TY - JOUR
T1 - Backflow in post-asymptotic giant branch stars
AU - Soker, Noam
N1 - Copyright:
Copyright 2005 Elsevier Science B.V., Amsterdam. All rights reserved.
PY - 2001/12/21
Y1 - 2001/12/21
N2 - We derive the conditions for a backflow toward the central star(s) of circumstellar material to occur during the post-asymptotic giant branch (post-AGB) phase. The backflowing material may be accreted by the post-AGB star and/or its companion, if such exists. Such a backflow may play a significant role in shaping the descendant planetary nebula, by, among other things, slowing down the post-AGB evolution, and by forming an accretion disc which may blow two jets We consider three forces acting on a slowly moving mass element: the gravity of the central system, radiation pressure, and fast wind ram pressure. We find that for a significant backflow to occur, a slow dense flow should exist, such that the relation between the total mass in the slow flow, Mi, and the solid angle it covers Ω, is given by (Mi/β) ≳ 0.1 M⊙, where β ≡ Ω/4π. The requirement for both a high mass-loss rate per unit solid angle and a very slow wind, such that it can be decelerated and flow back, probably requires close binary interaction, hence this process is rare.
AB - We derive the conditions for a backflow toward the central star(s) of circumstellar material to occur during the post-asymptotic giant branch (post-AGB) phase. The backflowing material may be accreted by the post-AGB star and/or its companion, if such exists. Such a backflow may play a significant role in shaping the descendant planetary nebula, by, among other things, slowing down the post-AGB evolution, and by forming an accretion disc which may blow two jets We consider three forces acting on a slowly moving mass element: the gravity of the central system, radiation pressure, and fast wind ram pressure. We find that for a significant backflow to occur, a slow dense flow should exist, such that the relation between the total mass in the slow flow, Mi, and the solid angle it covers Ω, is given by (Mi/β) ≳ 0.1 M⊙, where β ≡ Ω/4π. The requirement for both a high mass-loss rate per unit solid angle and a very slow wind, such that it can be decelerated and flow back, probably requires close binary interaction, hence this process is rare.
KW - Circumstellar matter
KW - Planetary nebulae: General
KW - Stars: Agb and post-agb
KW - Stars: Mass-loss
UR - http://www.scopus.com/inward/record.url?scp=0042368536&partnerID=8YFLogxK
U2 - 10.1046/j.1365-8711.2001.04975.x
DO - 10.1046/j.1365-8711.2001.04975.x
M3 - 文章
AN - SCOPUS:0042368536
VL - 328
SP - 1081
EP - 1084
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -