J/ApJS/277/62 Nonembedded massive star candidates in the SMC (Nakano+, 2025)
Evidence of galactic interaction in the Small Magellanic Cloud probed by Gaia-
selected massive star candidates.
Nakano S., Tachihara K., Tamashiro M.
<Astrophys. J. Suppl. Ser., 277, 62 (2025)>
=2025ApJS..277...62N 2025ApJS..277...62N
ADC_Keywords: Magellanic Clouds; Radial velocities; Proper motions;
Photometry; Optical; Stars, giant
Keywords: Massive stars ; Small Magellanic Cloud ; Galaxy interactions ;
Proper motions ; Optical astronomy ; Clustering
Abstract:
We present identifications and kinematic analysis of 7426 massive
(≥8M☉) stars in the Small Magellanic Cloud (SMC), using Gaia
DR3 data. We used the Gaia (GBP-GRP,G) color-magnitude diagram to
select the population of massive stars, and parallax to omit
foreground objects. The spatial distribution of the 7426 massive star
candidates is generally consistent with the spatial distribution of
the interstellar medium, such as Hα and HI emission. The
identified massive stars show inhomogeneous distributions over the
galaxy, showing several superstructures formed by massive stars with a
several hundred parsec scale. The stellar superstructures defined by
the surface density have opposite mean proper motions in the east and
west, moving away from each other. Similarly, the mean line-of-sight
velocities of the superstructures are larger to the southeast and
smaller to the northwest. The different east-west properties of the
superstructures' proper-motion, line-of-sight velocity indicate that
the SMC is being stretched by tidal forces and/or ram pressure from
the Large Magellanic Cloud to the southeast, thereby rejecting the
presence of galactic rotation in the SMC.
Description:
For the Small Magellanic Cloud (SMC) region, we obtained Gaia DR3 data
using a selection with RAJ2000=00h-03h and DEJ2000=-76° to -69°.
This region includes the main body of the SMC and its surroundings, as
well as a part of the Magellanic Bridge.
In section 3, we discuss the selection of massive stars using the
Gaia color-magnitude diagram. In the CMD of Figure 2, we selected
7426 stars as massive star candidates.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 268 7426 Catalog of 7426 massive star candidates in the SMC
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See also:
I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)
J/AJ/98/1305 : Stellar content of NGC 346 (Massey+, 1989)
J/ApJS/101/41 : SMC and Bridge extended catalog (Bica+ 1995)
J/MNRAS/339/105 : Western Magellanic Bridge HI observations (Muller+, 2003)
J/MNRAS/353/601 : 2dF survey of the Small Magellanic Cloud (Evans+, 2004)
J/A+A/456/623 : VLT-FLAMES survey of massive stars (Evans+, 2006)
J/MNRAS/386/826 : Radial velocities of SMC massive stars (Evans+, 2008)
J/AJ/140/416 : IR photometry of massive stars in the SMC (Bonanos+, 2010)
J/AJ/146/62 : HERschel HERITAGE in Magellanic Clouds (Meixner+, 2013)
J/MNRAS/442/1680 : Red giants in SMC. Abundances (Dobbie+, 2014)
J/MNRAS/442/1663 : Velocities of red giants in the SMC (Dobbie+, 2014)
J/AcA/65/297 : OGLE4 LMC and SMC Cepheids (Soszynski+, 2015)
J/ApJS/224/21 : VMC survey. XIX. Classical Cepheids in SMC (Ripepi+, 2016)
J/MNRAS/472/808 : YJKs light curves of SMC Classical Cepheids (Ripepi+, 2017)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/MNRAS/473/3131 : VMC survey. XXVI. SMC RR Lyrae stars (Muraveva+, 2018)
J/ApJ/863/181 : The fifth catalog of LMC Wolf-Rayet stars (Neugent+, 2018)
J/ApJ/867/L8 : Gaia data of runaway & field OB stars in SMC (Oey+, 2018)
J/ApJ/858/31 : VMC survey. XXIX. Star formation in the SMC (Sun+, 2018)
J/ApJ/887/267 : OB stars embedded in the HI gas of SMC (Murray+, 2019)
J/AJ/159/82 : Extended objects in Magellanic clouds (Bica+, 2020)
J/MNRAS/495/98 : Tidal scars of the Small Magellanic Cloud (De Leo+, 2020)
J/A+A/649/A7 : MC structure and properties (Gaia Collaboration+, 2021)
J/MNRAS/502/2859 : The VMC survey XLI - PMs within the SMC (Niederhofer+, 2021)
J/A+A/649/A3 : Gaia EDR3 photometric passbands (Riello+, 2021)
J/MNRAS/504/2983 : Reddening of SMC red clump stars (Tatton+, 2021)
J/ApJ/949/63 : CO survey toward SMC north with ACA. II. (Ohno+, 2023)
J/AJ/168/255 : U-SMAC II. FUV cat. of sources detected in SMC (Hota+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [0/7425] Unique identifier assigned to each
entry in the catalog
6- 24 I19 --- GaiaDR3 The source id of Gaia DR3
26- 39 F14.11 deg RAdeg [0.4/44.4] Right Ascension (J2000)
41- 55 F15.11 deg DEdeg [-76/-69] Declination (J2000)
57- 65 F9.6 mag Gmag [9.3/17.8] Gaia G band magnitude
67- 74 F8.6 mag e_Gmag [0.0027/0.02] Error of the G band magnitude
76- 84 F9.6 mag GBPmag [9.6/18] Gaia BP band magnitude
86- 93 F8.6 mag e_GBPmag [0.002/0.21] Error of the GBP band magnitude
95- 103 F9.6 mag GRPmag [8.78/18.2] Gaia RP band magnitude
105- 112 F8.6 mag e_GRPmag [0.003/0.2] Error of the GRP band magnitude
114- 120 F7.4 mas plx [-6/0.1] Parallax
122- 127 F6.4 mas e_plx [0.009/0.7] Error of the parallax
129- 134 F6.3 mas/yr pmRA [-10/36] Proper motion in Right Ascension
136- 140 F5.3 mas/yr e_pmRA [0.01/1] Error of the pmRA
142- 147 F6.3 mas/yr pmDE [-7.4/21] Proper motion in Declination
149- 153 F5.3 mas/yr e_pmDE [0.01/0.8] Error of the pmDE
155- 159 A5 --- PM2sc Indicates a proper motion 2 sigma clipped
sample (see Section 4.1)
161- 167 F7.3 mas/yr pmRAin [-10.7/35.2] The pmRA in the SMC Rest Frame
(see Section 4.1)
169- 174 F6.3 mas/yr pmDEin [-6.1/21.6] The pmDE in the SMC Rest Frame
(see Section 4.1)
176- 182 F7.2 km/s RVel [-134/515]? Radial velocity in the Solar
system barycentric reference frame (1)
184- 188 F5.2 km/s e_RVel [0.4/12.3]? Error of the radial velocity
190- 191 I2 --- Sstr [0/8]?=-1 Indicates a part of nine
superstructures (see Section 5.1) (2)
193- 197 A5 --- B10-1 Indicates matching B10 object within a
cross-match radius of 1"
199- 203 A5 --- B10-0.5 Indicates matching B10 object within a
cross-match radius of 0.5"
205- 221 A17 --- B10Name Name of the cross-matched B10
(Bonanos+ 2010, J/AJ/140/416) object if any
224- 233 A10 --- B10Name2 Name of a second cross-matched B10 object
for the single massive star candidate
(3 cases)
235- 260 A26 --- B10SpT Spectral type classification of the
cross-matched B10 object
262- 268 A7 --- B10SpT2 Spectral type classification of the second
cross-matched B10 object
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Note (1): Before correction for hot stars (see Section 5.2).
Note (2): Adding 1 to the label results in a match with the superstructure
label in the text.
NULL if not included in the superstructures.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-Feb-2026