J/AJ/166/12 Velocity data for 88 very high velocity stars (Li+, 2023)
On the Origins of Extreme Velocity Stars as Revealed by Large-scale Galactic
Surveys.
Li Q.-Z., Huang Y., Dong X.-B., Zhang H.-W., Beers T.C., Yuan Z.
<Astron. J., 166, 12 (2023)>
=2023AJ....166...12L 2023AJ....166...12L
ADC_Keywords: Stars, high-velocity; Spectra, infrared
Keywords: Hypervelocity stars ; Black holes ; Sagittarius dwarf
spheroidal galaxy ; Galaxy kinematics ; Galaxy dynamics
Abstract:
We assemble a large sample of 12784 high-velocity stars with total
velocity VGSR≳300km/s, selected from RAVE DR5, SDSS DR12, LAMOST DR8,
APOGEE DR16, GALAH DR2, and Gaia EDR3. In this sample, 52 are
marginally hypervelocity star (HVS) candidates that have VGSR
exceeding their local escape velocities within 2σ confidence
levels, 40 of which are discovered for the first time. All of the
candidates are metal-poor, late-type halo stars, which are
significantly different from the previously identified HVSs, which are
largely massive early-type stars, discovered by extreme radial
velocity. This finding suggests that our newly identified HVS
candidates are ejected by different mechanisms from the previous
population. To investigate their origins, for 547 extreme velocity
stars with VGSR≳0.8Vesc, we reconstruct their backward-integrated
trajectories in the Galactic potential. According to the orbital
analysis, no candidates are found to be definitely ejected from the
Galactic-center (GC), while eight metal-poor extreme velocity stars
are found to have a closest distance to the GC within 1kpc.
Intriguingly, 15 extreme velocity stars (including 2 HVS candidates)
are found to have experienced close encounters with the Sagittarius
dSph, suggesting that they originated from this dSph. This hypothesis
is supported by an analysis of the [α/Fe]-[Fe/H] diagram. From a
preliminary analysis of all of the 547 extreme velocity stars, we
propose a general picture-star ejection from Galactic subsystems such
as dwarf galaxies and globular clusters can be an important channel to
produce extreme velocity stars or even HVSs, particularly the
metal-poor late-type halo population.
Description:
After nearly 10 years of effort (2003-2013), the RAVE survey
collected 520781 moderate-resolution (R∼7500) spectra centered on the
CaI triplet (8410-8795Å) for 457588 unique stars, randomly selected
from stars in the Southern Hemisphere with 9<I<12, using the
multi-object spectrograph 6dF on the 1.2m UK Schmidt Telescope of the
Australian Astronomical Observatory.
The European Space Agency (ESA) satellite Gaia recently released the
Early Data Release 3, which provides astrometric and photometric data
for over 1.8 billion sources, with G-band magnitudes ranging from 3 to
21.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 148 52 The 52 hypervelocity star (HVS) candidates
assuming different escape velocity curves
table3.dat 150 8 8 HiVel pass through the Galactic plane within
1kpc of the Galactic-center (GC)
table4.dat 150 15 Extreme velocity stars probably originating from
the Sgr dSph
table5.dat 214 88 Basic parameters for 88 HVSs or candidates
(Table A1)
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+, 2007-2017)
II/282 : The SDSS Photometric Catalog, Release 6 (Adelman-McCarthy+, 2007)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
III/279 : RAVE 5th data release (Kunder+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
J/AJ/128/1177 : Galactic stellar abundances (Venn+, 2004)
J/ApJ/647/303 : Spectroscopic survey of hypervelocity stars (Brown+, 2006)
J/ApJ/671/1708 : Hypervelocity stars. III (Brown+, 2007)
J/AJ/136/2070 : SEGUE stellar parameter pipeline. III. (Allende Prieto+, 2008)
J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)
J/AJ/136/614 : Arp 2 and Ter 8 red giants equivalent widths (Mottini+, 2008)
J/ApJ/684/1143 : BHB candidates in the Milky Way (Xue+, 2008)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/A+A/520/A95 : Abundances of red giants in M54 and Sgr dSph (Carretta+, 2010)
J/ApJ/711/138 : Spectral analysis of HIP 60350 and 18 Peg (Irrgang+, 2010)
J/AJ/141/90 : SEGUE stellar parameter pipeline. V. (Lee+, 2011)
J/AJ/141/89 : SEGUE stellar parameter pipeline. IV. (Smolinski+, 2011)
J/ApJ/751/55 : MMT hypervelocity star survey. II. (Brown+, 2012)
J/AJ/144/4 : Properties dwarf galaxies in Local Group (McConnachie+, 2012)
J/ApJ/765/154 : RR Lyrae stars in the Catalina Sky Survey (Drake+, 2013)
J/ApJ/763/32 : Galactic halo RRab stars from CSS (Drake+, 2013)
J/A+A/561/A87 : FLAMES observations of Terzan 8 (Carretta+, 2014)
J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/MNRAS/446/2251 : Southern Catalina Survey type-ab RR Lyrae (Torrealba+, 2015)
J/MNRAS/469/3688 : CSS Periodic Variable Star Catalogue (Drake+, 2017)
J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)
J/AJ/156/90 : Catalog of APOGEE radial velocity std stars (Huang+, 2018)
J/A+A/623/A110 : Gaia DR2. Variable stars in CMD (Gaia Collaboration+, 2019)
J/MNRAS/482/4570 : Gaia DR2 white dwarf candidates (Gentile Fusillo+, 2019)
J/MNRAS/490/157 : Fastest stars in the Galaxy with Gaia DR2 (Marchetti+, 2019)
J/MNRAS/484/2832 : Proper motions Milky Way globular clusters (Vasiliev, 2019)
J/ApJS/245/34 : Abundances for 6 million stars from LAMOST DR5 (Xiang+, 2019)
J/MNRAS/504/356 : Updated parameters of 1743 open clusters (Dias+, 2021)
J/ApJS/252/3 : High-velocity stars in Gal. halo from LAMOST &Gaia (Li+, 2021)
J/A+A/653/A160 : Updated radial velocities from Gaia DR2 (Seabroke+, 2021)
J/MNRAS/505/5978 : Gaia EDR3 view Galactic globular clusters (Vasiliev+, 2021)
J/AJ/163/252 : Abundances for 15 extreme-velocity stars (Reggiani+, 2022)
J/ApJS/259/60 : SEGUE-2 updated stellar parameter pipeline (Rockosi+, 2022)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Source identifier
10- 28 I19 --- Gaia Gaia DR3 identifier
30- 39 F10.6 deg RAdeg [12/342] Right Ascension (J2000)
41- 50 F10.6 deg DEdeg [-18/61] Declination in decimal degrees (J2000)
52- 58 F7.3 mas/yr pmRA [-74.5/76] Gaia DR3 proper motion along
RA*cos(DE)
60- 64 F5.3 mas/yr e_pmRA [0.02/0.2] Uncertainty in pmRA
66- 73 F8.3 mas/yr pmDE [-129/13.3] Gaia DR3 proper motion along DE
75- 79 F5.3 mas/yr e_pmDE [0.02/0.2] Uncertainty in pmDE
81- 88 F8.3 km/s Vlos [-346/440] Line of sight velocity
90- 95 F6.3 km/s e_Vlos [1/20] Uncertainty in Vlos
97-101 F5.3 kpc Dist [1.17/4.51] Distance
103-107 F5.3 kpc e_Dist [0.06/1] Uncertainty in Dis
109-115 F7.3 km/s VGSR [484/717] Galactic Standard of Rest velocity
117-123 F7.3 km/s e_VGSR [32.8/174] Uncertainty in VGSR
125-128 F4.2 --- Pub-MW [0.13/0.92] MilkyWayPotential unbound
probability (1)
130-133 F4.2 --- Pub-M18 [0.12/0.91] Monari+, 2018A&A...616L...9M 2018A&A...616L...9M
unbound probability (1)
135-138 F4.2 --- Pub-D19 [0.34/0.96] Deason+, 2019MNRAS.485.3514D 2019MNRAS.485.3514D
unbound probability (1)
140-143 F4.2 --- Pub-BMW [0.51/0.97] BovyMWPotential2014 unbound
probability (1)
145-148 F4.2 --- Pub-W17 [0.37/0.96] Williams+, 2017MNRAS.468.2359W 2017MNRAS.468.2359W
unbound probability (1)
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Note (1): Unbound probability calculated from the Galactic escape
velocity curve under the Milky Way?s potential MilkyWayPotential
implemented in Gala (Pub-MW), adopted from Monari+ 2018A&A...616L...9M 2018A&A...616L...9M ,
adopted from Deason+, 2019MNRAS.485.3514D 2019MNRAS.485.3514D, BovyMWPotential2014
implemented in Gala (Pub-BWM), and derived by Williams+ 2017MNRAS.468.2359W 2017MNRAS.468.2359W.
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Byte-by-byte Description of file: table[34].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Source identifier
15- 33 I19 --- Gaia Gaia DR3 identifier
35- 44 F10.6 deg RAdeg Right Ascension (J2000)
46- 54 F9.6 deg DEdeg Declination (J2000)
56- 62 F7.3 mas/yr pmRA Gaia DR3 proper motion along RA*cos(DE)
64- 68 F5.3 mas/yr e_pmRA Uncertainty in pmRA
70- 76 F7.3 mas/yr pmDE Gaia DR3 proper motion along DE
78- 82 F5.3 mas/yr e_pmDE Uncertainty in pmDE
84- 91 F8.3 km/s Vlos Line of sight velocity
93- 98 F6.3 km/s e_Vlos Uncertainty in Vlos
100-104 F5.3 kpc Dist Distance
106-110 F5.3 kpc e_Dist Uncertainty in Dis
112-118 F7.3 km/s VGSR Galactic Standard of Rest velocity
120-126 F7.3 km/s e_VGSR Uncertainty in VGSR
128-131 F4.2 kpc CDis Closest distance
133-136 F4.2 kpc e_CDis Uncertainty in CDis
138-143 F6.1 Myr BTime Backward time
145-150 F6.1 Myr e_BTime Uncertainty in BTime
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID [1/88] Internal identifier
4- 22 A19 --- Name Source identifier (1)
24- 42 I19 --- Gaia Gaia EDR3 identifier (2)
44- 53 F10.6 deg RAdeg [12/353] Right Ascension (J2000) (2)
55- 64 F10.6 deg DEdeg [-75/75] Declination (J2000) (2)
66- 72 F7.3 mas/yr pmRA [-81/99]? Gaia EDR3 proper motion along
RA*cos(DE)
74- 78 F5.3 mas/yr e_pmRA [0.02/2]? Uncertainty in pmRA
80- 87 F8.3 mas/yr pmDE [-196/241]? Gaia EDR3 proper motion along DE
89- 93 F5.3 mas/yr e_pmDE [0.02/2]? Uncertainty in pmDE
95-101 F7.2 km/s Vlos [-485/1200] Line of sight velocity
103-107 F5.2 km/s e_Vlos [1/80]? Uncertainty in Vlos
109-114 F6.2 kpc Dist [0.3/115] Distance
116-120 F5.2 kpc e_Dist [0.01/22] Uncertainty in Dis
122-126 I5 K Teff [4673/47200]? Effective temperature
128-131 I4 K e_Teff [13/1200]? Uncertainty in Teff
133-136 F4.2 [cm/s2] logg [2.06/5.69]? log surface gravity
138-141 F4.2 [cm/s2] e_logg [0.02/0.9]? Uncertainty in log(g)
143-147 F5.2 [Sun] [Fe/H] [-2.38/0.29]? Metallicity
149-152 F4.2 [Sun] e_[Fe/H] [0/0.4]? Uncertainty in [Fe/H]
154-158 F5.2 [Sun] [a/Fe] [-0.08/0.47]? log α/Fe abundance ratio
160-163 F4.2 [Sun] e_[a/Fe] [0.01/0.8]? Uncertainty in [a/Fe]
165-171 F7.2 km/s Vrf [-638/1039] Galactic Rest-frame, line of
sight velocity
173-177 F5.2 km/s e_Vrf [1/80]? Uncertainty in Vrf
179-185 F7.2 km/s VGSR [383/2511]? Galactic Standard of Rest velocity
187-192 F6.2 km/s e_VGSR [2/720]? Uncertainty in VGSR
194-194 A1 --- f_Ref [ab] Flag on Ref (3)
196-214 A19 --- Ref Reference; ADS Bibcode if not this work
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Note (1): Name "LG-HVS18" at line 19 was a misprint for "LG-HVS19";
corrected at CDS.
Note (2): ID 79, "HV23" had incorrect right ascension and no Gaia counterpart;
corrected at CDS.
Note (3): Flags as follows:
a = This candidate is also reported by Li+, 2021, J/ApJS/252/3
b = This candidate is also reported by Bromley+ 2018ApJ...868...25B 2018ApJ...868...25B
and Li+ 2021, J/ApJS/252/3
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Acknowledgements:
Yang HUANG [huangyang at ucas.ac.cn]
History:
From electronic version of the journal
* 05-Sep-2024:Insert into VizieR
* 30-Jul-2025: misprint in "LG-HVS18" name corrected in Table 5.
* 01-Aug-2025: coordinates for "HVS23" in Table 5; corrected and
corresponding Gaia DR3 added
(End) Prepared by [AAS], Coralie Fix [CDS], 30-Jan-2024