J/A+A/686/A161 Fine structure in the Sigma Orionis cluster (Zerjal+, 2024)
Fine structure in the Sigma Orionis cluster revealed by Gaia DR3.
Zerjal M., Martin E.L., Perez-Garrido A.
<Astron. Astrophys. 686, A161 (2024)>
=2024A&A...686A.161Z 2024A&A...686A.161Z (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Spectroscopy
Keywords: catalogues - stars: kinematics and dynamics -
open clusters and associations: individual: Sigma Orionis
Abstract:
Sigma Orionis is an open cluster in the nearest giant star formation
site -- Orion. Its youth (3-5Myr), low reddening, and relative
vicinity make it an important benchmark cluster to study stellar and
substellar formation and evolution. Young star-forming sites are
complex and hierarchical. Precision astrometry from Gaia DR3 enables
the exploration of their fine structure. We used the modified
convergent point technique to kinematically re-evaluate the members in
the Sigma Orionis cluster and its vicinity. We present clear evidence
for three kinematically distinct groups in the Sigma Orionis region.
The second group, the RV Orionis association, is adjacent to the Sigma
Orionis cluster and is composed only of low-mass stars. The third
group, the Flame association, whose age is comparable to that of Sigma
Orionis, overlaps with the younger NGC 2024 in the Flame Nebula. In
total, we have discovered 105 members of this complex not previously
found in the literature (82 in Sigma Orionis, 19 in the Flame
association, and 4 in the RV Orionis association).
Description:
Table A1 contains members of the Sigma Orionis cluster in the Gaia
DR3 catalogue determined with the kinematic method. Table C1 is a
compilation of spectroscopic youth indicators (lithium, sodium and
Halpha) and spectral types from the literature.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 271 322 Members of Sigma Orionis
tablec1.dat 172 136 Spectroscopic indicators and spectral types
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source_id (source_id)
21- 37 F17.14 deg RAdeg Right ascension (ICRS) at Ep=2016.0 (ra)
39- 57 F19.16 deg DEdeg Declination (ICRS) at Ep=2016.0 (dec)
59- 79 F21.18 mas/yr pmRA Proper motion in RA (pmra)
81-101 F21.18 mas/yr pmDE Proper motion in Dec (pmdec)
103-120 F18.16 mas plx Parallax (parallax)
122-141 F20.18 mas e_plx Parallax error (parallax_error)
143-162 F20.16 km/s RV ?=- Radial velocity (radial_velocity)
164-183 F20.17 km/s e_RV ?=- Radial velocity error
(radialvelocityerror)
185 I1 --- r_RV [1/2]?=- Radial velocity reference
(radialvelocityreference2) (1)
187-197 F11.8 --- RUWE ?=- Ruwe from Gaia DR3 (ruwe)
199-216 F18.15 mag Gmag ?=- G magnitude from Gaia DR3
(photgmean_mag)
218-238 F21.18 mag G-RP ?=- G-RP color from Gaia DR3 (G-Rp)
240-252 A13 --- Memb Cluster membership (memb)
254-263 F10.7 --- c Membership parameter (c)
265-271 A7 --- outlier Outlier type (outlier)
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Note (1): References as follows:
1 = Gaia DR3, Cat. I/355
2 = Sacco et al. (2008A&A...488..167S 2008A&A...488..167S, Cat. J/A+A/488/167)
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source_id (source_id)
21- 39 F19.17 0.1nm pEWLi ?=- Pseudo equivalent width of lithium
(pEWLi)
41- 61 F21.19 0.1nm e_pEWLi ?=- Pseudo equivalent width of lithium error
(epEWLi)
63- 67 A5 --- r_pEWLi Reference for pEWLi (refLi) (1)
69- 89 F21.17 0.1nm EWHa ?=- Equivalent width of Halpha (EWHa)
91-111 F21.18 0.1nm e_EWHa ?=- Equivalent width of Halpha error (eEWHa)
113-117 A5 --- r_EWHa Reference for EWHa (refHa) (1)
119 A1 --- veiled? [Y/N] Is a star veiled?
[Y: yes, N: no] (veiledYN)
121-138 F18.16 0.1nm pEWNa ?=- Pseudo equivalent width of sodium (pEWNa)
140-159 F20.18 0.1nm e_pEWNa ?=- Pseudo equivalent width of sodium error
(epEWNa)
161-165 A5 --- r_pEWNa Reference for pEWNa (refNa) (1)
167-170 A4 --- SpType Spectral type (SpT)
172 I1 --- r_SpType ? Spectral type reference (refSpT) (1)
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Note (1): References as follows:
2 = Sacco et al., 2008A&A...488..167S 2008A&A...488..167S, Cat. J/A+A/488/167
3 = Caballero et al., 2019A&A...629A.114C 2019A&A...629A.114C, Cat. J/A+A/629/A114
4 = Kenyon et al., 2005MNRAS.356...89K 2005MNRAS.356...89K, Cat. J/MNRAS/356/89
5 = Maxted et al.,, 2008MNRAS.385.2210M 2008MNRAS.385.2210M, Cat. J/MNRAS/385/2210
6 = Zapatero Osorio et al., 2002A&A...384..937Z 2002A&A...384..937Z
7 = Hernandez et al., 2014ApJ...794...36H 2014ApJ...794...36H, Cat. J/ApJ/794/36
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Acknowledgements:
Maruska Zerjal, mzerjal(at)iac.es
(End) Patricia Vannier [CDS] 06-Apr-2024