1

Radio-mode Feedback

Alex WagnerGeoff Bicknell

(with previous contributions by Ralph Sutherland & Curtis Saxton)

2Research School of Astronomy & Astrophysics

Aims

• Provide “sub-grid” physics for cosmological AGN feedback calculations

• Understand the early stages of evolution of radio galaxies

• Theoretical basis for GMT and SKA observational programs

3Research School of Astronomy & Astrophysics

[OIII] and radio morphology of MRC0406-244

[OIII] morphology

[OIII] velocity

Contours of line-free continuum

[OIII] velocity dispersion

Nesvadba et al. ’08)

4Research School of Astronomy & Astrophysics

Effect of an inhomogeneous medium

QuickTime™ and aVideo decompressor

are needed to see this picture.

QuickTime™ and aVideo decompressor

are needed to see this picture.

5Research School of Astronomy & Astrophysics

QuickTime™ and aVideo decompressor

are needed to see this picture.

Typical run (D’)

6Research School of Astronomy & Astrophysics

Velocity-power diagram

7Research School of Astronomy & Astrophysics

Filling factor and cloud size

Low filling factor

Rcloud,max=50 pc

Rcloud,max=10 pc

8Research School of Astronomy & Astrophysics

3D view of Run 3D’

Blue-greenjet plasma

Purple cloudsForward shock of energy-driven bubble

9Research School of Astronomy & Astrophysics

Comparison of R-t relation with analytic energy-driven bubble

Analytic solution approached as filling factor decreases

10

Research School of Astronomy & Astrophysics

Energy imparted to clouds

Substantial fraction of jet energy ends up in warm clouds

11

Research School of Astronomy & Astrophysics

Effect of filling factor

Initial decrease of filling factor increases volume of flood channels for jet plasma

Increased cloud ablation

12

Research School of Astronomy & Astrophysics

Effect of cloud sizeClouds generated using Fourier code (Ralph) with a minimum wave number kmin

Maximum cloud radiusRcloud,max = 1/(2 kmin)

Unsurprisingly larger clouds are harder to accelerate

13

Research School of Astronomy & Astrophysics

Mechanical advantage

14

Research School of Astronomy & Astrophysics

Summary of cloud velocity vs Jet power

15

Research School of Astronomy & Astrophysics

Comparison with observations

Lehnert et al. (2011)691 radio galaxies

(Different estimates of Pjet from 1.4 GHz radio power)

16

Research School of Astronomy & Astrophysics

Distribution of velocities

Most of the galaxies with outflows have v > velocity dispersion

17

Research School of Astronomy & Astrophysics

3D jet plasma visualization - Ajay Limaye (NCI)

QuickTime™ and alibx264 decompressor

are needed to see this picture.

18

Research School of Astronomy & Astrophysics

3D density visualization

QuickTime™ and a decompressor

are needed to see this picture.