IAU 231, Asilomar 2005

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Odin observations and the lack of O2
Requested by SOC SIC !
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Odin detection of O2
Sorry SOC !
Bengt Larsson, Stockholm Observatory
and The Odin Team Canada Finland France Sweden
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THE ODIN SPACECRAFT

• Telescope 1.1 m offset Gregorian
• Material CFRP skins on honeycomb
• Surface 8 mm primary, 5 mm secondary
  (rms)
• Pointing 15 arcsec (rms)

• Launch 2001 on Start-1 (Svobodny, Russia)
• Orbit circular synchronous
• 620 km, ascending node
  _at_ 1800
• Lifetime 2 yr (specification)

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ODIN RECEIVERS SPECTROMETERS
Spectrometer Bandwidth - Resolution AOS
1000 MHz - 1 MHz Correlators
4 x 200 MHz - 1 MHz
4 x 100 MHz - 500 kHz
2 x 100 MHz - 250 kHz
1 x 100 MHz - 125 kHz
119
O2
C 118.24 - 119. 25 GHz
A2 486.1 - 503.9 GHz
A1 541.0 - 558.0 GHz
B1 568.0 - 580.4 GHz
NH3
572
O2
487
B2 547.0 - 564.0 GHz
H2O 557
CS 490 HDO 490 HD18O 493, 502
H218O 548
C I ( 3P1- 3P0 ) 492
C18O (5-4) 549
CO (5-4) 576
13C I ( 3P1- 3P0 ) 492 (F 1/2-1/2, 3/2-1/2)
13CO (5-4) 551
H217O 552
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LOW-LYING LEVELS OF O2
O2 (NJ 11 - 10) 118.75 GHz Odin
telescope 1.1 m Odin beam 10
arcmin
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Knut Lundmark et al. 1940s Lunda Panorama of
the Milky Way Lund Observatory, Sweden
L 134N
r Oph A IRAS 16293
S68 FIRS1
NGC 2071
TMC 1
G34.30.2
Ori A
M 17SW
G0.76-0.01
SMC
NGC 6334 I
published 119 GHz upper limits Pagani et al.
2003, AA 402, L77 Wilson et al. 2005, AA 433,
L5
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Knut Lundmark et al. 1940s Lunda Panorama of
the Milky Way Lund Observatory, Sweden
r Oph A
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Odin pointing r Oph A
dark at the front and bright in the back
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O2 (11-10)
tON-source 280 733 sec 3.25
days
O2 (11-10)
c-C2H4O (322-111) ?
c-C2H4O (322-111) ?
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• What is the abundance value X(O2) N(O2) /
  N(H) ?
• Analysis O2 excitation and radiative transfer in
  3 models
• Local Thermodynamic Equilibrium (LTE)
• Large Velocity Gradient
  (LVG)
• Monte Carlo Method
  (MCM)
• inc. energy balance

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N(O2) 1 1015 cm-2
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N(C18O) LTE map on 10 arcmin scale N(H2)
1023 cm-2
X(O2) 10-8
ave Tk 30 K cf. Kamegai et al. 2003, ApJ
589, 378
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LVG log N/dv 14.9 and N(H2) 2 1022 cm-2
X(O2) 7 10-8
Tkin 30 K n(H2)
2 104 cm-3 size 0.4
pc M(H2) 58 Mo L(O2)
7.4 10-5 Lo
cf. Kulesa et al. 2005, ApJ 625,194
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O2 spectrum of r Oph A HPBW 10 and fbeam
1.0
?
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Monte Carlo Odin H2O
compact O2 source 22 arcsec
X(O2) 6 10-7
X(H2O) 1 10-8
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Prediction O2 487 GHz line Odin TA
22 mK Herschel TA 0.2 K
Monte Carlo Odin H2O
Not doable..
compact O2 source 22 arcsec
Piece of cake
X(O2) 6 10-7
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O2 abundance in r Oph A
?
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?
In r Oph A How is O2 distributed ?
How / Where is O2 formed ?
PDRs, shocks, quiescent
gas... e.g.
O2/H, O2/O, O/C... Elsewhere Where is O2 found
? outside solar system
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Conclusions
On the basis of Odin observations of r Oph A In
the ground state line of O2 we conclude ...
... new observations are needed...
e.g. Herschel-HIFI mapping _at_ low resolution
line profile _at_ S/N 10
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Oxygen is desperately needed
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Thanks !
The O2din Team P. Bergman, P. Bernath, J.H.
Black, R.S. Booth, V. Buat, J. Crovisier, C.L.
Curry, P.J. Encrenaz, E. Falgarone, P.A.
Feldman, M. Fich, H.G. Floren, U. Frisk, M.Gerin,
J. Harju, T. Hasegawa, Å. Hjalmarson, L.E.B.
Johansson, S. Kwok, B. Larsson, A. Lecacheux, T.
Liljeström, R. Liseau, G.F. Mitchell, L.H. Nordh,
M.Olberg, A.O.H. Olofsson, G. Olofsson, L.
Pagani, R. Plume, I. Ristorcelli, Aa. Sandqvist,
F. v. Scheele, N.F. Tothill, K. Volk, T.
Wiklind, C.D. Wilson
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• r Oph POSTERS
  Odin
• I.10 Bottinelli et al.
• I.16 Cordiner et al.
• I.25 Friesen et al.
• I.60 Ristorcelli et al. I.60
  Ristorcelli et al.
• 
  I.76 Wirström et al.
• II.12 Caux et al.
• 
  II.18 Encrenaz et al.
• II.28 Kwan et al.
• 
  II.46 Persson et al.
• III.64 Schöier et al.
  

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• r Oph POSTERS
  Odin
• I.10 Bottinelli et al.
• I.16 Cordiner et al.
• I.25 Friesen et al.
• I.60 Ristorcelli et al. I.60
  Ristorcelli et al.
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  I.76 Wirström et al.
• II.12 Caux et al.
• 
  II.18 Encrenaz et al.
• II.28 Kwan et al.
• 
  II.46 Persson et al.
• III.64 Schöier et al.
  

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Odin observation of HC3N 118 GHz in DR 21
Hjalmarson et al. 2004
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119 GHz receiver
not phase-locked
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Digital Auto Correlator 100 MHz bandwidth
(Dv250 km s-1)
125 kHz resolution (dv0.32 km
s-1)
1/3 of orbital revolution telluric frequency
reference O2 and 16O18O
only half BW useful 150 km s-1 velocity
resolution 0.5 km s-1
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3 different data sets A (Aug 2002) B (Sep
2002) C (Feb 2003)
3 ave combinations AB AC BC
1 total average ABC
full resolution Dn 125 kHz
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CO (3-2)
H2O (110-101)
full resolution Dn 125 kHz 0.3 km s-1
O2 (11-10)
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CO (3-2) convolved to Odin 557 GHz beam for
PDR arc
Odin H2O 557 GHz PDR arc
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Goldsmith et al. 2002, ApJ 576, 814
6 km s-1
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Kamegai et al. 2003, ApJ 589, 378
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Spaans van Dishoeck 2001, ApJ 548, L217
homogeneous clumpy PDR
n103 Go10
r Oph model
n104 Go40
n104 Go10