J/MNRAS/500/3213 2D kinematics of massive stars (Libralato+, 2021)
2D kinematics of massive stars near the Galactic Centre.
Libralato M., Lennon D.J., Bellini A., van der Marel R., Clark S.J.,
Najarro F., Patrick L.R., Anderson J., Bedin L.R., Crowther P.A.,
de Mink S.E., Evans C.J., Platais I., Sabbi E., Sohn S.T.
<Mon. Not. R. Astron. Soc., 500, 3213-3239 (2021)>
=2021MNRAS.500.3213L 2021MNRAS.500.3213L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Galactic center ; Stars, fundamental ;
Proper motions ; Spectral types ; Photometry ; Optical
Keywords: proper motions - stars: massive - Galaxy: centre -
open clusters and associations: individual: Quintuplet -
open clusters and associations: individual: Arches
Abstract:
The presence of massive stars (MSs) in the region close to the
Galactic Centre (GC) poses several questions about their origin. The
harsh environment of the GC favours specific formation scenarios, each
of which should imprint characteristic kinematic features on the MSs.
We present a 2D kinematic analysis of MSs in a GC region surrounding
Sgr A* based on high-precision proper motions obtained with the Hubble
Space Telescope. Thanks to a careful data reduction, well-measured
bright stars in our proper-motion catalogues have errors better than
0.5mas/yr. We discuss the absolute motion of the MSs in the field and
their motion relative to Sgr A*, the Arches, and the Quintuplet. For
the majority of the MSs, we rule out any distance further than 3-4kpc
from Sgr A* using only kinematic arguments. If their membership to the
GC is confirmed, most of the isolated MSs are likely not associated
with either the Arches or Quintuplet clusters or Sgr A*. Only a few
MSs have proper motions, suggesting that they are likely members of
the Arches cluster, in agreement with previous spectroscopic results.
Line-of-sight radial velocities and distances are required to shed
further light on the origin of most of these massive objects. We also
present an analysis of other fast-moving objects in the GC region,
finding no clear excess of high-velocity escaping stars. We make our
astro-photometric catalogues publicly available.
Description:
The GC region was observed with the HST's NIR channel of the
Wide-Field Camera 3 (WFC3; pixel scale ∼130mas/pixel) in 2012 October
and 2015 August during programmes GO-12915 and GO-13771 (both PI:
Lennon). The FoV was covered by 36 WFC3/IR pointings per epoch, each
of which was observed with 4 images. Additional images were taken in
parallel mode with the Wide-Field Channel (WFC; pixel scale
∼50mas/pixel) of the Advanced Camera for Surveys (ACS). Parallel
fields were covered by 18 ACS/WFC pointings of 1 image each.
We computed two, independent sets of PMs, one using only WFC3/IR data
and one using only ACS/WFC data, so as to minimize mismatches between
images taken using significantly different bandpasses, but at the
unavoidable expense of having fewer images at our disposal in the
overlapping regions between the two data sets.
We release a photometric catalog for each instrument (see tables
wfc12915, wfc13771, acs12915 and acs13771), and a PM catalog for each
instrument (see tables wfcpm and acspm). We also publish a list of
confirmed massive stars, candidate massive stars and non-massive
objects analyzed in our work (see Table D1).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 87 3 Position and PMs of Sgr A*, the Arches, and the
Quintuplet
table3.dat 71 6 Overview of the confirmed MSs selected as
escaping candidates
table4.dat 25 10 List of confirmed MSs' likely members of the
Arches cluster
table5.dat 60 14 Overview of the candidate MSs selected as likely
escapers
wfcpm.dat 106 812377 Proper-motion catalog for WFC3/IR data
acspm.dat 106 14603 Proper-motion catalog for ACS/WFC data
wfc12915.dat 68 812377 Phometric catalog for WFC3/IR GO-12915 data
wfc13771.dat 68 812377 Phometric catalog for WFC3/IR GO-13771 data
acs12915.dat 60 14603 Phometric catalog for ACS/WFC GO-12915 data
acs13771.dat 60 14603 Phometric catalog for ACS/WFC GO-13771 data
tabled1.dat 65 112 List of confirmed massive stars, candidate
massive stars and non-massive objects analyzed
in our work
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See also:
J/MNRAS/417/114 : HST/NICMOS Galactic Center survey catalogue (Dong+, 2011)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Object name
12- 22 F11.7 deg RAdeg Right ascension (J2000) (1)
24- 35 F12.8 deg DEdeg Declination (J2000) (1)
37- 42 F6.3 mas/yr pmRA Proper motion in right ascension
µαcosδ (2)
44- 48 F5.3 mas/yr e_pmRA Error on pmRA (2)
50- 55 F6.3 mas/yr pmDE Proper motion in declination (2)
57- 61 F5.3 mas/yr e_pmDE Error on pmDE (2)
63- 68 F6.3 mas/yr pmGLON Proper motion in galactic longitude
µlcosb (2)
70- 74 F5.3 mas/yr e_pmGLON Error on pmGLON (2)
76- 81 F6.3 mas/yr pmGLAT Proper motion in galactic latitude (2)
83- 87 F5.3 mas/yr e_pmGLAT Error on pmGLAT (2)
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Note (1): Positions of Sgr A* are from Reid & Brunthaler (2020ApJ...892...39R 2020ApJ...892...39R)
and positions of the Arches and Quintuplet clusters are from the
SIMBAD data base
Note (2): Proper motions of Sgr A* are from Reid & Brunthaler
(2020ApJ...892...39R 2020ApJ...892...39R) and proper motions of the Arches and Quintuplet
clusters are from Libralato et al. (2020MNRAS.497.4733L 2020MNRAS.497.4733L)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 I7 --- ID Massive star (MS) identifier
9- 12 F4.2 mas/yr DPM Difference in proper motion between the star
and its origin ΔPM
14- 17 F4.2 mas/yr e_DPM Error on DPM
19- 22 F4.1 deg theta Proper motion position angle θ (G1)
24- 26 F3.1 deg e_theta Error on theta
28- 31 F4.2 Myr tflight Flight time (G2)
33- 36 F4.2 Myr e_tflight Error on tflight
38- 47 A10 --- Origin Possible origin
49- 57 A9 --- List Collection from which the star is taken (G3)
59- 71 A13 --- SpType Spectral type (1)
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Note (1): WC=Carbon-type Wolf-Rayet; WN=Nitrogen-type Wolf-Rayet; O=O supergiant
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 I7 --- ID Massive star (MS) identifier
9 A1 --- f_ID [*] Flag on ID (1)
11- 15 A5 --- List Collection from which the star is taken (G3)
17- 25 A9 --- SpType Spectral type (2)
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Note (1): Flag as follows:
* = Proper motions of this star were measured with one image per epoch
Note (2): WN=Nitrogen-type Wolf-Rayet; O=O supergiant
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 I7 --- ID Massive star (MS) identifier
9- 12 F4.2 mas/yr DPM Difference in proper motion between the star
and its origin ΔPM
14- 17 F4.2 mas/yr e_DPM Error on DPM
19- 23 F5.1 deg theta Proper motion position angle θ (G1)
25- 27 F3.1 deg e_theta Error on theta
29- 32 F4.2 Myr tflight Flight time (G2)
34- 37 F4.2 Myr e_tflight Error on tflight
39- 48 A10 --- Origin Possible origin
50 A1 --- f_Origin Flag on Origin (1)
52- 60 A9 --- List Collection from which the star is taken (G3)
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Note (1): Flag as follows:
a = Star 427662 passed the criteria for Sgr A*, the Arches, and the
Quintuplet
b = Star 1187124 passed the criteria for both Sgr A* and the Quintuplet
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Byte-by-byte Description of file: acspm.dat wfcpm.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.7 deg RAdeg Right ascension (J2000)
13- 23 F11.7 deg DEdeg Declination (J2000)
25- 34 F10.4 pix X X pixel position
36- 45 F10.4 pix Y Y pixel position
47- 56 F10.5 mas/yr pmRA Proper motion in right ascension
µαcosδ
58- 65 F8.5 mas/yr e_pmRA ?=99.99 Error on pmRA (1)
67- 76 F10.5 mas/yr pmDE Proper motion in declination µδ
78- 85 F8.5 mas/yr e_pmDE ?=99.99 Error on pmDE (1)
87- 92 F6.4 yr time Temporal baseline
94- 95 I2 --- n1 Number of measurements in epoch 1
97- 98 I2 --- n2 Number of measurements in epoch 2
100- 106 I7 --- ID Massive star (MS) identifier
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Note (1): Stars measured in only one image have a proper motion error of
99.99mas/yr in each coordinate
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Byte-by-byte Description of file: wfc12915.dat wfc13771.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 I7 --- ID [3/1389860] Massive star (MS) identifier
9- 15 F7.4 mag F139Mmag HST F139M Vega-mag magnitude
17- 22 F6.4 mag e_F139Mmag ?=9.99 Magnitude rms (G4)
24- 28 F5.3 --- qfit Quality of PSF fit (G5)
30- 38 F9.4 --- o Fraction of neighbor flux within the fitting
radius before neighbor subtraction (G5)
40- 47 F8.4 --- radxs Excess/deficiency of flux just outside of the
fitting radius with respect to that expected
from the PSF (G5)
49- 50 I2 --- nf Number of single exposures a star was found
(G5)
52- 53 I2 --- nu Number of measurements used to compute the
photometric quantities of a star (G5)
55- 60 F6.2 ct sky Local sky
62- 68 F7.2 ct rmssky Local-sky rms
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Byte-by-byte Description of file: acs12915.dat acs13771.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 I7 --- ID [1389861/1415773] Massive star (MS) identifier
9- 15 F7.4 mag F850LPmag HST F850LP Vega-mag magnitude
17- 22 F6.4 mag e_F850LPmag ?=9.99 Magnitude rms (G4)
24- 28 F5.3 --- qfit Quality of PSF fit (G5)
30- 36 F7.4 --- o Fraction of neighbor flux within the fitting
radius before neighbor subtraction (G5)
38- 44 F7.4 --- radxs Excess/deficiency of flux just outside of the
fitting radius with respect to that expected
from the PSF (G5)
46 I1 --- nf Number of single exposures a star was found
(G5)
48 I1 --- nu Number of measurements used to compute the
photometric quantities of a star (G5)
50- 54 F5.2 ct sky Local sky
56- 60 F5.2 ct rmssky Local-sky rms
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Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.7 deg RAdeg Right ascension (J2000)
13- 23 F11.7 deg DEdeg Declination (J2000)
25- 31 I7 --- ID Massive star (MS) identifier
33- 41 A9 --- List Collection from which the star is taken (G3)
43- 65 A23 --- OID Alternative ID (1)
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Note (1): Objects with Alternative IDs in the "Other" list starting with "C"
are from Clark et al. (2018A&A...617A..65C 2018A&A...617A..65C, Cat. J/A+A/617/A65)
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Global Notes:
Note (G1): The PM position angle θ and its error are defined as the median
and the error to the median values, respectively, of the 1000
realizations of θ obtained as described in the text
Note (G2): The flight time is defined as the distance from the current position
to the point of closest approach divided by the relative PM of the MS
in the reference frame where the origin source (Sgr A*, the Arches,
or the Quintuplet) is at rest
Note (G3): Most MSs in our field were identified by Dong et al.
(2011MNRAS.417..114D 2011MNRAS.417..114D, Cat. J/MNRAS/417/114) as part of the NICMOS
survey. Dong et al. (2011MNRAS.417..114D 2011MNRAS.417..114D, Cat. J/MNRAS/417/114)
found several Paschen α-emitting candidates, most of which are
evolved MSs with strong winds. The authors released a list of 152
confirmed Paschen α emitters (hereafter Primary list) and a
list of 189 potential candidates for which it was not possible to
perform a clear classification (Secondary list). We refer to the
collection of MSs in our field not included in these Primary and
Secondary lists simply as Other list (see Section 5).
Note (G4): Stars measured in only image have a magnitude rms equal to 9.99mag
Note (G5): Stars with rms mag, QFIT, o, RADXS, nf, and nu equal to 0 are
saturated in the majority of the images in which they were found
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 04-Oct-2023