J/MNRAS/495/3104 Runaway and walkaway stars from the ONC (Schoettler+, 2020)
Runaway and walkaway stars from the ONC with Gaia DR2.
Schoettler C., de Bruijne J., Vaher E., Parker R.J.
<Mon. Not. R. Astron. Soc., 495, 3104-3123 (2020)>
=2020MNRAS.495.3104S 2020MNRAS.495.3104S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, high-velocity ; Clusters, open ; Radial velocities ;
Stars, ages ; Stars, masses ; Spectral types ; Optical
Keywords: astrometry - stars: kinematics and dynamics -
open clusters and associations: individual: Orion Nebula Cluster
Abstract:
Theory predicts that we should find fast, ejected (runaway) stars of
all masses around dense, young star-forming regions. N-body
simulations show that the number and distribution of these ejected
stars could be used to constrain the initial spatial and kinematic
substructure of the regions. We search for runaway and slower walkaway
stars within 100pc of the Orion Nebula Cluster (ONC) using Gaia DR2
astrometry and photometry. We compare our findings to predictions for
the number and velocity distributions of runaway stars from
simulations that we run for 4Myr with initial conditions tailored to
the ONC. In Gaia DR2, we find 31 runaway and 54 walkaway candidates
based on proper motion, but not all of these are viable candidates in
three dimensions. About 40 per cent are missing radial velocities, but
we can trace back nine 3D runaways and 24 3D walkaways to the ONC, all
of which are low/intermediate mass (<8M☉). Our simulations show
that the number of runaways within 100pc decreases the older a region
is (as they quickly travel beyond this boundary), whereas the number
of walkaways increases up to 3Myr. We find fewer walkaways in Gaia DR2
than the maximum suggested from our simulations, which may be due to
observational incompleteness. However, the number of Gaia DR2 runaways
agrees with the number from our simulations during an age of
∼1.3-2.4Myr, allowing us to confirm existing age estimates for the ONC
(and potentially other star-forming regions) using runaway stars.
Description:
Our target for the search for RW and WW stars is the Orion Nebula
Cluster (ONC). This star-forming region is well suited for this
purpose due to its proximity to the Earth (∼400pc; e.g. Grossschedl et
al. 2018A&A...619A.106G 2018A&A...619A.106G, Cat. J/A+A/619/A106; Kuhn et al.
2019ApJ...870...32K 2019ApJ...870...32K, Cat. J/ApJ/870/32).
We adopt the centre of the ONC as described in Kuhn et al.
(2019ApJ...870...32K 2019ApJ...870...32K, Cat. J/ApJ/870/32). From this central location,
we select sources within a radius of 14°, which at the distance of
the ONC centre translates to a radius of ∼100pc. We apply the
distances from the catalogue by Bailer-Jones et al.
(2018AJ....156...58B 2018AJ....156...58B, Cat. I/347) to all sources within this radius
and reduce the sample by selecting only sources with distances between
300 and 500pc, adopting a central distance of 400pc.
We find 31 runaway (RW) stars and 54 walkaway (WW) stars 2D candidates
with an isochronal age <4Myr after applying our criteria for candidate
identification (see Tables 5 and 6). We exclude 1 RW and 1 WW
candidate without RV as based on their radial distance to the ONC the
RV required to get to their current position since ejection from the
ONC is unreasonably large for RW or WW stars (>|500|km/s). A few 2D
candidates (7 RWs and 8 WWs) with known RVs are excluded as their RVs
point towards the ONC instead of away from it, so these stars cannot
have originated from the ONC. Table A1 lists the excluded 2D
candidates, including their reason for being excluded.
Table B1 provides information on identified 2D candidates that would
not be identified as RWs or WWs only by their 2D velocity, but could
be when considering their RV measurements.
We also find several older 3D RW/WW stars below the isochrone along
the MS. These stars are possibly past 'visitors' to the ONC, having
travelled through the ONC from their origin. Information about these
visitors is provided in Table C1.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table5.dat 110 31 RW star 2D candidates sorted by decreasing 2D
velocity
table6.dat 111 54 WW star 2D candidates
tablea1.dat 106 17 Excluded RW and WW star 2D candidates
tableb1.dat 74 4 Slow 2D candidates with multiple, varying RV
measurements
tablec1.dat 66 42 Past visitors to the ONC
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/807/27 : IN-SYNC. III. Radial velocities of IC348 stars (Cottaar+, 2015)
III/252 : Pulkovo radial velocities for 35493 HIP stars
(Gontcharov, 2006)
J/AJ/156/84 : APOGEE-2 survey of Orion Complex. II. (Kounkel+, 2018)
J/ApJ/870/32 : Kinematics in young star clusters & associations (Kuhn+, 2019)
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 25 F5.1 km/s v2Drf Rest frame 2D velocity
27- 29 F3.1 km/s e_v2Drf Error on v2Drf
31- 35 F5.1 km/s RVrf ? Rest frame radial velocity
37- 40 F4.1 km/s e_RVrf ? Error on RVrf
42- 44 A3 --- r_RVrf Reference on RVrf (1)
46- 48 A3 --- 3Dcand Indication of 3D candidate status
50- 52 F3.1 Myr Tflight ? Minimum flight time since ejection
54- 63 A10 --- f_Tflight Flag on Tflight (2)
65- 68 F4.1 Myr Ageiso Age from PARSEC isochrones
(Bressan et al. 2012MNRAS.427..127B 2012MNRAS.427..127B)
70- 73 F4.1 Myr E_Ageiso Upper error on Ageiso
75- 78 F4.1 Myr e_Ageiso Lower error on Ageiso
80- 86 A7 Myr Age Age from literature
88- 90 A3 --- r_Age Reference for Age (3)
92- 98 A7 Msun Mass Mass from literature
100- 102 A3 --- r_Mass Reference for Mass (3)
104- 108 A5 --- SpType Spectral type
110 I1 --- r_SpType ? Reference for SpType (3)
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Note (1): Reference as follows:
a = Gaia DR2 (Gaia Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
b = Cottaar et al. (2015ApJ...807...27C 2015ApJ...807...27C, Cat. J/ApJ/807/27)
d = Multiple and varying RV measurements, possibly indicating a binary
system
Note (2): Reference as follows:
c = Age estimate is smaller than the flight time
Note (3): References as follows:
1 = van Altena et al. (1988AJ.....95.1744V 1988AJ.....95.1744V)
2 = Hillenbrand (1997AJ....113.1733H 1997AJ....113.1733H, Cat. J/AJ/113/1733)
3 = Houk & Swift (1999MSS...C05....0H 1999MSS...C05....0H, Cat. III/214)
4 = Rebull et al. (2000AJ....119.3026R 2000AJ....119.3026R, Cat. J/AJ/119/3026)
5 = Da Rio et al. (2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59)
6 = Nesterov et al. (1995A&AS..110..367N 1995A&AS..110..367N, Cat. III/182)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 24 F4.1 km/s v2Drf Rest frame 2D velocity
26- 28 F3.1 km/s e_v2Drf Error on v2Drf
30- 34 F5.1 km/s RVrf ? Rest frame radial velocity
36- 39 F4.1 km/s e_RVrf ? Error on RVrf
41 A1 --- r_RVrf Reference on RVrf (1)
43- 45 A3 --- 3Dcand Indication of 3D candidate status
47- 49 F3.1 Myr Tflight ? Minimum flight time since ejection
51- 60 A10 --- f_Tflight Flag on Tflight (2)
62 A1 --- u_Ageiso [~] Uncertainty flag on Ageiso
64- 67 F4.1 Myr Ageiso Age from PARSEC isochrones
(Bressan et al. 2012MNRAS.427..127B 2012MNRAS.427..127B)
69- 72 F4.1 Myr E_Ageiso ? Upper error on Ageiso
74- 77 F4.1 Myr e_Ageiso ? Lower error on Ageiso
79- 85 A7 Myr Age Age from literature
87- 90 A4 --- r_Age Reference for Age (3)
92- 98 A7 Msun Mass Mass from literature
100- 103 A4 --- r_Mass Reference for Mass (3)
105- 108 A4 --- SpType Spectral type
110- 111 I2 --- r_SpType ? Reference for SpType (3)
--------------------------------------------------------------------------------
Note (1): Reference as follows:
a = Gaia DR2 (Gaia Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
b = Cottaar et al. (2015ApJ...807...27C 2015ApJ...807...27C, Cat. J/ApJ/807/27)
c = Gontcharov (2006AstL...32..759G 2006AstL...32..759G, Cat III/252)
d = Kounkel et al. (2018AJ....156...84K 2018AJ....156...84K, Cat. J/AJ/156/84)
Note (2): Flag as follows:
e = Age estimate is smaller than the flight time
Note (3): References as follows:
1 = van Altena et al. (1988AJ.....95.1744V 1988AJ.....95.1744V)
2 = Hillenbrand (1997AJ....113.1733H 1997AJ....113.1733H, Cat. J/AJ/113/1733)
3 = Houk & Swift (1999MSS...C05....0H 1999MSS...C05....0H, Cat. III/214)
4 = Rebull et al. (2000AJ....119.3026R 2000AJ....119.3026R, Cat. J/AJ/119/3026)
5 = Da Rio et al. (2010ApJ...722.1092D 2010ApJ...722.1092D, Cat. J/ApJ/722/1092)
6 = Tetzlaff et al. (2011MNRAS.410..190T 2011MNRAS.410..190T, Cat. J/MNRAS/410/190)
7 = Da Rio et al. (2012ApJ...748...14D 2012ApJ...748...14D, Cat. J/ApJ/748/14)
8 = Hsu et al. (2012ApJ...752...59H 2012ApJ...752...59H, Cat. J/ApJ/752/59)
9 = Hsu et al. (2013ApJ...764..114H 2013ApJ...764..114H, Cat. J/ApJ/764/114)
10 = Da Rio et al. (2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59)
11 = Sota et al. (2011ApJS..193...24S 2011ApJS..193...24S, Cat. III/274)
12 = Hohle, Neuhauser & Schutz (2010AN....331..349H 2010AN....331..349H, Cat. J/AN/331/349)
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Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 21 A21 --- Sample Star candidate sample (RW or WW)
23- 41 I19 --- GaiaDR2 Gaia DR2 source identifier
43- 46 F4.1 km/s v2Drf Rest frame 2D velocity
48- 50 F3.1 km/s e_v2Drf Error on v2Drf
52- 56 F5.1 km/s RVrf ? Rest frame radial velocity
58- 60 F3.1 km/s e_RVrf ? Error on RVrf
62 A1 --- r_RVrf Reference on RVrf (1)
64- 84 A21 --- Exc Exclusion reason
86- 90 F5.1 Myr Age ? Age from literature
92 I1 --- r_Age ? Reference for Age (2)
94- 96 F3.1 Msun Mass ? Mass from literature
98 I1 --- r_Mass ? Reference for Mass (2)
100- 104 A5 --- SpType Spectral type
106 I1 --- r_SpType ? Reference for SpType (2)
--------------------------------------------------------------------------------
Note (1): Reference as follows:
a = Gaia DR2 (Gaia Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
b = Cottaar et al. (2015ApJ...807...27C 2015ApJ...807...27C, Cat. J/ApJ/807/27)
c = Gontcharov (2006AstL...32..759G 2006AstL...32..759G, Cat III/252)
Note (2): Reference as follows:
1 = Da Rio et al. (2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59)
2 = Houk & Swift (1999MSS...C05....0H 1999MSS...C05....0H, Cat. III/214)
3 = Nesterov et al. (1995A&AS..110..367N 1995A&AS..110..367N, Cat. III/182)
4 = Houk & Smith-Moore (1988mcts.book.....H 1988mcts.book.....H)
5 = Tetzlaff et al. (2011MNRAS.410..190T 2011MNRAS.410..190T, Cat. J/MNRAS/410/190)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 23 F3.1 km/s v2Drf Rest frame 2D velocity
25- 27 F3.1 km/s e_v2Drf Error on v2Drf
29- 31 A3 --- refRV References for the rest frame radial velocity
(1)
33 A1 --- 3Dcand Indication of 3D candidate status
35- 44 A10 --- fTflight Remark on flight time
46- 48 F3.1 Myr Ageiso Age from PARSEC isochrones
(Bressan et al. 2012MNRAS.427..127B 2012MNRAS.427..127B)
50- 53 F4.1 Myr E_Ageiso Upper error on Ageiso
55- 57 F3.1 Myr e_Ageiso Lower error on Ageiso
59- 61 F3.1 Myr Age Age from literature
63 I1 --- r_Age Reference for Age (2)
65- 67 F3.1 Msun Mass Mass from literature
69 I1 --- r_Mass Reference for Mass (2)
71- 72 A2 --- SpType Spectral type
74 I1 --- r_SpType ? Reference for SpType (2)
--------------------------------------------------------------------------------
Note (1): Reference as follows:
a = Gaia DR2 (Gaia Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
b = Cottaar et al. (2015ApJ...807...27C 2015ApJ...807...27C, Cat. J/ApJ/807/27)
c = Kounkel et al. (2018AJ....156...84K 2018AJ....156...84K, Cat. J/AJ/156/84)
Note (2): Reference as follows:
1 = Hillenbrand (1997AJ....113.1733H 1997AJ....113.1733H, Cat. J/AJ/113/1733)
2 = Da Rio et al. (2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablec1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Sample [RW/WW] Velocity type of the visitor
4- 22 I19 --- GaiaDR2 Gaia DR2 source identifier
24- 27 F4.1 km/s v2Drf Rest frame 2D velocity
29- 31 F3.1 km/s e_v2Drf Error on v2Drf
33- 37 F5.1 km/s RVrf Rest frame radial velocity
39- 42 F4.1 km/s e_RVrf Error on RVrf
44 A1 --- r_RVrf [a] Reference for RVrf (1)
46 A1 --- u_Ageiso [~] Uncertainty flag on Ageiso
48- 53 A6 Myr Ageiso Age from PARSEC isochrones
(Bressan et al. 2012MNRAS.427..127B 2012MNRAS.427..127B)
55- 58 F4.1 Myr Age ? Age from literature
60 I1 --- r_Age ? Reference for Age (2)
62- 64 F3.1 Msun Mass ? Mass from literature
66 I1 --- r_Mass ? Reference for Mass (2)
--------------------------------------------------------------------------------
Note (1): Reference as follows:
a = Gaia DR2 (Gaia Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345)
Note (2): Reference as follows:
1 = Da Rio et al. (2016ApJ...818...59D 2016ApJ...818...59D, Cat. J/ApJ/818/59)
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(End) Ana Fiallos [CDS] 19-Jun-2023