Astrometric signatures of self-gravitating protoplanetary discs

被引:23
作者
Rice, WKM
Armitage, PJ
Bate, MR
Bonnell, IA
机构
[1] Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife, Scotland
[2] Univ Colorado, JILA, Boulder, CO 80309 USA
[3] Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA
[4] Univ Exeter, Sch Phys, Exeter EX4 4QL, Devon, England
关键词
accretion; accretion discs; astrometry; stars : formation; planetary systems : protoplanetary discs; stars : pre-main-sequence;
D O I
10.1046/j.1365-8711.2003.06046.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We use high-resolution numerical simulations to study whether gravitational instabilities within circumstellar discs can produce astrometrically detectable motion of the central star. For discs with masses of M(disc)= 0.1 M (*), which are permanently stable against fragmentation, we find that the magnitude of the astrometric signal depends upon the efficiency of disc cooling. Short cooling times produce prominent filamentary spiral structures in the disc, and lead to stellar motions that are potentially observable with future high precision astrometric experiments. For a disc that is marginally unstable within radii of similar to10 au, we estimate astrometric displacements of 10-10(2) mu arcsec on decade time-scales for a star at a distance of 100 pc. The predicted displacement is suppressed by a factor of several in more stable discs in which the cooling time exceeds the local dynamical time by an order of magnitude. We find that the largest contribution comes from material in the outer regions of the disc and hence, in the most pessimistic scenario, the stellar motions caused by the disc could confuse astrometric searches for low-mass planets orbiting at large radii. They are, however, unlikely to present any complications in searches for embedded planets orbiting at small radii, relative to the disc size, or Jupiter-mass planets or greater orbiting at large radii.
引用
收藏
页码:227 / 232
页数:6
相关论文
共 29 条
[1]   ECCENTRIC GRAVITATIONAL INSTABILITIES IN NEARLY KEPLERIAN DISKS [J].
ADAMS, FC ;
RUDEN, SP ;
SHU, FH .
ASTROPHYSICAL JOURNAL, 1989, 347 (02) :959-976
[2]   Episodic accretion in magnetically layered protoplanetary discs [J].
Armitage, PJ ;
Livio, M ;
Pringle, JE .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2001, 324 (03) :705-711
[3]   Early planet formation as a trigger for further planet formation [J].
Armitage, PJ ;
Hansen, BMS .
NATURE, 1999, 402 (6762) :633-635
[4]   MODELING ACCRETION IN PROTOBINARY SYSTEMS [J].
BATE, MR ;
BONNELL, IA ;
PRICE, NM .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1995, 277 (02) :362-376
[5]   A SURVEY FOR CIRCUMSTELLAR DISKS AROUND YOUNG STELLAR OBJECTS [J].
BECKWITH, SVW ;
SARGENT, AI ;
CHINI, RS ;
GUSTEN, R .
ASTRONOMICAL JOURNAL, 1990, 99 (03) :924-945
[6]   THE FU ORIONIS OUTBURST AS A THERMAL ACCRETION EVENT - OBSERVATIONAL CONSTRAINTS FOR PROTOSTELLAR DISK MODELS [J].
BELL, KR ;
LIN, DNC ;
HARTMANN, LW ;
KENYON, SJ .
ASTROPHYSICAL JOURNAL, 1995, 444 (01) :376-395
[7]   USING FU ORIONIS OUTBURSTS TO CONSTRAIN SELF-REGULATED PROTOSTELLAR DISK MODELS [J].
BELL, KR ;
LIN, DNC .
ASTROPHYSICAL JOURNAL, 1994, 427 (02) :987-1004
[8]  
BENZ W, 1990, NATO ADV SCI I C-MAT, V302, P269
[9]   Possible rapid gas giant planet formation in the solar nebula and other protoplanetary disks [J].
Boss, AP .
ASTROPHYSICAL JOURNAL, 2000, 536 (02) :L101-L104
[10]   Astrometric signatures of giant-planet formation [J].
Boss, AP .
NATURE, 1998, 393 (6681) :141-143