Upload
odin
View
46
Download
0
Embed Size (px)
DESCRIPTION
Molecular Gas at High Redshift. Axel Weiss MPIfR Bonn. D. Downes, F. Walter, C. Henkel. SMGs with Laboca. 30’. Laboca: Wavelength: 870 µm Bandwidth: 60 GHz Resolution: 18.6’’ FoV: 10.4’ Pixels: 250 Sensitivity: 50 mJy √s. ~2mJy rms 100h. - PowerPoint PPT Presentation
Citation preview
Molecular Gas at High Redshift
Axel Weiss
MPIfR Bonn
D. Downes, F. Walter, C. Henkel
SMGs with Laboca
30’Laboca:
Wavelength: 870 µmBandwidth: 60 GHz
Resolution: 18.6’’FoV: 10.4’
Pixels: 250Sensitivity: 50 mJy √s
~2mJy rms 100h
High-z Lines : submm observations
@ mm wavelength
z 1-6:
1” ~ 5 - 10Kpc
single pointing determines the total flux density of a galaxy
average source properties
Molecular Gas tracers:
12 CO J >2 transitions
CI (1-0) & (2-1)
CII
HCN (J>2)
CO line SED of the MW
COBE (Fixen etal 1999)
CO(1-0)
Dame, Hartmann & Thadeus 2001
inner disk
diffusedense
outer diskGC
High-z Line Targets (z = 1.4 –6.4):
Source z LFIR(app)
x1013 SL
---------------------------APM08279 3.91 20.0BR1202 4.69 7.1 F10214 2.29 6.0Cloverleaf 2.56 5.9RXJ0911 2.79 5.1MG0751 3.20 4.9SMM16359 2.52 4.5LBQS1230 2.74 3.6VCVJ1409 2.58 3.5LBQS0018 2.62 3.3MG0414 2.64 3.2SMMJ04135 2.85 3.1PSS2322 4.12 3.0BR1335 4.40 2.8SDSSJ1148 6.41 2.7 :SMM14011 2.56 2.0 :HR10 1.44 0.65
Cloverleaf- Bure CO76 PSS2322 VLA CO21
Alloin etal 1997 Carilli etal 2003
Solomon & VandenBout 2005
IRAM 30m CO observations:
14 sources 40 detections (+literature) CO(3-2) to (11-10)
CO line SEDs at high-z
• 13/14 sources are described by a single gas component
•All molecular gas distributions are compact (<1.5kpc)
Cloverleaf F10214
BR1202
APM0827
PSS1409 MG0751 RXJ0911
SMM04431HR10SMM16359BSMM14011
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
diffuse
dense
center
No Evidence for disks/outflows/tidal streams
diffuse
total
M82 CO(1-0)High-z (QSOs):
No evidence for excess flux in J<5-4 transitions compared to the dominant CO component -> no/little gas with H2
densities < 104 cm-3
PSS2322 z=4.1:
Local Merger(s) & ULIRG(s)
Apex CO(4-3)
low density gas
Antennae Almost no data beyond CO(3-2)
Only examples:
Antennae & Mrk231
Mrk231
Papadopoulos etal 2007
Zhu etal 2003
Local starbursts centers:
Similar too high-z QSOs
Tkin ~ 50 - 70 K (Tdust ~ 50 K);
n(H2) ~ 10 4.0cm-3
But: mean CO(3-2)/CO(1-0) ~0.7 for local SB -> presumably due to low excitation gas in the surrounding disks.
Antennae:
low CO excitation in OLR
Tkin ~ 30K, n(H2) ~ 10 3.0cm-3
CO SEDs high and low-z:
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
quite disk galaxies
Early mergers
Advanced mergers & starbursts
AGN heating
Where is the SF gas in the CO SEDs?
Gao etal 2007
Local universe:
H2 densities of HCN emitting volume ~ 105 cm-3
High-z:
HCN observations at high-z extremely difficult and time consuming (IHCN ~ 0.2 ICO), but detected in a few cases.
H2 densities from CO ~ 104 cm-3
Where is the dense gas in the CO SEDs?
Relation to HCN
2 component CO model:
Tkin = Tdust=50K for both
n(H2) ~ 104 cm-3 (ff=85%)
n(H2) ~ 105.1 cm-3 (ff=15%)
PSS2322 z=4.1 GC