J/A+A/536/A63 Collinder 69 very low mass stars and brown dwarfs (Bayo+, 2011)
Spectroscopy of very low mass stars and brown dwarfs in the lambda Orionis
star forming region.
I. Enlarging the census down to the planetary mass domain in Collinder 69.
Bayo A., Barrado D., Stauffer J., Morales-Calderon M., Melo C., Huelamo N.,
Bouy H., Stelzer B., Tamura M., Jayawardhana R.
<Astron. Astrophys. 536, A63 (2011)>
=2011A&A...536A..63B 2011A&A...536A..63B
ADC_Keywords: Clusters, open ; Stars, early-type ; Equivalent widths
Keywords: brown dwarfs - stars: formation -
stars: luminosity function, mass function - infrared: stars -
star: low-mass -
open clusters and associations: individual: Collinder 69
Abstract:
We have studied age dependent features in optical and near-infrared
spectra of candidate members to the cluster (such as alkali lines and
accretion associated indicators).
In addition, we have complemented that study with the analysis of
other youth indicators like X-ray emission or mid-infrared excess.
We have confirmed the membership to Collinder 69 of ∼90 photometric
candidate members. As a byproduct we have determined a temperature
scale for young M, very low-mass stars and brown dwarfs. We have
assembled one of the most complete Initial Mass Functions from 0.016
to 20M☉. And, finally, we have studied the implications of the
spatial distribution of the confirmed members on the proposed
mechanisms of brown dwarfs formation.
Description:
Spectroscopic measurements and derived parameters for Collinder 69
candidate and confirmed members from this work and compiled from the
literature.
Some of the parameters provided in the table include spectral types,
effective temperatures, masses, etc. along with equivalent widths
measurements of several alkali lines.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 187 220 Summary of the parameters derived in this work
for Collinder 69 candidate members and
comparison with previous studies
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See also:
J/AJ/118/2409 : VRI photometry of lambda Ori PMS stars (Dolan+, 1999)
J/AJ/121/2124 : lambda Ori pre-main-sequence stars photometry (Dolan+, 2001)
J/ApJ/610/1064 : lambda Ori substellar population (Barrado y Navascues+ 2004)
J/ApJ/664/481 : Collinder 69 opt/IR photometry (Barrado y Navascues+ 2007)
J/A+A/488/167 : Low-mass stars in sigma Ori and lambda Ori (Sacco+, 2008)
J/A+A/492/277 : Analysis of Collinder 69 stars with VOSA (Bayo+, 2008)
J/MNRAS/385/2210 : Spectroscopy around lam Ori and sig Ori (Maxted+, 2008)
J/A+A/526/A21 : Collinder 69 X-ray sources (Barrado+, 2011)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Object name
14- 31 A18 --- ONames Alternative name(s)
33- 40 F8.5 deg RAdeg Right ascension in decimal degrees (J2000)
42- 50 F9.6 deg DEdeg Declination in decimal degrees (J2000)
52- 53 A2 --- Mm Membership (1)
55- 67 A13 --- r_Mm Reference for membership (2)
69- 85 A17 --- SpType MK spectral type(s)
87 A1 --- n_SpType [2/3] Note on SpType (3)
89- 92 I4 K Teff Effective temperature
94- 98 E5.3 Lsun Lbol ? Bolometric luminosity
100-105 E6.4 Lsun e_Lbol ? rms uncertainty on Lbol
107-111 F5.3 Msun Mass ? Mass
113 A1 --- VLi [Y] Y for variable in Li equivalent width
115-121 A7 ---- Inst Instrumental configuration (4)
124-128 F5.3 0.1nm W(Li)a ? Li 6708Å equivalent width from this work
130-134 F5.3 0.1nm e_W(Li)a ? rms uncertainty on W(Li)a
136-139 F4.2 0.1nm W(Li)b ? Li 6708Å equivalent width from Dolan &
Mathieu, 1999, Cat. J/AJ/118/2409;
2001, Cat. J/AJ/121/2124
141-145 F5.3 0.1nm W(Li)c ? Li 6708Å equivalent width from
Sacco et al., 2008, Cat. J/A+A/488/167
147-151 F5.3 0.1nm e_W(Li)c ? rms uncertainty on W(Li)c
153-157 F5.3 0.1nm W(KI)1 ? KI 7665Å equivalent width
159-163 F5.3 0.1nm e_W(KI)1 ? rms uncertainty on W(KI)1
165-169 F5.3 0.1nm W(KI)2 ? KI 7700Å equivalent width
171-175 F5.3 0.1nm e_W(KI)2 ? rms uncertainty on W(KI)2
177-181 F5.3 0.1nm W(NaI) ? NaI 8200Å equivalent width
183-187 F5.3 0.1nm e_W(NaI) ? rms uncertainty on W(NaI)
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Note (1): Membership code as follows:
Y = spectroscopically confirmed member
Y? = object showing some peculiarity already discussed but still
considered as very good candidate for membership
NM = non-member
Note (2): Membership confirmed by the following:
DM = Dolan & Mathieu, 1999, Cat. J/AJ/118/2409; 2001, J/AJ/121/2124
S08 = Sacco et al., 2008, Cat. J/A+A/488/167
M08 = Maxted et al., 2008, Cat. J/MNRAS/385/2210
B10 = This work
Note (3): Note on SpType as follows:
2 = Spectral type photometrically determined by Sacco et al., 2008,
Cat. J/A+A/488/167 (all the remaining spectral types were
obtained spectroscopically in this work)
3 = Infrared spectral type (see paper)
Note (4): Instrumental configuration (with resolution) as follows:
1 = LRIS (R≃2650)
2 = LRIS (R≃950)
3 = MIKE (R≃11250)
4 = B&C (R≃2600)
5 = B&C (R≃800)
6 = TWIN (R≃1100)
7 = CAFOS (R≃600)
8 = FLAMES (R≃8600)
9 = NIRSPEC (R≃2000)
10 = SOFI (R≃950)
11 = IRCS (R≃200)
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Acknowledgements:
Amelia Bayo, abayo(at)eso.org
History:
* 08-Dec-2011: on-line version
* 08-Mar-2013: 1 name corrected
(End) Amelia Bayo [ESO], Patricia Vannier [CDS] 23-Sep-2011