On the bar formation mechanism in galaxies with cuspy bulges

	On the bar formation mechanism in galaxies with cuspy bulges
	Polyachenko, E. V.1; Berczik, P.2,3,4 ; Just, A.2
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2016-11-11
卷号	462 期号:4 页码:3727-3738
关键词	galaxies: bulges galaxies: kinematics and dynamics
英文摘要	We show by numerical simulations that a purely stellar dynamical model composed of an exponential disc, a cuspy bulge, and a Navarro-Frenk-White halo with parameters relevant to the Milky Way is subject to bar formation. Taking into account the finite disc thickness, the bar formation can be explained by the usual bar instability, in spite of the presence of an inner Lindblad resonance, that is believed to damp any global modes. The effect of replacing the live halo and bulge by a fixed external axisymmetric potential (rigid models) is studied. It is shown that while the e-folding time of bar instability increases significantly (from 250 to 500 Myr), the bar pattern speed remains almost the same. For the latter, our average value of 55 kms(-1) kpc(-1) agrees with the assumption that the Hercules stream in the solar neighbourhood is an imprint of the bar-disc interaction at the outer Lindblad resonance of the bar. Vertical averaging of the radial force in the central disc region comparable to the characteristic scale length allows us to reproduce the bar pattern speed and the growth rate of the rigid models, using normal mode analysis of linear perturbation theory in a razor-thin disc. The strong increase of the e-folding time with decreasing disc mass predicted by the mode analysis suggests that bars in galaxies similar to the Milky Way have formed only recently.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	HUBBLE-DEEP-FIELDS ; MILKY-WAY ; DYNAMICAL FRICTION ; SPIRAL STRUCTURE ; GALACTIC DISCS ; EVOLUTION ; INSTABILITY ; MODES ; SIMULATIONS ; SATELLITES
收录类别	SCI
语种	英语
WOS记录号	WOS:000385231600022
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/6904]
专题	国家天文台_星系宇宙学研究部
作者单位	1.Russian Acad Sci, Inst Astron, 48 Pyatnitskya St, Moscow 119017, Russia 2.Astron Rechen Inst ZAH, Monchhofstr 12-14, D-69120 Heidelberg, Germany 3.Natl Acad Sci Ukraine, Main Astron Observ, 27 Akad Zabolotnoho St, UA-03680 Kiev, Ukraine 4.Chinese Acad Sci, Natl Astron Observ China, 20A Datun Rd, Beijing 100012, Peoples R China
推荐引用方式 GB/T 7714	Polyachenko, E. V.,Berczik, P.,Just, A.. On the bar formation mechanism in galaxies with cuspy bulges[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2016,462(4):3727-3738.
APA	Polyachenko, E. V.,Berczik, P.,&Just, A..(2016).On the bar formation mechanism in galaxies with cuspy bulges.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,462(4),3727-3738.
MLA	Polyachenko, E. V.,et al."On the bar formation mechanism in galaxies with cuspy bulges".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 462.4(2016):3727-3738.