J/MNRAS/475/1609 RV variability in NGC 2516 and NGC 2422 (Bailey+, 2018)
Radial velocity variability and stellar properties of FGK stars in the cores of
NGC 2516 and NGC 2422.
Bailey J.I. III, Mateo M., White R.J., Shectman S.A., Crane J.D.
<Mon. Not. R. Astron. Soc. 475, 1609-1632 (2018)>
=2018MNRAS.475.1609B 2018MNRAS.475.1609B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open; Spectroscopy; Abundances, [Fe/H];
Effective temperatures; Radial velocities; Binaries, spectroscopic
Keywords: techniques: radial velocities - techniques: spectroscopic -
planets and satellites: detection - stars: abundances -
binaries: spectroscopic -
open clusters and associations: individual (NGC 2516, NGC 2422)
Abstract:
We present multi-epoch, high-dispersion, optical spectra obtained with
the Michigan/Magellan Fiber System of 126 and 125 Sun-like stars in
the young clusters NGC 2516 (141Myr) and NGC 2422 (73Myr). We
determine stellar properties including radial velocity (RV), Teff,
[Fe/H], [α/Fe], and the line-of-sight rotation rate, vrsin(i),
from these spectra. Our median RV precision of 80m/s on individual
epochs that span a temporal baseline of 1.1yr enables us to
investigate membership, stellar binarity, and search for sub-stellar
companions. We determine membership probabilities and RV variability
probabilities for our sample along with candidate companion orbital
periods for a select subset of stars. We identify 81 RV members in
NGC 2516, 27 spectroscopic binaries (17 previously identified as
photometric binaries), and 16 other stars that show significant RV
variability after accounting for average stellar jitter found to be at
the 74m/s level. In NGC 2422 we identify 57 members, 11 spectroscopic
binaries, and 3 other stars that show significant RV variability after
accounting for an average jitter of 138m/s. We use Monte Carlo
simulations to verify our stellar jitter measurements, determine the
proportion of exoplanets and stellar companions to which we are
sensitive, and estimate companion mass limits for our targets. We also
report mean cluster metallicity, velocity, and velocity dispersion
based on our member targets and identify 58 non-member stars as RV
variables - 24 of which have RV amplitudes that imply stellar or
brown-dwarf mass companions. Finally, we note the discovery of a
separate RV clustering of stars in our NGC 2422 sample.
Description:
2729 R∼50,000 ∼130Å spectra centered at 7230Å and obtained with
the Michigan Magellan Fiber System between Nov 2013 and Dec 2014 were
modeled with PHOENIX synthetic spectra. Table 2 in the associated
publication describes the contents and links to relevant sections of
the text describing the determination of the various parameters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 210 126 NGC 2516
tablea2.dat 210 125 NGC 2422
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See also:
I/322 : UCAC4 Catalogue (Zacharias+, 2013)
J/A+A/375/863 : Photometry and membership in NGC 2516 (Jeffries+, 2001)
J/A+A/404/927 : Photometry and membership in NGC 2422 (Prisinzano+, 2003)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- UCAC4 UCAC4 (Cat. I/322) designation
12- 16 I5 --- J01 Jeffries et al. (2001, cat. J/A+A/375/863)
identification number (1)
19- 27 F9.5 deg RAdeg Right Ascension from UCAC4 (J2000)
30- 38 F9.5 deg DEdeg Declination from UCAC4 (J2000)
40- 44 F5.2 mag Vmag V magnitude from photometry source
46- 50 F5.3 mag B-V B-V color from photometry source
52- 54 A3 --- PSrc [J01 U] Photometry Source:
J01 or U (UCAC4) (1)
56- 57 I2 --- N Number of usable spectra obtained
59- 61 I3 --- S/N Mean S/N (per pixel)
63- 66 I4 K Teff ?=- Adopted effective temperature (G1)
69- 71 I3 K E_Teff ?=- Upper 1sigma uncertainty on Teff (G1)
74- 76 I3 K e_Teff ?=- Lower 1sigma uncertainty on Teff (G1)
78 I1 --- f_Teff [0/1]?=- Teff correction applied if 1 (G1)
80- 84 F5.2 [Sun] [Fe/H] ?=- Adopted [Fe/H] abundance (G1)
86- 89 F4.2 [Sun] E_[Fe/H] ?=- Upper 1sigma uncertainty on [Fe/H] (G1)
91- 94 F4.2 [Sun] e_[Fe/H] ?=- Lower 1sigma uncertainty on [Fe/H] (G1)
96-100 A5 [Sun] [a/Fe] ?=- Adopted [a/Fe] abundance (G1)
102-105 A4 [Sun] E_[a/Fe] ?=- Upper 1sigma uncertainty on [a/Fe] (G1)
107-110 A4 [Sun] e_[a/Fe] ?=- Lower 1sigma uncertainty on [a/Fe] (G1)
113-116 A4 km/s vrot ?=- Stellar rotational velocity (G1) (G2)
119-121 F3.1 km/s E_vrot ?=- Upper 1sigma uncertainty on vrot (G1)
124-126 F3.1 km/s e_vrot ?=- Lower 1sigma uncertainty on vrot (G1)
128-130 F3.1 [cm/s2] log(g) ?=- log(g) used for fitting (G1)
132-137 I6 m/s BRV ?=- Weighted mean barycentric RV (G1)
139-143 I5 m/s e_BRV ?=- Error on RVel (G1)
145-149 I5 m/s sigobs ?=- Standard deviation of measured RVs (G1)
152-155 I4 m/s sigmeas ?=- Mean RV measurement error (G1)
157-160 F4.2 --- Pmem ?=- RV membership probability (G3)
162 A1 --- Mem [MNPX] Membership Flag (G3)
164-166 A3 --- Type Target type flag (G4)
168-170 I3 m/s sigjit ?=- Adopted stellar jitter (G5)
172-175 F4.2 --- Pvar ?=- RV variable probability (G6)
177-180 F4.2 --- Pvarjit ?=- RV variable prob. incl. jitter (G6)
182-187 F6.1 d Period ?=- Optimized periodogram peak >95% CI (G6)
190-193 F4.1 Mjup M3 ?=- 95% companion mass limit at 3 d (G6)
196-199 F4.1 Mjup M10 ?=- 95% companion mass limit at 10 d (G6)
201-205 F5.1 Mjup M20 ?=- 95% companion mass limit at 20 d (G6)
207-210 F4.2 Msun Mstar ?=- Stellar mass for companion limit (G6)
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Note (1): Jeffries et al. 2001A&A...375..863J 2001A&A...375..863J, Cat. J/A+A/375/863.
Source identified as Cl* NGC 2516 JTH NNNNN in Simbad.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- UCAC4 UCAC4 (Cat. I/322) designation
13- 16 I4 --- P03 ?=- Prisinzano et al. (2003,
Cat. J/A+A/404/927) designation
if exist (1)
19- 27 F9.5 deg RAdeg Right Ascension from UCAC4 (J2000)
30- 38 F9.5 deg DEdeg Declination from UCAC4 (J2000)
40- 44 F5.2 mag Vmag V magnitude from photometry source
46- 50 F5.3 mag B-V B-V color from photometry source
52- 54 A3 --- PSrc Photometry Source: P03 or U (UCAC4) (1)
56- 57 I2 --- N Number of usable spectra obtained
59- 61 I3 --- S/N Mean S/N (per pixel)
63- 66 I4 K Teff ?=- Adopted effective temperature (G1)
69- 71 I3 K E_Teff ?=- Upper 1sigma uncertainty on Teff (G1)
74- 76 I3 K e_Teff ?=- Lower 1sigma uncertainty on Teff (G1)
78 I1 --- f_Teff [0/1]?=- Teff correction applied if 1 (G1)
80- 84 F5.2 [Sun] [Fe/H] ?=- Adopted [Fe/H] abundance (G1)
86- 89 F4.2 [Sun] E_[Fe/H] ?=- Upper 1sigma uncertainty on [Fe/H] (G1)
91- 94 F4.2 [Sun] e_[Fe/H] ?=- Lower 1sigma uncertainty on [Fe/H] (G1)
96-100 A5 [Sun] [a/Fe] ?=- Adopted [a/Fe] abundance (G1)
102-105 A4 [Sun] E_[a/Fe] ?=- Upper 1sigma uncertainty on [a/Fe] (G1)
107-110 A4 [Sun] e_[a/Fe] ?=- Lower 1sigma uncertainty on [a/Fe] (G1)
113-116 A4 km/s vrot ?=- Stellar rotational velocity (G1) (G2)
119-121 F3.1 km/s E_vrot ?=- Upper 1sigma uncertainty on vrot (G1)
124-126 F3.1 km/s e_vrot ?=- Lower 1sigma uncertainty on vrot (G1)
128-130 F3.1 [cm/s2] log(g) ?=- log(g) used for fitting (G1)
132-137 I6 m/s BRV ?=- Weighted mean barycentric RV (G1)
139-143 I5 m/s e_BRV ?=- Error on RVel (G1)
145-149 I5 m/s sigobs ?=- Standard deviation of measured RVs (G1)
152-155 I4 m/s sigmeas ?=- Mean RV measurement error (G1)
157-160 F4.2 --- Pmem ?=- RV membership probability (G3)
162 A1 --- Mem [MNPX] Membership Flag (G3)
164-166 A3 --- Type Target type flag (G4)
168-170 I3 m/s sigjit ?=- Adopted stellar jitter (G5)
172-175 F4.2 --- Pvar ?=- RV variable probability (G6)
177-180 F4.2 --- Pvarjit ?=- RV variable prob. incl. jitter (G6)
182-187 F6.1 d Period ?=- Optimized periodogram peak >95% CI (G6)
190-193 F4.1 Mjup M3 ?=- 95% companion mass limit at 3d (G6)
196-199 F4.1 Mjup M10 ?=- 95% companion mass limit at 10d (G6)
201-205 F5.1 Mjup M20 ?=- 95% companion mass limit at 20d (G6)
207-210 F4.2 Msun Mstar ?=- Stellar mass for companion limit (G6)
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Note (1): P03 references Prisinzano et al. 2003A&A...404..927P 2003A&A...404..927P.
Source identified as Cl* NGC 2422 PMS NNNN in Simbad.
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Global Notes:
Note (G1): See Section 3.2 of the text.
Note (G2): We are unable to resolve vrsin(i) values below ∼2km/s.
Such values are listed as <2.0.
Note (G3): See Section 5 of the text.
The one target with an X code has no data of sufficient S/N.
Note (G4): Target type codes are reported as follows:
S = RV single
B = RV binary
SB2 = double-lined spectroscopic binary
C = featureless star
X = no data
Note (G5): See Section 7 of the text.
Note (G6): See Section 8 of the text.
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Acknowledgements:
John I Bailey III, baileyji(at)strw.leidenuniv.nl
(End) John I Bailey III [ULeiden], Patricia Vannier [CDS] 15-Dec-2017