Multi-frequency VLBI observations of NRAO 530 | |
Feng, S. -W.; Shen, Z. -Q.; Cai, H. -B.; Chen, X.![]() ![]() | |
刊名 | ASTRONOMY & ASTROPHYSICS
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2006-09-01 | |
卷号 | 456期号:1页码:97-104 |
关键词 | galaxies : quasars : individual : NRAO 530 galaxies : jets radio continuum : galaxies |
英文摘要 | We report on VLBA observations of gamma-ray bright blazar NRAO 530 at multiple frequencies (5, 8, 15, 22, 39, 43, and 45 GHz) in 1997 and 1999. These multi-epoch multi-frequency high-resolution VLBI images exhibit a consistent core-dominated morphology with a bending jet to the north of the core. The quasi-simultaneous data observed at five frequencies (5, 8, 15, 22, and 43 GHz) in February 1997 enabled us to estimate the spectra of compact VLBI components in this highly variable source. Flat spectra are seen in the two central components (A and B), and the most compact component A that has the flattest spectral index at the south end is identified as the core. Based on the synchrotron cooling timescale argument, it is suggested that the observed inverted spectrum of component C is caused by the free-free absorption (FFA), although the synchrotron self-absorption (SSA) model cannot be ruled out definitely. While the SSA probably exists in component B, it is likely that the same FFA would produce the spectral turnover toward component B since the fitted FFA coefficients in both B and C components are almost the same. If so, the projected size of such an absorbing medium is at least 25 pc. |
学科主题 | 星系和宇宙学研究中心 |
WOS标题词 | Science & Technology ; Physical Sciences |
类目[WOS] | Astronomy & Astrophysics |
研究领域[WOS] | Astronomy & Astrophysics |
关键词[WOS] | GAMMA-RAY SOURCES ; ACTIVE GALACTIC NUCLEI ; RADIO-SOURCES ; X-RAY ; VARIABLE SOURCES ; MILLIMETER ; CENTIMETER ; SPECTRUM ; QUASARS ; MOTION |
收录类别 | SCI |
语种 | 英语 |
WOS记录号 | WOS:000240009800009 |
公开日期 | 2010-11-08 |
内容类型 | 期刊论文 |
源URL | [http://119.78.226.72//handle/331011/12309] ![]() |
专题 | 上海天文台_星系宇宙学重点实验室 |
作者单位 | 1.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 2.Chinese Acad Sci, Grad Sch, Beijing 100012, Peoples R China |
推荐引用方式 GB/T 7714 | Feng, S. -W.,Shen, Z. -Q.,Cai, H. -B.,et al. Multi-frequency VLBI observations of NRAO 530[J]. ASTRONOMY & ASTROPHYSICS,2006,456(1):97-104. |
APA | Feng, S. -W.,Shen, Z. -Q.,Cai, H. -B.,Chen, X.,Lu, R. -S.,&Huang, L..(2006).Multi-frequency VLBI observations of NRAO 530.ASTRONOMY & ASTROPHYSICS,456(1),97-104. |
MLA | Feng, S. -W.,et al."Multi-frequency VLBI observations of NRAO 530".ASTRONOMY & ASTROPHYSICS 456.1(2006):97-104. |
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