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J/A+A/600/A16      Six LMC star forming region spectra             (Tang+, 2017)

Kinetic temperature of massive star forming molecular clumps measured with formaldehyde. II. The Large Magellanic Cloud. Tang X.D., Henkel C., Chen C.-H.R., Menten K.M., Indebetouw R., Zheng X.W., Esimbek J., Zhou J.J., Yuan Y., Li D.L., He Y.X. <Astron. Astrophys. 600, A16 (2017)> =2017A&A...600A..16T (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; H II regions ; Spectroscopy Keywords: star formation - Magellanic Clouds - ISM: clouds - ISM: molecules - radio lines: ISM Abstract: The kinetic temperature of molecular clouds is a fundamental physical parameter affecting star formation and the initial mass function. The Large Magellanic Cloud (LMC), the closest star forming galaxy with low metallicity, provides an ideal laboratory to study star formation in such an environment. The classical dense molecular gas thermometer NH3 is rarely available in a low metallicity environment because of photoionization and a lack of nitrogen atoms. Our goal is to directly measure the gas kinetic temperature with formaldehyde toward six star-forming regions in the LMC. Three rotational transitions (JKAKC = 303-202, 322-221, and 321-220) of para-H2CO near 218GHz were observed with the Atacama Pathfinder EXperiment (APEX) 12m telescope toward six star forming regions in the LMC. Those data are complemented by C18O 2-1 spectra. Description: Our observations were carried out in 2008 and 2014 (summarized in Table 1) with the Atacama Pathfinder EXperiment (APEX) 12m telescope located on Chajnantor (Chile) using the APEX-1 (SHeFI) receiver. The beam size is ∼30" (∼7pc at 50kpc distance) at 218GHz. The main beam efficiency and the forward efficiency were 0.75 and 0.97, respectively. N113 and N159W were observed in 2008 with an old Fast Fourier Transform Spectrometer (FFTS), which consists of two units with a bandwidth of 1 GHz each and a velocity resolution of 0.1675km/s. The frequency is centered at 218.480GHz. Our data includes all three of the 218GHz para-H2CO lines. 30 Dor, N159E, N159S, and N44BC were observed in 2014. Here we used the new eXtended bandwidth Fast Fourier Transform Spectrometer (XFFTS) backend with two spectral windows of 2.5GHz bandwidth and a velocity resolution of 0.1047km/s. The central frequency is set at 218.550GHz. These data do not only include the three para-H2CO lines but also the 219.560GHz C18O (2-1) transition. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 49 6 Source parameters table2.dat 73 23 Para-H2CO and C18O spectral parameters table3.dat 90 6 Integrated intensity ratios, column densities, spacial densities and temperatures list.dat 142 22 List of fits spectra fits/* 0 22 Individual fits spectra
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Source Source name 9- 10 I2 h RAh Right ascension (J2000) 12- 13 I2 min RAm Right ascension (J2000) 15- 18 F4.1 s RAs Right ascension (J2000) 20 A1 --- DE- declination sign (J2000) 21- 22 I2 deg DEd declination (J2000) 24- 25 I2 arcmin DEm declination (J2000) 27- 30 F4.1 arcsec DEs declination (J2000) 32- 34 I3 min Tint Integrated time 36- 49 A14 --- Date Observation date
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Source Source name 9- 14 A6 --- Mol Molecule 16- 28 A13 --- Trans Transition 30 A1 --- l_intTmbdv Limit flag on intTmbdv 31- 35 F5.3 intTmbdv Velocity-integrated intensity 37- 41 F5.3 e_intTmbdv ? rms uncertainty on intTmbdv (1) 43- 48 F6.2 km/s Vlsr ?=- LSR velocity 50- 53 F4.2 km/s e_Vlsr ? rms uncertainty on Vlsr (1) 55- 58 F4.2 km/s FWHM ?=- Full width to half maximum line width 60- 63 F4.2 km/s e_FWHM ? rms uncertainty on FWHM (1) 65- 69 F5.3 K Tmb ?=- Peak mean brightness temperature 71- 73 F3.1 mk rms rms noise
Note (1): standard deviations from Gaussian fits using CLASS as part of the GILDAS software.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Source Source name 8 A1 --- n_Source [ab] Note on Source (1) 10 A1 --- l_R1 Limit flag on R1 11- 15 F5.3 --- R1 321-220/303-202 ratio 17- 20 F4.2 --- e_R1 ? rms uncertainty on 321-220/303-202 ratio 22- 25 F4.2 --- R2 H2CO 303-202/C18O 2-1 ratio 27- 30 F4.2 --- e_R2 rms uncertainty on H2CO 303-202/C18O 2-1 ratio 32- 34 F3.1 10+14cm-2 NC18O C18O column density 36- 38 F3.1 10+12cm-2 NpH2CO Para-H2CO column density 40- 42 F3.1 10+22cm-2 NH2a H2 column density from C18O 44- 46 F3.1 10+22cm-2 NH2b H2 column density from 12CO(1-0) 48 A1 --- l_nH2 Limit flag on nH2 49- 52 F4.2 10+5cm-3 nH2 H2 density number 54- 57 F4.2 10+5cm-3 E_nH2 ? Error on nH2 (upper value) 59- 62 F4.2 10+5cm-3 e_nH2 ? Error on nH2 (lower value) 64 A1 --- l_Tkin Limit flag on Tkin 65- 68 F4.1 K Tkin Kinematic temperature derived with the density n(H2) 70- 73 F4.1 K E_Tkin ? Error on Tkin (upper value) 75- 78 F4.1 K e_Tkin ? Error on Tkin (lower value) 80 A1 --- l_TLTE Limit flag on TLTE 81- 84 F4.1 K TLTE LTE temperature 86- 90 A5 K Tdust Interval of dust temperature (2)
Note (1): Notes as follows: a = N113: Para-H2CO 303-202/C18O 2-1 ratio data taken from Heikkila et al. (1998A&A...332..493H) and Wang et al. (2009ApJ...690..580W) N(C18O) derived from C18O 2-1 taken from Heikkila et al. (1998A&A...332..493H). b = N159W: Para-H2CO 303-202/C18O 2-1 ratio data taken from Heikkila et al. (1998A&A...332..493H, 1999A&A...344..817H). N(C18O) derived from C18O 2-1 taken from Heikkila et al. (1998A&A...332..493H). N(H2) data taken from Ott et al. (2010ApJ...710..105O). Note (2): Dust temperature references: 30 Dor = Werner et al. (1978MNRAS.184..365W); Heikkila et al. (1999A&A...344..817H); Gordon et al. (2014ApJ...797...85G) N113 = Wang et al. (2009ApJ...690..580W); Gordon et al. (2014ApJ...797...85G); Seale et al. (2014, Cat. J/AJ/148/124) N44BC = Gordon et al. (2014ApJ...797...85G) N159W = Heikkila et al. (1999A&A...344..817H); Bolatto et al. (2000ApJ...545..234B); Gordon et al. (2014ApJ...797...85G) N159E = Gordon et al. (2014ApJ...797...85G) N159S = Gordon et al. (2014ApJ...797...85G)
Byte-by-byte Description of file: list.dat
Bytes Format Units Label Explanations
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000) 10- 18 F9.5 deg DEdeg Declination of center (J2000) 20- 23 I4 --- Nx Number of points 25- 47 A23 --- Obs.Date Observation date (YYYY-MM-DDThh:mm:ss.sss) 49- 60 E12.6 Hz b_Freq Lower value of relative frequency interval 62- 72 E11.6 Hz B_Freq Upper value of relative frequency interval 74- 79 I6 Hz dFreq Frequency resolution 81- 82 I2 Kibyte size Size of FITS file 84-105 A22 --- FileName Name of FITS file, in subdirectory fits 107-142 A36 --- Title Title of the FITS file
Acknowledgements: Xindi Tang, xdtang(at)
(End) Patricia Vannier [CDS] 06-Jan-2017
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