Origin of radio emission from nearby low-luminosity active galactic nuclei

	Origin of radio emission from nearby low-luminosity active galactic nuclei
	Wu, QW ; Cao, XW
刊名	ASTROPHYSICAL JOURNAL
	2005-03-01
卷号	621 期号:1 页码:130-138
关键词	accretion black hole physics galaxies : active galaxies : jets galaxies : nuclei accretion disks
英文摘要	We use the observational data in radio, optical, and X-ray wave bands for a sample of active galactic nuclei (AGNs) with measured black hole masses to explore the origin of radio emission from nearby low-luminosity active galactic nuclei (LLAGNs). The maximal luminosity of an advection-dominated accretion flow (ADAF) can be calculated for a given black hole mass, as there is a critical accretion rate above which the ADAF is no longer present. We find that the radio luminosities are higher than the maximal luminosities expected from the ADAF model for most sources in this sample. This implies that the radio emission is predominantly from the jets in these sources. The radio emission from a small fraction of the sources (15/60; referred to as radio-weak sources) in this sample can be explained by the ADAF model. However, comparing the observed multiband emission data with the spectra calculated for the ADAF or adiabatic inflow-outflow solution (ADIOS) cases, we find that neither ADAF nor ADIOS models can reproduce the observed multiband emission simultaneously, with reasonable magnetic field strengths, for these radio-weak sources. A variety of other possibilities are discussed, and we suggest that the radio emission is probably dominated by jet emission even in these radio-weak LLAGNs.
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]	ADVECTION-DOMINATED ACCRETION ; SAGITTARIUS-A-ASTERISK ; OPTICALLY SELECTED QUASARS ; DWARF SEYFERT NUCLEI ; H-ALPHA EMISSION ; X-RAY-PROPERTIES ; BLACK-HOLE ; SPECTRAL MODELS ; QUIET QUASARS ; FLOWS
收录类别	SCI
语种	英语
WOS记录号	WOS:000227406200011
公开日期	2010-11-08
内容类型	期刊论文
源URL	[http://119.78.226.72//handle/331011/12439]
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 100039, Peoples R China
推荐引用方式 GB/T 7714	Wu, QW,Cao, XW. Origin of radio emission from nearby low-luminosity active galactic nuclei[J]. ASTROPHYSICAL JOURNAL,2005,621(1):130-138.
APA	Wu, QW,&Cao, XW.(2005).Origin of radio emission from nearby low-luminosity active galactic nuclei.ASTROPHYSICAL JOURNAL,621(1),130-138.
MLA	Wu, QW,et al."Origin of radio emission from nearby low-luminosity active galactic nuclei".ASTROPHYSICAL JOURNAL 621.1(2005):130-138.