J/MNRAS/526/1260 Properties of IC 4665 members (Jeffries+, 2023)
A revised age greater than 50 Myr for the young cluster IC 4665.
Jeffries R.D., Jackson R.J., Binks A.S.
<Mon. Not. R. Astron. Soc., 526, 1260-1267 (2023)>
=2023MNRAS.526.1260J 2023MNRAS.526.1260J (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Equivalent widths ;
Photometry ; Optical
Keywords: stars: abundances - stars: evolution - stars: low-mass -
stars: pre-main-sequence - open clusters and associations: general
Abstract:
IC 4665 is one of only a dozen young open clusters with a 'lithium
depletion boundary' (LDB) age. Using an astrometrically and
spectroscopically filtered sample of cluster members, we show that
both the positions of its low-mass stars in Gaia absolute
colour-magnitude diagrams and the lithium depletion seen among its
K- and early M-stars are discordant with the reported LDB age of
32+4-5Myr. Re-analysis of archival spectra suggests that the LDB
of IC 4665 has not been detected and that the published LDB age should
be interpreted as a lower limit. Empirical comparisons with similar
data sets from other young clusters with better-established LDB ages
indicate that IC 4665 is bracketed in age by the clusters IC 2602 and
IC 2391 at 55±3Myr.
Description:
Photometry from Gaia DR3 was added for all these members and
equivalent widths of the LiI 6708Å resonance line (EWLi) from (in
preference order) Jeffries et al. (2023MNRAS.523..802J 2023MNRAS.523..802J), Jeffries et
al. (2009MNRAS.400..317J 2009MNRAS.400..317J, Cat. J/MNRAS/400/317), and Manzi et al.
(2008A&A...479..141M 2008A&A...479..141M, Cat. J/A+A/479/141). For seven stars observed in
GES by both the medium resolution Giraffe spectrograph and at higher
resolution with UVES (see Gilmore et al., 2022A&A...666A.120G 2022A&A...666A.120G), a
weighted mean EWLi was taken. Effective temperatures (Teff) were taken
from homogenized GES spectroscopic estimates (Hourihane et al.
2023A&A...676A.129H 2023A&A...676A.129H, Cat. J/A+A/676/A129) or the spectral energy
distribution modelling of Galindo-Guil et al. (2022A&A...664A..70G 2022A&A...664A..70G,
Cat. J/A+A/664/A70).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 244 537 Properties of the individual cluster members
--------------------------------------------------------------------------------
See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Cluster Cluster identifier
10- 25 A16 --- Target Name (1)
27- 35 F9.5 deg RAdeg Right Ascension (J2000.0)
37- 45 F9.5 deg DEdeg Declination (J2000.0)
47- 51 F5.3 --- Mem [0/1]? Membership probability (2)
53- 56 I4 K Teff Effective temperature
58- 60 A3 --- l_EWLi [≤Y?-. ] Upper limit flag on EWLi (3)
62- 67 F6.1 0.1pm EWLi ? Equivalent width of Li line in mA
69- 74 F6.1 0.1pm EWLic ? EWLi corrected for blending (4)
76- 80 F5.1 0.1pm e_EWLic ? 1 sigma error in EWLic
82- 89 A8 --- --- [Gaia DR3]
91-109 I19 --- GaiaDR3 Identifier in Gaia DR3
111-116 F6.4 mas plx Parallax from Gaia DR3
118-123 F6.4 mas e_plx 1 sigma error in parallax
125-130 F6.2 pc Dist Inferred distance
132-136 F5.2 pc e_Dist 1 sigma error in distance
138-146 F9.6 mag Gmag G magnitude
148-155 F8.6 mag e_Gmag 1 sigma error in G magnitude
157-165 F9.6 mag BPmag ? Bp magnitude
167-174 F8.6 mag e_BPmag ? 1 sigma error in Bp magnitude
176-184 F9.6 mag RPmag ? Rp magnitude
186-193 F8.6 mag e_RPmag ? 1 sigma error in Rp magnitude
195-200 F6.3 --- photxs ? Ratio of corrected flux excess factor
to its dispersion (5)
202-207 F6.3 mag Gmag0 ? Extinction-corrected G magnitude
209-214 F6.3 mag GMAG ? Absolute G magnitude
216-220 F5.3 mag e_GMAG ? 1 sigma error in absolute G magnitude
222-226 F5.3 mag (BP-RP)0 ? Intrinsic Bp-Rp colour
228-232 F5.3 mag e_(BP-RP)0 ? 1 sigma error in intrinsic Bp-Rp
234-238 F5.3 mag (G-RP)0 ? Intrinsic G-Rp colour
240-244 F5.3 mag e_(G-RP)0 ? 1 sigma error in intrinsic G-Rp
--------------------------------------------------------------------------------
Note (1): This is the name given either in Jackson et al. (2022MNRAS.509.1664J 2022MNRAS.509.1664J)
or Galindo-Guil et al. (2022A&A...664A..70G 2022A&A...664A..70G, Cat. J/A+A/664/A70).
Note (2): Membership probability from Jackson et al. (2022MNRAS.509.1664J 2022MNRAS.509.1664J)
where available.
Note (3): This string is taken from the catalogue of Galindo-Guil et
al. (2022A&A...664A..70G 2022A&A...664A..70G, Cat. J/A+A/664/A70) as follows:
< = Equivalent width upper limit of a lithium-poor object
(notation depends on the previous work).
≤ = Equivalent width upper limit of a lithium-poor object
(notation depends on the previous work).
- = Lithium-poor object without any measure.
Y = Lithium-rich object without any measure, see Manzi et al.
(2008A&A...479...141M, Cat. J/A+A/479/141)
Y? = Lithium-rich object without any measure, see Manzi et al.
(2008A&A...479...141M, Cat. J/A+A/479/141)
... = Undetermined lithium content because of low resolving power, low
signal-to-noise ratio, bad quality, or it does not cover this part
of the spectrum.
Note (4): EWLi corrected for blending with a nearby Fe I line if EWLi
come from a source other than GES.
Note (5): This is the ratio defined in Riello et al. (2021A&A...649A...3R 2021A&A...649A...3R,
Cat. J/A+A/649/A3).
--------------------------------------------------------------------------------
Acknowledgements:
Rob Jeffries, r.d.jeffries(at)keele.ac.uk
(End) Patricia Vannier [CDS] 11-Apr-2024