J/ApJ/714/476 Complete spectrum of ethyl cyanide (Fortman+, 2010)
A new approach to astrophysical spectra: the complete experimental spectrum of
ethyl cyanide (CH3CH2CN) between 570 and 645 GHz.
Fortman S.M., Medvedev I.R., Neese C.F., De Lucia F.C.
<Astrophys. J., 714, 476-486 (2010)>
=2010ApJ...714..476F 2010ApJ...714..476F
ADC_Keywords: Atomic physics ; Spectroscopy ; Interstellar medium
Keywords: astronomical databases: miscellaneous - ISM: molecules -
molecular data - submillimeter: ISM - techniques: spectroscopic
Abstract:
There is a general consensus that many of the unidentified features
in astrophysical spectra are due to low lying excited vibrational and
torsional states of a few molecules -commonly referred to as the
astrophysical weeds. This is a challenging spectroscopic problem not
only because there are many such states, but also because these states
are often highly perturbed and difficult to analyze. We have
previously described an alternative approach based on experimental,
intensity-calibrated spectra taken at many temperatures. In this
paper, we describe the procedures and results obtained with this
approach for ethyl cyanide, strategies for archiving and disseminating
these results, and the prospects for using these results to reduce the
confusion limit in the powerful new observatories that are coming
online.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 36 3355 Astrophysical catalogue in strength - lower state
energy format
table3.dat 20 272 Spectroscopic temperature and nL/Q parameter for
each of the 271 scans, with the 0 index
representing the theoretical 77K spectrum used in
the analyses
table4.dat 18 1200000 Spectroscopically determined Sijµ2 and E
coefficients
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See also:
J/ApJS/184/133 : New ground-state measurements of ethyl cyanide (Brauer+, 2009)
J/ApJS/181/433 : Spectrum of ethyl formate (Medvedev+, 2009)
J/A+A/493/565 : Deuterated and 15N ethyl cyanides (Margules+, 2009)
J/A+A/466/255 : Isotopic ethyl cyanide (Demyk+, 2007)
http://www.splatalogue.net/ : Splatalogue home page (database for astronomical
spectroscopy)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 F10.3 MHz Fqu [570103/644962] Frequency
12- 19 E8.2 D2 Sijmu2 Sijµ2 coefficient (G1)
21- 25 I5 cm-1 E E coefficient (G1)
27- 36 A10 --- FoM Figures of Merit
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Index [0/271] Index of the temperature scan
5- 13 E9.3 nm-2 nL/Q Corresponding (nL/Q) factor
15- 20 F6.2 K T Spectroscopic Temperature
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 D2 Sijmu2 Sijµ2 coefficient (G1)
11- 18 F8.3 cm-1 E E coefficient (G1)
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Global Notes:
Note (G1):
The coefficients are defined in Eqs. (9) and (10), and represent
the lower state energy (E) and the line strength (<Sij>µ2).
Table4 contains 1.2 million pairs of Sijµ2 and E coefficients,
as a function of the frequency starting at 570GHz (570000.0MHz) and
incrementing in steps of 0.0625MHz, covering therefore the frequency
range 570-645GHz.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Apr-2012