J/A+A/652/A2 rho Oph region revisited with Gaia EDR3 (Grasser+, 2021)
The rho Oph region revisited with Gaia EDR3.
Two young populations, new members, and old impostors.
Grasser N., Ratzenboeck S., Alves J., Grossschedl J., Meingast S.,
Zucker C., Hacar A., Lada C., Goodman A., Lombardi M., Forbes J.C.,
Bomze I.M., Moeller T.
<Astron. Astrophys. 652, A2 (2021)>
=2021A&A...652A...2G 2021A&A...652A...2G (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Cross identifications ; Positional data
Keywords: astrometry - methods: data analysis - stars: formation -
stars: pre-main sequence
Abstract:
Young and embedded stellar populations are important probes of the
star formation process. Their properties and the environments they
create have the potential to affect the formation of new planets.
Paradoxically, we have a better census of nearby embedded young
populations than of the slightly more evolved optically visible young
populations. The high accuracy measurements and all-sky coverage of
Gaia data are about to change this situation. This work aims to
construct the most complete sample to date of YSOs in the ρ Oph
region. We compile a catalog of 1114 Ophiuchus YSOs from the
literature and crossmatch it with the Gaia EDR3, Gaia-ESO, and
APOGEE-2 surveys. We apply a multivariate classification algorithm to
this catalog to identify new, co- moving population candidates. We
find 191 high-fidelity new YSO candidates in the Gaia EDR3 catalog
belonging to the ρ Oph region. The new sources appear to be mainly
Class III M-stars and substellar objects and are less extincted than
the known members, while we find that 28 of previously unknown sources
are YSOs with circumstellar disks (Class I or Class II). The analysis
of the proper motion distribution of the entire sample reveals a
well-defined bimodality, implying two distinct populations sharing a
similar 3D volume. The first population comprises young stars'
clusters around the ρ Ophiuchi star and the main Ophiuchus clouds
(L1688, L1689, L1709). In contrast, the second population is slightly
older (∼10Myr), more dispersed, has a distinct proper motion, and is
possibly from the Upper-Sco group. The two populations are moving away
from each other at about 4.1km/s and will no longer overlap in about
4Myr. Finally, we flag 17 sources in the literature sample as likely
impostors, which are sources that exhibit large deviations from the
average properties of the ρ Oph population. Our results show the
importance of accurate 3D space and motion information for improved
stellar population analysis.
Description:
This work is based on studies of ρ Oph and L1688 from 11 papers.
Additionally, three surveys were selected for cross-matching with our
literature sample to obtain astrometric data (proper motions, and
radial velocities) of the sources, which is essential for identifying
new sources with the algorithm.
Proper motions and parallaxes were obtained from Gaia EDR3 (Gaia
Collaboration et al., 2020A&A...649A...1G 2020A&A...649A...1G, Cat. I/350). To complement
Gaia astrometry and constrain the models of the algorithm, we combine
it with radial velocities from APOGEE-2 (Majewski et al.,
2017AJ....154...94M 2017AJ....154...94M, Cat. III/284), a large-scale spectroscopic survey
conducted in the near-infrared, and Gaia-ESO (Gilmore et al.,
2012Msngr.147...25G 2012Msngr.147...25G), a spectroscopic survey by the European Southern
Observatory (ESO) combined with the Gaia astrometry catalog. Radial
velocities from these surveys deliver superior resolution and
statistics compared to radial velocities from Gaia.
We applied the classification strategy described in Ratzenboeck et al.
(2012A&A...539A..64A 2012A&A...539A..64A) for identifying new members of the ρ Oph
region in the Gaia EDR3 catalog.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tableh1.dat 1005 1343 Final catalog of ρ Oph (known and new sources)
--------------------------------------------------------------------------------
See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
Byte-by-byte Description of file: tableh1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaEDR3 ?=0 Gaia EDR3 ID (sourceidedr3)
21- 38 F18.14 deg RAdeg Right ascension (J2000) (ra)
40- 58 F19.15 deg DEdeg Declination (J2000) (dec)
60- 77 F18.14 deg GLON Galactic longitude (l)
79- 96 F18.15 deg GLAT Galactic latitude (b)
98- 115 F18.16 mas plx ? Parallax (parallax)
117- 136 F20.18 mas e_plx ? Parallax error (parallax_error)
138- 155 F18.14 pc Dist ? Distance (distance)
157- 177 F21.17 mas/yr pmRA ? Proper motion in ra (pmra)
179- 198 F20.18 mas/yr e_pmRA ? Error in pmra (pmra_error)
200- 218 F19.15 mas/yr pmDE ? Proper motion in dec (pmdec)
220- 239 F20.18 mas/yr e_pmDE ? Error in pmdec (pmdec_error)
241- 262 F22.17 km/s RV ? Heliocentric radial velocity
(radial_velocity)
264- 285 F22.19 km/s e_RV ? Error in radial velocity
(radialvelocityerror)
287- 308 F22.18 km/s VTRA ? Tangential velocity in RA (v_alpha)
310- 329 F20.18 km/s e_VTRA ? Error in VTRA (valphaerror)
331- 349 F19.15 km/s VTDE ? Tangential velocity in DE (v_delta)
351- 370 F20.18 km/s e_VTDE ? Error in VTDE (vdeltaerror)
372- 389 F18.14 pc X ? Galactic Cartesian X position (X)
391- 409 F19.15 pc Y ? Galactic Cartesian Y position (Y)
411- 428 F18.15 pc Z ? Galactic Cartesian Z position (Z)
430- 450 F21.16 km/s U ? Galactic Cartesian U velocity (U)
452- 470 F19.15 km/s V ? Galactic Cartesian V velocity (V)
472- 491 F20.16 km/s W ? Galactic Cartesian W velocity (W)
493- 503 F11.8 --- RUWE ? Renormalized unit weight error (ruwe)
505- 515 F11.9 --- amax ? Longest principal axis in the
5-dimensional error ellipsoid
(astrometricsigma5dmax)
517- 522 I6 --- Solved Which parameters have been solved for
(astrometricparamssolve)
524- 529 I6 --- Nper Number of visibility periods
(visibilityperiodsused)
531- 550 E20.15 e-/s FG ? G-band mean flux (photgmean_flux)
552- 566 F15.8 e-/s e_FG ? Error on G-band mean flux
(photgmeanfluxerror)
568- 577 F10.7 mag BPmag ? G-band mean magnitude (photbpmean_mag)
579- 588 F10.7 mag Gmag ? Integrated BP mean magnitude
(photgmean_mag)
590- 599 F10.7 mag RPmag ? Integrated RP mean magnitude
(photrpmean_mag)
601- 619 F19.17 --- BP-RP ? BP-RP color (bp_rp)
621 I1 --- Train [0/1] =1 for sources in the training set
(Train)
623 I1 --- Predict [0/1] =1 for predicted sources in
Gaia EDR3 (Predict)
625 I1 --- New [0/1] =1 for new sources in Gaia EDR3
(New)
627- 649 F23.19 --- Stability [0/100] Stability of the sources
(Stability)
651 I1 --- Impostors [0/1] =1 for impostor sources (Impostors)
653- 671 F19.15 mas/yr pmGLON ? Proper motion in l (pml)
673- 692 F20.16 mas/yr pmGLAT ? Proper motion in b (pmb)
694- 712 F19.15 km/s VGLON ? Velocity in l (v_l)
714- 733 F20.16 km/s VGLAT ? Velocity in b (v_b)
735- 752 F18.14 deg AngGLONH ? Heliocentric proper motion angle
to l-axis (anglelhel)
754- 776 F23.19 mas/yr pmGLONlsr ? Proper motion in l (LSR) (pml_lsr)
778- 799 E22.17 mas/yr pmGLATlsr ? Proper motion in b (LSR) (pmb_lsr)
801- 822 F22.18 km/s VGLONlsr ? Velocity in l (LSR) (vllsr)
824- 844 E21.16 km/s VGLATlsr ? Velocity in b (LSR) (vblsr)
846- 863 F18.14 deg AngGLONlsr ? LSR proper motion angle to
l-axis (anglellsr)
865 I1 --- Pop Popultion (2) (Pop) (1)
867 I1 --- IRexcess ? IR_excess (3) (IR_excess) (2)
869- 884 A16 --- 2MASS 2MASS ID, HHMMSSss+DDMMSSs
(designation_2MASS)
886- 891 F6.3 mag Jmag ? J-band magnitude (j_m)
893- 897 F5.3 mag e_Jmag ? Uncertainty in Jmag (j_cmsig)
899- 904 F6.3 mag Hmag ? H-band magnitude (h_m)
906- 910 F5.3 mag e_Hmag ? Uncertainty in Hmag (h_cmsig)
912- 917 F6.3 mag Kmag ? K-band magnitude (k_m)
919- 923 F5.3 mag e_Kmag ? Uncertainty in Kmag (k_cmsig)
925- 943 A19 --- WISE WISE ID, JHHMMSs.ss+DDMMSS.s
(designation_WISE)
945- 950 F6.3 mag W1mag ? WISE W1 magnitude (w1mpro)
952- 955 F4.1 --- W1snr ? W1 signal-to-noise ratio (w1snr)
957- 962 F6.3 mag W2mag ? WISE W2 magnitude (w2mpro)
964- 967 F4.1 --- W2snr ? W2 signal-to-noise ratio (w2snr)
969- 974 F6.3 mag W3mag ? WISE W3 magnitude (w3mpro)
976- 980 F5.1 --- W3snr ? W3 signal-to-noise ratio (w3snr)
983-1001 A19 --- Ref Reference for literature sources
(Ref) (3)
1003-1005 A3 --- r_RV Reference for proper motions and
radial velocity (Refpmrv) (4)
--------------------------------------------------------------------------------
Note (1): Pop as follows:
1 = for Pop 1 sources
2 = for Pop 2 sources
0 = if neither
Note (2): IR excess as follows:
1 = for YSOs with IR excess
0 = for Class III sources
Note (3): References as follows:
1 = Greene et al., 1994ApJ...434..614G 1994ApJ...434..614G
2 = Haisch et al., 2002AJ....124.2841H 2002AJ....124.2841H
3 = Padgett et al., 2008ApJ...672.1013P 2008ApJ...672.1013P
4 = Wilking et al., 2008hsf2.book..351W 2008hsf2.book..351W
5 = Evans et al., 2009ApJS..181..321E 2009ApJS..181..321E, Cat. J/ApJS/181/321
6 = Dunham et al., 2015ApJS..220...11D 2015ApJS..220...11D, Cat. J/ApJS/220/11
7 = Rigliaco et al., 2016A&A...588A.123R 2016A&A...588A.123R
8 = Ducourant et al., 2017A&A...597A..90D 2017A&A...597A..90D, Cat. J/A+A/597/A90
9 = Canovas et al., 2019A&A...626A..80C 2019A&A...626A..80C, Cat. J/A+A/626/A80
10 = Sullivan et al., 2019AJ....158...41S 2019AJ....158...41S
11 = Esplin & Luhman, 2020AJ....159..282E 2020AJ....159..282E, Cat. J/AJ/159/282
Note (4): References as follows:
1 = literature
2 = Gaia EDR3, Cat. I/350
3 = APOGEE
4 = Gaia-ESO
--------------------------------------------------------------------------------
Acknowledgements:
Natalie Grasser, natalie.grasser(at)univie.ac.at
(End) Patricia Vannier [CDS] 08-Jun-2021