...

N 体シミュレ ションで探る 銀河系中心部の若い星の起源

by user

on
Category: Documents
14

views

Report

Comments

Transcript

N 体シミュレ ションで探る 銀河系中心部の若い星の起源
N 890ῌ0065 1ῌ21ῌ35
e-mail: [email protected]
(1 pc) !"#$%&'( )*+,-./)0
12345 67%8
.9:;8%<=>?@
L
ABCD'( EFG
%8H2IJ3C)K,-23
.9MNC+OPQRS N TUVWXUYZ.[&3( \]^5
L_`abcT
/)d5 efg
,-23c5 \
L<ZhN&3. 1 : 1 ij9klm*&9:C+n2<=>?@
.o#23( p35 )<=>?@*&9qJ3rs
5 tuvJ'
rswx.*yzS')C
{%&3(
LkRINX{$y57)6 j1J< 1. !
2Qg7RINT„$VWRI%&'…†`
!
,‡.ˆ‰eŠ‹'
!Œi Ž
1 pc "#$%&' () Myr* +, (OB -
<>?@ABCDFGE3'kRIN
,* ./)0123'4'5
6 727 X{$y58)6 Ž‘{’< mnz,
!89:;$<
!=>?@
p ,‡.“m”•$–'4INqRu
1)ῌ3)
ABCDE5FG.HIJ ,KL<M7
!…,—Z ,‡#$
NOPQR56 SIJ TRQ,.UT$
ABCD.KL7INqRu IRS13E NX,‡
VWR UEX7'YZ:;[\3'4I
™š›œNOPQR'5,W~EX
2 ]^_N`3'56 ab2Q TR
`
Q%,cdefXg7h7&0'i5N
’y56 WI NT„$< Arches \ Quintuplet N3I
!%,<4&j1kR56
l1<
^˜>?@
!%,abˆcdežY$45
!2Q 30 pc &Q
! 0.1ῌ1 pc l1 WI<j1m
2ῌ3 Myr %…†`,‡.0123'
f X l 1 < rS-
59)6 l S-stars 1'< S:$KL<
starss NtuR5 0.1 pc "#vwxpq5
Ÿ $y5IJ ¡Q2$¢£2Q,e
n o p q 5 OB - ,
B -,$y5
5), 6)
2), 4)
6
¤¥$&5¦.y56 S§¨©ª«1'
YZ mnzp1'
`{<"|
j1$y56 l1J< !>?@ABCD
<kW¬W`{.­®kR'5. ¯NT„
`f<`6 $< !°
}~$4I+€mn$+‚ƒ2Q,.
‹5,‡±²³´µ¶C³·¸e¹ ,‡
VWRI 1W~ TRQ%,<S:$K
{.
186
!abº»ežY$4521
¼½
2011 4 ½
2. N !10), 11) "#"$
%&'()*+,-./ )*+012+-3+45$ )
*+016-47-82+
45
+9:-;<=>+? @
$ 3AB-CD##?EFG
H I0DJKLMN9:N?O9
Ž1
BRIDGE 'cŽ ŠE
FGH$ %¦JKLST
9:Ÿ?
: O(N 2)P$ 3QB-RAS
T IU=0#&
5O"
*
9: O(N log N)P -&?5-6
"#"$ 5MC9:N?VW$
3. BRIDGE N EFGH0169:CD
€,MeN?O‚"ƒ"
-##XNY$ ST3+
-$ ST5EFGH„F…T†‡
MZ"=9:<+5*,-[\?
.? ˆBRIDGE‰ .?13) BRIDGE %O$ N Š]M3AEFGHMe
$ 1) ]M N ^"$ 3A+
<$ %'‹JKL3Q+Œ.?S
.?EFGHM9:"$ _
TM? IŽ 1P )/$ ‘
`aMbc#&defg?
O5MC^’+CD
$ 2) N ^N?-$ ST
9:N?5-“5+/
M?Ohg+$ ij&#M?"#+#/
”•$ BRIDGE M$ qr N M
/ "#"$ &ij&,-.?
#&2"5– I—˜
k$ lmnMop+-&qr
VW 13 pcP -[
5™š
VW$ `abcaMZ"=s
"M›O?5$ `
<+O$ Z"_M? N
aMopqœ<$ #&
^N?
-.? t$ 1 pc .XžnŸ"
/ t$
)/-u-X$ %-lm
nv"iw[<x?#y!?O$
¡!¢W-£? WM¤X"
Mz"{XZ"|}
M
&+ O$ MZ"=h*
V)/¦M§<¨©?O$ ª«5-
O$ 5M~ N ^"$ C
W"< I#¬WP$ 1­®1 $¯%°
Z"=9:N?
-.?
±²N? IŽ 2P % 2ῌ3 Myr ³&-
12)
3+?O$ i*"
*5$ ¥%¥
´<$ µ¶…·†G¸¹+?5ºg&
» 104 ¼
»4½
187
62
0s‡ˆ„4‰Š‹F
Œ Ž|‘A’~ <
!@G)B“”J54
!"#
63
789: 0
*+<=>?@A*+B*+<=
!CDEFG5•HI(
0A–—H()B~ 0\]
^G)˜4)™<=Vš4)PQR
›œ$UA <=VXA5YKG5
4Z ( 0s~)<
!A 1 : 1 žaŸ ¡FG5
*+<=˜4$ad4Z)¢;
64
0£< ! z€|} B
žaŸ ¡FG5ab() z{|} xyŒ €|0s‡ˆ„4 z¤
<< !} *+<=
¥¦$9§: 9 Myr ;)&<
!xy¦=¨A©ªJ
¡«(54 Fujii et al.
(2010) 6 2 F&¬­14)
$%&'() *+,-. 600 / 0
1 6 / 5 2$3454
4.
6 3 789:
; 0*+<=>?@A*+B*+
<=
!CDEFG5HI(5J
KL MN0OB() P
QRST$U PQ<=VAW454
A VXA5YKG54Z ( [
0\]^G)A0AH()_`*
+<=ab(54B$cJ54 (K
0A$ad^B4Le 0
fgI(5ab(Bhi(54) JJ
jk$lB 0*+<=
1 1 pc H( _ m\nopq
*+<=ab(54)
rFLJ5 1 pc F&stuBa
b()^vLw
6 4 *+<=ab()
;xy z{|} B0s~)<
!xy z€|} ; ‚ƒ
0fgI(54 z{|B€|
„@G54} A 4 Myr F&…J†0f
188
®¯°±
2011 ² 4 °
i5
RS/T?,opqrs5,:; ,kl< X ¦Œ/mn +,:;Š§¨
< 1 7@tcb7@" ©†,€,vw,ayzt{|b} 2.5ῌ7 Myr ,/
ª?\ @,:; «‚1«a+,x‡,5,:;<ƒ7@¬2 ‹ŒRS/T
­ +,®RS/T?M,:; VŒ‘:; „“”,:;h 56 Fujii et al. (2009)
i 7 F2p¯15)
ƒ7@" V„,…†,iyzt{|b,
!"#$%&
‡:;ˆ‰F2Š"# ‚5JE5"
'()* +,-./01234*5
"h ‹Œ,i51[RS/T?@"" 
6 77 8,,+,9,:;<=
Œ5 1 : 1 NOPQRS,Ž†56‘:
9 Myr "15/>?
; Vopqrs5=…†,]^_`a L4
@ABC/DE5"
L5 ,<’?2
27 ,,‘/=
JK 8
Xh /T?@" 8,+,9 “”:
,L55M
; V,ˆ2<o?@"
, 1 : 1 NOPQRS/T?@"8U?
FG/=X •@"U45"h
V1 : 1 NOPQRS/T?@" WX
/–’\ Vi 5 „,€h
8,FG,:;<H7I
YZ[\ Z
L55M ,]^_`a/6bcdefg56h
—9u$%&'(/F?@ABC/D
i 5 RS/T?@"6,:;<ABC
E5" +,M/ ˜,™^š[?
<ja/ ›", 1 : 1 N
,kl< (1, 0) /mn7opqrs5tc
OPQRS/T2 Žœ/ABCDE5"
b7u,56 vw,a\
@,x,y
8,™žŸ ¡/F?@ L5
zt{|b}8,,kl5 ~
5M-¢ £¤
€+,x5,kl<‚1a5
—@71?9u›"<ABCP¥8
° 104 ±
°4²
189
Q6
/0|›*6/KL!MW
XYZ œRSTU žŸO—
/ Ÿ 20 ¡¢#$EhJ/,DO
£Ÿ /#$45¤-¥¦6?§
¨HI:©ª9
20 ¡¢#$EhJ/45 KL!MJ/«
I¬ .hJ/KL!M:N!
?P
Q7
wxyz*w{|€'[w{'] ­®
/¯Œ SŸKL!M%&'()*+
0.05 pc °;:R±8/„…,DO
Fujii et al. (2010) Q 1 Eh²³14)
Q8
/0:EFG
q/Š‹Œ45
/0„…Š,‘Š:´ 60 Œµ²9¶
’“ KLp!MV.
q/12·?6¥
¦¸Œ Fujii et al. (2010) Q 3 Eh²
³14)
!
"#$%&'()*+,-./0 0.1ῌ1 pc 12345678
9:;< S-stars =>?@ABC?,D
/0:E/FG
HI
J/
KL!M:N!O?-P Q 6 /0:EFG
/,RSTUVWXY
Z,[\']- /0;
J/
^/:_`+a*,b/0!M:N
cd
efA:E/0/g?hi
<=j J//0;:khlO
8
/0KL!M:mn/0g?
o
KL!M:J/N!O
KLp!Mq/J/r?
stu?cv
‰:
5. ῏ῐῌ῍ῑ῎
/0:EFG
/Š‹Œ45
,tu?Ž Q 8 Q 7 wxyz*w{|}~€'[
w{']!M4,‚ƒ
‘Š:’“
/0:EFG
/Š‹Œ45
/„…,†
tu q/45”•1.5 –—:
- /„… S-stars Eh-
?D˜9
3), 16), 17) wxyz*w{|
ll‡*+ƒ
190
E8ˆ45,
,™š?P ¹º»
2011 ¼ 4 º
<5 !LM >NOPQ
"RSLJ&T>
UVWX YZ[%&\!T>
!LE]^O"K<J5
6. ῍
ῌ
῎
_` a2 N b789:7;.c
d BRIDGE e2 f%&
'g>N!hH!789:7;.iJ
69
­t<$®F!¯°
7;
š'g
±.²" 0.3 pc ³!>!!/´µ
¶5 ,-./01 (e 2) 1J&
5 Fujii et al. (2010) 6 5 L(«¬14)5
5 f!jk >N>!lmXb"n(
PQ
"O >N"op
qrs[%t >N!u.vVJ>
"PQ
! 1 : 1 RS
LJ&=%"K<J5
% wx34$%&1<Ja2uy
z{0B5 x 789:7;.>N
LJ&=%>! |>!
}!~ T>!!1.5
€!O )*+./01 S-stars !
JYZjkLE]^2&5
ῐ
6 10 ­t<$®F!¯°
7;
š'g
>! ?@A5 >N
LJ&=%>·¸>N! $¹ (cos(i)I1) " DE,º
?@A=$FO .
/01DE5 Fujii et al. (2010) 6 5
L(«¬14)5
῏
‚ƒ!„!…2&x
5 „†‡'g_`ˆ2&EV[J
‰
Š‹!!"Œ#ŽE‘2x
5 S$_`ƒB’%p“Ž ”&'•Ž
–‘2x5 x ‚!—˜&E
V[( [$[x™x1cu.šEV[J
()
›Žœ*2žŸx5 ƒ+,_`
S-stars 2&-¡¢£¤¥L(¦§¨g&x
5 ‚ The American Astronomical Society
!
"#$%&'( )*+,-./01
2&34$%&
6), 18)
!©ª&6«¬2&x5
5 6 9 6
10 789:7;.<$$%
=%>!
!?@A!B
5 %C DEF% G
<$)*+1H2 ./01 ( f(e)Ie2) 1J&"K
» 104 ¼
»4½
191
῎῍῏ῌ
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
192
Krabbe A., et al., 1995, ApJL 447, L95
Paumard T., et al., 2006, ApJ 643, 1011
Bartko H., et al., 2010, ApJ 708, 834
Lu J. R., Ghez A. M., Hornstein S. D., Morris M.,
Matthews K., Thompson D. J., Becklin E. E., 2006,
Journal of Physics Conference Series 54, 279
Ghez A. M., et al., 2003, ApJL 586, L127
Gillessen S., Eisenhauer F., Trippe S., Alexander T.,
Genzel R., Martins F., Ott T., 2009, ApJ 692, 1075
Levin Y., Beloborodov A. M., 2003, ApJL 590, L33
Gerhard O., 2001, ApJL 546, L39
Figer D. F., 2004, ASP Conf. Ser. 322, 49
Portegies Zwart S. F., McMillan S. L. W., Gerhard O.,
2003, ApJ 593, 352
Kim S. S., Morris M., 2003, ApJ 597, 312
Fujii M., Funato Y., Makino J., 2006, PASJ 58, 743
Fujii M., Iwasawa M., Funato Y., Makino J., 2007,
PASJ 59, 1095
Fujii M., Iwasawa M., Funato Y., Makino J., 2010,
ApJL 716, L80
Fujii M., Iwasawa M., Funato Y., Makino J., 2009, ApJ
695, 1421
Buchholz R. M., Schödel R., Eckart A., 2009, A&A
499, 483
17) Do T., Ghez A. M., Morris M. R., Lu J. R., Matthews
K., Yelda S., Larkin J., 2009, ApJ 703, 1323
18) Schödel R., Ott T., Genzel R., Eckart A., Mouawad N.,
Alexander T., 2003, ApJ 596, 1015
The Origin of Young Stars near the
Galactic Center
Michiko FUJII
Kagoshima University, 1ῌ21ῌ35 Korimoto, Kagoshima 890ῌ0065, Japan
Abstract : Young massive stars have been found
within 1 pc from the Galactic center (GC). Since
in-situ formation of stars is di$cult because of
the strong tidal field of the central supermassive
black hole. We performed N-body simulations of
young star clusters migrating to the GC and
investigated whether the star clusters can carry
young stars to the GC. We found that
intermediate-mass black holes formed in the
clusters carry young stars to the GC by a 1 : 1
mean motion resonance and the migration
scenario can reproduce the distribution of the
observed young stars in the GC.
῍῏ῌῐ
2011 ῎ 4 ῌ
Fly UP