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J/ApJS/160/450   X-ray emission in Orion Nebula young stars   (Flaccomio+, 2005)
Rotational modulation of X-ray emission in Orion Nebula young stars.
    Flaccomio E., Micela G., Sciortino S., Feigelson E.D., Herbst W.,
    Favata F., Harnden F.R.JR, Vrtilek S.D.
   <Astrophys. J. Suppl. Ser., 160, 450-468 (2005)>
   =2005ApJS..160..450F
ADC_Keywords: X-ray sources ; Clusters, open ; Stars, pre-main sequence ;
              Equivalent widths
Keywords: open clusters and associations: individual (Orion Nebula Cluster) -
          stars: activity - stars: low-mass, brown dwarfs -
          stars: pre-main-sequence - X-rays: stars

Abstract:
    We investigate the spatial distribution of X-ray-emitting plasma in 
    a sample of young Orion Nebula Cluster stars by modulation of their
    X-ray light curves due to stellar rotation. The study, part of the
    Chandra Orion Ultradeep Project (COUP, Cat. J/ApJS/160/319), is made
    possible by the exceptional length of the observation: 10 days of ACIS
    integration during a time span of 13 days, yielding a total of 1616
    detected sources in the 17'x17' field of view. We here focus on a
    subsample of 233 X-ray-bright stars with known rotational periods. We
    search for X-ray modulation using the Lomb Normalized Periodogram
    method.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        60      295   COUP sources with assigned rotational period.


See also:
  J/AJ/113/1733  : Orion Nebula Cluster population (Hillenbrand 1997)
  J/A+A/396/513  : Stellar Rotation in the Orion Nebula Cluster (Herbst+, 2002)
  J/AJ/117/2941  : Rotation periods of Orion PMS stars (Stassun+, 1999)
  J/AJ/121/3160  : JHK photometry near the Trapezium region (Carpenter+, 2001)
  J/ApJS/160/319 : COUP: observations and source lists (Getman+, 2005)
  J/ApJ/582/382  : Chandra X-ray sources in Orion Nebula Cluster
                                                             (Flaccomio+, 2003)


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

   Bytes Format Units     Label      Explanations

   1-  4  I4    ---       COUP       The COUP source number
   6- 10  I5    ct        Cts        Net (background subtracted) ACIS counts
  12- 16  I5    ---       OptId      ? Optical identification (1)
      17  A1    ---       m_OptId    [ab] Multiplicity indicator (1)
  19- 23  F5.2  d         Per        Optically determined rotation period
      25  A1    ---       n_Per      Note on Per (2)
  27- 30  A4    ---       r_Per      Reference for Per (3)
  32- 36  F5.2  solMass   Mass       ? Stellar mass
  38- 40  F3.1  [yr]      LogAge     ? Log of the stellar age
  42- 45  F4.1  [10-7W]   LogLx      ? Log of the X-ray luminosity in erg/s
  47- 50  F4.1  [-]      Log(Lx/Lb)  ? Log of the X-ray to bolometric
                                       luminosity ratio
  52- 56  F5.1  0.1nm     WCaII      ? Ca II line equivalent width in Angstroms
  58- 60  A3    ---       Mod        The X-ray modulation flag (4)

Note (1): Identification number from Hillenbrand (1997, Cat. J/AJ/113/1733),
          Herbst+ (2002, Cat. J/A+A/396/513).
Note (2): Indicates other periods reported in the literature when differing by
          more than 10% from Per. References (note 3) are given in parentheses.
          Note on Per, defined as follows:
    a =  2.99 (Carpenter et al. 2001, Cat. J/AJ/121/3160);
    b =  1.40 (Herbst et al. 2000AJ....119..261H);
    c =  2.85 (Carpenter et al. 2001, Cat. J/AJ/121/3160);
    d = 20.10 (Herbst et al. 2000AJ....119..261H);
    e =  1.57 (Herbst et al. 2000AJ....119..261H);
    f =  7.78 (Stassun et al. 1999, Cat. J/AJ/117/2941);
    g = 13.43 (Carpenter et al. 2001, Cat. J/AJ/121/3160);
    h =  5.59 (Herbst et al. 2000AJ....119..261H);
    i =  2.13 (Stassun et al. 1999, Cat. J/AJ/117/2941);
    j = 11.19 (Carpenter et al. 2001, Cat. J/AJ/121/3160);
    k =  4.00 (Herbst et al. 2000AJ....119..261H);
    l =  2.40 (Carpenter et al. 2001, Cat. J/AJ/121/3160);
    m =  9.04 (Carpenter et al. 2001, Cat. J/AJ/121/3160);
    n =  1.55 (Herbst et al. 2000AJ....119..261H);
    o =  5.76 (Herbst et al. 2000AJ....119..261H);
    p =  8.69 (Stassun et al. 1999, Cat. J/AJ/117/2941);
    q =  0.84 (Stassun et al. 1999, Cat. J/AJ/117/2941 ;
               Herbst et al. 2002, Cat. J/A+A/396/513);
    r =  0.66 (Herbst et al. 2002, Cat. J/A+A/396/513);
    s =  3.51 (Herbst et al. 2000AJ....119..261H);
    t =  0.85 (Stassun et al. 1999, Cat. J/AJ/117/2941 ;
               Herbst et al. 2002, Cat. J/A+A/396/513);
    u =  8.44 (Herbst et al. 2000AJ....119..261H);
Note (3): Reference for Per, defined as follows:
    H = Herbst et al. (2002, Cat. J/A+A/396/513);
    h = Herbst et al. (2000AJ....119..261H);
    s = Stassun et al. (1999, Cat. J/AJ/117/2941);
    c = Carpenter et al. (2001, Cat. J/AJ/121/3160);
    U = W. Herbst (unpublished).
Note (4): Indicates filtered light curves (N,L or H) for which the LNP analysis
          yielded  FAP<0.1%. A '+' indicates that the periodogram analysis
          was not performed because either Per<2.0d or Cts<100.


History:
    From electronic version of the journal
(End)                   Greg Schwarz [AAS], Marianne Brouty [CDS]    05-Jul-2006