J/A+A/608/A95 GES: multi-line spectroscopic binary candidates (Merle+, 2017)
The Gaia-ESO Survey:
double-, triple-, and quadruple-line spectroscopic binary candidates.
Merle T., Van Eck S., Jorissen A., Van der Swaelmen M., Masseron T.,
Zwitter T., Hatzidimitriou D., Klutsch A., Pourbaix D., Blomme R.,
Worley C.C., Sacco G., Lewis J., Abia C., Traven G., Sordo R.,
Bragaglia A., Smiljanic R., Pancino E., Damiani F., Hourihane A.,
Gilmore G., Randich S., Koposov S., Casey A., Morbidelli L.,
Franciosini E., Magrini L., Jofre P., Costado M.T., Jeffries R.D.,
Bergemann M., Lanzafame A.C., Bayo A., Carraro G., Flaccomio E., Monaco L.,
Zaggia S.
<Astron. Astrophys., 608, A95 (2017)>
=2017A&A...608A..95M 2017A&A...608A..95M (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Radial velocities
Keywords: binaries: spectroscopic - techniques: radial velocities -
methods: data analysis - open clusters and associations: general -
globular clusters: general
Abstract:
The Gaia-ESO Survey (GES) is a large spectroscopic survey that
provides a unique opportunity to study the distribution of
spectroscopic multiple systems among different populations of the
Galaxy. Aims. Our aim is to detect binarity/multiplicity for stars
targeted by the GES from the analysis of the cross-correlation
functions (CCFs) of the GES spectra with spectral templates.
We developed a method based on the computation of the CCF successive
derivatives to detect multiple peaks and determine their radial
velocities, even when the peaks are strongly blended. The parameters
of the detection of extrema (DOE) code have been optimized for each
GES GIRAFFE and UVES setup to maximize detection. The DOE code
therefore allows to automatically detect multiple line spectroscopic
binaries (SBn, n≥2).
We apply this method on the fourth GES internal data release and
detect 354 SBn candidates (342 SB2, 11 SB3, and even one SB4),
including only nine SBs known in the literature. This implies that
about 98% of these SBn candidates are new because of their faint
visual magnitude that can reach V=19.
Visual inspection of the SBn candidate spectra reveals that the most
probable candidates have indeed a composite spectrum. Among the SB2
candidates, an orbital solution could be computed for two previously
unknown binaries: CNAME 06404608+0949173 (known as V642 Mon) in NGC
2264 and CNAME 19013257-0027338 in Berkeley 81 (Be 81). A detailed
analysis of the unique SB4 (four peaks in the CCF) reveals that CNAME
08414659-5303449 (HD 74438) in the open cluster IC 2391 is a
physically bound stellar quadruple system. The SB candidates belonging
to stellar clusters are reviewed in detail to discard false
detections. We suggest that atmospheric parameters should not be used
for these system components; SB-specific pipelines should be used
instead.
Our implementation of an automatic detection of spectroscopic binaries
within the GES has allowed the efficient discovery of many new
multiple systems. With the detection of the SB1 candidates that will
be the subject of a forthcoming paper, the study of the statistical
and physical properties of the spectroscopic multiple systems will
soon be possible for the entire GES sample.
Description:
Our analysis was performed on the iDR4 consisting of ∼260000 single
exposures (corresponding to ∼100 000 stacked spectra) of about 51000
distinct stars observed with the FLAMES instrument feeding the optical
spectrographs GIRAFFE (with setups HR3, HR5A, HR6, HR9B, HR10, HR14A,
HR15N, HR15, HR21) and UVES (with setups U520 and U580) covering the
optical and near-IR wavelength ranges.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 69 185 List of SB2 candidates in the field ordered
by right ascension
tablea2.dat 75 5 List of SB3 candidates in the field ordered
by right ascension
tableb1.dat 89 32 List of SB2 candidates in selected fields
ordered by right ascension
tablec1a.dat 30 24 Cluster informations
tablec1.dat 142 132 SB2, SB3, and SB4 candidates in clusters ordered
by increasing identifier
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- CName GES name (HHMMSSss+DDMMSSs, J2000)
18- 22 A5 --- Flag Final flag after visual inspection (G1)
24 I1 --- Nexp Number of exposures available for that star
26- 27 I2 --- NSp Number of available spectra (G2)
29- 37 A9 --- Setup Spectrograph setup(s)
39- 47 F9.3 d MJD Modified Julian date of the unique
observation listed
49- 55 F7.2 km/s RV1 Radial velocity of first component
57- 63 F7.2 km/s RV2 Radial velocity of second component
65- 69 F5.2 mag Vmag Visual magnitude of the source
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- CName GES name (HHMMSSss+DDMMSSs, J2000)
18- 22 A5 --- Flag Final flag after visual inspection (G1)
24 I1 --- Nexp Number of exposures available for that star
26- 27 I2 --- NSp Number of available spectra (G2)
29- 37 A9 --- Setup Spectrograph setup(s)
39- 47 F9.3 d MJD Modified Julian date of the unique
observation listed
49- 55 F7.2 km/s RV1 Radial velocity of first component
57- 62 F6.2 km/s RV2 Radial velocity of second component
64- 69 F6.2 km/s RV3 Radial velocity of third component
71- 75 F5.2 mag Vmag Visual magnitude of the source
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Field Field name (1)
14- 29 A16 --- CName GES name (HHMMSSss+DDMMSSs, J2000)
31- 35 A5 --- Flag Final flag after visual inspection (G1)
37- 38 I2 --- Nexp Number of exposures available for that star
40- 41 I2 --- NSp Number of available spectra (G2)
43- 57 A15 --- Setup Spectrograph setup(s)
59- 67 F9.3 d MJD Modified Julian date of the unique
observation listed
69- 75 F7.2 km/s RV1 Radial velocity of first component
77- 82 F6.2 km/s RV2 Radial velocity of second component
84- 88 F5.2 mag Vmag Visual magnitude of the source
89 A1 --- n_Vmag [b] Note on Vmag (2)
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Note (1): See text for references regarding target selection and membership
assessement in those fields.
Note (2): b: The visual magnitude of this star was incorrectly assessed by CASU.
The closest star resolved in Simbad is at a distance of 42.88 arcsec and
corresponds to CoRoT 100791478.
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Byte-by-byte Description of file: tablec1a.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Cluster Cluster name
13- 17 F5.2 [yr] logAge Cluster age
19- 24 F6.2 km/s RV Cluster radial velocity
26- 29 F4.2 km/s e_RV ? rms uncertainty on RV
30 A1 --- m_Cluster [AB] For NGC 2451
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Byte-by-byte Description of file: tablec1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 A12 --- Cluster Cluster name
13- 28 A16 --- CName GES name (HHMMSSss+DDMMSSs, J2000)
30- 34 A5 --- Flag Final flag after visual inspection (G1)
36- 37 I2 --- Nexp Number of exposures available for that star
39- 41 I3 --- NSp Number of available spectra (G2)
43- 76 A34 --- Setup Spectrograph setup(s)
78- 86 F9.3 d MJD Modified Julian date of the unique
observation listed
88- 94 F7.2 km/s RV1 Radial velocity of first component
96-101 F6.2 km/s RV2 Radial velocity of second component
103-108 F6.2 km/s RV3 ? Radial velocity of third component
110-113 A4 --- SB SB type
115 A1 --- Memb [yn] whether the SB candidate belongs to the
cluster or not (see Sect. 4.2) ?
116 A1 --- u_Memb [?] Uncertainy flag on Memb
118-142 A25 --- Rem Additional information after detailed
inspection of their spectra and CCFs(1)
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Note (1): Codes as:
CS: composite spectrum
1RRC/2RRC: one or two rapidly rotating component(s)
PULS: pulsating star
δ Scu: probable δ Scu type star
Hαe: Hα with emission
NaDe: Na I D with emission
NLC: nebular line contamination
ILC: interstellar line contamination
XR: X-ray source
ORB: orbit calculated
ST: see text for additional information
The "?" indicates some uncertainty in the preceding characterization.
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Global notes:
Note (G1): The choice of the final flag for an object can be downgraded if other
CCFs provide discrepant results. This procedure ensures that processes other
than binarity moderately contaminate SB candidates flagged C,
marginally contaminate SB candidates flagged B, and
exceptionally contaminate those flagged A.
Note (G2): larger than the number of exposures in the case of UVES data which
provide two spectra per exposure)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Feb-2018