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
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