C + As a Primary Coolant and Tracer of Star Formation Dec 21 st, 2012.
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Transcript of C + As a Primary Coolant and Tracer of Star Formation Dec 21 st, 2012.
de Looze et al. 2011
SF
R (
24 m
m +
FU
V)
ISO [CII]Herrera-Camus et al. 2013KINGFISH
PACS [CII]
~ 500 pc resolution
Sargsyan et al. 2012
[CII]/ LIR ~ const + SFR based on LIR SFR([CII])
Warm H T = 8000 Kn = 0.3 cm-3
Cold HT = 80 Kn = 30 cm-3Cold H2
T = 10 K
Classic PDR
Contributions to [CII] Line emission
OB star
H+
H+
H+
CNM
WNM
r ~ few pc
r ~ 10s pc
r~ 100s pc
C+/HI
C+/H2
FUV
Warm H+
T = 8000 K Ne = 5 cm-3
WIM
EUVr ~ 100s pc ?
[CII] a dominant coolant? Maybe
NO
NO
NO
YES!
Ionization: FUV, X-ray, C.R.Heating: P.E., C.R., X-ray/EUVCooling: [CII], [OI], Lya, e- recombination
nG = n2L
T
= n
T
Wolfire et al. (2003)
WNM stable
CNM
stableunstable
T = 7860 n = 0.35 cm-3 WNM
T = 85 n = 33 cm-3 CNM
Diffuse Gas Emission
= n
T158 mm
63 mm
Grain photoelectric
C II Cooling/H (CNM) > 10 CII Cooling/H (WNM)
PminPmax
** Note ** CNM in Thermal Balance:[CII] measures the total energy dumped into the gas.
Heating Rate = constn ZT [CII] = const
Wolfire et al. (2003)
Diffuse Gas Emission
Fraction of WNM/CNM ?
Dickey et al. 2009
CNM + WNM
CNM
[CNM + WNM]/CNM
Em
issi
on/L
Ab
sorp
tion
/LE
mis
sion
/Ab
sorp
tion
Heiles & Troland 2003: 60% WMN, 40% CNM locally in Galactic disk
Assume: 2/3 WNM, 1/3 CNM to outer galaxy
Mathis et al. 1982
Weingarter & Draine 2001 and
6eV
In diffuse ISM 10-20% of heating can come from PAH-
PAH + hn PAH+ + e-
PAH- + hn PAH + e-
2eV
Malloci et al. 2007
PDR Emission
Diffuse Gas
Classic PDRs
Orion PDR
[CII]
n
Kaufman et al. 1999 Kaufman et al. 1999
FU
V
FU
V
Heating Efficiency
G0/n = const
n
PDR Emission
Diffuse Gas
Classic PDRs
Orion PDR
n n
Kaufman et al. 1999 Kaufman et al. 1999
FU
V
FU
V
Heating Efficiency[OI]/[CII]
cr n[CII]
G0/n = const
Contribution from HII regionsTeff= 42000 K Abel et al 2005
Fraction of [CII]from HII region
Kaufman et al. 2006
Z=3Stellar association
Oberst et al. 2011
Carina Nebula
SPIFI[NII] 205 mm
ISO[CII]
30% [CII] diffuse ionised 70% [CII] neutral PDR
Oberst et al. 2006
Mookerjea et al. 2011 HerM33es
PACS [CII] [OI] M33 HII Region BCLMP 302
20-30% [CII] ionised gas80-70% [CII] neutral PDR
Bennett et al 1994, COBE FIRAS 7o beam Diffuse ionized gasWIM Emission
Wright et al. 1991 Line log L[C II] 158 mm 7.7[N II] 122 mm 6.9[N II] 205 mm 6.7[C I] 370 mm 5.5[C I] 610 mm 5.3
Bennett et al 1994, COBE FIRAS 7o beam
[CII]
[CII] from [NII]
[NII]
Diffuse ionized gas
Steiman-Cameron et al. 2010
Cygnus X
WIM Emission
What dominates the [CII] emission?
Galactic:WIM – Heiles 1994CNM – Bennett et al. 1994, Wolfire et al. 1995 GMC – Stacey et al. 1985; Shibai et al. 1991 Cubick et al 2008
What is the [CII] Budget ?
Beam size? galaxy type ? Metallicity ? Where ?
Extragalactic:
Cormier et al. 2012: Low Z galaxy Haro 11 – 10% PDR, 90% in diffuse ionized
Madden et al. 1997: Low Z galaxy IC 10 – 10% WIM, 10% CNM, 80% PDR with C+/H2
Malhotra et al. 2001: Normal Galaxies - 50% WIM, PDRs G0 = 102 - 104.5, n = 102 - 104.5
Aniano et al. 2012
Low average U ~ 5, low fPDR < 20%
Wolfire, Hollenbach in prep: average U on GMCs ~10-30
Also Cubick et al. 2008, Pineda et al. 2010 found U < 100
Mechanical Heating?
Jenkins & Tripp 2011
Small Scale StructureTurbulent Dissipation in CNM
3800
Log normal fit + 0.05% 3x105 K cm-3
1)Warm diffuse cloud chemistry: CH+, HCO+
Godard et al. 2009, Falgarone et al. 2010
2)Tiny-Scale Atomic Structure (TSAS): HI absorption 10s AUe.g. Heiles 1997 (TSIS), (TSMS)
3)Warm diffuse H2 seen in emission Falgarone et al. 2005
Small Scale Structure (Continued)Turbulent Dissipation in CNM
4) High H2/PAH ratios seen in high latitude clouds. Ingalls et al. 2011
5)Warm H2 in MC surfaces (low UV field). Goldsmith et al. 2010, Habart et al. 2011
Habart et al. 2011
Spitzer H2 observationsModel Meudon PDR code
FUV field strength FUV field strength
L1721CaliforniaNGC 7023EHorseheadRho OphNGC 2023N
MHD shocks: Pineau des Forêts et al 1986
Shears: Joulain et al. 1998
TDRs – 100s AU:Godard et al. 2009
Turbulent Dissipation Region (TDR)
adiabatic cooling
de Looze et al. 2011
SF
R (
24 m
m +
FU
V)
ISO [CII]Herrera-Camus et al. 2013KINGFISH
PACS [CII]
~ 500 pc resolution
[CII]/ LIR ~ const + SFR based on LIR SFR([CII])
Sargsyan et al. 2012
Herrera-Camus et al. 2013
Low [CII]/IR seen in AGN, regions of normal galaxies, and ULIRGs.
1)Grain charging2)Dust optical depth at 158 mm3)Dusty HII regions4)High density
Low [CII]/24 mm points do not measure SFR
de Looze et al. 2011
SF
R (
24 m
m +
FU
V)
ISO [CII]Herrera-Camus et al. 2013KINGFISH
PACS [CII]
~ 500 pc resolution
[CII]/ LIR ~ const + SFR based on LIR SFR([CII])
Sargsyan et al. 2012
SF
R
[CII]
Hea
tin
g
Cooling
1)[CII] not dominated by high G0 - high n PDRs:[OI]/[CII] > 1 and lowheating efficiency
2)WIM/HII contribution is uncertain ~ 30%
3)[CII] mainly comes from low to moderate G0 and moderate n PDRs plus some neutral diffuse gas (mainly in outer galaxy).Keeps CII/CO relation and [CII] as a dominant coolant.
5)Mechanical heating does not dominate due to correlation with radiative tracers (24 mm)
4)Dust fits correct? [CII] comes mainly from low UV fields (everywhere in galaxy). [CII]/CO correlation? [OI] problem?