Frequency-dependent core shifts and parameter estimation for the blazar 3C 454.3
文献类型：期刊论文
| 作者 | Mohan, P.1; Agarwal, A.1,2; Mangalam, A.3; Gupta, Alok C.1,2,4; Wiita, Paul J.5; Volvach, A. E.6,7; Aller, M. F.8; Aller, H. D.8; Gu, M. F.4; Lahteenmaki, A.9 |
| 刊名 | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
 |
| 出版日期 | 2015-09-11 |
| 卷号 | 452期号:2页码:2004-2017 |
| 关键词 | methods: data analysis galaxies: active quasars: general quasars: individual: 3C 454.3 |
| 英文摘要 | We study the core shift effect in the parsec-scale jet of the blazar 3C 454.3 using the 4.836.8 GHz radio light curves obtained from three decades of continuous monitoring. From a piecewise Gaussian fit to each flare, time lags Delta t between the observation frequencies. and spectral indices a based on peak amplitudes A are determined. From the fit Delta t..1/kr, kr = 1.10 +/- 0.18 indicating equipartition between the magnetic field energy density and the particle energy density. From the fit A proportional to nu(alpha) alpha, a is in the range -0.24 to 1.52. A mean magnetic field strength at 1 pc, B-1 = 0.5 +/- 0.2 G, and at the core, B-core = 46 +/- 16 mG, are inferred, consistent with previous estimates. The measure of core position offset is Omega(r nu) = 6.4 +/- 2.8 pc GHz(1/kr) when averaged over all frequency pairs. Based on the statistical trend shown by the measured core radius r(core) as a function of., we infer that the synchrotron opacity model may not be valid for all cases. A Fourier periodogram analysis yields power-law slopes in the range -1.6 to -3.5 describing the power spectral density shape and gives bend timescales in the range 0.52-0.66 yr. This result, and both positive and negative a, indicate that the flares originate from multiple shocks in a small region. Important objectives met in our study include: the demonstration of the computational efficiency and statistical basis of the piecewise Gaussian fit; consistency with previously reported results; evidence for the core shift dependence on observation frequency and its utility in jet diagnostics in the region close to the resolving limit of very long baseline interferometry observations. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | ACTIVE GALACTIC NUCLEI ; EXTRAGALACTIC RADIO-SOURCES ; X-RAY VARIABILITY ; BASE-LINE ARRAY ; BL LACERTAE ; XMM-NEWTON ; INTRADAY VARIABILITY ; SUPERLUMINAL MOTION ; RELATIVISTIC JETS ; MAGNETIC-FIELD |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000360851900073 |
| 公开日期 | 2015-11-10 |
| 源URL | [http://119.78.226.72/handle/331011/28250]  |
| 专题 | 上海天文台_星系宇宙学重点实验室 |
| 作者单位 | 1.Aryabhatta Res Inst Observat Sci ARIES, Manora Peak 263002, Nainital, India 2.DDU Gorakhpur Univ, Dept Phys, Gorakhpur 273009, Uttar Pradesh, India 3.Indian Inst Astrophys, Bangalore 560034, Karnataka, India 4.Chinese Acad Sci, Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, Shanghai 200030, Peoples R China 5.Coll New Jersey, Dept Phys, Ewing, NJ 08628 USA 6.Radio Astron Lab, Crimean Astrophys Observ, UA-298409 Crimea, Ukraine 7.Taras Shevchenko Natl Univ Kyiv, UA-01601 Kiev, Ukraine 8.Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA 9.Univ Aalborg, Metsahovi Radio Observ, FI-02540 Kylmala, Finland |
| 推荐引用方式 GB/T 7714 | Mohan, P.,Agarwal, A.,Mangalam, A.,et al. Frequency-dependent core shifts and parameter estimation for the blazar 3C 454.3[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2015,452(2):2004-2017. |
| APA | Mohan, P..,Agarwal, A..,Mangalam, A..,Gupta, Alok C..,Wiita, Paul J..,...&Volvach, L. N..(2015).Frequency-dependent core shifts and parameter estimation for the blazar 3C 454.3.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,452(2),2004-2017. |
| MLA | Mohan, P.,et al."Frequency-dependent core shifts and parameter estimation for the blazar 3C 454.3".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 452.2(2015):2004-2017. |
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