J/MNRAS/358/13 Faint dwarfs in NGC 2547 (Jeffries+, 2005)
The Lithium depletion boundary in NGC 2547 as a test of pre-main-sequence
evolutionary models.
Jeffries R.D., Oliveira J.M.
<Mon. Not. R. Astron. Soc., 358, 13-29 (2005)>
=2005MNRAS.358...13J 2005MNRAS.358...13J
ADC_Keywords: Clusters, open ; Stars, dwarfs ; Radial velocities ;
Abundances
Keywords: stars: abundances - stars: late-type -
open clusters and associations: individual: NGC 2547
Abstract:
Intermediate resolution spectroscopy from the European Southern
Observatory Very Large Telescope is analysed for 63 photometrically
selected low-mass (0.08-0.30M☉) candidates of the open cluster
NGC 2547. We have confirmed membership for most of these stars using
radial velocities, and found that lithium remains undepleted for
cluster stars with I>17.54±0.14 and Ks>14.86±0.12. From these
results, several pre-main-sequence evolutionary models give almost
model independent ages of 34-36Myr, with a precision of 10%.
These ages are only slightly larger than the ages of 25-35(±5)Myr
obtained using the same models to fit isochrones to higher mass stars
descending towards the zero-age main-sequence, both in empirically
calibrated and theoretical colour-magnitude diagrams. This agreement
between age determinations in different mass ranges is an excellent
test of the current generation of low-mass pre-main-sequence stellar
models and lends confidence to ages determined with either method
between 30 and 120Myr.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 114 63 Targets observed
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See also:
J/MNRAS/335/291 : BVI photometry of NGC 2547 (Naylor+, 2002)
J/MNRAS/351/1401 : RcIcZ photometry of NGC 2547 (Jeffries+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- JO Identifier used in this paper,
Cl* NGC 2547 JO NN in Simbad
4- 5 A2 --- Field Field designation, from Jeffries et al., 2004,
Cat. J/MNRAS/351/1401
7- 10 I4 --- ID1 Star designation from Jeffries et al., 2004,
Cat. J/MNRAS/351/1401
(Cl* NGC 2547 JND FF-NNNN in Simbad)
11 A1 --- n_ID1 [N] if source was not considered a photometric
member in J/MNRAS/351/1401
13- 14 I2 h RAh Right Ascension J2000 (hours)
16- 17 I2 min RAm Right Ascension J2000 (minutes)
19- 24 F6.3 s RAs Right Ascension J2000 (seconds)
26 A1 --- DE- Declination J2000 (sign)
27- 28 I2 deg DEd Declination J2000 (degrees)
30- 31 I2 arcmin DEm Declination J2000 (minutes)
33- 37 F5.2 arcsec DEs Declination J2000 (seconds)
39- 44 F6.3 mag Icmag Cousins I magnitude from J/MNRAS/351/1401
46- 50 F5.3 mag Rc-Ic Rc-Ic colour index from J/MNRAS/351/1401
52- 56 F5.3 mag Ic-Z Ic-Z colour index from J/MNRAS/351/1401
58- 63 F6.3 mag Jmag ? J magnitude from 2MASS II/246
65- 70 F6.3 mag Hmag ? H magnitude from 2MASS II/246
72- 77 F6.3 mag Ksmag ? Ks magnitude from 2MASS II/246
79- 82 A4 --- SpType Estimated MK spectral type
84- 88 F5.1 km/s RV1 Relative radial velocity on night 1
89 A1 --- n_RV1 [b] indicates broadened lines
91- 95 F5.1 km/s RV2 ? Relative radial velocity on night 2
96 A1 --- n_RV2 [b] indicates broadened lines
97 A1 --- f_RV2 [V] indicates a variable velocity
99-100 I2 --- SNR empirical spectrum signal-to-noise ratio
102 A1 --- l_Li Limit flag (<) on Li
103-106 F4.2 0.1nm Li Equivalent width of the Li 6708Å feature
108-111 F4.2 0.1nm e_Li ? Mean error on Li
112 A1 --- n_Li [b] indicates a broadened Li line
114 I1 --- Mem [1,4] Membership status (1)
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Note (1): The status takes the following values:
1 = RV member with no Li
2 = RV member with Li
3 = RV non-member with Li
4 = RV non-member with no Li
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Acknowledgements:
Thanks to Rob Jeffries for a complete source table, kindly forwarded
by Brian Skiff.
(End) Francois Ochsenbein [CDS] 07-Sep-2005