VIII/66 IRAM observations in pre-star forming regions (Falgarone+ 1998-2001)
IRAM key-project ``Small-scale structure of pre-star forming regions''
I. Observational results
Falgarone E., Panis J.-F., Heithausen A., Perault M., Stutzki J.,
Puget J.-L., Bensch F.
<Astron. Astrophys. 331, 669 (1998)>
=1998A&A...331..669F 1998A&A...331..669F
III. Influence of and correction for the error beam pick-up
Bensch F., Panis J.-F., Stutzki J., Heithausen A., Falgarone E.
<Astron. Astrophys. 365, 275 (2001)>
=2001A&A...365..275B 2001A&A...365..275B
ADC_Keywords: Radio lines ; Carbon monoxide
Keywords: turbulence - methods: data analysis - techniques: miscellaneous -
radio lines: ISM - line: profiles - ISM: kinematics and dynamics -
ISM: clouds - ISM: molecules
Description:
The goal of the IRAM key-project ``Small-scale structure of pre-star
forming regions'' is to map three nearby (d∼150pc), quiescent
molecular clouds with a high angular and spectral resolution to study
the molecular cloud structure down to the smallest linear scales
currently accessible by single dish radio telescopes.
The key-project maps are available as data cubes (velocity, right
ascension or galactic longitude, declination or galactic latitude)
available as a set of 40 FITS files stored in the fits subdirectory;
a summary of these 40 files is contained in the file "list.dat". The
observations reported concern the molecular clouds L1512, L134A, and
MCLD 123.5+24.9 in the Polaris Flare.
The released data set of the IRAM key-project (Falgarone et al.,
1998A&A...331..669F 1998A&A...331..669F) are error beam corrected using the beam pattern
parameters published by Garcia-Burillo, Guelin and Cernicharo
(1993A&A...274..123G 1993A&A...274..123G) and observations made with the KOSMA 3m
telescope. Bensch et al. (2001A&A...365..275B 2001A&A...365..275B) present the corrected
maps using the 30m beam pattern recently published by Greve et al.
(1998A&AS..133..271G 1998A&AS..133..271G). They estimate the accuracy of the maps of the
key-project as 10-15% for the CO(2-1), except for two 13CO(2-1) maps
of the MCLD 123.5+24.9/Polaris Flare and of L1512 where the
uncertainties are estimated to 22% and 18% respectively. For the
CO(1-0) data, the overall accuracy is 11%.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 171 40 List of data
fits/* . 40 FITS files (IRAM & KOSMA)
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Common properties of the data cubes stored in the 'fits' subdirectory:
* Data is in fits format.
* Orientation of the data cube is
(1) velocity [m/s],
(2) spatial coord 1,
(3) spatial coord 2;
For Polaris Flare/MCLD 123.5+24.9 the spatial coordinates are galactic
longitude/latitude; for L1512 and L134A the spatial coordinates are
RA/Dec (J1950)
Properties of IRAM data (datafiles with a digit in the second byte):
* the intensities are in units of Tmb,c (corrected main beam brightness
temperature scale; Bensch, F., Heithausen, A., Stutzki, J., in prep.)
* the effective velocity resolution is
85m/s for the CO(1-0) data and
43m/s for the CO(2-1) data
* the sampling is 7"5x7"5 for all maps (square grid)
* the angular resolution is
22arcmin for the CO(1-0) data and
13.5arcmin for the CO(2-1) data
The digit in the second byte takes the values:
1 : the released data set of the IRAM key-project (Paper I)
3 : the data set presented in paper III.
Properties of KOSMA observations (datafiles with 'k' in the second byte):
(used to correct for the error beam pick-up in the IRAM key-project data)
* the intensities are in units of TA* (antenna temperature), EXCEPT for
the 12CO(1-0) observations of the Polaris Flare/MCLD 123.5+24.9,
which is in Tmb (main beam brightness temperature). The latter map
is published by Grossmann et al., 1990A&A...240..400G 1990A&A...240..400G.
* For the KOSMA CO(2-1) observations, a main beam efficiency of
Beff=0.62 and Feff=0.91 was applied (Beff, Feff follow the
definition by Downes, A., 1989, "Introductory courses in Galaxies",
Springer Verlag, Lecture Notes in Physics 333, 351).
* The main beam HPBW of the telescope is:
234arcsec (for the observations at 115 GHz)
132arcsec (observations at 220/230 GHz)
This information (temperature scale, efficiency, HPBW) also appears
in the header of the FITS files.
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- FITSfile FITS cube filename, in "fits" subdirectory (1)
14- 25 A12 --- Obs Observatory name
27- 40 A14 --- Name Source name
42- 50 A9 --- Line Line designation
52- 62 F11.4 MHz Freq Central frequency
64- 70 F7.4 MHz Step Frequency step
72- 74 I3 --- Nv Number of velocity points
75 A1 --- --- [x]
76- 78 I3 --- N1 Number of RA (or longitude) points
79 A1 --- --- [x]
80- 82 I3 --- N2 Number of Dec (or latitude) points
84- 91 F8.1 m/s Vmin Minimal velocity
93- 99 F7.1 m/s Vmax Maximal velocity
101-105 F5.1 m/s Vstep Velocity resolution
107 A1 --- Orient [RG] Orientation along RA/DE (R) or Galactic (G)
109-116 F8.4 deg Amin RA or GLON minimum
118-125 F8.4 deg Amax RA or GLON maximum
127-131 F5.1 arcsec Astep RA or GLON step
133-140 F8.4 deg Dmin DE or GLAT minimum
142-149 F8.4 deg Dmax DE or GLAT maximum
151-155 F5.1 arcsec Dstep DE or GLAT step
157-164 F8.4 deg Amed Median RA or GLON
165-172 F8.4 deg Dmed Median DE or GLAT
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Note (1): The names of the FITS files use the following conventions:
- the first character is 'a' for L134A, 'b' for L1512, and 'p' for
the Polaris flare/MCLD 123.5+24.9
- the second character is
'1' for the released data set of the IRAM key-project (paper I)
'3' for the IRAM data set presented in Paper III
'k' for the KOSMA data
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Acknowledgements: Frank Bensch
(End) Patricia Bauer [CDS] 26-Sep-2000