J/A+A/622/A110 Spectroscopic membership for NGC 3532 (Fritzewski+, 2019)
Spectroscopic membership for the populous 300 Myr-old open cluster NGC 3532.
Fritzewski D.J., Barnes S.A., James D.J., Geller A.M., Meibom S.,
Strassmeier K.G.
<Astron. Astrophys. 622, A110 (2019)>
=2019A&A...622A.110F 2019A&A...622A.110F (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Populations, stellar ; Radial velocities ;
Proper motions ; Abundances, [Fe/H] ; Photometry, UBVRI
Keywords: techniques: radial velocities - stars: abundances -
stars: kinematics and dynamics - stars: late-type -
open clusters and associations: individual: NGC 3532 -
Galaxy: stellar content
Abstract:
NGC 3532 is an extremely rich open cluster embedded in the Galactic
disc, hitherto lacking a comprehensive, documented membership list. We
provide membership probabilities from new radial velocity observations
of solar-type and low-mass stars in NGC 3532, in part as a prelude to
a subsequent study of stellar rotation in the cluster. Using extant
optical and infra-red photometry we constructed a preliminary
photometric membership catalogue, consisting of 2230 dwarf and
turn-off stars. We selected 1060 of these for observation with the
AAOmega spectrograph at the 3.9m Anglo-Australian Telescope and 391
stars for observations with the Hydra-South spectrograph at the 4m
Victor Blanco Telescope, obtaining spectroscopic observations over a
decade for 145 stars. We measured radial velocities for our targets
through cross-correlation with model spectra and standard stars, and
supplemented them with radial velocities for 433 additional stars from
the literature. We also measured logg, Teff, and [Fe/H] from the
AAOmega spectra. The radial velocity distribution emerging from the
observations is centred at 5.43±0.04km/s and has a width (standard
deviation) of 1.46km/s. Together with proper motions from Gaia DR2 we
find 660 exclusive members, of which five are likely binary members.
The members are distributed across the whole cluster sequence, from
giant stars to M dwarfs, making NGC∼3532 one of the richest Galactic
open clusters known to date, on par with the Pleiades. From further
spectroscopic analysis of 153 dwarf members we find the metallicity to
be marginally sub-solar, with [Fe/H]=-0.07±0.10. We confirm the
extremely low reddening of the cluster, EB-V=0.034±0.012mag,
despite its location near the Galactic plane. Exploiting trigonometric
parallax measurements from Gaia DR2 we find a distance of
484+35-30pc [(m-M)0=8.42±0.14mag]. Based on the membership we
provide an empirical cluster sequence in multiple photometric
passbands. A comparison of the photometry of the measured cluster
members with several recent model isochrones enables us to confirm the
300Myr cluster age. However, all of the models evince departures from
the cluster sequence in particular regions, especially in the lower
mass range.
Description:
The radial velocities were measured from spectroscopic observations
with the Hydra-South spectrograph at the Victor Blanco Telescope at
CTIO and the AAOmega on the Anglo-Australian Telescope at AAO. The
observations at CTIO were carried out from February 2008 to March 2010
on 15 nights and at AAO we observed on 10 and 11 March 2017.
Objects:
-----------------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------------
11 05 39 -58 45.2 NGC 3532 = Cl VDBH 109
-----------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 83 2232 Photometric and proper motion membership for
NGC 3532
table3.dat 112 1613 Radial velocity membership
table4.dat 69 355 Stellar parameters from the spectra
table5.dat 41 22 Empirical cluster sequence
--------------------------------------------------------------------------------
See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/141/115 : BV(RI)c photometry on NGC 3532 (Clem+, 2011)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- CLHW CLHW identification number,
[CLH2011b] NNNNNN in Simbad
8- 16 F9.5 deg RAdeg Right ascension (J2000) (G1)
18- 26 F9.5 deg DEdeg Declination (J2000) (G1)
28- 35 F8.4 mas/yr pmRA ? Gaia DR2 proper motion in right ascension
direction (pmRA*cosDE)
37- 44 F8.4 mas/yr pmDE ? Gaia DR2 PRoper motion in declination
direction
46 A1 --- PM [y/n] Proper motion membership
48- 66 I19 --- GaiaID ? Gaia DR2 source identifier
68- 83 A16 --- 2MASSID 2MASS name (HHMMSSss+DDMMSSs)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- CLHW ? CLHW identification number,
[CLH2011b] NNNNNN in Simbad
8- 16 F9.5 deg RAdeg Right ascension (J2000) (G1)
18- 26 F9.5 deg DEdeg Declination (J2000) (G1)
28- 34 F7.2 km/s RV Radial velocity
36- 40 F5.2 km/s e_RV ? rms uncertainty on RV
42- 45 F4.2 --- pRV Radial velocity membership probability
47 A1 --- PM [y/n] Pproper motion membership
49 A1 --- Member [mn] Exclusive membership
51- 53 A3 --- Class Membership class (1)
55- 59 F5.2 mag Vmag V magnitude (G1)
61- 65 F5.2 mag B-V B-V colour index (G1)
67- 71 F5.2 mag V-Ic ? V-Ic colour index (G1)
73- 77 F5.2 mag V-Ks ? V-Ks colour index (2)
79-108 A30 --- Name Name
110-112 A3 --- r_RV Reference for radial velocity (3)
--------------------------------------------------------------------------------
Note (1): Classification as follows:
B = binary
G = background giant
L = likely
M = member
N = non-member
P = photometric (only non-members)
S = single
U = unknown multiplicity
Note (2): From Clem et al., 2011, Cat. J/AJ/141/115 and 2MASS (Cat. II/246).
Note (3): Reference as follows:
1 = This work, AAO observations
2 = This work, CTIO observations
3 = Gieseking (1981A&A....99..155G 1981A&A....99..155G)
4 = Gaia DR2
5 = Gaia ESO Survey DR2
6 = Gonzalez & Lapasset (2002AJ....123.3318G 2002AJ....123.3318G)
7 = Mermilliod et al. (2008A&A...485..303M 2008A&A...485..303M)
8 = RAVE survey DR5
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- CLHW CLHW identification number,
[CLH2011b] NNNNNN in Simbad
8- 13 I6 --- ID Identification number
15- 23 F9.5 deg RAdeg Right ascension (J2000) (G1)
25- 33 F9.5 deg DEdeg Declination (J2000) (G1)
35- 38 F4.2 --- pRV Radial velocity membership probability
40- 43 I4 K Teff Effective temperature
45- 48 I4 K e_Teff rms uncertainty on Teff
50- 53 F4.2 [cm/s2] logg Surface gravity
55- 58 F4.2 [cm/s2] e_logg ? rms uncertainty on logg
60- 64 F5.2 [-] [Fe/H] ? Metallicity
66- 69 F4.2 [-] e_[Fe/H] ? rms uncertainty on [Fe/H]
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 F5.2 mag VMAG Absolute V magnitude
7- 10 F4.2 mag GMAG Absolute G magnitude,
Gaia DR2 photometric system
12- 17 F6.3 mag (B-V)0 Derredenned (B-V) colour index (1)
19- 23 F5.3 mag (V-Rc)0 Derredenned (V-Rc) colour index (1)
25- 29 F5.3 mag (Bp-Rp)0 Derredenned (Bp-Rp) colour index,
Gaia DR2 photometric system
31- 36 F6.3 mag (V-Ic)0 Derredenned (V-Ic) colour index (1)
38- 41 F4.2 mag (V-Ks)0 Derredenned (V-Ks) colour index (2)
--------------------------------------------------------------------------------
Note (1): based on Clem et al. (2011, Cat. J/AJ/141/115)
Note (2): based on Clem et al. (2011, Cat. J/AJ/141/115) and 2MASS (Cat. II/246)
--------------------------------------------------------------------------------
Global notes:
Note (G1): From Clem et al., 2011, Cat. J/AJ/141/115.
--------------------------------------------------------------------------------
Acknowledgements:
Dario Fritzewski, dfritzewski(at)aip.de
(End) Patricia Vannier [CDS] 18-Dec-2018