J/AJ/156/98 Runaway stars in the 30 Doradus region of the LMC (Platais+, 2018)
HST astrometry in the 30 Doradus region.
II. Runaway stars from new proper motions in the Large Magellanic Cloud.
Platais I., Lennon D.J., van der Marel R.P., Bellini A., Sabbi E.,
Watkins L.L., Sohn S.T., Walborn N.R., Bedin L.R., Evans C.J.,
de Mink S.E., Sana H., Herrero A., Langer N., Crowther P.
<Astron. J., 156, 98 (2018)>
=2018AJ....156...98P 2018AJ....156...98P (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Populations, stellar ; Proper motions ;
Positional data ; Photometry, VRI ; Spectral types ;
Rotational velocities ; Stars, OB
Keywords: astrometry - galaxies: Magellanic Clouds -
galaxies: individual (30 Dor) - proper motions
Abstract:
We present a catalog of relative proper motions for 368787 stars in
the 30 Doradus region of the Large Magellanic Cloud (LMC), based on a
dedicated two-epoch survey with the Hubble Space Telescope and
supplemented with proper motions from our pilot archival study. We
demonstrate that a relatively short epoch difference of three years is
sufficient to reach a level of precision of ∼0.1 mas/yr or better. A
number of stars with relative proper motions exceeding a 3σ error
threshold represent a mixture of Milky Way denizens and 18 potential
LMC runaway stars. Based upon 183 VFTS OB stars with the best proper
motions, we conclude that none of them moves faster than ∼0.3 mas/yr
in each coordinate-equivalent to ∼70 km/s. Among the remaining 351 VFTS
stars with less accurate proper motions, only one candidate OB runaway
can be identified. We rule out any OB star in our sample moving at a
tangential velocity exceeding ∼120 km/s. The most significant result
of this study is finding 10 stars over a wide range of masses that
appear to have been ejected from the massive star cluster R136 in the
tangential plane to angular distances from 35" out to 407", equivalent
to 8-98 pc. The tangential velocities of these runaways appear to be
correlated with apparent magnitude, indicating a possible dependence on
the stellar mass. Lastly, a comparison to proper motions from Gaia DR 2
shows that for several relatively bright stars the DR 2 has an
unexpected scatter that cannot be accounted for by the formal errors.
Description:
One of the main intentions in our astrometric survey was to use the
Wide Field Camera 3 (WFC3/UVIS) and the Advanced Camera for Surveys
(ACS/WFC) in parallel, so as to cover as much of 30 Dor as possible
and particularly to focus on the VLT-FLAMES Tarantula Survey (VFTS)
stars (Evans et al. 2011, J/A+A/530/A108). The first-epoch observations
(GO-12499; PI: D. Lennon) were mainly obtained in 2011 October 3-8,
while nearly identical second-epoch observations (GO-13359) were
repeated three years later in 2014 October 6-11. Altogether, there are
a total of 149 ACS/WFC and the same number of WFC3/UVIS frames, both
sets obtained through filter F775W.
Objects:
---------------------------------------------------------------
RA (ICRS) DE Designation(s)
---------------------------------------------------------------
05 23 34.6 -69 45 22 Large Magellanic Cloud = NAME LMC
05 38 42.40 -69 06 03.4 R136 = RMC 136
---------------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 268 368787 Consolidated proper motion catalog
table2.dat 93 7 Candidate OB proper-motion runaway stars
table3.dat 90 11 Candidate young A-F proper-motion runaways
table4.dat 33 10 Likely-escaped stars from R136
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See also:
II/187 : 30 Doradus OB Associations (Parker 1992)
III/220 : 30 Dor spectral types and UBV magnitudes (Schild+, 1998)
J/ApJ/413/604 : 30 Dor (Hill+, 1993)
J/AJ/107/1054 : UBV photometry of the 30 Dor region (Malumuth+, 1994)
J/ApJ/466/254 : NIR Imaging of R136 in 30 Dor (Brandl+ 1996)
J/A+A/341/98 : The ionizing cluster of 30 Doradus. I. (Selman+ 1999)
J/A+A/438/663 : JHKL photometry of 30 Dor (Maercker+, 2005)
J/ApJ/707/1347 : HST F160W photometry in RMC 136 (Andersen+, 2009)
J/A+A/530/A108 : VLT-FLAMES Tarantula Survey (Evans+, 2011)
J/ApJ/746/15 : Runaway massive stars from R136 (Banerjee+, 2012)
J/A+A/550/A107 : RV catalogue of O stars in 30 Doradus (Sana+, 2013)
J/A+A/558/A134 : VLT-FLAMES Tarantula Survey. 30 Dor luminous stars
(Doran+, 2013)
J/A+A/560/A29 : O-stars in VLT-FLAMES Tarantula Survey
(Ramirez-Agudelo+ 2013)
J/ApJ/774/73 : ALMA CO observations of 30 Dor (Indebetouw+, 2013)
J/A+A/564/A40 : VFTS. O-type stellar content of 30 Dor (Walborn+, 2014)
J/A+A/574/A13 : VFTS. B-type stars classification and RV (Evans+, 2015)
J/A+A/580/A93 : VLTS. B stars multiplicity (Dunstall+, 2015)
J/ApJS/222/11 : Hubble Tarantula Treasury Project (HTTP). III.
(Sabbi+, 2016)
J/A+A/600/A81 : VLTS. 30Dor O giants and supergiants
(Ramirez-Agudelo+, 2017)
J/A+A/601/A79 : VLTS. Properties of O dwarf in 30 Dor
(Sabin-Sanjulian+, 2017)
J/other/Sci/359.69 : Massive stars in 30 Dor (Schneider+, 2018)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID [1/396589] Sequential identifier
8- 13 F6.3 mag F775 [14.026/25.547] Preliminary F775W magnitude (1)
15- 20 F6.2 mas/yr px-m [-21.07/24.84] Weighed proper motion in X
22- 27 F6.2 mas/yr py-m [-25.89/25.94] Weighed proper motion in Y
29- 32 F4.2 mas/yr e_px-m [0/8.31] Error of the weighed mean motion in X
34- 37 F4.2 mas/yr e_py-m [0/9.71] Error of the weighed mean motion in Y
39- 39 I1 --- Flag [1/7] Proper motion flag (2)
41- 46 F6.2 mas/yr px-a [-17.58/24.56] Proper motion in X, ACS/WFC
48- 53 F6.2 mas/yr py-a [-24.6/25.94] Proper motion in Y, ACS/WFC
55- 56 I2 --- n-a [0/34] Total number of datapoints (epochs)
58- 63 F6.2 mas/yr px-u [-21.07/24.84] Proper motion in X, WFC3/UVIS
65- 70 F6.2 mas/yr py-u [-25.89/25.65] Proper motion in Y, WFC3/UVIS
72- 73 I2 --- n-u [0/24] Total number of datapoints
75- 79 F5.2 mas/yr px-c [-9.09/8.86] Proper motion in X, (Platais et al.
2015AJ....150...89P 2015AJ....150...89P, Paper I)
81- 85 F5.2 mas/yr py-c [-8.98/9.01] Proper motion in Y, Paper I
87- 88 I2 --- n-c [0/92] Total number of datapoints
90- 93 F4.2 mas/yr e_px-a [0/2.5] Standard error of px-a
95- 98 F4.2 mas/yr e_py-a [0/2.5] Standard error of py-a
100-104 F5.2 --- cx-a [0/45.43] Normalized χ2 for proper motion
in X, ACS/WFC
106-110 F5.2 --- cy-a [0/38.72] Normalized χ2 for proper motion
in Y, ACS/WFC
112-116 F5.3 --- qx-a [0/1] Goodness-of-fit probability Q in X, ACS/WFC
118-122 F5.3 --- qy-a [0/1] Goodness-of-fit probability Q in Y, ACS/WFC
124-127 F4.2 mas/yr e_px-u [0/2.5] Standard error of px-u
129-132 F4.2 mas/yr e_py-u [0/2.49] Standard error of py-u
134-138 F5.2 --- cx-u [0/23.17] Normalized χ2 for proper motion
in X, WFC3/UVIS
140-144 F5.2 --- cy-u [0/22.97] Normalized χ2 for proper motion
in Y, WFC3/UVIS
146-150 F5.3 --- qx-u [0/1] Goodness-of-fit probability Q in X,
WFC3/UVIS
152-156 F5.3 --- qy-u [0/1] Goodness-of-fit probability Q in Y,
WFC3/UVIS
158-161 F4.2 mas/yr e_px-c [0/2.5] Standard error of px-c
163-166 F4.2 mas/yr e_py-c [0/2.49] Standard error of py-c
168-172 F5.2 --- cx-c [0/99.99] Normalized χ2 for proper motion
in X, Paper I
174-178 F5.2 --- cy-c [0/99.99] Normalized χ2 for proper motion
in Y, Paper I
180-184 F5.3 --- qx-c [0/1] Goodness-of-fit probability Q in X, Paper I
186-190 F5.3 --- qy-c [0/1] Goodness-of-fit probability Q in Y, Paper I
192-197 F6.3 mag Vmag [12.447/27.998]?=99.999 V band magnitude (3)
199-203 F5.3 mag e_Vmag [0/4.777]?=9.999 Standard error of Vmag
205-210 F6.3 mag Imag [12.893/27.708]?=99.999 I band magnitude (3)
212-216 F5.3 mag e_Imag [0/2.587]?=9.999 Standard error of Imag
218-223 F6.3 mag V-I [-4.803/4.98]?=9.999 V-I color index
225-232 F8.2 pix X [-850.14/29448.31] X-coordinate in WFC3/UVIS
pixels (4)
234-241 F8.2 pix Y [-1607.3/24160.81] Y-coordinate in WFC3/UVIS
pixels (4)
243-252 F10.7 deg RAdeg Right Ascension in decimal degrees (J2000,
Epoch 2011.76) (5)
254-264 F11.7 deg DEdeg Declination in decimal degrees (J2000,
Epoch 2011.76) (5)
266-268 I3 --- VFTS [0/923] VFTS identifier, if different from zero
(G1)
--------------------------------------------------------------------------------
Note (1): This F775W magnitude is on the system of WFC3/UVIS, obtained from
the recent observations (GO-12499 & GO-13359).
Note (2): Flag indicating the source of available proper motion or their
combination:
1 = ACS/WFC, GO-12499 & 13359, suffix "a";
2 = WFC3/UVIS, GO-12499 & 13359, suffix "u";
3 = Archival WFPC2 and GO-12499 observations with both cameras, ACS/WFC and
WFC3/UVIS, suffix "c". This catalog is described in Platais et al.
(2015AJ...150...89P), Paper I;
4 = 1+2, only "a" & "u";
5 = 1+3, only "a" & "c";
6 = 2+3, only "u" & "c";
7 = 1+2+3, all "a" & "u" & "c" available.
Note (3): Vmag (filter F555W) and Imag (filter F775W) on the system of ACS/WFC
are from Sabbi et al. (2016, J/ApJS/222/11).
In order to obtain an optimal match to the entries of calibrated photometry
by Sabbi et al. (2016, J/ApJS/222/11), we had to apply a large 0.2 arcsec
window. In many cases that generated multiple matches which were resolved by
choosing the nearest-by-magnitude counterpart from the corresponding
photometry in F775W filter. In the case of a single match but grossly
discrepant photometry, no attempt was made to find out the reason of such
disagreement.
Note (4): X and Y are aligned with RA and DE accordingly. The X-coordinate has
a flipped sign.
Note (5): Our global master list of 396616 entries is known to have positional
systematics reaching about 50 mas near the edges of the field. These
systematics are not eliminated from the calculated RA and DE despite the fact
that we used Gaia DR1 as a reference frame. The epoch of these positions is
2011.76.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- VFTS [8/838] VFTS identifier (G1)
5- 10 I6 --- ID [143204/349614] Sequential identifier
12- 17 F6.3 mag Vmag [14.34/17.043] V band magnitude
19- 23 F5.3 mag V-I [0.052/0.382] V-I color index
25- 34 A10 --- SpType Spectral type
36- 38 I3 km/s vLOS [228/304] Line-of-sight velocity
40- 40 A1 --- l_vsini [<] Upper limit flag on vsini
42- 44 I3 km/s vsini [40/600] Projected rotational velocity
46- 47 I2 km/s e_vsini [15/30]? Uncertainty in vsini
49- 53 F5.2 mas/yr px-u [-0.34/0.24] Proper motion in X, WFC3/UVIS (1)
55- 59 F5.2 mas/yr py-u [-0.07/0.41] Proper motion in Y, WFC3/UVIS (1)
61- 64 F4.2 mas/yr e_px-u [0.04/0.2] Standard error of px-u
66- 69 F4.2 mas/yr e_py-u [0.06/0.15] Standard error of py-u
71- 74 F4.2 --- cx-u [0.04/1.03] Normalized χ2 for proper
motion in X
76- 79 F4.2 --- cy-u [0.06/0.62] Normalized χ2 for proper
motion in Y
81- 85 F5.3 --- qx-u [0.355/0.996] Goodness-of-fit probability Q in X
87- 91 F5.3 --- qy-u [0.646/0.944] Goodness-of-fit probability Q in Y
93- 93 I1 --- Nframe [3/6] Number of frames (epochs)
--------------------------------------------------------------------------------
Note (1): One exception - for the last star VFTS 838, all astrometric parameters
are based on the recent observations with ACS/WFC (GO-12499 & GO-13359).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID [204988/373715] Sequential identifier
8- 13 F6.3 mag Vmag [17.79/20.735] V band magnitude
15- 20 F6.3 mag V-I [-0.029/0.429] V-I color index
22- 31 F10.7 deg RAdeg Right Ascension in decimal degrees (J2000)
33- 43 F11.7 deg DEdeg Declination in decimal degrees (J2000)
45- 49 F5.2 mas/yr px-u [-0.49/0.59] Proper motion in X, WFC3/UVIS
51- 55 F5.2 mas/yr py-u [-0.54/0.66] Proper motion in Y, WFC3/UVIS
57- 60 F4.2 mas/yr e_px-u [0.04/0.17] Standard error of px-u
62- 65 F4.2 mas/yr e_py-u [0.06/0.14] Standard error of py-u
67- 70 F4.2 --- cx-u [0.03/1.31] Normalized χ2 for proper
motion in X
72- 75 F4.2 --- cy-u [0.12/1.35] Normalized χ2 for proper
motion in Y
77- 81 F5.3 --- qx-u [0.234/0.977] Goodness-of-fit probability Q in X
83- 87 F5.3 --- qy-u [0.183/0.999] Goodness-of-fit probability Q in Y
89- 90 I2 --- Nframe [4/17] Number of frames (epochs)
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID [204988/373715] Sequential identifier
8- 14 F7.4 arcmin Xoffset [-6.3708/0.0976] X offset from center of R136
16- 22 F7.4 arcmin Yoffset [-1.8681/3.9299] Y offset from center of R136
24- 28 F5.1 deg Angle [-20.8/35.9] Positional angle of proper motion
wrt R136
30- 33 F4.2 mas/yr pm-tot [0.2/0.54] Total proper motion
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Global notes:
Note (G1): VLT-FLAMES Tarantula Survey, VFTS; Evans et al. (2011,
J/A+A/530/A108).
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History:
From electronic version of the journal
References:
Platais et al. Paper I. 2015AJ....150...89P 2015AJ....150...89P
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 18-Feb-2019