J/A+A/567/A109 Carina nebula optically identified YSOs (Kumar+, 2014)
Investigation of the stellar content in the western part of the Carina nebula.
Kumar B., Sharma S., Manfroid J., Gosset E., Rauw G., Naze Y., Yadav R.K.
<Astron. Astrophys. 567, A109 (2014)>
=2014A&A...567A.109K 2014A&A...567A.109K
ADC_Keywords: Stars, Wolf-Rayet ; Stars, pre-main sequence ; YSOs ;
Photometry, UBVRI ; Stars, ages
Keywords: stars: massive - stars: individual: WR 22 -
stars: luminosity function, mass function - stars: pre-main-sequence
Abstract:
The low obscuration and proximity of the Carina nebula make it an
ideal place to study the ongoing star formation process and impact of
massive stars on low-mass stars in their surroundings. To investigate
this process, we have generated a new catalogue of the
pre-main-sequence (PMS) stars in the Carina west (CrW) region and
studied their nature and spatial distribution. We have also determined
various parameters (reddening, reddening law, age, mass) which are
further used to estimate the initial mass function (IMF) and K-band
luminosity function (KLF) for the region under study. We obtained deep
UBVRI Hα photometric data of the field situated to the west
of the main Carina nebula and centered around WR22. Medium-resolution
optical spectroscopy of a subsample of X-ray selected objects along
with archival data sets from Chandra, XMM-Newton and 2MASS surveys
are used for the present study. Our spectroscopic results indicate
that the majority of the X-ray sources are late spectral type stars.
The region shows a large amount of differential reddening with minimum
and maximum values of E(B-V) as 0.25 and 1.1mag, respectively. Our
analysis reveals that the total to selective absorption ratio RV is
∼3.7±0.1 suggesting an abnormal grain size in the observed region.
We identify 467 young stellar objects (YSOs) and study their
characteristics. The ages and masses of the 241 optically identified
YSOs range from ∼0.1 to 10Myr and ∼0.3 to 4.8M☉, respectively.
However, the majority of them are younger than 1Myr and have masses
below 2M☉. The high mass star WR22 does not seem to have
contributed to the formation of YSOs in the CrW region. The initial
mass function slope, Gamma in this region is found to be -1.13±0.20
in the mass range of 0.5<M/M☉<4.8. The K-band luminosity
function slope (α) is also estimated as 0.31±0.01. We also
performed minimum spanning tree analysis of the YSOs in this region
which reveals that there are at least ten YSO cores associated with
the molecular cloud and that leads to an average core radius and
median branch length 0.43pc and 0.28pc, respectively.
Description:
File table3.dat contains V magnitude, (V-I) colour index, Age and mass
of optically identified YSOs. The numbering is in the increasing order
of V magnitude of YOSs. Error-bars in magnitude and colour represent
formal internal (comparative) errors and do not include the colour
transformation and zero-point uncertainties.
The observations were obtained with the Wide Field Imager (WFI)
instrument at the ESO/MPG 2.2 m telescope at La Silla in March 2004
(service mode, 72.D-0093; PI: E.Gosset). The WFI instrument has a
field of view of about 34'x33i', covered by a mosaic of eight CCD
chips with a pixel size of 0.238arcsec.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 75 241 List of the optically identified YSOs along
with their derived ages and masses
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See also:
J/AJ/105/258 : UBVRI polarimetry in Car Nebula (Marraco+ 1993)
J/A+A/423/579 : Diffuse emissions in Carina nebula (Mizutani+, 2004)
J/ApJ/667/963 : Near-infrared photometry of Carina nebula (Sanchawala+, 2007)
J/ApJS/194/2 : Chandra Carina Complex Project (CCCP) catalog (Broos+, 2011)
J/ApJS/194/6 : Candidate X-ray emitting OB stars in Carina (Povich+, 2011)
J/ApJS/194/10 : NIR properties of YSO in the CCCP (Preibisch+, 2011)
J/ApJS/194/14 : A Pan-Carina YSO catalog (Povich+, 2011)
J/ApJ/739/100 : [NII] observations of Carina Nebula (NGC 3372) (Oberst+, 2013)
J/A+A/549/A67 : Embedded YSOs in Carina Nebula complex (Gaczkowski+, 2013)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/241] YSO identification number
5- 14 F10.6 deg RAdeg Right ascension in decimal degrees (J2000)
16- 25 F10.6 deg DEdeg Declination in decimal degrees (J2000)
27- 32 F6.3 mag Vmag Johnson V-band magnitude
34- 38 F5.3 mag e_Vmag Uncertainty on Vmag
40- 44 F5.3 mag V-I Johnson V-I colour index
46- 50 F5.3 mag e_V-I Uncertainty on V-I
52- 55 F4.1 Myr Age YSOs ages
57- 59 F3.1 Myr e_Age Uncertainty in YSOs ages
61- 63 F3.1 Msun Mass Mass
65- 67 F3.1 Msun e_Mass Uncertainty in Mass
69- 75 A7 --- Rem Remarks (1)
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Note (1): Remarks as follows:
1 = Spitzer identified sources
2 = Hα sources
3 = CTTS (classical T Tau star)
4 = Chandra sources (X-ray)
5 = XMM-Newton sources (X-ray)
6 = Probable NIR excess
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Acknowledgements:
Brajesh Kumar, brajesh(at)aries.res.in
(End) Patricia Vannier [CDS] 06-May-2014