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J/A+A/357/1001      The λ-Orionis ring in CO         (Lang+ 2000)
The λ-Orionis ring in CO.
    Lang W.J., Masheder M.R.W., Dame T.M., Thaddeus P.
   <Astron. Astrophys. 357, 1001 (2000)>
   =2000A&A...357.1001L
ADC_Keywords: Molecular clouds ; Radio lines

Keywords: ISM: clouds - Galaxy: structure - radio lines: ISM - ISM: molecules -
          ISM: bubbles

Description:
    The table shows clump parameters for 130 peaks in CO(J=1->0) emission
    detected in the Lambda-Orionis ring in the survey of Lang et al.
    (1998PASA...15...70L). The clumps were isolated using the Clumpfind
    algorithm of Williams et al. (1994, Cat. J/ApJ/428/693). They are
    ordered and labelled according to the relative brightness of the peak
    temperatures within them, so clump 1 contains the emission maximum,
    but not necessarily the maximum W(CO) or largest mass.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table2.dat        75      130   Clump parameters
table2.tex       101      201   LaTeX version of table 2


Byte-by-byte Description of file: table2.dat

   Bytes Format Units   Label     Explanations

   1-  3  I3    ---     LMD2000   [1/130] Clump sequential number
   5- 11  F7.3  deg     GLON      Galactic longitude
  13- 19  F7.3  deg     GLAT      Galactic latitude
  21- 25  F5.2  km/s    Vel       Centroid velocity of the clump emission
  27- 31  F5.2  K       Tmax      Maximum brightness temperature within the peak
  33- 36  F4.2  pc      Dl        Approximate FWHM clump dimension in longitude
  38- 41  F4.2  pc      Db        Approximate FWHM clump dimension in latitude
  43- 46  F4.2  pc      R         Effective clump radius, R=sqrt(area/π)
  48- 51  F4.2  km/s    DVel      Average FWHM linewidth
  53- 58  F6.1  solMass MCO       CO mass estimates (1)
  60- 66  F7.2  solMass Mvir      Virial mass estimates (2)
  68- 75  A8    ---     Complex   Section of the ring in which the clump
                                    is to be found (See fig. 2)

Note (1): We define M(CO) as the molecular cloud mass derived
    on the assumption that the velocity-integrated CO intensity, W(CO), 
    is directly proportional to the H2 column density. Here we use the
    conversion factor: 
    X=N(H2)/W(CO)=1.1*1020 (molecules/cm2)/(K.km/s).
Note (2): We define the virial mass such that virial equilibrium
    between kinetic energy and potential energy would be satisfied, with
    Mvir=k*R*(Δv)2, where R is the effective radius of the cloud
    and Δv the FWHM of the CO emission. Here k is a constant of
    proportionality which depends weakly on the assumed radial density
    profile of clouds. For uniform density, k=210 in the units used here.


Acknowledgements: M.R.W. Masheder 

(End)                                       Patricia Bauer  [CDS]    04-Sep-2000