DOI: 10.1016/j.scib.2020.01.008
论文题名: Fast jet proper motion discovered in a blazar at z=4.72
作者: Zhang Y. ; An T. ; Frey S.
刊名: Science Bulletin
ISSN: 20959273
出版年: 2020
卷: 65, 期: 7 起始页码: 525
结束页码: 530
语种: 英语
中文关键词: High-redshift
; Individual
; J1430+4204
; Nuclei
; Quasars
; Radio continuum
英文关键词: Kinematics
; Radio astronomy
; Red Shift
; High-redshift
; Individual
; J1430+4204
; Nuclei
; Quasars
; Radio continuum
; Cosmology
英文摘要: High-resolution observations of high-redshift (z>4) radio quasars offer a unique insight into jet kinematics at early cosmological epochs, as well as constraints on cosmological model parameters. Due to the general weakness of extremely distant objects and the apparently slow structural changes caused by cosmological time dilation, only a couple of high-redshift quasars (HRQs) have been studied with parsec-scale resolutions, and with limited number of observing epochs. Here we report on very long baseline interferometry (VLBI) observations of a high-redshift blazar J1430 + 4204 (z=4.72) in the 8 GHz frequency band at five different epochs spanning 22 years. The source shows a compact core–jet structure with two jet components being identified within 3 milli-arcsecond (mas) scale. The long time span and multiple-epoch data allow for the kinematic studies of the jet components. That results in a jet proper motion of μ(J1) = 0.017 ± 0.002 mas a-1 and μ(J2) = 0.156 ± 0.015 mas a-1, respectively. For the fastest-moving outer jet component J2, the corresponding apparent transverse speed is (19.5±1.9)c. The inferred bulk jet Lorentz factor Γ=14.6±3.8 and viewing angle θ=2.2°±1.6° indicate highly relativistic beaming. The Lorentz factor and apparent proper motion are the highest measured to date among the z>4 jetted radio sources, while the jet kinematics is still consistent with the cosmological interpretation of quasar redshifts. © 2020 Science China Press Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170160
Appears in Collections: 气候变化与战略
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作者单位: Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai, 200030, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Nanjing, 210008, China; Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Konkoly Thege Miklós út 15-17, H-1121 Budapest, Hungary
Recommended Citation:
Zhang Y.,An T.,Frey S.. Fast jet proper motion discovered in a blazar at z=4.72[J]. Science Bulletin,2020-01-01,65(7)