Radio spectral index from NVSS and TGSS

doi:10.1088/1674-4527/19/7/96

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	Radio spectral index from NVSS and TGSS
	Tiwari, Prabhakar
刊名	RESEARCH IN ASTRONOMY AND ASTROPHYSICS
	2019-07-01
卷号	19 期号:7 页码:8
关键词	galaxies: high-redshift galaxies: active galactic nuclei
ISSN号	1674-4527
DOI	10.1088/1674-4527/19/7/96
英文摘要	I extract the radio spectral index. a, from 541 195 common sources observed in the 150 MHz TIFR GMRT Sky Survey (TGSS) and the 1.4 GHz NRAO VLA Sky Survey (NVSS). This large common source catalog covers about 80% of the sky. The flux density limits in these surveys are such that the observed galaxies are presumably hosts of active galactic nuclei (AGNs). I confirm the steepening of a with increasing flux density for this large sample and provide a parametric fit between a and flux density. Next, I divide the data into low flux (LF) and high flux (HF) density samples with roughly equal numbers of galaxies. The LF sample contains all galaxies below 100 mJy TGSS and 20 mJy NVSS flux density and the HF sample is all galaxies above 100 mJy TGSS and 20 mJy NVSS. I observe an increase in a with source size (TGSS measured), saturating for large sizes to 0.89 +/- 0.22 and 0.76 +/- 0.21 for the LF and HF sources, respectively. I discuss the observed results and possible physical mechanisms to explain observed a dependence with source size for LF and HF samples.
资助项目	NAOC Youth Talent Fund[110000JJ01]
WOS关键词	LOCKMAN HOLE ; PARTICLE-ACCELERATION ; RELATIVISTIC JETS ; LOW-FREQUENCIES ; SOURCE COUNTS ; GALAXIES ; SKY ; I. ; EVOLUTION ; LOBES
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	NATL ASTRONOMICAL OBSERVATORIES, CHIN ACAD SCIENCES
WOS记录号	WOS:000475427200007
资助机构	NAOC Youth Talent Fund ; NAOC Youth Talent Fund ; NAOC Youth Talent Fund ; NAOC Youth Talent Fund ; NAOC Youth Talent Fund ; NAOC Youth Talent Fund ; NAOC Youth Talent Fund ; NAOC Youth Talent Fund
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/26912]
专题	中国科学院国家天文台
通讯作者	Tiwari, Prabhakar
作者单位	Chinese Acad Sci, Natl Astron Observ, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	Tiwari, Prabhakar. Radio spectral index from NVSS and TGSS[J]. RESEARCH IN ASTRONOMY AND ASTROPHYSICS,2019,19(7):8.
APA	Tiwari, Prabhakar.(2019).Radio spectral index from NVSS and TGSS.RESEARCH IN ASTRONOMY AND ASTROPHYSICS,19(7),8.
MLA	Tiwari, Prabhakar."Radio spectral index from NVSS and TGSS".RESEARCH IN ASTRONOMY AND ASTROPHYSICS 19.7(2019):8.