The Irradiated and Stirred The Irradiated and Stirred ISM of Active GalaxiesISM of Active Galaxies

Marco Spaans, Rowin Meijerink (Leiden), Frank Israel Marco Spaans, Rowin Meijerink (Leiden), Frank Israel (Leiden), Edo Loenen (Leiden), Willem Baan (ASTRON), (Leiden), Edo Loenen (Leiden), Willem Baan (ASTRON),

Dominik Schleicher (Leiden/ESO), Ralf Klessen Dominik Schleicher (Leiden/ESO), Ralf Klessen (Heidelberg) Juan Pablo Perez Beaupuits (Groningen)(Heidelberg) Juan Pablo Perez Beaupuits (Groningen)

PDRs: 6 < E < 13.6 eVPDRs: 6 < E < 13.6 eV

Heating: Heating: Photo-electric emission from Photo-electric emission from grains and cosmic rays grains and cosmic rays

Cooling: Fine-structure lines like Cooling: Fine-structure lines like [OI] 63, 145; [CII] 158 μm [OI] 63, 145; [CII] 158 μm and emission by H and emission by H22, CO, , CO,

HH22OO 10 eV photon penetrates 0.5 10 eV photon penetrates 0.5 magmag of of

dustdust

XDRs: E > 1 keVXDRs: E > 1 keV

Heating: X-ray photo-ionization --> Heating: X-ray photo-ionization --> fast electrons; fast electrons; H and H H and H22 vibvib excitation; excitation; UV emission UV emission (Ly α, Lyman-Werner)(Ly α, Lyman-Werner)

Cooling: [FeII] 1.26, 1.64; [OI] 63; Cooling: [FeII] 1.26, 1.64; [OI] 63; [CII] 158; [SiII] 35 [CII] 158; [SiII] 35 μm; μm; thermal H thermal H22vib; gas-dustvib; gas-dust

1 keV photon penetrates 101 keV photon penetrates 1022 22 cmcm-2 -2 of Nof NHH

PDR (left) with n=10PDR (left) with n=1055 cm cm-3-3 and G=10 and G=103.53.5

XDR with n=10XDR with n=105 5 cmcm-3 -3 and Fand FX X = 5.1 erg s= 5.1 erg s-1 -1 cmcm--

33

Note NNote NHH dependence H dependence H22, C, C++, C, CO, OH, H, C, CO, OH, H22O: O: FIR lines of species trace different regionsFIR lines of species trace different regions

A comment on AGN: A comment on AGN: Relative Size PDR/XDRRelative Size PDR/XDR

101077 M M๏๏ BH at BH at 3% 3% Eddington Eddington forh Gforh G00=10 =10 and 1-100 and 1-100 keV keV powerlaw of powerlaw of slope -1 slope -1 (with 10% L)(with 10% L)

MDRsMDRs: how about : how about kinetics?kinetics?

Mechanically Dominated RegionsMechanically Dominated Regions Turbulent dissipation heats the Turbulent dissipation heats the

gas, which leads to IR emissiongas, which leads to IR emission UV only heats cloud surfaceUV only heats cloud surface Cosmic rays also heat deep inside Cosmic rays also heat deep inside

cloud, but strongly affect HCOcloud, but strongly affect HCO++

E.g., at T>100K: HNC + H E.g., at T>100K: HNC + H HCN HCN + H+ H

Sources of TurbulenceSources of Turbulence

YSOsYSOs SNeSNe Sloshing motions (accretion)Sloshing motions (accretion)

Assume 1-10% efficiency through a Assume 1-10% efficiency through a turbulent cascade -> mechanical turbulent cascade -> mechanical heating competes with normal CR heating competes with normal CR heating for SF rates of 10 – 100 Mheating for SF rates of 10 – 100 Moo/yr/yr

g g

E.g., P cygni profiles in E.g., P cygni profiles in Arp220: 100 km/s outflow Arp220: 100 km/s outflow ((100 pc scale100 pc scale))

changes in high density tracerschanges in high density tracers

temperature increasestemperature increases E.g., HNC, HCN, HCOE.g., HNC, HCN, HCO+ + affectedaffected

normalmechanical

Sample of ULIRGsSample of ULIRGs combined PV, SEST and literaturecombined PV, SEST and literature

– low density gas: CO(1-0) & CO(2-1)low density gas: CO(1-0) & CO(2-1)– high density gas: HCN(1-0), HNC(1-0), high density gas: HCN(1-0), HNC(1-0),

HCOHCO++(1-0), CN(1-0), CN(2-1), CS(3-2)(1-0), CN(1-0), CN(2-1), CS(3-2) total of 117 sources, but total of 117 sources, but incomplete: incomplete:

– 110 CO(1-0), but 32 CO(2-1)110 CO(1-0), but 32 CO(2-1)– 84 HCN84 HCN– only 33 have HCN, HNC and HCOonly 33 have HCN, HNC and HCO++

Note: single dish, so integrated Note: single dish, so integrated propertiesproperties

Relation with LRelation with LFIRFIR

relation Lrelation LFIRFIR – L – Lmoleculemolecule reflects reflects Kennicutt-Schmidt laws: Kennicutt-Schmidt laws: ΣΣSFRSFR ~ ~ ΣΣgasgas

αα , , αα=1.4 =1.4 Krumholz & Thompson (2007):Krumholz & Thompson (2007):

– if nif ncritcrit < n < naveave: : αα ≈ ≈ 1.5 (KS law) 1.5 (KS law)

– if nif ncritcrit > n > naveave: : αα ≤ 1 ≤ 1

– Note: slope in fits = 1/Note: slope in fits = 1/αα

A few fitsA few fits

2e3

1e4

3e6

3e6

2e5

4e5

2e7

1e6

CO(1-0) CO(1-0) αα ~ 1.4~ 1.4

CO(2-1) closer to 1CO(2-1) closer to 1

Others Others αα ≤≤ 1; 1; black squares OH-MMblack squares OH-MM

Relation with LRelation with LFIRFIR

Kennicutt-Schmidt laws: Kennicutt-Schmidt laws: ΣΣSFRSFR ~ ~ ΣΣgasgas

αα , , αα=1.4 =1.4 Krumholtz & Thompson (2007):Krumholtz & Thompson (2007):

– if nif ncritcrit < n < naveave: : αα ≈ ≈ 1.5 (K-S law) 1.5 (K-S law)– if nif ncritcrit > n > naveave: : αα ≤ 1 ≤ 1– Note: slope in fits = 1/Note: slope in fits = 1/αα

Our data follow the K&T predictions, Our data follow the K&T predictions, but can we learn more?but can we learn more?

Toy model: starburst that decays; Toy model: starburst that decays; deplete dense gas and go from SF -deplete dense gas and go from SF -

> SNe> SNe

For some ULIRGs, dense gas tracers that For some ULIRGs, dense gas tracers that correlate with IR may trace more SN than correlate with IR may trace more SN than UV exposure, see Loenen et al. (2008)UV exposure, see Loenen et al. (2008)

Lowering the metallicity to 1% Zo: Lowering the metallicity to 1% Zo: CO no longer dominant molecular CO no longer dominant molecular

gas coolantgas coolant

SummarySummary

In addition to fine structure lines, In addition to fine structure lines, CO, HCN, HNC, HCO CO, HCN, HNC, HCO++ lines are lines are good diagnostics to get to SF good diagnostics to get to SF propertiesproperties

Turbulence (and cosmic rays) Turbulence (and cosmic rays) matter!matter!

so IR response of the ISM may not be tracing star so IR response of the ISM may not be tracing star formation directly; [CII] en [CI] lines probe this formation directly; [CII] en [CI] lines probe this

directlydirectly

How about CRs?How about CRs? PDR model with CR rate = 5x10PDR model with CR rate = 5x10-15-15 s s-1-1; ;

so SN rate for ~100 M so SN rate for ~100 M00/yr/yr Note small changes in C, OH and HNote small changes in C, OH and H22OO

In fact, CRs can dominate the In fact, CRs can dominate the thermodynamics of molecular gas for star thermodynamics of molecular gas for star

formation rates > 100 Mo/yr; think of formation rates > 100 Mo/yr; think of Arp220Arp220