The radio structure of ultra-high-energy synchrotron-peak BL Lacs

	The radio structure of ultra-high-energy synchrotron-peak BL Lacs
	Wu, Zhongzu 1; Jiang, D. R.2; Gu, Minfeng2
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2012-08-01
卷号	424 期号:4 页码:2733-2745
关键词	galaxies: active BL Lacertae objects: general quasars: general
英文摘要	We present the results of European Very Long Baseline Interferometry Network (EVN) and Multi-Element Radio Linked Interferometer Network (MERLIN) 5-GHz observations of nine ultra-high-energy synchrotron-peak BL Lacs (UHBLs), consisting of all BL Lacs with log?(?peak/Hz) > 20 from the work of Nieppola et al. The radio structure was investigated for these sources, in combination with available Very Long Baseline Array (VLBA) archive data. We found that a corejet structure is detected in five sources, while four sources only have a compact core at the pc scale. The cores of all sources show high brightness temperature (with mean and median values log?(Tb/K) 11), which implies that the beaming effect is likely present in all sources. When multi-epoch Very Long Baseline Interferometry (VLBI) data are available, we find no significant variations for either core or total flux density in two sources (2E 0414+0057 and EXO 0706.1+5913) and no evident proper motion in 2E 0414+0057, while superluminal motion is likely detected in EXO 0706.1+5913. Our sources are found to be less compact than the typical high-frequency peaked BL Lac objects (HBLs) of Giroletti et al., by comparing the ratio of the VLBI total flux and the core flux at the arcsec scale. Combining all our results, we propose that the beaming effect might be present in the jets of UHBLs; however, it is likely weaker than that for typical HBLs. Moreover, we found by comparing the distributions of redshift and radio luminosity that UHBLs could be less Doppler-beamed versions of HBLs with similar jet power. These results are in good consistence with the expectations of our previous work.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	ACTIVE GALACTIC NUCLEI ; LACERTAE OBJECTS ; BLAZAR SEQUENCE ; BRIGHT BLAZARS ; SAMPLE ; DISTRIBUTIONS ; QUASARS
收录类别	SCI
语种	英语
WOS记录号	WOS:000307385100026
公开日期	2015-01-27
内容类型	期刊论文
源URL	[http://119.78.226.72//handle/331011/15462]
专题	上海天文台_星系宇宙学重点实验室
作者单位	1.Guizhou Univ, Coll Sci, Guiyang 550025, Peoples R China 2.Chinese Acad Sci, Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, Shanghai 200030, Peoples R China
推荐引用方式 GB/T 7714	Wu, Zhongzu,Jiang, D. R.,Gu, Minfeng. The radio structure of ultra-high-energy synchrotron-peak BL Lacs[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2012,424(4):2733-2745.
APA	Wu, Zhongzu,Jiang, D. R.,&Gu, Minfeng.(2012).The radio structure of ultra-high-energy synchrotron-peak BL Lacs.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,424(4),2733-2745.
MLA	Wu, Zhongzu,et al."The radio structure of ultra-high-energy synchrotron-peak BL Lacs".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 424.4(2012):2733-2745.