a slightly different slope of LR ∝ LX^1.1. This relation implies that the explosions that occur on different scales may have a common underlying origin. 展开更多
关键词 gamma-ray bursts general -- quasars general -- stars black holes
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Does black hole spin play a key role in the FSRQ/BL Lac dichotomy? 被引量:2
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作者 Debbijoy Bhattacharya Parameswaran Sreekumar +1 位作者 Banibrata Mukhopadhyay Ishan Tomar 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第4期7-14,共8页
Blazars are characterized by large intensity and spectral variations across the electromagnetic spectrum It is believed that jets emerging from them are almost aligned with the line-of-sight. The major- ity of identif... Blazars are characterized by large intensity and spectral variations across the electromagnetic spectrum It is believed that jets emerging from them are almost aligned with the line-of-sight. The major- ity of identified extragalactic sources in γ-ray catalogs of EGRET and Fermi are blazars. Observationally, blazars can be divided into two classes: fiat spectrum radio quasars (FSRQs) and BL Lacs. BL Lacs usually exhibit lower γ-ray luminosity and harder power law spectra at γ-ray energies than FSRQs. We attempt to explain the high energy properties of FSRQs and BL Lacs from Fermi γ-ray space telescope observations. It was argued previously that the difference in accretion rates is mainly responsible for the large mismatch in observed luminosity in "7-ray. However, when intrinsic luminosities are derived by correcting for beaming effects, this difference in 7-ray luminosity between the two classes is significantly reduced. In order to ex- plain this difference in intrinsic luminosities, we propose that spin plays an important role in the luminosity distribution dichotomy of BL Lacs and FSRQs. As the outflow power of a blazar increases with increasing spin of a central black hole, we suggest that the spin plays a crucial role in making BL Lac sources low luminous and slow rotators compared to FSRQ sources. 展开更多
关键词 BL Lacertae objects: general -- quasars general -- galaxies: jets -- black hole physics --relativistic processes -- gravitation
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The beaming effect and γ-ray emission for Fermi blazars
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作者 Yong-Yun Chen Xiong Zhang +2 位作者 Ding-Rong Xiong Si-Ju Wang Xiao-Ling Yu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第1期107-116,共10页
We study the γ-ray luminosity and beaming effect for Fermi blazars.Our results are as follows.(i) There are significant correlations between γ-ray luminosity and radio core luminosity,and between γ-ray luminosity... We study the γ-ray luminosity and beaming effect for Fermi blazars.Our results are as follows.(i) There are significant correlations between γ-ray luminosity and radio core luminosity,and between γ-ray luminosity and R_v,which suggests that the γ-ray emissions have a strong beaming effect,(ⅱ) Using the L_(ext)/M_(abs) as an indicator of environment effects,we find that there is no significant correlation betweenγ-ray luminosity and L_(ext)/M_(abs) for all sources when we remove the effect of redshift.Flat spectrum radio quasars considered alone also do not show a significant correlation,but BL Lacertae objects(BL Lacs) still show a significant correlation when we remove the effect of redshift.These results suggest that the γ-ray emission may be affected by the environment on a kiloparsec scale for BL Lacs. 展开更多
关键词 BL Lacerate objects: general -- quasars general -- gamma-rays: galaxies -- radio continuumgalaxies
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