銀河物理学特論 I
Galactic Astrophysics I
I 2 Dynamical
I-2:
D
i l properties
ti off galaxies
l i
2015/04/20
Dynamical structure of Milky-Way galaxy 1
銀河系の力学構造 1
•
Rotation curve of the Milky-Way galaxy determined with HI, CO
observations.
Sofue, 2009, PASJ, 61, 227
Sofue, 2012, PASJ, 64, 75
Dynamical structure of Milky-Way galaxy 2
銀河系の力学構造 2
•
Rotation curve model of the Milky-Way galaxy and expected velocity
dispersions of stars at the solar position. For the disc component, the
velocity dispersion is much smaller than the rotational velocity.
Robin et al. A&A, 409, 523
Dynamical structure of disk galaxies : Milky-Way Galaxy
Rotation curve model of the Milky-Way galaxy and velocity dispersion of stars.
Robin et al. A&A, 409, 523
Flat rotation curves of disc galaxies
円盤銀河の平坦な回転曲線
•
Rotation curves of disk galaxies in the local universe measured with
atomic hydrogen 21cm line (hyperfine structure line ‒ originated
from proton-electron spin).
Bosma 1981, AJ, 86, 1791
Bosma 1981, AJ, 86, 1825
Flat rotation curves of disc galaxies
円盤銀河の平坦な回転曲線
•
Early-type disc galaxies show steeper rise in the central region.
Bosma 1981, AJ, 86, 1791
Bosma 1981, AJ, 86, 1825
Rotation and double peak velocity profile
回転運動とダブル
回転運動とダブルピークの速度プロファイル
クの速度プ ファイル
•
Rotation curves of disk galaxies in the local universe measured with
HI line. (Contours per 50km/s for velocity field, 5km/s for velocity
dispersion.)
Walter et al. AJ, 136, 2563
Rotation and double peak velocity profile
回転運動とダブル
回転運動とダブルピークの速度プロファイル
クの速度プ ファイル
•
Rotation curves of disk galaxies in the local universe measured with
HI line. (Contours per 50km/s for velocity field, 5km/s for velocity
dispersion )
dispersion.)
Walter et al. AJ, 136, 2563
Rotation curve with Halpha line
H アルファ輝線で求められた回転曲線
Dicaire et al. 2008, MNRAS, 385, 553
Velocity dispersion profile of disc galaxies
円盤銀河の速度分散のプ ファイル
円盤銀河の速度分散のプロファイル
Martinsson et al. A&A, 557, 130
Tully-Fisher relation
タリ
タリー・フィッシャー関係
フィッシャ 関係
•
There is a tight relation between the absolute magnitude (or
luminosity) and rotation velocity of disk galaxies. The relation is called
T ll Fi h relation.
Tully-Fisher
l ti
Pierce & Tully 1992, ApJ, 387, 47
Tully-Fisher relation 2
タリー・フィッシャー関係
タリ
フィッシャ 関係 2
•
The relation between Velocity ‒ Luminosity ‒ Size. The relation
between Velocity ‒ Luminosity relation is tighter than Luminosity-Size
and
d Si
Size-Velocity
V l it relations.
l ti
Courteau et al. 2007, ApJ, 671, 203
Baryonic (Stellar+Gas) Tully-Fisher relation
星とガ の成分を合わせたタリ
星とガスの成分を合わせたタリー・フィッシャー関係
フィッシャ 関係
•
The correlation between massvelocity is better with including
gas component.
McGaugh et al. 2000, ApJL, 533, 99
Dynamical structure of disk galaxies : velocity dispersion profile
Rotation curves and velocity distribution maps of [OIII] and stellar component.
Martinsson et al. A&A, 557, 130
Dynamical structure of elliptical galaxies
楕円銀河の力学構造
•
Luminous elliptical galaxies are dominated by velocity dispersion,
on the contrary, less-luminous elliptical galaxies show significant
rotation which can explain the flattening from sphere.
Davies et al. 1983,, ApJ,
p , 266,, 41
Elliptical galaxies, ellipticity = type 10x(1-a/b)
Buta, 2011, arXiv:1102.0550
Dynamical structure of elliptical galaxies
楕円銀河の力学構造
•
Updated version of the V/sigma distribution. Effect of viewing angle
is corrected for some objects.
Red: slow-rotator
Blue: fast-rotator
Cappellari et al. 2007, MNRAS, 379, 418
Green: isotropic velocity dispersion
Black: un-isotropic velocity dispersion
Faber-Jackson relation and Fundamental plane
フ
フェーバー・ジャクソン関係と基本平面
ジャク ン関係と基本平面
•
Elliptical galaxies show a tight relation between luminosity and velocity dispersion.
The relation is called Faber-Jackson relation. The dispersion is smaller is the relation is
examined in 3-D space
p
of luminosity,
y velocity
y dispersion,
p
and size. They
y distribute on
a fundamental plane in the 3-D space.
Kormendy & Djorgovski
1989, ARAA, 27, 235
Velocity dispersion vs. rotation
速度分散と回転
•
Rotatoin/velocity dispersion and its relation with other physical
parameters.
Kormendy & Djorgovski
1989, ARAA, 27, 235
Reversely-rotating core
逆回転 ア
逆回転コア
•
Some elliptical galaxies show core-region with reverse rotation.
Emsellem et al. 2007, MNRAS, 379, 401
Lambda = <R V> / <R sqrt( V^2 + R^2 )>
<> Lumoinosity weighted sky average
Elliptical galaxies vs. Bulges of disk galaxies
楕円銀河と円盤銀河の ルジ
楕円銀河と円盤銀河のバルジ
•
Dynamics of pseudo-bulge can be dominated by rotation.
Kormendy 2004, ARAA, 42, 603
Laurikainen et al. 2007, MNRAS, 381, 401
What does determine the observed relation between
SMBH mass and spheroid mass ?
Possible two populations ?
Massive spheroids:
• Velocity dispersion supported, triaxial system,
independent velocity dispersions for the three axis.
axis
Less-massive spheroids:
• Significant rotation component
• Pseudo-bulge
P
d b l ?
Where are the spheroids in the early universe ?
Internal dynamics of galaxies at z~2 (Forster Schreiber et al. 2009)
Between 0<z<1 : Disk galaxies : Disk dynamics
Internal dynamics of galaxies at z~2 (Forster Schreiber et al. 2009)
Between 0<z<1 : Disk galaxies : Disk dynamics
Disk-like z 2 galaxies: Rotation and velocity dispersion
ディスク的
ディ
ク的 z 2 銀河
銀河: 回転と速度分散
• Rotation curve like patterns are observed, but contribution from velocity
dispersion is large.
Mean velocity
M
l i (black)
(bl k) vs.
velocity dispersion (red)
12 galaxies at z=2
z=2.0
0-2
2.5
5 and 1 galaxy at
z=3.3 ([OIII]) observed with Keck LGSAO (typical resolution 0.15 ) + OSIRIS
with 1.0-4.5hours with 100/150mas
FWHM (50mas sampling)
sampling).
Law et al. (2009, ApJ, 697, 2057)
Rotation velocity and velocity dispersion
回転速度と速度分散
• Galaxies with large stellar mass shows larger shear velocity.
• Galaxies with small g
gas mass fraction shows larger
g V/sigma.
g
• Galaxies with M* 10^11 Msolar should be dominated by early-type galaxies in
the local universe.
typical velocity dispersion
Law et al. (2009, ApJ, 697, 2057)
Dynamical structure of z 3 galaxy
z 3 銀河の力学構造
• Stark et al. 2008 Nature, 455, 755; z=3.07 lensed
galaxy
• Thanks to gravitational lensing and LGSAO,
effective spatial resolution was very high (2040mas = 150-300pc resolution) . Smooth
velocity shear field support the rotational
structure of the galaxy.
•+-50km/s
•+
50km/s rotation (inner 0
0.5kpc)
5kpc) + flat
rotation curve, logMdyn=9.3 vs. logMstr=9.8
•Sigma=54km/s, v/sigma=1.2 (heating by
star formation activity ?),
star-formation
?)
• 4.4 Msolar/yr/kpc2 (Similar to nuclear Star
burst in local galaxies)
• 12+log(O/H)=8.6 = 0.9Zsolar,
• CO luminosity-gas mass conversion factor
<0 8; local LIRG (1) << local spiral (5)
<0.8;
Massive galaxies at high redshifts
高赤方偏移の大質量銀河
•
•
Rotation supported
pp
or velocity
y dispersion
p
supported
pp
?
•
Large stellar mass galaxies are rotation dominated ?
•
g velocity
y dispersion
p
imply
p y large
g Jean s mass resulting
g big
g
Large
star-forming complexes (Elmegreen et al 2008).
•
Thick disk ? : hz/R = 0.5(sigma/v)^2
Toomre s Q parameter is small : unstable disks ?
•
Q= sigma k / 3.36 G Sigma
•
MW: sigma=30km/s, Sigma=50Msolar/pc^2, k=36km/s/kpc ->
Q=1 4
Q=1.4
•
High-z: sigma=50-100km/s, Sigma=300Msolar/pc^2,
k=V/R=30km/s/kpc resulting Q=0.2