Submillimeter-wave lines of H 2 D + and D 2 H + as probes into chemistry in cold dark clouds

Submillimeter-wave lines ofSubmillimeter-wave lines ofHH22DD++ and D and D22HH++ as probes into as probes into

chemistry in cold dark cloudschemistry in cold dark clouds

T. Amano

Institute for Astrophysics and Planetary Sciences

Ibaraki University

In this talkIn this talk

Overview of spectroscopy of D2H+ 　 and H2D+

TuFIR lines of H2D+

H5+ and its deuterated species

Spectroscopy of HSpectroscopy of H22DD++ and D and D22HH++

Shy, Farley, Wing (1981): Ion beam Shy, Farley, Wing (1981): Ion beam Amano & Watson (1984), Amano (1985): Amano & Watson (1984), Amano (1985): 11 band (H band (H22DD++))

Lubic & Amano (1984): Lubic & Amano (1984): 11 band (D band (D22HH++) )

Foster et al. (1986): Foster et al. (1986): 2 2 / /3 3 bands (Hbands (H22DD++))

Foster, McKellar, Watson. (1986): Foster, McKellar, Watson. (1986): 2 2 / /3 3 bands (Dbands (D22HH++ ) )

Polyansky & McKellar (1990): All available data were fitted togetPolyansky & McKellar (1990): All available data were fitted together to improve molecular constants. (Dher to improve molecular constants. (D22HH++) )

Amano & Hirao, J. Mol. Spectrosc. 233, 7 (2005)

IR

Bogey et al. (1984): 1Bogey et al. (1984): 11010-1-11111 H H22DD++ (372.4 GHz) (372.4 GHz)

Warner et al.(1984): Warner et al.(1984): Saito, Kawaguchi, Hirota (1985): 2Saito, Kawaguchi, Hirota (1985): 22020-2-22121 H H22DD++ (156.0 GHz) (156.0 GHz)

Jennings, Demuynck, Banek, Evenson (unpublished): Jennings, Demuynck, Banek, Evenson (unpublished):

110101-0-00000 H H22DD+ + (1370.1 GHz) (1370.1 GHz)

111111-0-00000 D D22HH++ (1476.6 GHz) (1476.6 GHz)

222020-2-21111 D D22HH++ (1370.1 GHz) (1370.1 GHz)

Hirao & Amano (2003): 1Hirao & Amano (2003): 11010-1-10101 D D22HH++ (691.7 GHz) (691.7 GHz)

Amano & Hirao (2005): 3Amano & Hirao (2005): 32121-3-32222 H H22DD++ (646.4 GHz) (646.4 GHz)

mm-, sub-mm, FIR

Theoretical workTheoretical work

Carney and Porter(1977)Carney and Porter(1977)

Tennyson, Polyansky and coworkers carried Tennyson, Polyansky and coworkers carried out very high level out very high level ab initioab initio calculations, an calculations, and interactions between theory and experimed interactions between theory and experiments were often very crucial in assigning the nts were often very crucial in assigning the spectra and in deriving the accurate spectrosspectra and in deriving the accurate spectroscopic constants .copic constants .

See for example, Polyansky and Tennyson, See for example, Polyansky and Tennyson, JCPJCP,,110110, 50, 5056(1999)56(1999)

Ibaraki sub-mm systemIbaraki sub-mm system

Russian BWO(Backward-wave oscillator)

270-860 GHz ~1 mW

stabilized, using double phase-lock loop

Double modulation technique frequency-discharge

frequency-magnetic field

extended negative glow discharge

Double modulation sub-mm system at Ibaraki(University of Waterloo)

Submillimeter-wave system in Ibaraki

Extended negative glow discharge source.Extended negative glow discharge source. (Magnetic field: 200G).(Magnetic field: 200G).

Double modulation.Double modulation. HH22/D/D22/Ar = 4 /2 /17 mTorr/Ar = 4 /2 /17 mTorr 　　　　 for Hfor H22DD++

=3 /2 /17 mTorr for D=3 /2 /17 mTorr for D22HH++

I = 8 mA, T ~ 77 KI = 8 mA, T ~ 77 K

Experimental DetailsExperimental Details

Ap.J. Lett. 597, L85-L87(2003). 691660.440(20) MHz

TuFIR Spectrometer ( Toyama University )

Energy Level Diagram of HEnergy Level Diagram of H22DD++

Energy Level Diagram of HEnergy Level Diagram of H22DD++

Hyperfine structure of H2D+ and D2H+

Jensen et al. Mol. Phys. 91, 319(1997)H2D+

D2H+

H2D+

Yamaguchi, Gaw, Remington, Schaefer.J. Chem. Phys. 80, 5072(1987)

H5+

Xie, Braams, Bowman. J. Chem. Phys.122,224307(2005)

1-C2v

2-D2d

3-C2v

4-D2h

4 low energy conformers of H5+

Financial support

•Ministry of Education, Science, and Culture of Japan•Japan Society for Promotion of Science(JSPS)•Japan Space Forum(JSF)•JEM/SMILES Project