Global fit of rotational transitions of methyl formate (HCOOCH3) in the ground and first excited torsional states

Ogata, Kazumi; Odashima, Hitoshi; Takagi, Kojiro; Tsunekawa, Shozo

doi:10.1016/j.jms.2004.02.004

Cited by 30 publications

(63 citation statements)

References 16 publications

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“…Chronologically the measurements carried out for the ground torsional state (v t = 0) were performed in the spectral range 8-58 GHz (Bauder 1979), 150-313 GHz (Demaison et al 1983), 216-506 GHz (Plummer et al 1984), 200-352 GHz (Plummer et al 1986), 250-510 GHz (Oesterling et al 1999), 7-200 GHz (Karakawa et al 2001), 567-669 GHz (Carvajal et al 2007), and 110-380 GHz (Maeda et al 2008a). In 2003 and 2004, a number of transitions were analyzed for the first time in the first excited torsional state v t = 1 (Odashima et al 2003;Ogata et al 2004). In 2007, 4270 transition lines covering the spectral range up to 669 GHz (with J max = 62, K max = 22 for v t = 0; and J max = 18, K max = 7 for v t = 1) were globally analyzed using the RAM or Rho-Axis Method (Lin & Swalen 1959;Herbst et al 1984;Hougen et al 1994).…”

Section: Introductionmentioning

confidence: 99%

Rotational spectrum of¹³C₂-methyl formate (HCOO¹³CH₃) and detection of the two¹³C-methyl formate in Orion

Carvajal¹,

Margulès

Tercero

et al. 2009

A&A

116

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Context. Laboratory measurements and analysis of the microwave and millimeter-wave spectra of potential interstellar molecules are a prerequisite for their subsequent identification by radioastronomical techniques. The spectral analysis provides spectroscopic parameters that are used in the assignment procedure of the laboratory spectra, and that also predict the frequencies of transitions not measured in the laboratory with a high degree of precision.Aims. An experimental laboratory study and its theoretical analysis is presented for 13 C 2 -methyl formate (HCOO 13 CH 3 ) allowing a search for this isotopologue in the Orion molecular cloud. The 13 C 1 -methyl formate (H 13 COOCH 3 ) molecule was also searched for in this interstellar cloud, using previously published spectroscopic data. Methods. The experimental spectra of 13 C 2 -methyl formate were recorded in the microwave and sub-mm energy ranges (4-20 GHz, 8-80 GHz, 150-700 GHz). The spectra were analyzed using the Rho-Axis Method (RAM), which takes the CH 3 internal rotation and the coupling between internal rotation and global rotation into account. Results. Twenty-seven spectroscopic constants of 13 C 2 -methyl formate have been obtained from a fit of 936 transitions of the ground torsional state with a standard (unitless) deviation of 1.08. A prediction of line positions and intensities is also produced. This prediction allowed us to identify 230 13 C 2 -methyl formate lines in the Orion interstellar molecular cloud. We refitted all previously published ground state transitions of the 13 C 1 -methyl formate molecule in order to provide a prediction of its ground state spectrum. 234 lines of 13 C 1 -methyl formate were detected in the Orion interstellar cloud using that prediction.

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Section: Introductionmentioning

confidence: 99%

Rotational spectrum of¹³C₂-methyl formate (HCOO¹³CH₃) and detection of the two¹³C-methyl formate in Orion

Carvajal¹,

Margulès

Tercero

et al. 2009

A&A

116

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“…Following Curl (1959), numerous spectroscopic studies of its rotational 1 Also Departments of Astronomy and Chemistry. spectrum were undertaken for normal methyl formate (Brown et al 1975;Bauder 1979;Demaison et al 1983;Plummer et al 1984Plummer et al , 1986Oesterling et al 1999;Karakawa et al 2001;Odashima et al 2003;Ogata et al 2004). The most recent studies (Odashima et al 2003;Ogata et al 2004) have extended the analysis to include the first excited torsional state.…”

Section: Introductionmentioning

confidence: 99%

“…Besides our study of 13 C 1 -methyl formate, we have remeasured the rotational spectrum of normal methyl formate in the 110Y377 GHz region with the FASSST spectrometer. Newly measured and remeasured lines were analyzed together with previous data ( Bauder 1979;Demaison et al 1983;Plummer et al 1984Plummer et al , 1986Oesterling et al 1999;Ogata et al 2004) with the same effective rotational Hamiltonian approach used for 13 C 1 -methyl formate.…”

Section: Introductionmentioning

confidence: 99%

The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State

Maeda

Medvedev

Lucia

et al. 2008

ASTROPHYS J SUPPL S

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A large number of rotational transitions of 13 C 1 -methyl formate in its ground A and E torsional substates were measured in the 110Y380 GHz region with the Fast Scan Submillimeter Spectroscopic Technique (FASSST). Besides strong a-type transitions, many b-type transitions through rotational quantum numbers J 00 ¼ 59 and K 00 a ¼ 16 were newly measured, and some forbidden c-and x-type transitions in the E substate were also assigned. The new lines were analyzed together with previous submillimeter-wave data using an effective rotational-torsional Hamiltonian method designated ''ERHAM'' developed for a molecule with one or two internal rotors. In total, over 4900 transitions of 13 C 1 -methyl formate were analyzed. Systematic deviations due to perturbations were found in Q-branch transitions at high J, and higher order Coriolis-type interaction terms were included to fit the data better. A standard deviation of 86 kHz was obtained by varying 33 parameters. In addition to 13 C 1 -methyl formate, the normal isotopologue was studied anew and some high-K a transitions were newly assigned. The previous data of the normal species in the ground state were reanalyzed with the ERHAM method together with new transitions measured in the present study. The same deviations in Q-branch transitions, not observed in previous studies, were also found in the normal species. Using spectroscopic parameters obtained in this study, predictions have been made for many strong lines of 13 C 1 -methyl formate through 620 GHz in frequency not analyzed in the fit.

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“…Since its discovery in Sgr B2 (Brown et al 1975;Churchwell et al 1975), extensive spectroscopic studies have been carried out for the main species (Bauder 1979;Demaison et al 1983;Plummer et al 1984Plummer et al , 1986Oesterling et al 1999;Karakawa et al 2001;Ogata et al 2004;Carvajal et al 2007;Maeda et al 2008b;Ilyushin et al 2009;Full Tudorie et al 2012;Kobayashi et al 2013) and for its isotopologs (Curl 1959;Oesterling et al 1995;Willaert et al 2006;Maeda et al 2008a,b;Margulès et al 2009Margulès et al , 2010Carvajal et al 2009Carvajal et al , 2010Coudert et al 2012Coudert et al , 2013Tercero et al 2012;Haykal et al 2014). This spectroscopic database for the methyl formate molecule has given rise to an increasing identification of the spectral lines in different interstellar surveys.…”

Section: Introductionmentioning

confidence: 99%

THz extended spectrum of the monodeuterated methyl formate (DCOOCH₃)

Duan

Carvajal

et al. 2015

A&A

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Context. Laboratory spectral recordings and an accurate molecular spectral analysis of any potential interstellar molecule are essential for generating a complete spectroscopic line list. This permits predicting the frequencies and intensities of any transition so that subsequently, it can be identified in the interstellar medium. Aims. Our analysis of DCOOCH 3 aims to provide a comprehensive spectral catalog that encompasses as much as possible the frequency coverage of the new-generation far-IR and submillimeter wave observation facilities. Methods. We newly measured the rotational spectrum of DCOOCH 3 in the laboratory of the Jet Propulsion Laboratory in the frequency range of 0.85 to 1.5 THz. We jointly analyzed the new data with literature data using the rho axis method, which is a tool developed for the spectral analysis of molecules with large-amplitude internal CH 3 rotors. Results. We fit 27 spectroscopic constants of DCOOCH 3 to 3763 transitions with highest values of J = 69 and K a = 36 of the ground torsional state with a standard (unitless) deviation of 0.97. With respect to previous work, this is a significantly better result that was obtained with 2060 more transitions, and we also achieved a better accuracy for the new parameter values.

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Global fit of rotational transitions of methyl formate (HCOOCH3) in the ground and first excited torsional states

Cited by 30 publications

References 16 publications

Rotational spectrum of¹³C₂-methyl formate (HCOO¹³CH₃) and detection of the two¹³C-methyl formate in Orion

Rotational spectrum of¹³C₂-methyl formate (HCOO¹³CH₃) and detection of the two¹³C-methyl formate in Orion

The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State

THz extended spectrum of the monodeuterated methyl formate (DCOOCH₃)

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Global fit of rotational transitions of methyl formate (HCOOCH3) in the ground and first excited torsional states

Cited by 30 publications

References 16 publications

Rotational spectrum of13C2-methyl formate (HCOO13CH3) and detection of the two13C-methyl formate in Orion

Rotational spectrum of13C2-methyl formate (HCOO13CH3) and detection of the two13C-methyl formate in Orion

The Millimeter‐ and Submillimeter‐Wave Spectrum of13C1‐Methyl Formate (H13COOCH3) in the Ground State

THz extended spectrum of the monodeuterated methyl formate (DCOOCH3)

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Resources

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Rotational spectrum of¹³C₂-methyl formate (HCOO¹³CH₃) and detection of the two¹³C-methyl formate in Orion

Rotational spectrum of¹³C₂-methyl formate (HCOO¹³CH₃) and detection of the two¹³C-methyl formate in Orion

The Millimeter‐ and Submillimeter‐Wave Spectrum of¹³C₁‐Methyl Formate (H¹³COOCH₃) in the Ground State

THz extended spectrum of the monodeuterated methyl formate (DCOOCH₃)