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J/ApJ/691/1560      Dense core survey in the Orion B cloud        (Ikeda+, 2009)
A survey of dense cores in the Orion B cloud.
    Ikeda N., Kitamura Y., Sunada K.
   <Astrophys. J., 691, 1560-1582 (2009)>
   =2009ApJ...691.1560I
ADC_Keywords: Surveys ; Molecular clouds ; Radio lines ;
              Millimetric/submm sources ; Interstellar medium
Keywords: ISM: clouds - ISM: individual (Orion B) - stars: formation


Abstract:
    We have carried out an H13CO+(J=1-0 at 86.75433GHz) core survey 
    in a large area of 1deg2, covering most of the dense region in the
    Orion B molecular cloud, using the Nobeyama 45m radio telescope with
    the 25-BEam Array Receiver System. We cataloged 151 dense cores using
    the clumpfind method. The cores have mean radius, velocity width, and
    mass of 0.10±0.02pc, 0.53±0.15km/s, and 8.1±6.4M☉,
    respectively, which are very similar to those in the Orion A cloud. We
    examined the spatial relation between our H13CO+ cores and the
    850um cores observed by Johnstone and colleagues in 2001 (Cat.
    J/ApJ/559/307) and 2006 (Cat. J/ApJ/639/259), and found that there are
    two types of spatial relationships: H13CO+ cores with and without
    the 850um cores. Since the mean density of the 850um cores is higher
    than that of the H13CO+ cores, we can interpret the H13CO+
    cores with 850um cores as being more centrally concentrated and hence
    more evolved, compared with those without.

Description:
    All of our observations have been carried out with the Nobeyama 45m
    radio telescope in the period from 2004 December to 2006 May.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        72      151   Physical properties of the H13CO+ cores in
                             the Orion B cloud
table4.dat        45       64   How the 850um cores are associated with the
                             H13CO+ cores in the Orion B cloud


See also:
   J/ApJ/665/1194 : Dense cores in the Orion A cloud survey (Ikeda+, 2007)
   J/ApJ/639/259  : Sub-mm clumps in Orion B South molecular cloud (Johnstone+,
                    2006)
   J/ApJ/559/307  : Sub-mm mapping in Orion B molecular cloud (Johnstone+, 2001)


Byte-by-byte Description of file: table1.dat

   Bytes Format Units   Label     Explanations

   1-  3  I3    ---     ID        H13CO+ (86.754GHz) core identification 
                                 (<[IKS2009] H13CO+ NNN> in Simbad)
       5  I1    h       RAh       Hour of right ascension (J2000)
   7-  8  I2    min     RAm       Minute of right ascension (J2000)
  10- 11  I2    s       RAs       Second of right ascension (J2000)
      13  A1    ---     DE-       Declination sign (J2000)
      14  I1    deg     DEd       Degree of declination (J2000)
  16- 17  I2    arcmin  DEm       Arcminute of declination (J2000)
  19- 22  F4.1  arcsec  DEs       Arcsecond of declination (J2000)
  24- 27  F4.1  km/s    VLSR      LSR velocity of H13CO+ core (86.754GHz)
  29- 31  F3.1  K       Tpk       Peak T*A temperature
  33- 36  F4.1  arcsec  Rad       Core radius in arcsec (1)
  38- 41  F4.2  pc      Radp      Core radius in parsec (1)
  43- 46  F4.2  km/s    dV        Core velocity width (1)
  48- 51  F4.1  Msun    MLTE      LTE core mass (1)(2)
  53- 56  F4.1  K       Tex       Excitation temperature
  58- 61  F4.1  Msun    Mvir      Virial mass (1)
  63- 66  F4.2 10+4cm-3 n         Mean number density of the core (1)
  68- 72  F5.3 10pc2.m/s Vol      Observed volume of the core (Ω_obs_) in
                                 10-2pc2.km/s unit (1)

Note (1): The typical uncertainty of each quantity is:
    Rad = 0.04pc, derived from the uncertainty in the estimation of the
          core projected area
    dV  = 0.13km/s, corresponding to the velocity resolution
   MLTE = a factor of 3 (see text)
   Mvir = a factor of 3, derived from the uncertainties in Rad and dv
      n = a factor of 4, derived from the uncertainties in Rad and MLTE
    Vol = 0.5x10-2pc2km/s, derived from the uncertainties in Rad and dv
Note (2): MLTE as in equation (5) of Paper I (Ikeda et al., 2007,
          Cat. J/ApJ/665/1194)


Byte-by-byte Description of file: table4.dat

   Bytes Format Units   Label     Explanations

   1-  3  I3    ---     ID        Core identification (<[IKS2009] H13CO+ NNN>
                                  in Simbad)
   5-  6  A2    ---     Type      [AB' ] Type of H^13^CO^+^ core (1)
   8- 19  A12   ---     LocPk     Name of the 850um core located at the
                                  H13CO+ peak (HHMMmm+DDMMm) (2)
  21- 32  A12   ---     NotPk1    Name of the 850um core not at the H^13^CO^+^
                                  peak (HHMMmm+DDMMm) (2)
  34- 45  A12   ---     NotPk2    Name of the second 850um core not at the
                                  H13CO+ peak (HHMMmm+DDMMm) (2)

Note (1): Types as follows:
    A  = cores whose H13CO+ emission peak coincides with a peak of the 850um
         continuum emission. There are 35 Type A cores.
    A' = cores whose peak coincides with a 850um peak, where one or more 850um
         cores are located within the projected extent of the H13CO+ core.
         There are 12 Type A' cores.
    B  = H13CO+ cores do not contain any 850um counterparts. There are 45
         Type B cores.
    B' = cores whose H13CO+ emission peak does not coincide with any 850um
         peak, but where one or more 850um peaks are found within the H13CO+
         core. There are 17 Type B' cores.
Note (2): The 850um cores are <[IKS2009] SMM JHHMMmm+DDMMm> in Simbad and
     come from Johnstone et al. (2001, Cat. J/ApJ/559/307 -
     <[JFM2001] SMM JHHMMmm+DDMMm> in Simbad- and 2006, Cat. J/ApJ/639/259,
     <[JMM2006] SMM JHHMMmm+DDMMm> in Simbad).


History:
    From electronic version of the journal

References:
    Ikeda et al. Paper I. 2007ApJ...665.1194I Cat. J/ApJ/665/1194
(End)                                     Emmanuelle Perret [CDS]    24-Feb-2011