J/ApJ/821/8 Spectroscopic binary population of ONC and NGC2264 (Kounkel+, 2016)
Spectroscopic binaries in the Orion Nebula Cluster and NGC 2264.
Kounkel M., Hartmann L., Tobin J.J., Mateo M., Bailey III J.I., Spencer M.
<Astrophys. J., 821, 8-8 (2016)>
=2016ApJ...821....8K 2016ApJ...821....8K (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Radial velocities ;
Effective temperatures
Keywords: binaries: spectroscopic; ISM: individual: (ONC, NGC 2264)
ISM: structure; stars: formation
Abstract:
We examine the spectroscopic binary population for two massive nearby
regions of clustered star formation, the Orion Nebula Cluster (ONC)
and NGC 2264, supplementing the data presented by Tobin et al. (2009,
J/ApJ/697/1103) with more recent observations and more extensive
analysis. The inferred multiplicity fraction up to 10 au based on
these observations is 5.3±1.2% for NGC 2264 and 5.8±1.1% for the
ONC; these values are consistent with the distribution of binaries in
the field in the relevant parameter range. Eight of the multiple
systems in the sample have enough epochs to perform an initial fit for
the orbital parameters. Two of these sources are double-lined
spectroscopic binaries; for them, we determine the mass ratio. Our
reanalysis of the distribution of stellar radial velocities toward
these clusters presents a significantly better agreement between
stellar and gas kinematics than was previously thought.
Description:
We reanalyzed all of the spectra previously obtained by T09 (Tobin et
al. 2009, J/ApJ/697/1103) for the ONC region and by T15 (Tobin et al.
2015, J/AJ/149/119) for the NGC 2264 region (including several stars
observed but not included in their published catalog) using
Hectochelle and MIKE fibers. In addition to these data, we include new
observations from these instruments (spanning 2008 Oct to 2009 Dec)
and from the Michigan/Magellan Fiber System (M2FS).
We observed a total of four fields toward the ONC and two fields
toward NGC 2264 in 2013 November and 2014 February using M2FS. The MgI
filter was used covering a wavelength range of ∼5100-5210Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sources.dat 36 2057 List of sources from tables 2 and 3;
table added by CDS
table2.dat 85 8407 Sources that show no variation in radial velocity
between multiple observations (1927 unique sources)
table3.dat 97 633 Sources with variable radial velocity
(130 unique sources)
table4.dat 65 154 Sources that were surveyed for the presence of Li I
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See also:
J/ApJ/818/59 : IN-SYNC. IV. YSOs in Orion A (Da Rio+, 2016)
J/AJ/150/108 : Spectroscopy and HST imaging in ONC (O'Dell+, 2015)
J/AJ/149/119 : Radial velocities of stars in NGC 2264 (Tobin+, 2015)
J/A+A/564/A29 : Optical and near-infrared photometry in Orion A (Bouy+, 2014)
J/AJ/146/85 : Spectral types of optical stars in ONC (Hillenbrand+, 2013)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/138/963 : Rotation of NGC 2264 members (Baxter+, 2009)
J/ApJ/697/1103 : Kinematics of Orion Nebula Cluster (Tobin+, 2009)
J/ApJ/676/1109 : Velocities of stars in the ONC (Furesz+, 2008)
J/AJ/134/2272 : Visual binaries in the Orion Nebula Cluster (Reipurth+, 2007)
J/A+A/458/461 : Binary stars in the Orion Nebula Cluster (Koehler+, 2006)
J/ApJ/648/1090 : Radial velocities of NGC 2264 stars (Furesz+, 2006)
J/AJ/129/363 : Spectroscopy in Orion Nebula Cluster (Sicilia-Aguilar+, 2005)
J/AJ/114/2644 : UBVRIHa photometry of NGC2264 (Sung+, 1997)
J/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)
Byte-by-byte Description of file: sources.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Var "no"=no variation in RV (objects from table 2);
"var"=variable RV (objects from table 3)
5- 8 I4 --- Seq [1/2057] RV Sequencial Running number
10 A1 --- f_Seq [c] Variability Flag (G1)
12 I1 --- Reg [0/1] Region: 0=ONC; 1=NGC 2264
14- 15 I2 h RAh Hour of Right Ascension (J2000)
17- 18 I2 min RAm Minute of Right Ascension (J2000)
20- 24 F5.2 s RAs Second of Right Ascension (J2000)
26 A1 --- DE- Sign of the Declination (J2000)
27- 28 I2 deg DEd Degree of Declination (J2000)
30- 31 I2 arcmin DEm Arcminute of Declination (J2000)
33- 36 F4.1 arcsec DEs Arcsecond of Declination (J2000)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/2057] RV Sequencial Running number (1)
8 I1 --- Reg [0/1] Region: 0=ONC; 1=NGC 2264
10- 11 I2 h RAh Hour of Right Ascension (J2000)
13- 14 I2 min RAm Minute of Right Ascension (J2000)
16- 20 F5.2 s RAs Second of Right Ascension (J2000)
22 A1 --- DE- Sign of the Declination (J2000)
23- 24 I2 deg DEd Degree of Declination (J2000)
26- 27 I2 arcmin DEm Arcminute of Declination (J2000)
29- 32 F4.1 arcsec DEs Arcsecond of Declination (J2000)
34- 42 F9.1 d JD Julian Date of Observation
44- 49 F6.2 km/s HRV [-93/100] Heliocentric radial velocity
51- 55 F5.2 km/s e_HRV [0.2/15.1] Uncertainty in HRV
57- 61 F5.2 --- R [3/41] Cross-correlation signal to noise
63- 66 I4 K Teff [3500/7000] Effective Temperature from spectral
synthesis
68 A1 --- RR [0y] Filtering parameters (G2)
70- 85 A16 --- Inst Instrument and line used in Observation
(Hectochelle; MIKE; or M2FS Hα, Li, MgI,
Li+Hα)
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Note (1): Table includes sources with insufficient number of detections to
determine variability.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [10/2039] RV Sequencial Running number
6 A1 --- f_Seq [c] Variability Flag (G1)
10- 11 I2 h RAh Hour of Right Ascension (J2000)
13- 14 I2 min RAm Minute of Right Ascension (J2000)
16- 20 F5.2 s RAs Second of Right Ascension (J2000)
22 A1 --- DE- Sign of the Declination (J2000)
23- 24 I2 deg DEd Degree of Declination (J2000)
26- 27 I2 arcmin DEm Arcminute of Declination (J2000)
29- 32 F4.1 arcsec DEs Arcsecond of Declination (J2000)
34- 42 F9.1 d JD Julian Date of Observation
44- 49 F6.2 km/s HRV1 [-95/100]? Velocity of first component
51- 55 F5.2 km/s e_HRV1 [0.3/22]? Uncertainty in HRV1
57- 62 F6.2 km/s HRV2 [-58/114]? Velocity of second component (1)
64- 67 F4.2 km/s e_HRV2 [2/5]? Uncertainty in HRV2
69- 73 F5.2 --- R [3/38] Cross-correlation signal to noise
75- 78 I4 K Teff [3500/7000] Effective Temperature from spectral
synthesis
80 A1 --- RR [0y] Filtering parameters (G2)
82- 97 A16 --- Inst Instrument and line used in Observation
(Hectochelle; MIKE; or M2FS Hα, Li, MgI,
or Li+Hα)
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Note (1): v2 velocity obtained from the second peak of the cross-correlation
for double-lined binaries.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [113/2268] RV Sequencial Running number (1)
6- 7 I2 h RAh Hour of Right Ascension (J2000)
9- 10 I2 min RAm Minute of Right Ascension (J2000)
12- 16 F5.2 s RAs Second of Right Ascension (J2000)
18 A1 --- DE- [-] Sign of the Declination (J2000)
19- 20 I2 deg DEd Degree of Declination (J2000)
22- 23 I2 arcmin DEm Arcminute of Declination (J2000)
25- 28 F4.1 arcsec DEs Arcsecond of Declination (J2000)
30- 35 F6.2 km/s HRV [-35.4/82.1] Heliocentric Radial Velocity (2)
37- 41 F5.2 km/s e_HRV [0.3/13] Uncertainty in HRV
43- 47 F5.2 --- R-Li [3/25.2] Cross-correlation signal to noise
49- 55 F7.2 0.1nm l-Li [6708.1/6709.1]? Line center for LiI6707Å (3)
57- 60 F4.2 0.1nm EW-Li [0.1/1.9]? Equivalent Width of LiI6707Å,
in Angstroms (4)
62- 65 I4 K Teff [3500/7000] Effective Temperature from
spectral synthesis
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Note (1): Sources with Seq greater than 2057 have cross correlation R<6 for
all detections, and are not included in the Tables 2 and 3.
Note (2): Velocity and other properties were measured only from Li I data.
Note (3): Typical uncertainty in λ-Li is 0.01 Angstroms
Note (4): Typical uncertainty in EW-Li is 0.01 Angstroms
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Global notes:
Note (G1): Variability flag:
c = These objects had at least 4 R>6 measurements separated by more than
3 days with only single variable velocity observed.
Note (G2): Filtering parameters as follows:
0 = Filtering of low_bin=5, top_low=20, top_nrun=125, nrun=255 (default)
y = Filtering of low_bin=3, top_low=10, top_nrun=125, nrun=255 (rapid rotator)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 02-Jun-2016