molecular gas (excitation) at high redshift
DESCRIPTION
Molecular Gas (Excitation) at High Redshift. Fabian Walter Max Planck Institute for Astronomy Heidelberg. A. Weiss ( MPIfR ) D. Downes (IRAM), D . Riechers (Caltech), C. Carilli (NRAO) , F. Bertoldi ( AIfA ) , P . Cox (IRAM), R. Wang (U Peking), E. Daddi (CES), Ran Wang (UA). - PowerPoint PPT PresentationTRANSCRIPT
Molecular Gas (Excitation) at High Redshift
Fabian WalterMax Planck Institute for Astronomy Heidelberg
A. Weiss (MPIfR) D. Downes (IRAM), D. Riechers (Caltech), C. Carilli (NRAO), F. Bertoldi (AIfA), P. Cox (IRAM), R. Wang (U Peking), E. Daddi (CES), Ran Wang (UA)
Molecular Gas with ALMA and EVLA
CO line SEDs: excitation and structure analysis
multiple components
LVG: n(H2), Tkin –>Tb
S ~ m Ωs bff Tb , m = magnificationΩs bff = r0
2 bff = source filling
CO excitation
free parameters n(H2) Tkin r0
[CO]/[H2]/dv/dr fixed to 10-5 pc (km/s)-1
LVG model degeneracy
well determined:Gas pressure (n T)equivalent radius L’CO(1-0)
Tkin, n(H2) ambiguityBut: shape of the CO SED is temperature dependent!
Solve ambiguity via:Dust (dust temperature, dust to gas mass ratio) Atomic Carbon (Tex)
APM08279 :
log(nH2)=4.2 Tkin=220K r=790pc log(nH2)=4.0 Tkin=350K r= 700pc log(nH2)=5.4 Tkin =40K r=1800pc
Tdust, Tex CI
Dust to gas mass ratio
CO line SED of the MW
COBE (Fixen etal 1999)
CO(1-0)Dame, Hartmann & Thadeus 2001
inner disk
diffusedense
outer diskGC
diffusedense
center
Integrated CO SED M82
diffuse
total
M82 CO(1-0)
M82
Walter et al. 2003
Weiss et al. 2005
molecular gasoutflow. 2005
CO SEDs of local (U)LIRGs:
Two components for all sources; SED peak ~ CO(4-3) Consistent with:LE: Tkin ~ 30 K; n(H2) ~ 10 3.2cm-3 HE: Tkin ~ 50 K; n(H2) ~ 10 4.0cm-3
CO(3-2) APEX2, CO(4-3) FLASH, CO(6-5) CHAMP+, CO(7-6) CHAMPCO(1-0) & CO(2-1) from SEST (Elfhag etal 1996, Aalto etal 1999)
N986; logIR 10.8 N7130 logIR 11.4 Arp186 logIR 11.6
N3256 logIR 11.6 VV114 logIR 11.7 F18293 logIR 11.8 I13120 logIR 12.3
CO line SEDs / Ladders
IRAM 30m CO SED survey(1, 2, 3mm bands)
CO(1-0) Transition: ‘cm’ Telescopes
Riechers, Walter, Carilli et al. 2006
GBT
Effelsberg
PSS J2322 (z=4.1)APM08279 (z=3.9)
+
CO line SEDs at high-z
Cloverleaf F10214 BR1202APM0827
PSS1409 MG0751 RXJ0911
SMM04431HR10
SMM16359BSMM14011
J11148
SMM123549 SMM163650 SMM163658
Tkin ~40 – 60 K (Tdust ~ 50 K)n(H2) ~ 10 3.6-4.3cm-3
Tkin ~ 200 K (Tdust ~ 200 K)n(H2) ~ 10 4.2 cm-3
Strongly lensed (m=80-100) central ~200pc surrounding the QSO. AGNheating!
Normalized high-z CO SEDs
Tkin ~ 30-50 K (Tdust ~ 30-50 K)n(H2) ~ 10 2.7-3.5 cm-3
• All sources ( 8 QSOs & SMGs, 7) are described by a single gas component• CO excitation (peak of the CO SED) in SMGs is lower than in QSO hosts • Molecular gas distributions are compact (r0 = 0.3-1.2 kpc)• Molecualr gas surface densities are high (Msol pc-2
Tkin ~40 – 60 K (Tdust ~ 50 K)n(H2) ~ 10 3.6-4.3cm-3
Tkin ~ 200 K (Tdust ~ 200 K)n(H2) ~ 10 4.2 cm-3
Strongly lensed (m=80-100) central ~200pc surrounding the QSO. AGNheating!
Normalized high-z CO SEDs
Tkin ~ 30-50 K (Tdust ~ 30-50 K)n(H2) ~ 10 2.7-3.5 cm-3
• All sources ( 8 QSOs & SMGs, 7) are described by a single gas component• CO excitation (peak of the CO SED) in SMGs is lower than in QSO hosts • Molecular gas distributions are compact (r0 = 0.3-1.2 kpc)• Molecualr gas surface densities are high (Msol pc-2
Potential effect of galaxy merging on the CO SEDs
LFIR, SFR, n(H2)
M51 Antennae Arp220 Mrk 231
rCO ~ 4kpc rCO ~ 1.5kpc rCO ~ 500 pc rCO ~200 pc
quiet disk galaxies
Early mergers
Advanced mergers & starbursts
AGN heating
z~2 SF gal’s: not extreme starbursts, but massive gas reservoirs
6 of 6 detected in CO, ~10 kpc size Mgas> 1010 Mo ~ high-z HyLIRG
(SMG, QSO host)But: SFR < 10% HyLIRG
5 arcmin-2 (vs 0.05 for SMGs) => common, ‘normal’ high-z galaxies
Daddi ea. 2007, 2008, 2009Linda’s talk
3.2”
HST
PdBI
CO(2-1)
CO excitation = Milky Way (but Mgas > 10x MW) LFIR/L’CO = MW << ULIRGs/SMGs Gas depletion timescales > few x108 yrs
LFIR/L’CO
MW
z~2 SF gal’s: Milky-Way like conditions for SF, not ULIRG-like
BzK-21000 Milky Way
low z
high z
Milky Way
ALMA/EVLA CO discovery space
QSO
ALMA/EVLA CO discovery space
SMG
QSO
ALMA/EVLA CO discovery space
CO N
OT
EXCI
TED
BzK
SMG
QSO
…bad news for ISM studies in EoR!
ALMA/EVLA CO discovery space
CO N
OT
EXCI
TED
BzK
SMG
QSO
…bad news for ISM studies in EoR!
TCMB !
ALMA/EVLA CO discovery space
CO N
OT
EXCI
TED
BzK
SMG
QSO
…bad news for ISM studies in EoR!
Freq. of
[CII]
ALMA/EVLA CO discovery space
[CII] resolved at z=6.4
1.9THz line observed at 258 GHzbeamsize: 0.35”, spatially resolved on 2kpc scales
Direct evidence for formation of stellar disk/bulge in host galaxy < 1Gyr after big bang Bure rocks!
Wal
ter e
t al.
09
SFRSD=1000 Msun yr-1 kpc-2
C+ at high z
(Walter et al 2009; Maiolino et al 2005, 2009; Iono et al 2006; Bertoldi et al in prep)
Summary
CO observations still workhorse for high-z studies
imaging and high density tracers great.... .....but excitation also provide key information.
distinct differences in high-z galaxy populations local universe: extremely bright future with Herschel
high-z: ALMA, but still needs quite some observing time.
[CII] will be key diagnostic line for z>7 Universe for ALMA