J/MNRAS/346/1143 VI photometry of Collinder 121 (Burningham+, 2003)
On the nature of Collinder 121: insights from the low-mass pre-main sequence.
Burningham B., Naylor T., Jeffries R.D., Devey C.R.
<Mon. Not. R. Astron. Soc., 346, 1143-1150 (2003)>
=2003MNRAS.346.1143B 2003MNRAS.346.1143B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; X-ray sources ;
Photometry
Keywords: techniques: photometric - stars: formation -
stars: low-mass, brown dwarfs -
open clusters and associations: Cr 121 -
open clusters and associations: CMa OB 2 - X-rays: stars
Abstract:
We present a VI photometric catalogue towards the open cluster Cr 121.
XMM-Newton and ROSAT data are used to discover a low-mass pre-main
sequence (PMS) along this sightline. de Zeeuw et al. (1999, Cat.
J/AJ/117/354) have identified Cr 121 as a moving group, using
Hipparcos data, at a distance of 592pc; we reject the scenario that
these low-mass PMS stars are associated with that association.
By considering the higher mass main sequence stellar membership of the
groups along this sightline, the density of low-mass PMS stars and
their age spread we argue that the low-mass PMS stars are associated
with a young, compact cluster at a distance of 1050pc.
Description:
The VI CCD imaging of 8 13.5-arcmin FoVs centred on WR 6 was carried
out using the 0.9-m telescope at the Cerro Tololo Interamerican
Observatory (CTIO) in Chile on the night of 2002 February 12/13.
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
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06 54 12 -24 25.0 Collinder 121
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 112 27502 Photometric catalogue
table2.dat 63 138 XMM-Newton source list
table3.dat 64 13 The reduced ROSAT source list
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See also:
IX/30 : Second ROSAT PSPC Catalog (ROSAT, 2000)
IX/37 : XMM-Newton Serendipitous Source Catalogue (1XMM) (XMM-SSC, 2003)
J/AJ/117/354 : OB associations from Hipparcos (de Zeeuw+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- BNJ Star designation, Cl* Collinder 121 BNJ N-NNNN
9- 10 I2 h RAh Right ascension (J2000.0)
12- 13 I2 min RAm Right ascension (J2000.0)
15- 20 F6.3 s RAs Right ascension (J2000.0)
22 A1 --- DE- Declination sign (J2000.0)
23- 24 I2 deg DEd Declination (J2000.0)
26- 27 I2 arcmin DEm Declination (J2000.0)
29- 33 F5.2 arcsec DEs Declination (J2000.0)
36- 43 F8.3 pix Xpos X position
46- 53 F8.3 pix Ypos Y position
58- 64 F7.3 mag Vmag ?=99.999 V magnitude
69- 75 F7.3 mag e_Vmag ?=99.999 rms uncertainty on Vmag
78 A1 --- q_Vmag Quality flag on Vmag (1)
79 A1 --- q_Icmag Quality flag on Icmag (1)
81- 88 F8.3 mag V-Ic ?=99.999 Cousins V-I colour index
93- 99 F7.3 mag e_V-Ic ?=99.999 rms uncertainty on V-Ic
102-103 A2 --- --- Same as 78- 79
105-107 A3 --- PMM [PMM ] PMM: X-ray-selected PMS stars which
were also proper motion members
109-112 A4 --- NPMM [NPMM ] NPMM: X-ray-selected PMS stars which
were not proper motion members
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Note (1): Quality flags are as follows:
O: O.K.
N: Non-stellar
E: Too close to CCD edge
B: Background fit failed
I: Ill-determined background
P: Position fit failed
S: Saturated
E: Too close to edge
F: Flagged pixel
R: Uncalibrated region
A: Absent input data
M: Negative (minus) counts
V: Variable
C: Large relative transparency correction (cloudy)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- XMM XMM source index number (1)
4 A1 --- n_XMM [s] s: source from the S308 XMM-Newton pointing
6- 7 I2 h RAh XMM Right ascension (J2000.0)
9- 10 I2 min RAm XMM Right ascension (J2000.0)
12- 17 F6.3 s RAs XMM Right ascension (J2000.0)
19 A1 --- DE- XMM Declination sign (J2000.0)
20- 21 I2 deg DEd XMM Declination (J2000.0)
23- 24 I2 arcmin DEm XMM Declination (J2000.0)
26- 30 F5.2 arcsec DEs XMM Declination (J2000.0)
32- 37 F6.3 arcsec Offset Offset from optical position
39- 43 F5.3 ct/s CR EPIC count rate
45- 49 F5.3 ct/s e_CR rms uncertainty on CR
51- 56 A6 --- BNJ ? Star number for optical counterpart
58- 63 A6 --- Old Old star number, in version before 07-Oct-2004
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Note (1): XMM numbers:
[BNJ2003] XMM NNN, 1-152
[BNJ2003] XMM NNNs, 4s-118s
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ROSAT ROSAT source index number, [BNJ2003] ROSAT NN
5- 6 I2 h RAh ROSAT Right ascension (J2000.0)
8- 9 I2 min RAm ROSAT Right ascension (J2000.0)
11- 16 F6.3 s RAs ROSAT Right ascension (J2000.0)
18 A1 --- DE- ROSAT Declination sign (J2000.0)
19- 20 I2 deg DEd ROSAT Declination (J2000.0)
22- 23 I2 arcmin DEm ROSAT Declination (J2000.0)
25- 29 F5.2 arcsec DEs ROSAT Declination (J2000.0)
31- 36 F6.3 pix Xpos X position in the PSCP FoV
38- 43 F6.3 pix Ypos Y position in the PSCP FoV
45- 50 F6.3 10-15W/m2 Flux ROSAT flux
52- 57 A6 --- BNJ Star designation, for optical counterpart
59- 64 A6 --- Old Old star number, in version before 07-Oct-2004
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History: Copied at http://www.astro.ex.ac.uk/people/timn/Catalogues/
(End) James Marcout, Patricia Vannier [CDS] 15-Jan-2004