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J/A+A/608/A144     Strongly lensed submm galaxies CO spectra       (Yang+, 2017)

Molecular gas in the Herschel-selected strongly lensed submillimeter galaxies at z∼2.4 as probed by multi-J CO lines. Yang C., Omont A., Beelen A., Gao Y., van der Werf P., Gavazzi R., Zhang Z.-Y., Ivison R., Lehnert M., Liu D., Oteo I., Gonzalez-Alfonso E., Dannerbauer H., Cox P., Krips M., Neri R., Riechers D., Baker A.J., Michalowski M.J., Cooray A., Smail I. <Astron. Astrophys. 608, A144 (2017)> =2017A&A...608A.144Y (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra; Interstellar medium; Millimetric/submm sources Keywords: galaxies: high-redshift - galaxies: ISM - infrared: galaxies - submillimeter: galaxies - radio lines: ISM - ISM: molecules Abstract: We present the IRAM-30m observations of multiple-J CO (Jup mostly from 3 up to 8) and [CI](3P2 -> 3P1) ([CI](2-1) hereafter) line emission in a sample of redshift ∼2-4 submillimeter galaxies (SMGs). These SMGs are selected among the brightest lensed galaxies discovered in the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS). 47 CO lines and 7 [CI](2-1) lines have been detected in 15 lensed SMGs. A non-negligible effect of differential lensing is found for the CO emission lines, which could have caused significant underestimations of the linewidths, hence of the dynamical masses. The CO spectral line energy distributions (SLEDs), peaking around Jup∼5-7, are found to be similar to those of the local starburst-dominated ultra-luminous infrared galaxies and of the previously studied SMGs. After correcting for lensing amplification, we derived the global properties of the bulk of molecular gas in the SMGs using non-LTE radiative transfer modelling, such as the molecular gas density nH2∼102.5-104.1cm-3 and the kinetic temperature Tk∼20-750K. The gas thermal pressure P_{th} ranging from ∼105K/cm3 to 106K/cm3 is found to be correlated with star formation efficiency. Further decomposing the CO SLEDs into two excitation components, we find a low-excitation component with nH2∼102.8-104.6cm-3 and Tk∼20-30K, which is less correlated with star formation, and a high-excitation one (nH2∼102.7-104.2cm-3, Tk∼60-400K) which is tightly related to the on-going star-forming activity. Additionally, tight linear correlations between the far-infrared and CO line luminosities have been confirmed for the Jup≥5 CO lines of these SMGs, implying that these CO lines are good tracers of star formation. The [CI](2-1) lines follow the tight linear correlation between the luminosities of the [CI](2-1) and the CO(1-0) line found in local starbursts, indicating that [CI] lines could serve as good total molecular gas mass tracers for high-redshift SMGs as well. The total mass of the molecular gas reservoir, (1-30)x1010M, derived based on the CO(3-2) fluxes and αCO(1-0)=0.8M/(K.km/s/pc^2), suggests a typical molecular gas depletion time tdep∼20-100Myr and a gas to dust mass ratio δGDR∼30-100 with ∼20%-60% uncertainty for the SMGs. The ratio between CO line luminosity and the dust mass L'CO(1-0)/M_{dust} appears to be slowly increasing with redshift for high-redshift SMGs, which CO need to be further confirmed by a more complete SMG sample at various redshifts. Finally, through comparing the linewidth of CO and H2O lines, we find that they agree well in almost all our SMGs, confirming that the emitting regions of the CO and H2O lines are co-spatially located. Description: The FITS file of the 1D spectra of the CO lines from IRAM-30m observations are presented. The data files are corresponding to Table 2 in the paper. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file list.dat 98 55 List of spectra sp/* 0 55 Individual fits spectra
See also: J/A+A/595/A80 : H2O lines reduced spectra in 11 ULIRGs or HyLIRGs (Yang+, 2016) Byte-by-byte Description of file: list.dat
Bytes Format Units Label Explanations
1- 2 I2 h RAh Right Ascension (J2000) 4- 5 I2 min RAm Right Ascension (J2000) 7- 12 F6.3 s RAs Right Ascension (J2000) 14 A1 --- DE- Declination sign (J2000) 15- 16 I2 deg DEd Declination (J2000) 18- 19 I2 arcmin DEm Declination (J2000) 21- 25 F5.2 arcsec DEs Declination (J2000) 27- 29 I3 --- Nx Number of pixels along X-axis 31 I1 Kibyte size Size of FITS file 33- 54 A22 --- FileName Name of FITS file, in subdirectory sp 56- 98 A43 --- Title Title of the FITS file
Acknowledgements: Chentao Yang, yangcht(at)pmo.ac.cn
(End) C. Yang [PMO, China; IAS & IAP, France], P. Vannier [CDS] 18-Sep-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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