Presentation is loading. Please wait.

Presentation is loading. Please wait.

Grand Rotation Curves & Galactic Roche Lobes in the Galaxy and M31 Yoshiaki Sofue (Meisei Uni.) 2012.08.14 at Meisei University.

Similar presentations


Presentation on theme: "Grand Rotation Curves & Galactic Roche Lobes in the Galaxy and M31 Yoshiaki Sofue (Meisei Uni.) 2012.08.14 at Meisei University."— Presentation transcript:

1 Grand Rotation Curves & Galactic Roche Lobes in the Galaxy and M31 Yoshiaki Sofue (Meisei Uni.) at Meisei University

2 Contents 1. Rotation Curve 2. Mass models 3. Grand RC 4
Contents 1. Rotation Curve 2. Mass models 3. Grand RC 4. Local DM Density 5. Roche Lobes Galactic Territory

3 1. Rotation Curve

4 銀河中心

5 inside/outside Solar Circle
Rotation velocities inside/outside Solar Circle

6 Define: Vrot =Vvirial≒ √2 VGC
Rotation curve at R>30 kpc assuming random motion of satellite galaxies Define: Vrot =Vvirial≒ √2 VGC

7 Solar Circular Velocity V0=200 km/s @ R0=8kpc

8 2. Mass Model

9 RC Fitting by (1) Bulge: de Vaucouleurs Law (2) Disk: Exponential
(3) Dark Halo: NFW

10 de V ∝ exp(-r1/4) Expo. Plummer Kepler

11 (1) Bulge de Vaucouleurs: exp(-r1/4)

12 Mass models: Bulge: de Vaucouleurs (r1/4)

13 (2) Exponential Disk +Arm/Ring
(If Δ=0, V(R)=written by modified Bessel functions)

14 Disk: Exponential

15 (3) Dark Halo Density Profile (Navaro-Frenk-White 1994)
NFW Profile (Navaro-Frenk-White 1994)

16 Volume Densities for Bulge, Disk, and Halo(Isoth, NFW, Burkert)

17 Sofue, Honma, Omodaka 2009

18 Total Masses Dark Halo Expo. Disk de Vaucl. Bulge

19 3. Grand Rotation Curve

20 Dark Halo Density Profiles
(X=R/h) NFW density ∝ 1/X(1+X) 2 (Navaro-Frenk-White 1994) Burkert ∝ 1/(1+X)(1+X2) Isothermal ∝ 1/(1+X2) =>X-2

21

22 Local Group of Galaxies

23 Grand Rotation Curve Sattelite’s velocity =>Virial Mass V(R)=√2 Vr

24 Solar Circular Velocity V0=200 km/s @ R0=8kpc

25 Grand RC

26 MW ⇔ M31 border de V. Bulge Milky Way GRC Expo. Disk NFW Halo

27 4. Galaxy Parameters & Locad DM Density

28 Dispersion Scale radius fit Mass fit

29

30 The Local Dark Matter Density @ Sun
ρ☉= 0.235±0.030 GeV cm-3

31 M ~ RV2/G => ρ0 ~ M/R3 ~ (V/R)2 ~ Ω2
V0/R0=Ω0 (km s-1 kpc-1) ρ0 (GeV cm-3) Sofue (2012) 200/8.0 = ±0.030 ( 248/8.2 = ± ) Salucci, et al. (2011)≒Honma et al (2012) 248/8.2 = ± 0.11 ( 200/8.0 = ± 0.07 ) Weber and de Boer (2010) 0.2 ~ 0.4

32 6. Galactic Roche Lobe - Territory problem –

33 Grand RC of M31 √2 Vr Vrot

34 GRC of M31 M31⇔ MW de V. Bulge Expo. Disk NFW Halo M31

35 Grand RC of M31 ≒ Galaxy MW M31 de V. Bulge NFW Halo NFW Halo
Expo. Disk NFW Halo M31⇔ MW de V. Bulge Expo. Disk NFW Halo M31

36 M31 ≒ Galaxy>> M33, dwarfs
MW+M31≒Binary

37 2D Matsuda et al. 2000

38 Binary (2 point masses) Roche Lobes

39 Galactic Roche Lobe Φ=ΦG+ΦM31+ΦΩ Rigid rot coordi
Galactic Roche Lobe Φ=ΦG+ΦM31+ΦΩ Rigid rot coordi. = -GM1/r1 - GM2/r2 - (1/2)Ω2 r2

40 NFW Roche Lobe Mh(R) = 4πρ0h3{ln(1+X)−X/(1+X)} X=R/h } :

41 Galactic DM Roche Lobe MW-M31 Binary

42

43 Local Group of Galaxies

44 Galaxy + M31 =>What in future?

45 Galaxy – M31

46 Summary 1. Rotation Curve 2. Mass models 3. Grand RC (Log RC) 4
Summary 1. Rotation Curve 2. Mass models 3. Grand RC (Log RC) 4. Local DM Density & G-parameters 5. Roche Lobe Galactic Territory MW vs M31

47 7.Grand RC (Log RC) for the Galactic Center

48 Bulge is in between de Vaucouleurs and Exponential

49 de V ∝ exp(-r1/4) Expo. Plummer Kepler

50 MW ⇔ M31 border de V. Bulge Milky Way GRC Expo. Disk NFW Halo

51


Download ppt "Grand Rotation Curves & Galactic Roche Lobes in the Galaxy and M31 Yoshiaki Sofue (Meisei Uni.) 2012.08.14 at Meisei University."

Similar presentations


Ads by Google