J/A+A/561/A12 W3 Main JHKs photometry (Bik+, 2014)
Deep near-infrared imaging of W3 Main: constraints on stellar cluster formation.
Bik A., Stolte A., Gennaro M., Brandner W., Gouliermis D., Hussmann B.,
Tognelli E., Rochau B., Henning T., Adamo A., Beuther H., Pasquali A.,
Wang Y.
<Astron. Astrophys. 561, A12 (2014)>
=2014A&A...561A..12B 2014A&A...561A..12B
ADC_Keywords: Infrared sources ; Stars, pre-main sequence ;
Photometry, infrared ; Photometry, CCD
Keywords: stars: luminosity function, mass function - infrared: stars -
stars: pre-main sequence - open clusters and associations: W3 Main
Abstract:
Embedded clusters like W3 Main are complex and dynamically evolving
systems that represent an important phase in the star formation
process. We aim to characterize of the entire stellar content of W3
Main in a statistical sense, which will then identify possible
differences in evolutionary phase of the stellar populations and find
clues about the formation mechanism of this massive embedded cluster.
Deep JHKs imaging is used to derive the disk fraction, Ks-band
luminosity functions, and mass functions for several subregions in W3
Main. A two-dimensional completeness analysis using artificial star
experiments is applied as a crucial ingredient for assessing realistic
completeness limits for our photometry. We find an overall disk
fraction of 7.7±2.3%, radially varying from 9.4±3.0 in the
central 1pc to 5.6±2.2% in the outer parts of W3 Main. The mass
functions derived for three subregions are consistent with a Kroupa
and Chabrier mass function. The mass function of IRSN3 is complete
down to 0.14M☉ and shows a break at M∼0.5M☉. We interpret
the higher disk fraction in the center as evidence that the cluster
center is younger. We find that the evolutionary sequence observed in
the low-mass stellar population is consistent with the observed age
spread among the massive stars. An analysis of the mass function
variations does not show evidence of mass segregation. W3 Main is
currently still actively forming stars, showing that the ionizing
feedback of OB stars is confined to small areas (∼0.5pc). The FUV
feedback might be influencing large regions of the cluster as
suggested by the low overall disk fraction.
Description:
We provide the photometric JHKs catalogs used in this paper. The
observations are carried out with LUCI1 at the LBT. The photometry is
calibrated with 2MASS. For each star the photometric completeness
derived from our two dimensional completeness analysis is given. The
three files give the JHKs matched, HK matched and K-only catalogs.
These 3 catalogs are used in the different sections of the paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
jhk.dat 87 1033 JHKs matched photometry and photometric completeness
hk.dat 65 1681 HKs matched photometry and photometric completeness
k.dat 43 2220 Ks photometry and photometric completeness
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See also:
J/A+AS/124/205 : W3 star-forming region 345 GHz survey (Helmich+ 1997)
J/AJ/129/393 : UBV photometry in W3 (Oey+, 2005)
J/ApJ/654/338 : Spitzer photometry in W3 molecular cloud (Ruch+, 2007)
J/MNRAS/379/663 : 850um observations of W3 giant molecular cloud (Moore+, 2007)
J/ApJ/743/39 : Spitzer obs. of W3 molecular cloud (Rivera-Ingraham+, 2011)
Byte-by-byte Description of file: jhk.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right ascension (J2000.0)
4- 5 I2 min RAm Right ascension (J2000.0)
7- 10 F4.1 s RAs Right ascension (J2000.0)
13 A1 --- DE- Declination sign (J2000.0)
14- 15 I2 deg DEd Declination (J2000.0)
17- 18 I2 arcmin DEm Declination (J2000.0)
20- 21 I2 arcsec DEs Declination (J2000.0)
24- 29 F6.3 mag Jmag J-band magnitude
32- 36 F5.3 mag e_Jmag J-band magnitude error
39- 43 F5.3 --- Jcmpl [0/1.02] J-band completeness
46- 51 F6.3 mag Hmag H-band magnitude
54- 58 F5.3 mag e_Hmag H-band magnitude error
61- 65 F5.3 --- Hcmpl [0/1.02] H-band completeness
68- 73 F6.3 mag Ksmag Ks-band magnitude
76- 80 F5.3 mag e_Ksmag Ks-band magnitude error
83- 87 F5.3 --- Kscmpl [0/1.02] Ks-band completeness
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Byte-by-byte Description of file: hk.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Right ascension (J2000.0)
4- 5 I2 min RAm Right ascension (J2000.0)
7- 10 F4.1 s RAs Right ascension (J2000.0)
13 A1 --- DE- Declination sign (J2000.0)
14- 15 I2 deg DEd Declination (J2000.0)
17- 18 I2 arcmin DEm Declination (J2000.0)
20- 21 I2 arcsec DEs Declination (J2000.0)
24- 29 F6.3 mag Hmag H-band magnitude
32- 36 F5.3 mag e_Hmag H-band magnitude error
39- 43 F5.3 --- Hcmpl [0/1.02] H-band completeness
46- 51 F6.3 mag Ksmag Ks-band magnitude
54- 58 F5.3 mag e_Ksmag Ks-band magnitude error
61- 65 F5.3 --- Kscmpl [0/1.02] Ks-band completeness
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Byte-by-byte Description of file: k.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Right ascension (J2000.0)
4- 5 I2 min RAm Right ascension (J2000.0)
7- 10 F4.1 s RAs Right ascension (J2000.0)
13 A1 --- DE- Declination sign (J2000.0)
14- 15 I2 deg DEd Declination (J2000.0)
17- 18 I2 arcmin DEm Declination (J2000.0)
20- 21 I2 arcsec DEs Declination (J2000.0)
24- 29 F6.3 mag Ksmag Ks-band magnitude
32- 36 F5.3 mag e_Ksmag Ks-band magnitude error
39- 43 F5.3 --- Kscmpl [0/1.02] Ks-band completeness
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Acknowledgements:
Arjan Bik, abik(at)mpia.de
(End) Arjan Bik [MPIA], Patricia Vannier [CDS] 08-Nov-2013