Molecular Spectroscopy Symposium 2011 20-25 June 2011 ROTATIONAL SPECTROSCOPY OF HD 18 O John C. Pearson, Shanshan Yu, Harshal Gupta, and Brian J. Drouin,

Molecular Spectroscopy Symposium 2011 20-25 June 2011

ROTATIONAL ROTATIONAL SPECTROSCOPY OF HDSPECTROSCOPY OF HD1818OO

John C. Pearson, Shanshan Yu, Harshal Gupta, and Brian John C. Pearson, Shanshan Yu, Harshal Gupta, and Brian J. Drouin, J. Drouin,

Jet Propulsion Laboratory, California Institute of Technology, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109Pasadena, CA 91109

2Molecular Spectroscopy Symposium 2011 20-25 June 2011

Why HDWhy HD1818O?O?

Trace constituent of the Earth’s Atmosphere

– ODIN satellite detected it in the limb of the Earth’s atmosphere

Interesting physics

– Watson Hamiltonian has convergence problems for water

– Separation of rotation and vibration begins to fail at K>9 Available spectrum extensively critically review

– Tennyson et al., 2010, JSQRT 111, 2160

– Mikhailenko et al., 2009, JSQRT 110, 597

Are the levels as good as claimed?

The Herschel HIFI Orion Surprise

– H2O, H218O , H2

17O & HDO can all be optically thick!!

– Rotational transitions of HD18O are detected Thankfully they are not optically thick


Herschel HIFI Orion SpectraHerschel HIFI Orion Spectra

HDO is OpticallyThick!!!

HD18O is 10% of HDO in

Red component

optical depth this component

is ~50i.e. a lot of

water


Previous WorkPrevious Work

One microwave study (27 lines)

– From Steenbeckeliers published by F. Lovas, 1978, J. Chem. Phys. Ref. Data 7, 1445

Several IR studies of ground state at 2 band

– J.W. Fleming & M.J. Gibson, 1976, JMS 62, 326 (16-34 cm-1)

– J.W.C. Johns, 1985, J. Opt. Soc. Am. B 2, 1340 (20-350cm-1)

– R.A. Toth, 1993, JMS 162, 20 (2 band)

– A.-W. Liu et al., 2006, JMS 237, 149 (2 band)

– A.-W. Liu et al., 2011, JMS 265, 26 (2 band)

All but the most recent were part of the critical review

– Predicted accuracy from MARVEL deserved a test


ExperimentalExperimental

The direct multiplication spectrometer at JPL was utilized for most measurements

Multiplication factors up to 162 were utilized (to 2.72 THz!!!)

Transitions between 530 and 660 were measured with a phase locked BWO at JPL

Measurements were performed on a 50/50 H2O/D2O sample with 18O in “natural” abundance

– There appeared to be a slight enhancement of 18O in presumably from the D2O

– Only the ground state strong lines were attempted


Some Example LinesSome Example Lines

1(1,0)-1(0,1) 4(1,3)-4(0,4)

6(0,6)-5(0,5)8(3,6)-8(2,7)


DataData

51 new microwave accuracy transitions

– Accuracy 20-350 kHz

– Measurements between 453 and 2718 GHz

– Highest J is 10 (previous data was 12)

– Highest K is 6 (previous data was 5)

27 previous microwave transitions

3031 Infrared transitions (000-000 & 010-000)

– All not rejected by MASTER review (~20 more weighted out)

– All from Liu et al. 2011 (~50 weighted out) Some oblate paired doublets and quartets added

– Highest J is 19 in 010, 18 in 000

– Highest K is 11 in 010, 10 in 000


Levels connected with microwave measurementsLevels connected with microwave measurements

This work

Previous


AnalysisAnalysis

Analyzed the spectrum using Euler Series Hamiltonian

– Pickett, Pearson, & Miller, 2005, JMS 233, 174.

{,} is an anti-commutator. The a’s and b’s are parameters (manually adjusted)

nmnm

vvv

nm

nmSJJbKba

KJJKDH

,2

22

,11

1

22

1'2''

22

,,

,11

1

2

1cbnm

vvv

nm

nmnm

A PPJJbKba

KJJKdH

0,10,20

0,2

0,11,001,1

0,12,00

2,0

2

DaDDDDD

DbDaDDD

DbDDD

vJJKK

vvJJK

vJ


Potential Problems 1/4Potential Problems 1/4

GS K=9010 J(0,J), J(1,J)

@J=15

GS K=10010 J(1,J-1), J(2,J-1)

@ J=11



GS K=11010 J(4,J-4)

@ J=12

GS K=11010 J(4, J-3)

@ J=15



GS K=12010 K=6@J=13

010 K=8100 J(0,J), J(1,J)

@J=15, 16



010 K=8100 J(1,J-1), J(2,J-1)

@J=13

GS K=14100 J(1,J-1),J(2,J-1)

@ J=14


Problematic LevelsProblematic Levels

Six lines were identified in the infrared data set that showed local perturbations

– 010 15(4,12) & 010 16(4,13) levels are slightly perturbed

Liu et al., 2011 data did not properly blend the oblate paired high J lines

– Adding the omitted a- and b-type transitions in the blended lines improved the fit

Most weighted out lines were weak and their “badness” was supported by other measurements of the same level.

68 constants used to fit all 34 in 000, 34 in 010

Reduced RMS is 1.253 (with about 70 rejected lines out of 3000)

– All the microwave data fits to 3 sigma


Constants DiagonalConstants Diagonal

000 010Parameters value valueb_Jx103 0.15 0.13a_Kx103 1.9 2b'_Jx103 0.19 0.14a'_Kx103 3.85 3.5Constant Value MHz Uncert. value MHz Uncert.E 0 41859021.87 1.51(B+C)/2 231140.7322 0.0042 231903.666 0.086A-(B+C)/2 692830.888 0.199 754474.44 0.44D0,2 24.075191 0.000137 17.9914 0.0149D1,1 483.54512 0.00177 503.8149 0.0173D2,0 911.4372 0.0033 791.524 0.046D0,3x103 3.18524 0.00149 2.7588 0.0095D1,2 0.169573 0.000055 0.22879 0.00211D2,1 0.779162 0.000176 0.69946 0.00103D3,0 2.159857 0.000251 3.59363 0.00217D0,4x106 0.4575 0.0042 0.0909 0.0195D1,3x106 -7.07 0.62 -0.04351 0.00128D2,2x103 -0.4198 0.0051 -2.5267 0.007D3,1x103 2.0644 0.0077 3.5567 0.02D4,0x103 1.8074 0.0091 -5.72 0.5D1,4x106 0.02941 0.00176 0.0337 0.026D2,3x106 0.1516 0.016 0 fixedD3,2x106 5.409 0.172 17.132 0.076D4,1x106 2.45 1.62 -0.743 0.16D5,0x103 0.010599 0.00135 0.05502 0.00054D6,0x109 5.48 0.71 -105.83 2.12


Constants Off-DiagonalConstants Off-Diagonal

000 010 Constant Value MHz Uncert. value MHz Uncert.(B-C)/4 20223.7099 0.0054 21847.898 0.037d0,1 0.290463 0.000076 -1.30469 0.00077d1,0 11.1647 0.0065 -33.3475 0.0253d0,2x106 -6.71 0.36 298.1 5.4d1,1 0.014551 0.000091 0.020002 0.000245d2,0 0.36413 0.00115 1.1499 0.0033d0,3x106 0 fixed -0.0729 0.0115d1,2x103 -0.02597 0.00044 -0.06538 0.00063d2,1x103 0.0329 0.0097 0.0758 0.0261d3,0x103 -0.657 0.07 -10.111 0.094d1,3x109 9.1 8.0 0 fixedd2,2x106 0.4639 0.0273 0.882 0.056d2,3x106 2.103 0.256 -3.509 0.256d4,0x106 -0.03824 0.00214 -0.05619 0.00155d5,0x106 0.271 0.034 0.1335 0.0148


ConclusionsConclusions

51 Transitions of HD18O were measured to microwave accuracy

Approximately 70 lines of suspicious accuracy were identified in the infrared data set

One local perturbation involving 000 K=11 and 010 K=4 was identified at J=15 and J=16

Transitions frequencies for the ground state of HD18O can be calculated to microwave accuracy for J<10, K<7.


AcknowledgementAcknowledgement

This research was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. NASA support for Herschel Heterodyne Instrument for Far Infrared guaranteed time holders is gratefully acknowledged.

© 2011 California Institute of Technology all rights reserved

Documents

Molecular Spectroscopy Symposium 2011 20-25 June 2011 ROTATIONAL SPECTROSCOPY OF HD 18 O John C. Pearson, Shanshan Yu, Harshal Gupta, and Brian J. Drouin,