EVN observations of eleven GHz-Peaked-Spectrum radio sources at 2.3/8.4 GHz

	EVN observations of eleven GHz-Peaked-Spectrum radio sources at 2.3/8.4 GHz
	Xiang, L ; Dallacasa, D ; Cassaro, P ; Jiang, D ; Reynolds, C
刊名	ASTRONOMY & ASTROPHYSICS
	2005-04-01
卷号	434 期号:1 页码:123-132
关键词	galaxies : nuclei galaxies : quasars : general radio continuum : galaxies
英文摘要	We present results of EVN observations of eleven GHz- Peaked- Spectrum ( GPS) radio sources at 2.3/ 8.4 GHz. These sources are from the classical " bright" GPS source samples with peak flux densities > 0.2 Jy and spectral indices alpha < - 0.2 ( S proportional to nu(-alpha)) in the optically thick regime of their convex spectra. Most of the target sources did not have VLBI images at the time this project started. The aim of the work is to find Compact Symmetric Object ( CSO) candidates from the " bright" GPS samples. These CSOs play a key role in understanding the very early stage of the evolution of individual radio galaxies. The reason for investigating GPS source samples is that CSO candidates are more frequently found among this class of radio sources. In fact both classes, GPS and CSO, represent a small fraction of the flux limited and flat- spectrum samples like PR+ CJ1 ( PR: Pearson- Readhead survey, CJ1: the first Caltech- Jodrell Bank survey) and CJF ( the Caltech- Jodrell Bank flat spectrum source survey) with a single digit percentage progressively decreasing with decreasing flux density limit. Our results, with at least 3, but possibly more CSO sources detected among a sample of 11, underline the effectiveness of our approach. The three confirmed CSO sources ( 1133+ 432, 1824+ 271, and 2121- 014) are characterized by a symmetric pair of resolved components, each with steep spectral indices. Five further sources ( 0144+ 209, 0554- 026, 0904+ 039, 0914+ 114 and 2322- 040) can be considered likely CSO candidates. The remaining three sources ( 0159+ 839, 0602+ 780 and 0802+ 212) are either of core- jet type or dominated by a single component at both frequencies.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	COMPACT SYMMETRIC OBJECTS ; MULTIFREQUENCY VLA OBSERVATIONS ; B3-VLA CSS SAMPLE ; BANK VLBI SURVEY ; STEEP-SPECTRUM ; OPTICAL-IDENTIFICATION ; HOST GALAXIES ; YOUNG ; JETS ; SPECTROSCOPY
收录类别	SCI
语种	英语
WOS记录号	WOS:000228097300015
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/19477]
专题	上海天文台_天文地球动力学研究中心
作者单位	1.Chinese Acad Sci, Natl Astron Observ, Urumqi 830011, Peoples R China 2.Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy 3.CNR, Ist Radioastron, I-96017 Noto SR, Italy 4.CNR, Ist Radioastron, I-40129 Bologna, Italy 5.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 6.Joint Inst VLBI Europe, NL-7990 AA Dwingeloo, Netherlands
推荐引用方式 GB/T 7714	Xiang, L,Dallacasa, D,Cassaro, P,et al. EVN observations of eleven GHz-Peaked-Spectrum radio sources at 2.3/8.4 GHz[J]. ASTRONOMY & ASTROPHYSICS,2005,434(1):123-132.
APA	Xiang, L,Dallacasa, D,Cassaro, P,Jiang, D,&Reynolds, C.(2005).EVN observations of eleven GHz-Peaked-Spectrum radio sources at 2.3/8.4 GHz.ASTRONOMY & ASTROPHYSICS,434(1),123-132.
MLA	Xiang, L,et al."EVN observations of eleven GHz-Peaked-Spectrum radio sources at 2.3/8.4 GHz".ASTRONOMY & ASTROPHYSICS 434.1(2005):123-132.