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

The environment of the most massive galaxies in the early universe in the light of the jet impact 5,75cm 100 kpc Background image: 4C 41.17, Z=3.8, composite (Michiel Reuland, www.strw.leidenuniv.nl/~reuland) Martin Krause Landessternwarte Heidelberg-Königstuhl

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?

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 of nearby emission line objects in five cases

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 of protoclusters • All cluster centers were active at Z > 2

✓ ✟ � ✄ ✍ ✂ ✌ ✞ ✂ ☞ ✝ ☛ � ☛ ✠ ✡ ✡ ✆ ✡ ✡ ✝ ✌ ✡ ✑ ✒ ✎ ✒ ✒ ✎ ✒ ✒ � ✁ ✆ ☛ ✍ ✂ ✏ ✄ ✄ ✌ ☎ ✎ ✞ 2) How does the IGM change by the jet impact? It depends ... Basic parameter : the density contrast jet / IGM Constraints: non-relativistic jet 2 3 L r j j v j j 0 3 L 47 r kpc 2 n 0 1 v 3 3 6 10 0.2 cm 0.5c relativistic jet 2 3 L 2 r j h 1 c j 2 h j 0 4 L 47 r kpc 2 n 0 3 1 1 4 10 0.2 cm

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 of 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)

What kind of halo do we produce? No shock disruption (Mellema 2003) Shocked external gas has high temperature ( ≅ 10 Mio K) Pressure may activate preexisting emission line cloud population

✂ ☎ ✄ � ✁ Pressure Central part behaves as spherical blastwave 1 5 3 L t r c Central bow shock radius Pressure distribution

bremsstrahlung: comparison to other results and X-ray data from Cygnus A Cygnus A (Chandra archive, courtesy P. Strub) Compare details! Cygnus A´s: η 10 -4 Nirvana (Krause, 2003 in prep) Cocoon width: Sim: 25 jet radii Obs: 40 jet radii

✁ � ✂ � ✁ Cooling important? t c t d 7 n 0 1 6 7 Cooling in expanding halo: 36 Myr L 47 t c Cygnus A High Redshift Radio Galaxies 100 Myr 5 Myr M87 50 Myr 2 Myr luminosity 20 Myr 1 Myr 10 Myr Central density

How does IGM change by jet impact? b)radiative bow shocks Density Temperature 1 Myr Before cooling: some mixing in the central regions 3 Myr Immediately after cooling: Thin Cool (10,000K) Shell has formed. 7 Myr Long after cooling: Shell fragments, cool clouds, SF

Cooling produces turbulence Jet beam probability everywhere! Likely area of big Log normal: starburst. supersonic turbulence Cooling Density TI tail Probability Log normal: supersonic turbulence Res. Limit Density

IC cocoon appearance Compton upscattering: ν ´= γ 2 ν Typical γ needed for CMB or FIR background in 4C41.17: γ = a few 100 - 1000 IC cooling time on microwave background: t ½ = 13 Myr (1000/ γ 0 ) (4.8/z+1) 4 Given strong cooling & coupling to protons, electrons in cocoon should obey Maxwell distribution, i.e. (kT >> mc 2 ): P IC ∝ γ 2 x γ 2 e - γ / θ / θ 3 θ =kT/m e c 2 T j ≈ ( Γ−1) 10 12 K

IC cocoon appearance Non-radiative, const. illumination Radiative, constant illumination Radiative, r -2 illumination Non-radiative, r -2 illumination

Simulated inverse Compton emission Cooled jet, thermal cocoon electrons, γ =1000 Apparent cocoon width fills most of jet-affected region

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

Is there a common mechanism for line absorbers in normal and small radio galaxies? Ly alpha absorption, Ly alpha emission, normal galaxy, Z=2.73 radio galaxy Z=2.77 Typical V= -300 km/s Van Ojik et al. 1997 Pettini et al. 2002 Models: Model: super wind bubble with a) low density shell (Binette et al.2000) cooled high density shell b) high density shell (Krause 2002)

Thin, dense shell from the cooled jet Thin Shell: • internal velocity (sound speed) 20 km/s (very good!) • 10,000 K • May explain blue shifted • 10 pc width absorption systems in small high redshift radio galaxies • very high density

Why don't we see the shell in emission? Radiation transfer on simulation (Sabine Richling)

� ✂ ✁ � ✂ ✁ ✁ ✂ ✂ ✁ ✁ ✁ Comparison of energetics for radio galaxies: Jet bubble Starburst superwind bubble 3 (jet driven bubble) 3 n 1 3 r 10 kpc 1 1 2 483 km/s L 46 v 3 (galactic wind) 3 n 0 3 r 10 kpc 1 1 2 194 km/s SN/year v High external densities n > 1 cm -3 are required for the jet bubble model. Alternative: jet starts in the superwind.

Possible Cartoon-Scenario Faint shell Fragmented shell 50 kpc 3) destroy shell by 2) start jet inside 1) make superwind jet impact, superwind with right velocities fill shell with turbulence, ~ 10 Myr ~ 100 Myr make big starburst LyA luminosity: ~10 41 erg/s x SN/yr Needs test by hydrodynamic simulation!

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 observed X-ray and LyA size. Summary 3) Superwinds may help to explain absorbers in normal and small radio galaxies