High resolution spectroscopy and perturbation analysis of the CO A1Π −X1Σ+ (0,0) and (1,0) bands

Niu, Mei; Salumbides, E. J.; Zhao, Dongfeng; Oliveira, N. de; Joyeux, D.; Nahon, Laurent; Field, Robert W.; Ubachs, Wim

doi:10.1080/00268976.2013.793889

Cited by 31 publications

(76 citation statements)

References 32 publications

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“…We used the updated molecular data summarised in Daprà et al (2016). Accurate wavelengths were obtained through calibration by laser and VUV synchrotron studies (Salumbides et al 2012;Niu et al 2013Niu et al , 2015, while oscillator strengths and damping constants were carefully re-evaluated taking into account an updated perturbation analysis. We did not consider the ν = 5 AX system, which was completely blended with the extended Si ivλ1393 absorption.…”

Section: Carbon Monoxidementioning

confidence: 99%

Discovery of a Perseus-like cloud in the early Universe

Noterdaeme

Krogager

Balashev

et al. 2017

A&A

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We present the discovery of a molecular cloud at z abs ≈ 2.5255 along the line of sight to the quasar SDSS J 000015.17+004833.3. We use a high-resolution spectrum obtained with the Ultraviolet and Visual Echelle Spectrograph together with a deep multi-wavelength medium-resolution spectrum obtained with X-shooter (both on the Very Large Telescope) to perform a detailed analysis of the absorption lines from ionic, neutral atomic and molecular species in different excitation levels, as well as the broad-band dust extinction.We find that the absorber classifies as a Damped Lyman-α system (DLA) with log N(H i) (cm −2 ) = 20.8 ± 0.1. The DLA has supersolar metallicity (Z ∼ 2.5 Z , albeit to within a factor of two to three) with a depletion pattern typical of cold gas and an overall molecular fraction f = 2N(H 2 )/(2N(H 2 ) + N(H i)) ∼ 50%. This is the highest f -value observed to date in a high-z intervening system. Most of the molecular hydrogen arises from a clearly identified narrow (b ∼ 0.7 km s −1 ), cold component in which carbon monoxide molecules are also found, with log N(CO) ≈ 15. With the help of the spectral synthesis code Cloudy, we study the chemical and physical conditions in the cold gas. We find that the line of sight probes the gas deep after the H i-to-H 2 transition in a ∼4−5 pc-size cloud with volumic density n H ∼ 80 cm −3 and temperature of only 50 K. Our model suggests that the presence of small dust grains (down to about 0.001 µm) and high cosmic ray ionisation rate (ζ H ∼ a few times 10 −15 s −1 ) are needed to explain the observed atomic and molecular abundances. The presence of small grains is also in agreement with the observed steep extinction curve that also features a 2175 Å bump. Interestingly, the chemical and physical properties of this cloud are very similar to what is seen in diffuse molecular regions of the nearby Perseus complex, despite the former being observed when the Universe was only 2.5 Gyr old. The high excitation temperature of CO rotational levels towards J0000+0048 betrays however the higher temperature of the cosmic microwave background. Using the derived physical conditions, we correct for a small contribution (0.3 K) of collisional excitation and obtain T CMB (z = 2.53) ≈ 9.6 K, in perfect agreement with the predicted adiabatic cooling of the Universe.

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Section: Carbon Monoxidementioning

confidence: 99%

Discovery of a Perseus-like cloud in the early Universe

Noterdaeme

Krogager

Balashev

et al. 2017

A&A

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“…A similar methodology as in previous works [19,20] is used in the present analysis of the perturbations affecting the A 1 (0) state of 13 C 16 O. Using the Pgopher software [47], we simulate all measured transition frequencies with the same effective Hamiltonian model previously adopted in Ref.…”

Section: Perturbation Analysismentioning

confidence: 99%

“…The frequency chirp between the PDA output and cw seed laser is measured on-line, yielding an average chirp offset that is included in the frequency calibration. For further details on the two-photon Doppler-free laser experiments on CO, we refer to previous publications [18,19].…”

Section: Laser Experimentsmentioning

confidence: 99%

“…Further experimental and analytical details of the VUV-FT spectra are provided in Refs. [18][19][20].…”

Section: Vuv-ft Synchrotron Experimentsmentioning

confidence: 99%

“…[14][15][16][17]). Recently, the spectrum of A 1 −X 1 + in 12 C 16 O was reinvestigated by Doppler-free laser methods [18] and vacuum-ultraviolet Fourier-transform (VUV-FT) spectroscopy [19,20], both at high resolution. The A 1 −X 1 + system of the 13 C 16 O isotopologue was investigated in detail by Haridass and Huber [14], after the observation of unresolved band heads by Tilford and Simmons [9].…”

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Spectroscopy and perturbation analysis of the A¹π (v=0) state of ¹³ C¹⁶ O

et al. 2016

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The lowest v = 0 level of the A 1 state of the 13 C 16 O isotopologue of carbon monoxide has been reinvestigated with a variety of high-resolution spectroscopic techniques. The A 1 −X 1 + (0, 0) band has been studied by vacuum-ultraviolet Fourier-transform absorption spectroscopy, using the SOLEIL synchrotron as a radiation source. Spectra were obtained under quasi-static gas conditions at liquidnitrogen temperature, room temperature and at an elevated temperature of 900 K, with absolute accuracies of 0.01−0.03 cm −1 . Two-photon Doppler-free laser spectroscopy has been applied to a limited number of transitions in the A 1 −X 1 + (0, 0) band, under collision-free circumstances of a molecular beam, yielding an absolute accuracy of 0.002 cm −1 . The third technique is high-resolution Fourier-transform emission spectroscopy in the visible region applied to the B 1 + −A 1 (0, 0) band in a gas discharge, at an absolute accuracy of up to 0.003 cm −1 . With these methods, rotational levels of A 1 (0) could be studied in both parity components up to a rotational quantum number of J = 46. The frequencies of 397 transitions were used to analyse the perturbations between the A 1 (0) level by vibrational levels of the D 1 , e 3 − , d 3 , and a 3 + states.

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Efficiency of a compact CO2 coaxial plasma torch driven by ultrafast microwave power pulsing: Stability and plasma gas flow dynamics

Soldatov

Carbone

Kühn

et al. 2022

Journal of CO2 Utilization

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High resolution spectroscopy and perturbation analysis of the CO A¹Π −X¹Σ⁺ (0,0) and (1,0) bands

Cited by 31 publications

References 32 publications

Discovery of a Perseus-like cloud in the early Universe

Discovery of a Perseus-like cloud in the early Universe

Spectroscopy and perturbation analysis of the A¹π (v=0) state of ¹³ C¹⁶ O

Efficiency of a compact CO2 coaxial plasma torch driven by ultrafast microwave power pulsing: Stability and plasma gas flow dynamics

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High resolution spectroscopy and perturbation analysis of the CO A1Π −X1Σ+ (0,0) and (1,0) bands

Cited by 31 publications

References 32 publications

Discovery of a Perseus-like cloud in the early Universe

Discovery of a Perseus-like cloud in the early Universe

Spectroscopy and perturbation analysis of the A1π (v=0) state of 13 C16 O

Efficiency of a compact CO2 coaxial plasma torch driven by ultrafast microwave power pulsing: Stability and plasma gas flow dynamics

Contact Info

Product

Resources

About

High resolution spectroscopy and perturbation analysis of the CO A¹Π −X¹Σ⁺ (0,0) and (1,0) bands

Spectroscopy and perturbation analysis of the A¹π (v=0) state of ¹³ C¹⁶ O