Jun 23, 2011 - Marie-Aline Martin-Drumel,. Olivier Pirali, Didier Balcon & Michel Vervloet ..... Dressler & Ramsay, Ph. Trans. Roy. Soc. London 251 (1959).
The NH2 Radical
Experimental Work
Analysis
High resolution Far Infrared Fourier Transform Spectroscopy of the NH2 Radical Marie-Aline Martin-Drumel, Olivier Pirali, Didier Balcon & Michel Vervloet Institut des Sciences Moléculaires d’Orsay (ISMO) SOLEIL synchrotron - AILES beamline
66th International Symposium on Molecular Spectroscopy
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
1
The NH2 Radical
Experimental Work
Analysis
ESO/APEX & MSX/IPAC/NASA
Astrophysical Background
1st detection towards SgrB2 Van Dishoek et al., Astrophys. J. 416 (1993)
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
2
The NH2 Radical
Experimental Work
Analysis
ESO/APEX & MSX/IPAC/NASA
Astrophysical Background
1st detection towards SgrB2 Van Dishoek et al., Astrophys. J. 416 (1993)
Recently detected by Herschel (HIFI) towards G10.6-0.4 (W31) Persson et al., A&A 521 (2010) M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
2
The NH2 Radical
Experimental Work
Analysis
State of the Art
NH2 : extensively studied from the sub-mm to the UV
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
3
The NH2 Radical
Experimental Work
Analysis
State of the Art
NH2 : extensively studied from the sub-mm to the UV Sub-mm / THz / FIR Müller et al., J. Mol. Spect. 195 (1999)
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
3
The NH2 Radical
Experimental Work
Analysis
State of the Art
NH2 : extensively studied from the sub-mm to the UV Sub-mm / THz / FIR Müller et al., J. Mol. Spect. 195 (1999)
FIR Fourier transform spectroscopy (one study up to date): Morino & Kawaguchi et al., J. Mol. Spect. 182 (1997)
R=0.007 cm−1 Absorption spectroscopy in the ground vibrational state 200 pure rotational transitions reported (Nmax =12)
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
3
The NH2 Radical
Experimental Work
Analysis
State of the Art
NH2 : extensively studied from the sub-mm to the UV Sub-mm / THz / FIR Müller et al., J. Mol. Spect. 195 (1999)
FIR Fourier transform spectroscopy (one study up to date): Morino & Kawaguchi et al., J. Mol. Spect. 182 (1997)
R=0.007 cm−1 Absorption spectroscopy in the ground vibrational state 200 pure rotational transitions reported (Nmax =12) Objective
High resolution and high temperature
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
3
The NH2 Radical
Experimental Work
Analysis
Spectroscopy of the NH2 Radical
˜ 2 B1 Electronic: fundamental state X
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
4
The NH2 Radical
Experimental Work
Analysis
Spectroscopy of the NH2 Radical
˜ 2 B1 Electronic: fundamental state X Vibrational: 3N − 6 = 3 vibration modes (ν1 , ν2 , ν3 ) Symmetric stretching
Bending
Asymmetric stretching
ν1 = 3219cm−1
ν2 = 1497cm−1
ν3 = 3301cm−1
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
4
The NH2 Radical
Experimental Work
Analysis
Spectroscopy of the NH2 Radical
˜ 2 B1 Electronic: fundamental state X Vibrational: 3N − 6 = 3 vibration modes (ν1 , ν2 , ν3 ) Symmetric stretching
Bending
Asymmetric stretching
ν1 = 3219cm−1
ν2 = 1497cm−1
ν3 = 3301cm−1
Rotational: Asymmetric top rotor Hund’s case (b) Rotational quantum numbers: N, Ka , Kc (000), (010): b-type transitions M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
4
The NH2 Radical
Experimental Work
Analysis
Rotational Structure
N, Ka Ka =0...N
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
5
The NH2 Radical
Experimental Work
Analysis
Rotational Structure
Asymmetric Splitting
Kc =N−Ka
N, Ka Ka =0...N Kc =N+1−Ka
Ka + Kc = N or N + 1
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
5
The NH2 Radical
Experimental Work
Analysis
Rotational Structure
Asymmetric Splitting Fine Structure J=N−1/2 F2 Kc =N−Ka
N, Ka
J=N+1/2 F1
Ka =0...N Kc =N+1−Ka
Spin Rotation Coupling
M.A. Martin-Drumel
Ka + Kc =
~J = N ~ + ~S
N or N + 1
S=1/2 (2 B1 )
FIR spectroscopy of NH2
June 23, 2011
5
The NH2 Radical
Experimental Work
Analysis
Rotational Structure
Asymmetric Splitting Fine Structure Hyperfine Structure F1 =J−1
J=N−1/2
F1 =J
F2
F1 =J+1
Kc =N−Ka
N, Ka
J=N+1/2
Ka =0...N
F1
F1 =J+1 F1 =J F1 =J−1
Kc =N+1−Ka
Ka + Kc = N or N + 1
M.A. Martin-Drumel
Spin Rotation Coupling
Nuclear spin Rotation Coupling
~J = N ~ + ~S
F~1 = ~J + I~N
2
S=1/2 ( B1 )
FIR spectroscopy of NH2
IN =1 (14 N)
June 23, 2011
5
The NH2 Radical
Experimental Work
Analysis
Rotational Structure
Asymmetric Splitting Fine Structure Hyperfine Structure F1 =J−1
J=N−1/2
F1 =J
F2
F1 =J+1
Kc =N−Ka
N, Ka
J=N+1/2
Ka =0...N
F1
F1 =J+1 F1 =J F1 =J−1
Kc =N+1−Ka
Ka + Kc = ∆N=0,±1 ∆Ka =0,±1 M.A. Martin-Drumel
Spin Rotation Coupling
Nuclear spin Rotation Coupling
~J = N ~ + ~S
F~1 = ~J + I~N
N or N + 1
S=1/2 ( B1 )
IN =1 (14 N)
∆Kc =0,±1
F1 ↔F2
∆F1 =0,+1
2
FIR spectroscopy of NH2
June 23, 2011
5
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Experimental Set-ups Emission Interferometer Spectral range Precursor Discharge Power Pressure Light Source Resolution Accuracy (l.p.) Length Rot. temp.
M.A. Martin-Drumel
Absorption Bruker IFS 125 15-700 cm−1 NH3
RF 1000 W ∼10 mbar plasma 4·10−3 cm−1 < 5·10−4 cm−1 (12 MHz) 0.7 m 2500 K
DC 1-3 kV, 0.6-2 A ∼0.1 mbar (+ 2 mbar He) SR 1·10−3 cm−1 < 1·10−4 cm−1 (3 MHz) 24 m 300 K
FIR spectroscopy of NH2
June 23, 2011
6
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Experimental Set-ups Emission Interferometer Spectral range Precursor Discharge Power Pressure Light Source Resolution Accuracy (l.p.) Length Rot. temp.
M.A. Martin-Drumel
Absorption Bruker IFS 125 15-700 cm−1 NH3
RF 1000 W ∼10 mbar plasma 4·10−3 cm−1 < 5·10−4 cm−1 (12 MHz) 0.7 m 2500 K
DC 1-3 kV, 0.6-2 A ∼0.1 mbar (+ 2 mbar He) SR 1·10−3 cm−1 < 1·10−4 cm−1 (3 MHz) 24 m 300 K
FIR spectroscopy of NH2
June 23, 2011
6
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Experimental Set-ups Emission Interferometer Spectral range Precursor Discharge Power Pressure Light Source Resolution Accuracy (l.p.) Length Rot. temp.
M.A. Martin-Drumel
Absorption Bruker IFS 125 15-700 cm−1 NH3
RF 1000 W ∼10 mbar plasma 4·10−3 cm−1 < 5·10−4 cm−1 (12 MHz) 0.7 m 2500 K
DC 1-3 kV, 0.6-2 A ∼0.1 mbar (+ 2 mbar He) SR 1·10−3 cm−1 < 1·10−4 cm−1 (3 MHz) 24 m 300 K
FIR spectroscopy of NH2
June 23, 2011
6
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Experimental Set-ups Emission Interferometer Spectral range Precursor Discharge Power Pressure Light Source Resolution Accuracy (l.p.) Length Rot. temp.
M.A. Martin-Drumel
Absorption Bruker IFS 125 15-700 cm−1 NH3
RF 1000 W ∼10 mbar plasma 4·10−3 cm−1 < 5·10−4 cm−1 (12 MHz) 0.7 m 2500 K
DC 1-3 kV, 0.6-2 A ∼0.1 mbar (+ 2 mbar He) SR 1·10−3 cm−1 < 1·10−4 cm−1 (3 MHz) 24 m 300 K
FIR spectroscopy of NH2
June 23, 2011
6
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Experimental Set-ups Emission Interferometer Spectral range Precursor Discharge Power Pressure Light Source Resolution Accuracy (l.p.) Length Rot. temp.
M.A. Martin-Drumel
Absorption Bruker IFS 125 15-700 cm−1 NH3
RF 1000 W ∼10 mbar plasma 4·10−3 cm−1 < 5·10−4 cm−1 (12 MHz) 0.7 m 2500 K
DC 1-3 kV, 0.6-2 A ∼0.1 mbar (+ 2 mbar He) SR 1·10−3 cm−1 < 1·10−4 cm−1 (3 MHz) 24 m 300 K
FIR spectroscopy of NH2
June 23, 2011
6
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Resolution of the Asymmetric Splitting
4
Transmission
3
2
6
1
61
5
6 50
60
5
51
(F1-F1)
0
150 MHz
saturation level
previous assignment (unresolved) Morino & Kawaguchi 1997
-1 260.17
260.18
260.19
260.20
260.21
260.22
260.23
260.24
-1
Wavenumber (cm )
⋆ Absorption: Resolution of the asymmetric splitting for several new lines M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
7
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Resolution of the Fine Structure 8
Transmission
6
4
7
17
¬
6
06
F2-F2
F1-F1 2
J'=7.5
J'=6.5
J''=6.5
J''=5.5
0
previous assignment (unresolved)
110 MHz
Morino & Kawaguchi 1997
122.89
122.90
122.91
122.92
122.93
122.94
122.95
-1
Wavenumber (cm )
⋆ Absorption: Resolution of the fine structure for several new lines M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
8
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Resolution of the
14
N Hyperfine Structure
8
4
Transmission
6
3
22
13 J''=2.5)
(F2-F2, J'=3.5
4
F' =2.5
F'' =1.5
F' =3.5
F'' =2.5
1
1
1
1
F' =4.5 1
40 MHz
F'' =3.5 1
50 MHz
2
previous assignment (unresolved)
Morino & Kawaguchi 1997 152.72
152.73
152.74
152.75
152.76
-1
Wavenumber (cm )
⋆ Absorption: Resolution of the hyperfine structure for several new lines M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
9
The NH2 Radical
Experimental Work
Analysis
Experimental Set-ups Observed Spectra
Transition Involving Excited Energy Levels
(000) 9
37
F1-F1
200.7
200.8
200.9
(010) 5
8
42
26
F2-F2
201.0
4
F2-F2
F1-F1
201.1
208.1
208.2
31
208.3
208.4
208.5
208.6
-1
Wavenumber (cm )
⋆ Emission: Pure rotational transitions within (000) and ν2 = 1 M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
10
The NH2 Radical
Experimental Work
Analysis
Analysis (in progress)
Use of the SPFIT/SPCAT suite Pickett et al., J. Mol. Spect. (1991)
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
11
The NH2 Radical
Experimental Work
Analysis
Analysis (in progress)
Use of the SPFIT/SPCAT suite Pickett et al., J. Mol. Spect. (1991)
Fit: pure rotational transitions within (000) 684 previously reported transitions (0-2 THz ∼ 0-60 cm−1 ) Müller et al., J. Mol. Spect. 195 (1999)
∼ 700 transitions observed at Soleil (20-700 cm−1 ) Watson’s A-reduced rotational Hamiltonian (Ir representation) IR RMS=1.1·10−3 cm−1 RMS ERROR=1.58
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
11
The NH2 Radical
Experimental Work
Analysis
Fit Fit 1
Fit 2
Fit 3
1191 lines (507 SOLEIL) Nmax = 12 (Ka = 3) Kamax = 9 (N = 9) 73 parameters
1365 lines (681 SOLEIL) Nmax = 24 (Ka = 2) Kamax = 9 (N = 13) 86 parameters
1385 lines (701 SOLEIL) Nmax = 24 (Ka = 2) Kamax = 11 (N = 13) 86 parameters
IR RMS=0.00029 cm−1 RMS ERROR=1.66
IR RMS=0.00075 cm−1 RMS ERROR=1.49
IR RMS=0.00112 cm−1 RMS ERROR=1.58
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
12
The NH2 Radical
Experimental Work
Analysis
Fit Fit 1
Fit 2
Fit 3
1191 lines (507 SOLEIL) Nmax = 12 (Ka = 3) Kamax = 9 (N = 9) 73 parameters
1365 lines (681 SOLEIL) Nmax = 24 (Ka = 2) Kamax = 9 (N = 13) 86 parameters
1385 lines (701 SOLEIL) Nmax = 24 (Ka = 2) Kamax = 11 (N = 13) 86 parameters
IR RMS=0.00029 cm−1 RMS ERROR=1.66
IR RMS=0.00075 cm−1 RMS ERROR=1.49
IR RMS=0.00112 cm−1 RMS ERROR=1.58
Light molecule: anormal centrifugal distorsion Renner-Teller effect Dressler & Ramsay, Ph. Trans. Roy. Soc. London 251 (1959)
Unidentified transitions within (000) and (010)... M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
12
The NH2 Radical
Experimental Work
Analysis
Rotational and Centrifugal Distortion Constants (MHz) Parameter A B C ∆K ∆NK ∆N δK δN ΦK · 103 ΦKN · 103 ΦNK · 103 ΦN · 103 φK · 103 φNK · 103 φN · 103 LK · 106 LNNK · 106 LN · 106 LNK · 106 LKKN · 106 lK · 106 lKN · 106 lNK · 106 lN · 106 PK · 106 SK · 106 M.A. Martin-Drumel
Present 710 302.011 4(104) 388 289.646 8(113) 245 013.373 9(70) 659.752 41(262) -125.142 86(169) 31.686 89(50) 29.751 6(38) 12.709 480(182) 1 991.01(34) -283.00(46) -49.337(121) 13.069 4(128) 539.25(37) -15.742( 53) 6.506 1(59) -10 626.3(162) 63.68(139) -9.846(135) -1 045.4(66) 3 882.4(179) -4 646.3(161) 72.0(32) 3.889(256) -4.891(67) 44.16(41) -0.119 4(38)
Müller et al. 710 302.131 9(250) 388 288.871 8(1491) 245 013.954 4(1316) 659.765 23(1561) -125.045 19(1631) 31.664 38(428) 29.375 5(761) 12.701 85(208) 1 991.49(350) -267.88(472) -48.98(139) 12.518 3(1195) 490.64(778) -18.655(1194) 6.294 3(432) -10 156.(278) 70.39(1281) -4.786(792) -736.9(1070) 2 472.(290) -2 501.(208) 44.3(432) 45.87(818) -3.043(295) 49.01(426) -0.184 4(299)
FIR spectroscopy of NH2
June 23, 2011
13
Conclusion Complement of NH2 database
∼ 500 new transitions identified in (000)
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
14
Conclusion Complement of NH2 database
∼ 500 new transitions identified in (000) Emission: Observation of transitions involving excited energy levels (000) Nmax = 24 (Ka = 2) et Kamax = 12 (N = 24) (010) (in progress)
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
14
Conclusion Complement of NH2 database
∼ 500 new transitions identified in (000) Emission: Observation of transitions involving excited energy levels (000) Nmax = 24 (Ka = 2) et Kamax = 12 (N = 24) (010) (in progress)
Absorption: High resolution and accuracy on line position 1st resolution of the rotational splitting for ∼ 40 transitions // (asymmetric splitting (10), fine (10) and hyperfine (20) structures) Improvement on line position accuracy for lines already reported (< 3MHz/ ∼ 1 · 10−4 cm−1 )
M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
14
Study of the
15
NH2 Isotope
Investigations on
14 N/15 N
ratio
Objectives: Observation of pure rotational transitions of the
15
NH2 radical
Identification on Herschel spectra ?
Collaboration: Astrophysicians: OBSPM, Evelyne Roueff; LRA, Maryvonne Gerin PhLAM: Laurent Margulès, Stéphane Bailleux ISMO-SOLEIL: Olivier Pirali, Marie-Aline Martin-Drumel
The THz Cosmos, June 24, Laurent Margulès (FA06, 10h27) M.A. Martin-Drumel
FIR spectroscopy of NH2
June 23, 2011
15
