carbon in low metallicity pdrs

Workshop in Extragalactic and Galactic ISM - Modelling in an ALMA PerspectiveWorkshop in Extragalactic and Galactic ISM - Modelling in an ALMA Perspective

Carbon in low Metallicity Carbon in low Metallicity PDRsPDRs

Markus RölligMarkus Röllig11

V. OssenkopfV. Ossenkopf1,31,3, J. Stutzki, J. Stutzki11, A. Sternberg, A. Sternberg44, C. Kramer, C. Kramer11, , M.CubickM.Cubick11, H. Jakob, H. Jakob11, B. Mookerjea, B. Mookerjea22, R. Simon, R. Simon11, F. , F.

BenschBensch55, ,

1KOSMA, Universität zu Köln2University of Maryland, USA

3SRON, Groningen, Netherlands4Tel Aviv University, Israel

5Radioastronomisches Institut der Universität Bonn

Onsala - 2005Onsala - 2005Workshop in Extragalactic and Galactic ISM - Modelling in an ALMA PersWorkshop in Extragalactic and Galactic ISM - Modelling in an ALMA Perspectivepective

•IntroductionIntroduction

•The KOSMA-The KOSMA- CodeCode

•Low Z PDRsLow Z PDRs

•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)

•Clumpy PDRsClumpy PDRs

•Modeling the MWModeling the MW

•SummarySummary

IntroductionIntroduction• PDR – a working definition:PDR – a working definition:

PPhotohotoDDissociationissociationRRegionegion

• This implies the existence of atomic and This implies the existence of atomic and molecular gas PLUS the dissociating molecular gas PLUS the dissociating photonsphotons

• Also used: Also used: Photon Dominated RegionPhoton Dominated Region

• But much broader classification (HII But much broader classification (HII regions, PNe, …) regions, PNe, …)





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

IntroductionIntroduction

• PDRs occur where far-ultraviolet (FUV) PDRs occur where far-ultraviolet (FUV) radiation (6-13.6 eV) dominates the radiation (6-13.6 eV) dominates the physics (e.g. heating and cooling) and physics (e.g. heating and cooling) and determines the chemical composition determines the chemical composition of the gas. of the gas.





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


0.0 0.2 0.4 0.6 0.8 1.0-15

-10

-5

0

n=104 cm-3, =100, M=10

log

n

r/Rtot

nCO

nC

nC+

CC++CC00COCO

typical stratification: Ctypical stratification: C++/C/CO, H/H/C/CO, H/H22, S, S++,S,SO,…,S,SO,…

cent

er o

f th

e cl

oud

edg

e o

f th

e cl

oud

FU

V





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


0.0 0.2 0.4 0.6 0.8 1.0-15

-10

-5

0

0

20

40

60

80

100

120

140

160

180

200

n=104 cm-3, =100, M=10

log

n

r/Rtot

nCO

nC

nC+

Tga

s [K]

Tgas

FU

V





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

The KOSMA-The KOSMA- Code Code

0.0 0.2 0.4 0.6 0.8 1.0-15

-10

-5

0

0

20

40

60

80

100

120

140

160

180

200

0

50

100

150

200

250

300

log

n

n=103 cm-3, =100, M=10

r/Rtot

nC

nC+

[CII] 158µm

TB [K

km

/s]

nCO

CO(1-0)[CI] 610µm

Tga

s [K]

Tgas

r/Rtot

0 1





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


0.0 0.2 0.4 0.6 0.8 1.0-15

-10

-5

0

0

20

40

60

80

100

120

140

160

180

200

0

20

40

60

80

100

120

140

160

180

200

n=104 cm-3, =100, M=10

log

n

r/Rtot

nCO

nC

nC+

[CII] 158µm TB [K

km

/s]

CO(1-0)

[CI] 610µm

Tga

s [K]

Tgas

r/Rtot

0 1





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


DR21 in Cygnus X: CO 7-6 & [CI] 3P2-3P1

Figure: Figure: 3m-KOSMA maps of 3m-KOSMA maps of [CI] 2-1 (color) and [CI] 2-1 (color) and CO 7-6 (contours) atCO 7-6 (contours) at42'' HPBW (0.35 pc)42'' HPBW (0.35 pc)(Jakob et al. 2005 in prep.)(Jakob et al. 2005 in prep.)





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


Radiative Transfer

Chemical Models PDR-Models

LTE Esc. Prob. Monte Carlo

Gas Phase Dust Phase Time Dep.

Energy Balance

Heating/Cooling B fields Shocks





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

The KOSMA-The KOSMA- Code CodeModel NameModel Name AuthorsAuthors

AikawaAikawaH.-H. Lee, E. Herbst, G. Pineau des Forets, J. Le Bourlot, Y. Aikawa, H.-H. Lee, E. Herbst, G. Pineau des Forets, J. Le Bourlot, Y. Aikawa, N. KuboiN. Kuboi

KOSMA-KOSMA--2-2 H. Störzer, B. Köster, M. Zilinsky, U. Leuenhagen, S.Jeyakumar, F. BenschH. Störzer, B. Köster, M. Zilinsky, U. Leuenhagen, S.Jeyakumar, F. Bensch

CLOUDYCLOUDY G.J. Ferland, P. van Hoof, N. P. Abel, G. ShawG.J. Ferland, P. van Hoof, N. P. Abel, G. Shaw

COSTARCOSTAR I. Kamp, F. Bertoldi, G.-J. van ZadelhoffI. Kamp, F. Bertoldi, G.-J. van Zadelhoff

HTBKWHTBKWD. Hollenbach, A.G.G.M. Tielens, M.G. Burton, M.J. Kaufman, M.G. D. Hollenbach, A.G.G.M. Tielens, M.G. Burton, M.J. Kaufman, M.G. Wolfire Wolfire

KOSMA-KOSMA--1-1H. Störzer, B. Köster, M. Zilinsky, U. Leuenhagen, S.Jeyakumar, M.Röllig, H. Störzer, B. Köster, M. Zilinsky, U. Leuenhagen, S.Jeyakumar, M.Röllig, A.SternbergA.Sternberg

Lee96modLee96mod H.-H. Lee, E. Herbst, G. Pineau des Forets, E. Roueff, J. Le BourlotH.-H. Lee, E. Herbst, G. Pineau des Forets, E. Roueff, J. Le Bourlot

LeidenLeiden J. Black, E. van Dishoeck, J. Black, E. van Dishoeck, D. Jansen and B. JonkheidD. Jansen and B. Jonkheid

MeijerinkMeijerink R.Meijerink, M.SpaansR.Meijerink, M.Spaans

MeudonMeudon J. Le Bourlot, E. Roueff, F. Le PetitJ. Le Bourlot, E. Roueff, F. Le Petit

SternbergSternberg A.Sternberg, A.DalgarnoA.Sternberg, A.Dalgarno

UCL_PDRUCL_PDR S. Viti, Wing-Fai Thi, T. BellS. Viti, Wing-Fai Thi, T. Bell





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

The KOSMA-The KOSMA- Code Code• spherical symmetry spherical symmetry • isotropic FUV fieldisotropic FUV field• density profile (4 parameter)density profile (4 parameter)• D/G, Z as free parameterD/G, Z as free parameter• 20 heating/cooling processes20 heating/cooling processes• modular, steady-state, gas-phase modular, steady-state, gas-phase

chemistry (UMIST95/99/…)chemistry (UMIST95/99/…)• pre-shielding possiblepre-shielding possible• external multi-shell RT code computes external multi-shell RT code computes

emergent line intensitiesemergent line intensities ( (CO,CO,1313CO,CI,CII,OI,…)CO,CI,CII,OI,…) • clump-mass & mass-size relations clump-mass & mass-size relations

applicableapplicable

0( )r

n r nR





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


• The KOSMA-The KOSMA- Code is designed to Code is designed to supply a large parameter grid of pre-supply a large parameter grid of pre-calculated model clouds.calculated model clouds.

• results available per web-interfaceresults available per web-interface• Standard parameters: Standard parameters:

D/G, nD/G, n00, M, , M, , standard chemistry, standard chemistry

• Extra: Extra: , R, Rcorecore, pre-shielding, , pre-shielding, DD, CR, , CR, ΔΔvvDD, , XXii, chemical composition , chemical composition





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary






•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


1E-5 1E-4 1E-3 0.01 0.1 1 101E-20

1E-19

1E-18

1E-17

1E-16

1E-15

1E-14

1E-13

1E-12

1E-11

1E-10

1E-9

H2 p

ho

tod

isso

ciat

ion

rat

e [s

-1]

AV,eff

rescaled to effective Av

1E-5 1E-4 1E-3 0.01 0.1 1 10

1E-20

1E-19

1E-18

1E-17

1E-16

1E-15

1E-14

1E-13

1E-12

1E-11

1E-10

1E-9

AV

H2 p

ho

tod

isso

ciat

ion

rat

e [s

-1]

directed illumination isotropic illumination

perpendicular Av





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


, ( )dust gasT r

Solve energy balance

( , , , ) ( , , , )i ii i

n nr T r T

heat cooling

Solve chemical network

( ) ( )i i q qi rs r s t tiq r s t

n n k kT n n nT

destruction formation

( )n r





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


Radiative Transfer CalculationsRadiative Transfer Calculationsmulti-shell ray-tracing ONION, SimLine, etc.multi-shell ray-tracing ONION, SimLine, etc.calculates emergent intensities per beamcalculates emergent intensities per beamand averaged over the whole clumpand averaged over the whole clump





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

Low Z-PDRsLow Z-PDRsTheory and observations suggest that metallicity Z Theory and observations suggest that metallicity Z significantly changes the structure of PDR’s : significantly changes the structure of PDR’s :

• altered Z altered Z altered gas-phase chemistry altered gas-phase chemistry • altered Z altered Z less dust less dust

– altered grain surface chemistry (e.g. formation of Haltered grain surface chemistry (e.g. formation of H22))– weaker extinction weaker extinction deeper FUV penetration deeper FUV penetration

stronger photo-reactionsstronger photo-reactions• altered Z altered Z altered heating/cooling rates altered heating/cooling rates altered altered

TTequil.equil.

• dissociation/formation of Hdissociation/formation of H22 and CO change and CO change differently with Z differently with Z standard X standard XCOCO factors yield factors yield incorrect results incorrect results molecular gas in low-Z systems molecular gas in low-Z systems not well traced by CO.not well traced by CO.

temperature structure and chemical temperature structure and chemical

stratification depend on metallicitystratification depend on metallicity





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

0 1 2 3 4 5 63.0

3.5

4.0

4.5

5.0

5.5

6.0

Z=0.2

Z=1

[OI]

< [CII]

[OI]

> [CII]

Lo

g(n

)

Log()

0 1 2 3 4 5 63.0

3.5

4.0

4.5

5.0

5.5

6.0

Z=0.2

PE

< H

2*,net

Lo

g(n

)

Log()

PE

> H

2*,net

Z=1

Low Z PDRsLow Z PDRsTemperature determinedTemperature determinedby balancing heating andby balancing heating andcoolingcooling

At the Surface: At the Surface: 4 primary h/c processes:4 primary h/c processes:

• PE heatingPE heating• H2 vib. de-excitationH2 vib. de-excitation• [CII] 158µm fine-[CII] 158µm fine-

structure coolingstructure cooling• [OI] 63µm fine-[OI] 63µm fine-

structure coolingstructure cooling





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

Low Z PDRsLow Z PDRs

nn

[OI] [CII]

PE H2*

PE~Z…Z1.5

H2*~Z

T~Z0.5…Z

[OI] [CII]

PE H2*

PE~Z

H2*~Z

T~const.

[OI] [CII]

PE H2*

PE~Z

H2*~Z/(1+2 Z)

T~1 /(1+2 Z)

[OI] [CII]

PE H2*

PE~Z2

H2*~Z

T~Z





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


0.2 0.4 0.6 0.8 1.0

100

1000

Tsu

rf [K

]

Z

=106

n=103 cm-3

n=104 cm

-3

n=105 cm

-3

n=106 cm

-3





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


0.2 0.4 0.6 0.8 1.010

100

1000

n=106 cm-3

n=103 cm-3

n=104 cm-3

n=105 cm-3

n=106 cm-3

Tsu

rf [K

]

Z

=100





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


0.2 0.4 0.6 0.8 1.0100

1000

n=103 cm

-3

n=104 cm

-3

n=105 cm

-3

n=106 cm-3

Z

Tsu

rf [K

]

=103





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


0.1 1

0.1

1

n0=104 cm-3

=100

De

pth

of

C+ L

aye

r [p

c]

Z

constant density

density gradient

0.1 1

0.1

1

n0=104 cm-3

=100

De

pth

of

C+ L

aye

r [p

c]

Z

constant density

density gradient

C + C+ + e-

C++ H2 CH2++





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CII]/CO(1-0)[CII]/CO(1-0)

Nakagawa et al. 2005

LMC

[CII]





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CII]/CO(1-0)[CII]/CO(1-0)

0.1 1 101E-5

1E-4

[CII]

su

rfa

ce

bri

gh

tne

ss

[e

rg s

-1 c

m-2 s

r-1]

Z

n=103 cm-3

n=104 cm-3

n=105 cm-3

n=106 cm-3=100, M=10

line integrated, clump averaged surface brightness of [CII]158µmline integrated, clump averaged surface brightness of [CII]158µm





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CII]/CO(1-0)[CII]/CO(1-0)

7.5 8.0 8.5 9.0 9.51E-15

1E-14

1E-13

1E-12

1E-11

1E-10

1E-9

1E-8

1E-7

1E-6

1E-5

1E-4

1E-3

surf

ace

bri

ghtn

ess

[erg

-1cm

-2sr

-1]

12+log(O/H)

n=103cm-3

n=104cm-3

n=105cm-3

12CO(1-0)

[CII]

M=10=100





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CII]/CO(1-0)[CII]/CO(1-0)

7.5 8.0 8.5 9.0 9.51E-15

1E-14

1E-13

1E-12

1E-11

1E-10

1E-9

1E-8

1E-7

1E-6

1E-5

1E-4

1E-3

103

104

105

106

107

108

109

surf

ace

bri

ghtn

ess

[erg

-1cm

-2sr

-1]

12+log(O/H)

n=103cm-3

n=104cm-3

n=105cm-3

12CO(1-0)

[CII]

M=10=100

[C

II]/C

O(1

-0)





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CII]/CO(1-0)[CII]/CO(1-0)

7.4 7.6 7.8 8.0 8.2 8.4 8.6 8.8 9.0 9.2 9.4 9.6

103

104

105

106

NGC 1156

NGC 1569

IC 4662

NGC 4449

M51

ORIONLMC

30 Doradus

IC 10SMC

NGC 1313

IZw 36

NGC 1068M83

NGC 4736

NGC 6946

I [CII

]158

µ/I

12C

O(1

-0)

12+log(O/H)





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CII]/CO(1-0)[CII]/CO(1-0)

7.4 7.6 7.8 8.0 8.2 8.4 8.6 8.8 9.0 9.2 9.4 9.6

103

104

105

106

NGC 1156

NGC 1569

IC 4662

NGC 4449

M51

ORIONLMC

30 Doradus

IC 10SMC

NGC 1313

IZw 36

NGC 1068M83

NGC 4736

NGC 6946

=10 4,n=10 4

,M=1

=10

2,n=

103,M

=10

=10 1,n=10 4

,M=10

=10 4,n=10 4,M

=10

=10 2,n=10 4,M=1

I [CII

]158

µ/I

12C

O(1

-0)

12+log(O/H)

=10 2,n=10 4

,M=10





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CI][CI]610µm610µm/CO(1-0)/CO(1-0)

7.5 8.0 8.5 9.0 9.51E-15

1E-14

1E-13

1E-12

1E-11

1E-10

1E-9

1E-8

1E-7

1E-6

1E-5 [CI]610µn

surf

ace

brig

htn

ess

[erg

-1cm

-2sr

-1]

12+log(O/H)

n=103cm-3

n=104cm-3

n=105cm-3

12CO(1-0)

M=10=100





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

7.5 8.0 8.5 9.0 9.51E-15

1E-14

1E-13

1E-12

1E-11

1E-10

1E-9

1E-8

1E-7

1E-6

1E-5

101

102

103

0.13

1.28

12.82

[CI]610µn

surf

ace

brig

htn

ess

[erg

-1cm

-2sr

-1]

12+log(O/H)

n=103cm-3

n=104cm-3

n=105cm-3

12CO(1-0)

M=10=100

[C

I]61

0µm/C

O(1

-0)

[CI][CI]610µm610µm/CO(1-0)/CO(1-0)

Galactic values





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CI][CI]610µm610µm/CO(1-0)/CO(1-0)

7.6 7.8 8.0 8.2 8.4 8.6 8.8 9.0 9.2 9.4 9.6

101

southern MW

M51

ORION

LMC (N159)

30 Doradus

IC 10

SMC (N27)

M83

NGC 4736

NGC 6946

D 478 (M31)

NGC 604-2

NGC 604-4

IC 342Milky Way MC 20 (M33)

MC 32 (M33)

GC

GC, foreground

southern MW

I [CI]

610µ

/I12

CO

(1-0

)

12+log(O/H)





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

[CI][CI]610µm610µm/CO(1-0)/CO(1-0)

7.6 7.8 8.0 8.2 8.4 8.6 8.8 9.0 9.2 9.4 9.6

101

southern MW

M51

ORION

LMC (N159)

30 Doradus

IC 10

SMC (N27)

M83

NGC 4736

NGC 6946

D 478 (M31)

NGC 604-2

NGC 604-4

IC 342Milky Way MC 20 (M33)

MC 32 (M33)

GC

GC, foreground

southern MW

I [CI]

610µ

/I12

CO

(1-0

)

12+log(O/H)

M=1,=100 M=1, =1

n=105cm-3

n=104cm-3

n=106cm-3





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

Modeling the MWModeling the MW

COBE-FIRAS:far-infrared survey of the spectral line emission from the Galaxy with a 7° beam

(Fixsen et al. 1999)





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


• a single, spherical a single, spherical clump scenario is a very clump scenario is a very special casespecial case

• usually molecular clouds usually molecular clouds have a highly irregular, have a highly irregular, clumpy structure, far clumpy structure, far from simple plane-from simple plane-parallel or spherical parallel or spherical model cloudsmodel clouds

• furthermore, molecular furthermore, molecular clouds are embedded in clouds are embedded in atomic gas, also atomic gas, also contributing to the total contributing to the total emissionemission





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


• observations show observations show an almost universal an almost universal clump-mass clump-mass distribution with distribution with dN/dMdN/dMMM-1.6…1.8 -1.6…1.8 and a and a mass-size relation of mass-size relation of MMRR2.32.3

(Kramer et al. (Kramer et al. 1998)1998)





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

Modeling the MWModeling the MW• MW as disk with MW as disk with

RRtottot=18kpc and h=59pc=18kpc and h=59pc

• nn, , , and , and Z Z as function of as function of galactocentric radius galactocentric radius (Wolfire et al. 2003)(Wolfire et al. 2003)

• n(Rn(R)=10)=1044cmcm-3-3, , (R(R)=3)=3

• molecular gas distributed molecular gas distributed according to C-M and M-according to C-M and M-S relation S relation

• COBE beam (1°COBE beam (1°5°)5°)

• area- and volume filling area- and volume filling per concentric ringper concentric ring

Credit: NASA/JPL-Caltech/R. Hurt (SSC)

(Fixsen et al. 1999)





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary






•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary


=100

=3





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

SummarySummary

• KOSMA-KOSMA- model, a spherical PDR code model, a spherical PDR code featuring isotropic FUV illumination and featuring isotropic FUV illumination and a highly modular chemistrya highly modular chemistry

• Z-dependence of the gas temperature Z-dependence of the gas temperature in PDR in PDR

• Z-dependence of the CZ-dependence of the C++-layer-layer• Influence of geometrical beam filling on Influence of geometrical beam filling on

the total surface brightnessthe total surface brightness• Observational trend in Galactic and Observational trend in Galactic and

extragalactic [CII]/CO(1-0) with extragalactic [CII]/CO(1-0) with metallicity observations can be metallicity observations can be explained with spherical PDR model explained with spherical PDR model resultsresults





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

SummarySummary• The connection between [CI]/CO(1-0) and Z The connection between [CI]/CO(1-0) and Z

is more complicated, but again the is more complicated, but again the observational trend can be reproducedobservational trend can be reproduced

• By applying C-M spectra and M-S relations By applying C-M spectra and M-S relations to the KOSMA-to the KOSMA- database it is possible to database it is possible to analyze large surveys, i.e. observations analyze large surveys, i.e. observations with large beam filling with large beam filling → → application to a simple MW-model in application to a simple MW-model in order to explain COBE results as PDR order to explain COBE results as PDR emission emission ([CII] can only be explained partly)([CII] can only be explained partly)

• Clump-ensemble approach suitable for any Clump-ensemble approach suitable for any single position observation, face-on galaxy single position observation, face-on galaxy scan, etc. with considerable beam filling. scan, etc. with considerable beam filling.





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

Thank you for your attention!Thank you for your attention!





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

http://www.ph1.uni-koeln.de/workgroups/http://www.ph1.uni-koeln.de/workgroups/theo_astronomy/pdr/theo_astronomy/pdr/





•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary






•[CII]/CO(1-0)[CII]/CO(1-0)

•[CI]/CO(1-0)[CI]/CO(1-0)



•SummarySummary

C+

C

CO

Z=1Z=0.5Z=0.1

carbon in low metallicity pdrs

Documents

clumpy pdrs

kosma code low z pdrs

alma perspectiveintroduction

galactic ism modelling

mw summarythe kosma

kosma maps of ci

mw summaryintroductionworkshop

mw summaryintroductionpdrs