Transcript Columbus-C3.ppt

The 68th International Symposium on Molecular Spectroscopy
The ‘4050 Å Group’ of
the A1Πu-X1Σg+ Transition System of C3
D. Zhao, H. Linnartz
Sackler Laboratory for Astrophysics, Leiden Observatory, University of Leiden, the Netherlands;
M.A. Haddad, W. Ubachs
Department of Physics and Astronomy, LaserLaB,VU University Amsterdam, the Netherlands;
M.R. Schmidt
Department of Astrophysics, N. Copernicus Astronomical Center, ul. Rabiańska 8, 87-100 Toruń, Poland;
J. Krełowski
Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, 87-100 Toruń, Poland;
G. Galazutdinov
Instituto de Astronomia, Universidad Catolica del Norte, Chile.
Columbus June 19, 2013
Outline
 Introduction
 UVES-VLT detection of vibronic bands of C3
in diffuse translucent clouds
 Laboratory experiment
 Electronic spectra of
(12)C
3
in 375-410 nm
 The electronic origin band of 13C substituted C3
isotopologues
The 4050Å group of cometary spectra
Wavelength (Angstrom)
• Emitter identified as C3 by Douglas in 1951;
• Electronic transition assigned to the A1Πu-X1Σg+ transition upon detailed
rovibrational analysis by Gausset et al. in 1965.
C3 in the interstellar medium
 Not accessible to radio astronomy because of the lack of a
permanent dipole moment.
 Detected in the (dense) interstellar medium or circumstellar shells
via ro-vibrational transitions in mid-/far-infrared.
 In the diffuse interstellar medium, C3 was discovered via the
observations of the A1Πu-X1Σg+ 000-000 band at 4051.6 Å in
absorption towards reddened stars.
 These observations serve as a remote diagnostic of the physicalchemical conditions in translucent interstellar clouds
Spectra of C3 in translucent
sightlines
(Maier et al. ApJ, 2001, 553, 267;
Ádámkovics et al., ApJ, 2003, 595, 235;)
(See also:
Haffner et al., ApJ, 1995, 453, 450;
Galazudinov et al., A&A, 2002, 395, 969;
Roueff et al., A&A, 2002, 384, 629;
Oka et al., ApJ, 2003, 582, 823;
…)
Detection of vibronic bands of C3 in
translucent interstellar clouds
 UVES-VLT
 Seven
vibronic bands of C3 in
addition to the 000-000 band, are
detected at high resolution towards
HD 169454.
 Four of them are also detected
towards HD 73882 and HD 154368.
 Accurate laboratory data on these
observed bands are still required.
M.R. Schmidt, J. Krelowski, G.A. Galazutdinov, D. Zhao,
M.A. Haddad, W. Ubachs, H. Linnartz, submitted (2013).
Relative line intensities in the 000-000 band
UVES-VLT
(Schmidt et al. 2013)
CRDS by McCall et al. (2003)
Digitized spectra (Gausset et al. 1965)
Fluorescence: Zhang et al. (2005)
Laboratory experiment
 Pulsed cavity ring-down spectroscopy
 Pulsed planar plasma source
 375 -410 nm
 Spectral resolution of ~ 0.05 cm-1
 Wavelength precision better than 0.04 cm-1
New laboratory data, combined with previously reported data,
allow us to build a highly precise line list, and to support the
analysis of the observed C3 bands towards HD 169454.
The 000-000 origin band
Strong discharge
(spectral pattern similar with McCall et al. 2003)
Unreliable line intensities in the band origin
region due to laser-linewidth effect in CRDS.
Weaker discharge
Arrows: perturber lines that have been discussed by Zhang et al. (2005)
are observed towards HD 169464.
The 000-000 origin band
Column densities and
excitation temperature
The effective Hamiltonian including perturber components in the A1Πu state is
•improved significantly based the new laboratory data, and
•used to derive the columdensities of C3.
M. R. Schmidt, J. Krelowski, G.A. Galatzutdinov,
D. Zhao, M.A. Haddad, W. Ubachs, H. Linnartz,
MNRAS, submitted
Other vibronic bands
The A1Πu-X1Σg+ 000-000 band of C3 isotopologues:
laboratory study
13C
3
13C
2H2/He/Ar
Plasma
Haddad, Zhao, Linnartz, Ubachs, in prep. (2013).
The A1Πu-X1Σg+ 000-000 band of C3 isotopologues
Haddad, Zhao, Linnartz, Ubachs, in prep. (2013).
Molecular constants of C3 isotopologues
12C12C13C
13C12C13C
12C13C12C
12C13C13C
13C13C13C
T00
24677.78 (4)
24680.05(4)
24684.30(4)
24686.64 (4)
24688.99(4)
B"
0.413743a
0.39832(86)
0.430276a
0.4143(12)
0.397024a
B'
0.39718(52)
0.38179(71)
0.4123(10)
0.39734(65)
0.380720(96)
q' ×10-4
--
--
--
--
2.01(28)
D"×10-6
1.398a
1.220c
1.30a
1.398b
1.220a
D'×10-6
0.504b
0.440b
0.470b
0.504b
0.440b
1.042
1.043
1.043
1.042
1.043
B"/B'
a
Values taken from previouos mid-infrared work.
b Values fixed in the fits.
Haddad, Zhao, Linnartz, Ubachs, in prep. (2013).
Conclusion
 High resolution detection of the vibronic bands of C3 in the
diffuse translucent clouds towards HD 169454, HD 154368,
HD 73882.
 A laboratory re-examination of the C3 vibronic bands
observed towards HD 169454.
 A systematic laboratory investigation on the A1Πu-X1Σg+
000-000 electronic origin band of
isotopologues.
13C-substituted
C3
ACKNOWLEDGEMENTS
Collaborators (observers)
 Prof. dr. J. Krełowski (Poland)
 Dr. M.R. Schmidt (Poland)
 Prof. dr. G. Galazutdinov
(Chile)
Technical Support
 Mr. J. Bouma (Amsterdam)
Financial support in the Netherlands:
• NWO-VICI
• NOVA
• FOM
• Templetion Fundation
• Dutch Astrochemistry Network.