The Multiphase gas cycle and star-formation in the CGM of a distant - - PowerPoint PPT Presentation

The Multiphase gas cycle and star-formation in the CGM of a distant radio galaxy

Matt Lehnert (IAP, Paris)

MS0735.6+7421 credit: McNamara & Bizan (Chandra press release)

AGN-global heating and entropy fmuctuations AGN-global heating and entropy fmuctuations

From theoretical studies of low redshift clusters, multiphase ICM develops from global heating and cooling balance, e.g., radio galaxies mechanical energy and accretion. While global heating may balance the overall cooling, the energy injection into gas can still cause local cooling and fragmentation through entropy fluctuations and instabilities, leading to turbulent clouds in the CGM. Radio galaxies good for phenomenological studies of CGM Ideas presented here are from and inspired by Voit, Sharma, McCourt, Churazov, and collaborators.

Best studied radio galaxy embedded in a proto-cluster … at z=2.16, has a high stellar mass, ~few x 1011 solar masses, giant Ly-alpha halo … X-ray emission ... Jets are powerful, will pump about 1060 erg or more into the halo – about the binding energy of a massive galaxy.

The “Spider web” The “Spider web”

Miley et al. (2006), Kuiper et al. (2011), Carilli et al. (2002)

22” 33”

Ly-alpha + HST 814W J-band + Dynamics with SINFONI

Difguse star formation Difguse star formation

Hatch et al. (2008; 2011)

Deep UV imaging from HST

g475+I814+J110+H160

300x300 kpc

g475with galaxies removed to emphasize diffuse light

Ruled out faint cluster galaxies, nebular continuum, scatter QSO light, etc. favoring in situ star formation

Dissipation of mechanical energy Dissipation of mechanical energy

SPITZER IRS observations suggest strong dissipation of turbulence in the warm molecular gas through slow molecular shocks … but where is this taking place?

Ogle et al. (2012)

Large halo of CO emission. Not from the galaxies, VLA sensitivity rules that out

Extended CO(1-0) emission Extended CO(1-0) emission

Emonts, Lehnert, Villar-Martin et al. (2016, Science)

Extended CO(1-0) emission Extended CO(1-0) emission

The velocity differences between the gas and galaxies are vastly different …. No companions detected in VLA data

Emonts, Lehnert, Villar-Martin et al. (2016, Science)

Velocity of the CO is much different from that of the gas. Not from the galaxies. Dynamical time of the CGM is about 100 Myrs and so it settled for a long time. Massive stars live an order of magnitude less.

Extended CO(1-0) emission Extended CO(1-0) emission

Emonts et al. (2016), Hatch et al. (2008)

Star forming like galaxies but in a halo Star forming like galaxies but in a halo

Emonts, Lehnert, Villar-Martin et al. (2016, Science)

How do stars form in a halo?

Questions Questions

These results raise a lot of questions: 1) Is the gas really in the CGM and if yes, what is its source? 2) How do stars form in such gas? 3) Does the radio jet also cause cooling in the halo? 4) Is this analogous to star formation seen in clusters at low redshift? Perhaps we can address some of these questions by looking at the chemistry and energy dissipation in the gas.

Extended atomic and molecular line emission Extended atomic and molecular line emission

Emonts, Lehnert, De Breuck et al. (2017, MNRAS submitted)

[CI] 3P1-3P0 and CO(4-3) with ALMA at low spatial resolution [CI] trace low density molecular gas, while CO(4-3) traces denser, more highly excited gas and it all looks like the CO(1-0).

Abundance and excitation Abundance and excitation

Abundances and Excitation of the molecular gas in the IGM

Emonts, Lehnert, De Breuck et al. (2017, MNRAS submitted)

Excitation and abundance, X[CI]/XH2~2x10-5, similar to the MW and other proto- cluster galaxies. The CGM is similar to gas in galaxies, “metal rich”, low excitation, not “diffuse” Provides another link between gas and SF

ALMA observations of water ALMA observations of water

In cycle 1, we observed the Spider web for ~50 minutes in:

H20 211-202 @ 753.03 GHz

[CI] 3P2 – 3P1 @ 809.34 GHz CO(7-6) @ 806.65 GHz 235 GHz continuum (~775 GHz continuum in the rest-frame)

These observations were intended to:

*trace the diffuse and dense molecular gas *trace the dissipation of mechanical energy through slow molecular shocks in dense gas.

Address questions of:

What is the impact of the radio jets on the dense circum-nuclear molecular gas? Where does the mechanical energy go? Is some of it dissipated through turbulence in the dense molecular gas?

The Quantum mechanics of water The Quantum mechanics of water

3 quantum numbers, J, KA, KC with permanent dipole, μ. These are total angular momentum and its two projections. ΔJ=0, +-1. ΔKA, ΔKC = +-1 or +-3 plus 3 unequal moments of inertia means large N of closely spaced transitions Levels determined by Tex, which can be either Trad or Tcollisional

Shocks IR pumping

Large dipole moment allows for fast dipole transitions. H2O is an important coolant for dense gas with T~100-1000 K

Dew drops in a dusty web Dew drops in a dusty web

Gullberg, Lehnert, De Breuck et al. (2016)

Not in the radio galaxy, but in the halo

Strong water emission implies dissipation in slow, 10-40 km/s, molecular shocks in dense gas, 103 to 105 H2 cm-2. Rapid dissipation of mechanical energy from the

• jet. Water winks on and off as energy dissipates.

Dew drops in a dusty web Dew drops in a dusty web

Gullberg, Lehnert, De Breuck et al. (2016)

A “model” A “model”

Do the clouds dissipate turbulence rapidly enough to form stars? ALMA cycle 4 and 5 proposals to find this out.

Some fjnal thoughts Some fjnal thoughts

We need to figure out multiphase CGM forms. What is the balance between heating and cooling? How does this regulate galaxy growth? How far can the gas cool? Down to stars? How is the kinetic energy dissipated? How does this depend on the environment – halo mass, epoch, location in large scale structure? Is the Spiderweb now becoming an interesting study of how stars form? Advantage: projected against the faint sky, not ‘within’ a galaxy. Radio galaxies provide a nice test bed for understanding the gas physics phenomenology, but not necessarily for CGM demographics.