J/MNRAS/487/2977 Runaway stellar groups in the Orion A cloud (Getman+, 2019)
Gaia stellar kinematics in the head of the Orion A cloud:
runaway stellar groups and gravitational infall.
Getman K.V., Feigelson E.D., Kuhn M.A., Garmire G.P.
<Mon. Not. R. Astron. Soc., 487, 2977-3000 (2019)>
=2019MNRAS.487.2977G 2019MNRAS.487.2977G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, early-type ; Stars, pre-main sequence ; Clusters, open ;
Parallaxes, trigonometric ; Proper motions ; Magnitudes ;
Radial velocities ; Stars, ages ; Infrared ; Optical ;
X-ray sources
Keywords: stars: early-type - stars: formation - stars: pre-main sequence -
open clusters and associations: general - infrared: stars -
X-rays: stars
Abstract:
This work extends previous kinematic studies of young stars in the
head of the Orion A cloud (OMC-1/2/3/4/5). It is based on large
samples of infrared, optical, and X-ray selected pre-main-sequence
stars with reliable radial velocities and Gaia-derived parallaxes and
proper motions. Stellar kinematic groups are identified assuming they
mimic the motion of their parental gas. Several groups are found to
have peculiar kinematics: the NGC 1977 cluster and two stellar groups
in the extended Orion nebula (EON) cavity are caught in the act of
departing their birthplaces. The abnormal motion of NGC 1977 may have
been caused by a global hierarchical cloud collapse, feedback by
massive Ori OB1ab stars, supersonic turbulence, cloud-cloud collision,
and/or slingshot effect; the former two models are favoured by us. EON
groups might have inherited anomalous motions of their parental
cloudlets due to small-scale 'rocket effects' from nearby OB stars. We
also identify sparse stellar groups to the east and west of Orion A
that are drifting from the central region, possibly a slowly expanding
halo of the Orion nebula cluster. We confirm previously reported
findings of varying line-of-sight distances to different parts of the
cloud's Head with associated differences in gas velocity. 3D movies of
star kinematics show contraction of the groups of stars in OMC-1 and
global contraction of OMC-123 stars. Overall, the head of Orion A
region exhibits complex motions consistent with theoretical models
involving hierarchical gravitational collapse in (possibly turbulent)
clouds with OB stellar feedback.
Description:
To produce a rich sample of Gaia young stars in the Orion A region, we
combine data from several different young stellar catalogues. We
utilize X-ray/IR data from the Star Formation in Nearby Clouds project
(SFiNCs; Getman et al. 2017ApJS..229...28G 2017ApJS..229...28G, Cat. J/ApJS/229/28) and
the Chandra Orion Ultradeep Project (COUP; Getman et al.
2005ApJS..160..319G 2005ApJS..160..319G, Cat. J/ApJS/160/319); the latter is part of the
Massive Young Star-Forming Complex Study in Infrared and X-ray
(MYStIX; Broos et al. 2013ApJS..209...32B 2013ApJS..209...32B, Cat. J/ApJS/209/32). The
COUP-MYStIX observations, centred on the Trapezium core of the ONC
cluster, cover about 17x17arcmin2 area on the sky. The SFiNCs
observations encompass the NGC 1977, OMC-2/3, and OMC-4 regions,
covering three 17x17arcmin2 and three roughly 20x30arcmin2 areas
with Chandra and Spitzer, respectively. We add optical/IR young stars
from Furesz et al. (2008ApJ...676.1109F 2008ApJ...676.1109F, Cat. J/ApJ/676/1109) and
Tobin et al. (2009ApJ...697.1103T 2009ApJ...697.1103T, Cat. J/ApJ/697/1103) that were
selected on the basis of their 2MASS, Spitzer-IRAC, radial velocity,
and Hα emission properties. These catalogues cover the
83.4<α<84.3deg and -6.6<δ←4.4deg stripe on the sky
(roughly 55x130arcmin2) encompassing the NGC 1977, OMC-1/2/3/4/5,
and L1641-N regions. We also incorporate the catalogue of young stars
from Da Rio et al. (2012ApJ...748...14D 2012ApJ...748...14D, Cat. J/ApJ/748/14), selected
on the basis of their optical/IR photometry and spectroscopy; these
lie within the area of roughly 33x33arcmin2 enclosing OMC-1 and part
of OMC-4. The catalogue of young stars from Da Rio et al.
(2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59) is added; it is composed of
IR-bright stars whose youthfulness was supported by various
IR/optical/X-ray indicators from the literature as well as by a
follow-up near-IR APOGEE spectroscopy. This catalogue covers the
entire Orion A cloud, approximately within the sky band of
Δα=1.1deg and -9.7<δ←4.1deg. We also include the
Spitzer-selected discy young stellar objects (YSOs) from Megeath et
al. (2012AJ....144..192M 2012AJ....144..192M, Cat. J/AJ/144/192); its coverage of Orion A
is roughly similar to that of the Da Rio et al. (2016ApJ...818...59D 2016ApJ...818...59D,
Cat. J/ApJ/818/59) catalogue. Finally, the large VISTA catalog of
near-IR JHKs (Meingast et al. 2016A&A...587A.153M 2016A&A...587A.153M, Cat.
J/A+A/587/A153) and mid-IR Spitzer-IRAC (Megeath et al.
2012AJ....144..192M 2012AJ....144..192M, Cat. J/AJ/144/192) point sources covering the
entire Orion A are accessed.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 94 1487 Gaia-selected catalogue of young stars in
Orion A; Gaia properties
tablea2.dat 80 1487 Gaia-selected catalogue of young stars in
Orion A; Other properties
tablea3.dat 83 2752 Catalogue of young stars with radial velocities
in Orion A
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJS/229/28 : SFiNCs: X-ray, IR and membership catalogs (Getman+, 2017)
J/ApJS/209/32 : Probable young stars in the MYStIX project (Broos+, 2013)
J/ApJ/676/1109 : Velocities of stars in the Orion Nebula Cluster
(Furesz+, 2008)
J/ApJ/697/1103 : Kinematics of Orion Nebula Cluster (Tobin+, 2009)
J/ApJ/748/14 : ONC population data from WFI observations (Da Rio+, 2012)
J/ApJ/818/59 : IN-SYNC. IV. YSOs in Orion A (Da Rio+, 2016)
J/AJ/144/192 : Spitzer survey of Orion A and B. I. YSO catalog
(Megeath+, 2012)
J/A+A/587/A153 : VISION I. VISTA Orion A Survey (Meingast+, 2016)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 29 F9.6 deg RAdeg Right ascension (J2000)
31- 39 F9.6 deg DEdeg Declination (J2000)
41- 45 F5.3 mas plx Parallax
47- 51 F5.3 mas e_plx Error on plx (1)
53- 59 F7.3 mas/yr pmRA Proper motion in right ascension
61- 65 F5.3 mas/yr e_pmRA Error on pmRA
67- 73 F7.3 mas/yr pmDE Proper motion in declination
75- 79 F5.3 mas/yr e_pmDE Error on pmDE
81- 86 F6.3 mag Gmag Gaia DR2 G-band magnitude
88- 92 F5.3 mag e_Gmag Error on Gmag
94 I1 --- FEC [0/1] Flag indicating Gaia photometric BP/RP
flux excess (2)
--------------------------------------------------------------------------------
Note (1): Only stars with statistical error e_plx<0.1mas are included in this
catalogue
Note (2): Flag as follows:
1 = Flux excess is small, (IBP+IRP)/IG<1.35+0.06x(GBP-GRP)2
(Evans et al. 2018A&A...616A...4E 2018A&A...616A...4E)
0 = Otherwise
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21 I1 --- Cat1 [0/1] Flag indicating the presence of the Gaia
source in the MYStIX/SFiNCs catalogues (G1)
22 I1 --- Cat2 [0/1] Flag indicating the presence of the Gaia
source in Furesz et al. (2008) catalogue (G2)
23 I1 --- Cat3 [0/1] Flag indicating the presence of the Gaia
source in Tobin et al. (2009) catalogue (G3)
24 I1 --- Cat4 [0/1] Flag indicating the presence of the Gaia
source in Da Rio et al. (2012) catalogue (G4)
25 I1 --- Cat5 [0/1] Flag indicating the presence of the Gaia
source in Da Rio et al. (2016) catalogue (G5)
26 I1 --- Cat6 [0/1] Flag indicating the presence of the Gaia
source in Megeath et al. (2012) catalogue (G6)
28- 33 F6.3 mag Jmag ? J-band magnitude from Meingast et al.
(2016A&A...587A.153M 2016A&A...587A.153M, Cat. J/A+A/587/A153)
35- 39 F5.3 mag e_Jmag ? Error on Jmag
41- 46 F6.3 mag Hmag ? H-band magnitude from Meingast et al.
(2016A&A...587A.153M 2016A&A...587A.153M, Cat. J/A+A/587/A153)
48- 52 F5.3 mag e_Hmag ? Error on Hmag
54- 57 F4.1 mag Av ? Visual source extinction based on the
extinction scale from Da Rio et al.
(2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59) (1)
59- 63 F5.1 Myr AgeD16 ? Stellar age estimate from Da Rio et al.
(2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59) (2)
65- 67 F3.1 Myr AgeJX ? Age from MYStIX (Getman et al.
2014ApJ...787..108G 2014ApJ...787..108G, Cat. J/ApJ/787/108) and
SFiNCs (Getman et al. 2017ApJS..229...28G 2017ApJS..229...28G,
Cat. J/ApJS/229/28) (2)
69- 73 F5.2 --- alpha ? Apparent MIR spectral energy distribution
(SED) slope measured in the Spitzer-IRAC
wavelength range from 3.6 to 8.0µm (3)
75- 78 F4.2 --- e_alpha ? Error on alpha
80 I1 --- Member [0/5] Membership flag (G7)
--------------------------------------------------------------------------------
Note (1): AV is either directly taken from the catalogue of IR bright stars
from Da Rio et al. (2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59) when
available or derived from the AV-(J-H) relationship assuming the
source is a low-mass star
Note (2): Both types of ages are corrected for individual Gaia parallaxes and
calibrated to isochrones by Siess et al. (2000A&A...358..593S 2000A&A...358..593S)
Note (3): We have αIRAC=dlog(λFλ)/dlog(λ), using
IRAC data from the extended Spitzer catalog of point sources in
Orion A/B by Megeath et al. (2012AJ....144..192M 2012AJ....144..192M, Cat. J/AJ/144/192)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.6 deg RAdeg Right ascension (J2000)
11- 19 F9.6 deg DEdeg Declination (J2000)
21 I1 --- Cat1 [0/1] Flag indicating the presence of the
source in the MYStIX/SFiNCs catalogues (G1)
22 I1 --- Cat2 [0/1] Flag indicating the presence of the
source in Furesz et al. (2008) catalogue (G2)
23 I1 --- Cat3 [0/1] Flag indicating the presence of the
source in Tobin et al. (2009) catalogue (G3)
24 I1 --- Cat4 [0/1] Flag indicating the presence of the
source in Da Rio et al. (2012) catalogue (G4)
25 I1 --- Cat5 [0/1] Flag indicating the presence of the
source in Da Rio et al. (2016) catalogue (G5)
26 I1 --- Cat6 [0/1] Flag indicating the presence of the
source in Megeath et al. (2012) catalogue (G6)
27 I1 --- Cat7 [0/1] Flag indicating the presence of the
source in the Gaia catalog listed in Tables A1
and A2 (1)
29- 35 F7.3 km/s RVK18 ? Average heliocentric radial velocity from
Kounkel et al. (2018AJ....156...84K 2018AJ....156...84K,
Cat. J/AJ/156/84)
37- 41 F5.3 km/s e_RVK18 ? Error on RVK18
43- 48 F6.1 km/s RVT09 ? Average heliocentric radial velocity from
Tobin et al. (2009ApJ...697.1103T 2009ApJ...697.1103T,
Cat. J/ApJ/697/1103) (2)
50- 53 F4.1 km/s e_RVT09 ? Error on RVT09
55 I1 --- Mult ? [1/2] Spectroscopic binary flag, multiplicity
from Tobin et al. (2009ApJ...697.1103T 2009ApJ...697.1103T,
Cat. J/ApJ/697/1103)
57- 62 F6.3 mag Jmag ? J-band magnitude from Meingast et al.
(2016A&A...587A.153M 2016A&A...587A.153M, Cat. J/A+A/587/A153)
64- 68 F5.3 mag e_Jmag ? Error on Jmag
70- 75 F6.3 mag Hmag ? H-band magnitude from Meingast et al.
(2016A&A...587A.153M 2016A&A...587A.153M, Cat. J/A+A/587/A153)
77- 81 F5.3 mag e_Hmag ? Error on Hmag
83 I1 --- Member [0/5] Membership flag (G7)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
1 = Source present in our Gaia-selected young star catalog (Tables A1/A2)
(1192/2752)
0 = Otherwise
Note (2): Velocities from Tobin et al. (2009ApJ...697.1103T 2009ApJ...697.1103T,
Cat. J/ApJ/697/1103) are listed only for stars that are not present
in the Kounkel et al. (2018AJ....156...84K 2018AJ....156...84K, Cat. J/AJ/156/84) APOGEE
catalog
--------------------------------------------------------------------------------
Global Notes:
Note (G1): Flag as follows:
1 = Source present in the MYStIX (Broos et al. 2013ApJS..209...32B 2013ApJS..209...32B,
Cat. J/ApJS/209/32) and/or SFiNCs (Getman et al. 2017ApJS..229...28G 2017ApJS..229...28G,
Cat. J/ApJS/229/28) catalogues (528/1487)
0 = Otherwise
Note (G2): Flag as follows:
1 = Source present in Furesz et al. (2008ApJ...676.1109F 2008ApJ...676.1109F, Cat. J/ApJ/676/1109)
(532/1487)
0 = Otherwise
Note (G3): Flag as follows:
1 = Source present in Tobin et al. (2009ApJ...697.1103T 2009ApJ...697.1103T, Cat. J/ApJ/697/1103)
(633/1487)
0 = Otherwise
Note (G4): Flag as follows:
1 = Source present in Da Rio et al. (2012ApJ...748...14D 2012ApJ...748...14D, Cat. J/ApJ/748/14)
(357/1487)
0 = Otherwise
Note (G5): Flag as follows:
1 = Source present in Da Rio et al. (2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59)
(1185/1487)
0 = Otherwise
Note (G6): Flag as follows:
1 = Source present in Megeath et al. (2012AJ....144..192M 2012AJ....144..192M, Cat. J/AJ/144/192)
(568/1487)
0 = Otherwise
Note (G7): Membership flag as follows:
1 = Stars in the main NGC 1977 cluster
2 = Stars in the NGC 1977 south group
3 = Stars in EONn group (Extended Orion Nebula north)
4 = Stars in EONs group (Extended Orion Nebula south)
5 = Stars in Group X (stellar group located at the south-west corner of
the field)
0 = Stars outside those cluster/groups
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 15-Nov-2022