The environment of the most massive galaxies in the early universe - - PowerPoint PPT Presentation

SLIDE 1

The environment of the most massive galaxies in the early universe in the light of the jet impact

Martin Krause

Landessternwarte Heidelberg-Königstuhl

Background image: 4C 41.17, Z=3.8, composite (Michiel Reuland, www.strw.leidenuniv.nl/~reuland)

5,75cm

100 kpc

SLIDE 2

Overview

1)What kind of galaxy hosts a powerful

radio source in the early universe (Z>2) and how many? 2)How does the IGM change by the jet impact? Hydrodynamic Simulations. 3)Is there a common mechanism for line absorbers in normal and radio galaxies?

SLIDE 3

1) What kind of galaxy hosts a powerful radio galaxy in the early universe (Z>2) and how many?

• brightest galaxies at their redshift
• large rotation measures
• comoving space density of galaxy clusters at

low redshift is comparable to space density of radio galaxies at high redshift

• direct evidence by detection of some dozens
• f nearby emission line objects in five cases

SLIDE 4

1) What kind of galaxy hosts a powerful radio galaxy in the early universe (Z>2) and how many?

• Radiogalaxies are located at the centers
• f protoclusters
• All cluster centers were active at Z > 2

SLIDE 5

2) How does the IGM change by the jet impact? It depends ...

Basic parameter : the density contrast jet / IGM Constraints: non-relativistic jet relativistic jet

L

• 2

✁

r j

2

✂

j

✄ ✄

h

☎

1

✆

c

3

✝

• ✄

2 h

✂

j

✞ ✂ ✟ ✝

• 4

✠

10

✡

4 L 47 r kpc

✡

2 n 0

✞

0.2 cm

✡

3

✡

1

✆ ✡

1

L

☛ ☞

r j

2

✌

j v j 3

✍ ☛ ✌

j

✎ ✌ ✏ ✍ ☛

6

✑

10

✒

3 L 47 r kpc

✒

2 n 0

✎

0.2 cm

✒

3

✒

1 v

✎

0.5c

✒

3

✓

SLIDE 6

How does the IGM change by the jet impact? So we need simulations of jets: 1) at low density contrast and 2) big enough and depending on the cooling timescale

• f the environment

a) non-radiative Bipolar simulation, King profile η=10- 4 Final size: > 200 jet radii = 100 kpc b) radiative (same but only 60 jet radii final size)

SLIDE 7

What kind of halo do we produce? Shocked external gas has high temperature (≅10 Mio K) Pressure may activate preexisting emission line cloud population

No shock disruption (Mellema 2003)

SLIDE 8

Central part behaves as spherical blastwave

Pressure Central bow shock radius Pressure distribution

r

• c

✁

L t

3

✂

1

✄ ☎

5

SLIDE 9

bremsstrahlung: comparison to other results and X-ray data from Cygnus A

Nirvana (Krause, 2003 in prep) Cygnus A (Chandra archive, courtesy P. Strub)

Compare details! Cygnus A´s: η 10-4

Cocoon width: Sim: 25 jet radii Obs: 40 jet radii

SLIDE 10

Cooling important? Cooling in expanding halo:

t c

• t d

t c

• 36 Myr L 47

1

✁

7 n 0

✂

6

✁

7

50 Myr 1 Myr 2 Myr 5 Myr 10 Myr 20 Myr 100 Myr Central density luminosity M87 Cygnus A High Redshift Radio Galaxies

SLIDE 11

Density Temperature 1 Myr 3 Myr 7 Myr Before cooling: some mixing in the central regions

Immediately after cooling: Thin Cool (10,000K) Shell has formed.

Long after cooling: Shell fragments, cool clouds, SF

How does IGM change by jet impact? b)radiative bow shocks

SLIDE 12

Density Density probability Probability

Cooling

Log normal: supersonic turbulence Jet beam Log normal: supersonic turbulence TI tail

• Res. Limit

Cooling produces turbulence everywhere! Likely area of big starburst.

SLIDE 13

IC cocoon appearance

Compton upscattering: ν´= γ2 ν Typical γ needed for CMB or FIR background in 4C41.17: γ= a few 100 - 1000 IC cooling time on microwave background: t½= 13 Myr (1000/γ0) (4.8/z+1)4 Given strong cooling & coupling to protons, electrons in cocoon should obey Maxwell distribution, i.e. (kT >> mc2): PIC ∝ γ2 x γ2 e- γ/θ/ θ3 θ=kT/mec2 Tj ≈ (Γ−1) 1012K

SLIDE 14

IC cocoon appearance

Radiative, constant illumination Radiative, r-2 illumination Non-radiative, r-2 illumination Non-radiative, const. illumination

SLIDE 15

Simulated inverse Compton emission Cooled jet, thermal cocoon electrons, γ =1000

Apparent cocoon width fills most of jet-affected region

SLIDE 16

4C 41.17: large cocoon width, mixed into emission line region =>> evidence for the cooled jet model

SLIDE 17

Is there a common mechanism for line absorbers in normal and small radio galaxies?

Ly alpha emission, radio galaxy Z=2.77 Ly alpha absorption, normal galaxy, Z=2.73

Van Ojik et al. 1997 Pettini et al. 2002 Models: a) low density shell (Binette et al.2000) b) high density shell (Krause 2002) Model: super wind bubble with cooled high density shell Typical V= -300 km/s

SLIDE 18

Thin, dense shell from the cooled jet

• 10,000 K
• 10 pc width
• very high density
• internal velocity (sound

speed) 20 km/s (very good!)

• May explain blue shifted

absorption systems in small high redshift radio galaxies Thin Shell:

SLIDE 19

Why don't we see the shell in emission?

Radiation transfer on simulation (Sabine Richling)

SLIDE 20

Comparison of energetics for radio galaxies:

v

• 483 km/s L 46

1

✁

3 n 1

✂

1

✁

3 r 10 kpc

✂

2

✁

3 (jet driven bubble)

v

• 194 km/s SN/year

1

✁

3 n 0

✂

1

✁

3 r 10 kpc

✂

2

✁

3 (galactic wind)

High external densities n > 1 cm-3 are required for the jet bubble model. Alternative: jet starts in the superwind.

Jet bubble Starburst superwind bubble

SLIDE 21

Possible Cartoon-Scenario

1) make superwind with right velocities ~ 100 Myr LyA luminosity: ~1041 erg/s x SN/yr

50 kpc

2) start jet inside superwind ~ 10 Myr

Faint shell Fragmented shell

3) destroy shell by jet impact, fill shell with turbulence, make big starburst

Needs test by hydrodynamic simulation!

SLIDE 22

1) High Z Radio Galaxies mark protocluster centers which were all active in the early universe.

2) The jet can influence a large region perpendicular to it, and drive thermally instable turbulence. This could explain

• bserved X-ray and LyA size.

3) Superwinds may help to explain absorbers in normal and small radio galaxies

Summary