J/A+A/667/A163 Upper Scorpius and Ophiuchus members (Miret-Roig+, 2022)
The star formation history of Upper Scorpius and Ophiuchus.
A 7D picture: positions, kinematics, and dynamical traceback ages.
Miret-Roig N., Galli P.A.B., Olivares J., Bouy H., Alves J., Barrado D.
<Astron. Astrophys. 667, A163 (2022)>
=2022A&A...667A.163M 2022A&A...667A.163M (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Radial velocities ; Optical
Keywords: stars: formation - stars: kinematics and dynamics -
Galaxy: kinematics and dynamics - solar neighborhood -
open clusters and associations: individual: Ophiuchus -
open clusters and associations: individual: Upper Scorpius
Abstract:
Understanding how star formation begins and propagates through
molecular clouds is a fundamental but still open question.
One major difficulty in addressing this question is the lack of
precise 3D kinematics and age information of young stellar
populations. Thanks to Gaia's astrometry, large spectroscopic surveys,
and improved age-dating methods, this picture is changing.
We aim to study spatial and kinematic substructures of the region
encompassed by Upper Scorpius and Ophiuchus star forming regions. We
want to determine dynamical traceback ages and study the star
formation history of the complex.
We combined our spectroscopic observations with spectra in public
archives and large radial velocity surveys to obtain a precise radial
velocity sample to complement the Gaia astrometry. We used a Gaussian
Mixture Model to identify different kinematic structures in the 6D
space of positions and velocities. We applied an orbital traceback
analysis to estimate a dynamical traceback age for each group and
determine the place where it was born.
We identified seven different groups in this region. Four groups
(nu Sco, beta Sco, sigma Sco and delta Sco) are part of Upper
Scorpius, two groups (rho Oph and alpha Sco) are in Ophiuchus, and
another group (pi Sco) is a nearby young population. We found an age
gradient from the rho Oph group (the youngest) to the delta Sco group
(≲5Myr), showing that star formation was a sequential process for the
past 5Myr. Our traceback analysis shows that Upper Scorpius and rho
Oph groups share a common origin. The closer group of pi Sco is
probably older, and the traceback analysis suggests that this group
and the alpha Sco group have a different origin, likely related to
other associations in the Sco-Cen complex.
Our study shows that this region has a complex star formation history
that goes beyond the current formation scenario, likely a result of
stellar feedback from massive stars, supernovae explosions, and
dynamic interactions between stellar groups and the molecular gas. In
particular, we speculate that photo-ionisation from the massive
delta Sco star could have triggered star formation first in the beta
Sco group and then in the nu Sco group. The perturbations of stellar
orbits due to stellar feedback and dynamical interactions could also
be responsible for the 1-3Myr difference that we found between
dynamical traceback ages and isochronal ages.
Description:
This table contains new radial velocities measured in this study and
the membership to the different sub-populations identified in this
study.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 3444 2812 New radial velocities measured and membership
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID [1/3457] Internal identification
6- 24 I19 --- GaiaDR3 ?=- Gaia DR3 source id
26- 56 A31 --- Name Simbad name
58- 72 F15.11 deg RAdeg Right ascension (ICRS) at Ep=2016.0
74- 88 F15.11 deg DEdeg Declination (ICRS) at Ep=2016.0
90- 104 F15.11 pc X ?=- Galactic Heliocentric X coordinate
106- 120 F15.11 pc Y ?=- Galactic Heliocentric Y coordinate
122- 136 F15.11 pc Z ?=- Galactic Heliocentric Z coordinate
138- 145 F8.4 km/s U ?=- Heliocentric U velocity
147- 154 F8.4 km/s V ?=- Heliocentric V velocity
156- 163 F8.4 km/s W ?=- Heliocentric W velocity
165- 179 F15.12 pc e_X ?=- Uncertainty in Galactic Heliocentric
X coordinate
181- 195 F15.12 pc e_Y ?=- Uncertainty in Galactic Heliocentric
Y coordinate
197- 211 F15.12 pc e_Z ?=- Uncertainty in Galactic Heliocentric
Z coordinate
213- 220 F8.5 km/s e_U ?=- Uncertainty in Heliocentric U velocity
222- 229 F8.5 km/s e_V ?=- Uncertainty in Heliocentric V velocity
231- 238 F8.5 km/s e_W ?=- Uncertainty in Heliocentric W velocity
240 I1 --- memb5D [0/1] Bonafide member with 5D astrometry
(see text)
242 I1 --- memb6D [0/1] Bonafide member with 5D astrometry +
radial velocity (see text)
244- 252 F9.6 mag Gmag ?=- Gaia DR3 G band photometry
254- 262 F9.6 mag BPmag ?=- Gaia DR3 BP band photometry
264- 272 F9.6 mag RPmag ?=- Gaia DR3 RP band photometry
274- 288 F15.11 deg GLON []?=- Galactic longitude
290- 304 F15.11 deg GLAT ?=- Galactic latitude
306- 868 A563 --- allRV Individual radial velocity measurements,
in km/s
870-2296 A1427 --- e_allRV Uncertainty in individual radial velocity
measurements, in km/s
2298-2307 F10.5 km/s RV ?=- Final radial velocity measured in this
study
2309-2317 F9.6 km/s e_RV ?=- Uncertainty in final radial velocity
measured in this study
2319-2337 A19 --- r_RV Reference of the instruments used
2339-3432 A1094 --- allMJD Julian date of the individual radial
velocity measurements
3434 I1 --- Bin [0/1] Boolean suspected binary (see text)
3436-3444 A9 --- GroupName Membership (1)
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Note (1): Group names:
alpha_Sco, beta_Sco, delta_Sco, nu_Sco, pi_Sco, rho_Oph or sigma_Sco
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Acknowledgements:
Nuria Miret-Roig, nuria.miret.roig(at)univie.ac.at
(End) Patricia Vannier [CDS] 26-Sep-2022