J/ApJ/891/L19 Gaia DR2 stars in the Sgr stream with STREAMFINDER (Ibata+, 2020)
A panoramic landscape of the Sagittarius Stream in Gaia DR2 revealed with the
STREAMFINDER spyglass.
Ibata R., Bellazzini M., Thomas G., Malhan K., Martin N., Famaey B.,
Siebert A.
<Astrophys. J., 891, L19 (2020)>
=2020ApJ...891L..19I 2020ApJ...891L..19I
ADC_Keywords: Local group; Associations, stellar; Proper motions; Colors;
Magnitudes; Optical; Surveys
Keywords: Dwarf galaxies ; Milky Way Galaxy ; Local Group ; Milky Way dynamics
Abstract:
We present the first full six-dimensional panoramic portrait of the
Sagittarius stream, obtained by searching for wide stellar streams in
the Gaia DR2 data set with the STREAMFINDER algorithm. We use the
kinematic behavior of the sample to devise a selection of Gaia RR
Lyrae, providing excellent distance measurements along the stream. The
proper motion data are complemented with radial velocities from public
surveys. We find that the global morphological and kinematic
properties of the Sagittarius stream are still reasonably well
reproduced by the simple Law & Majewski model (LM10), although the
model overestimates the leading arm and trailing arm distances by up
to ∼15%. The sample newly reveals the leading arm of the Sagittarius
stream as it passes into very crowded regions of the Galactic disk
toward the Galactic anticenter direction. Fortuitously, this part of
the stream is almost exactly at the diametrically opposite location
from the Galactic center to the progenitor, which should allow an
assessment of the influence of dynamical friction and self-gravity in
a way that is nearly independent of the underlying Galactic potential
model.
Description:
We reanalyzed the Gaia DR2 data set with the STREAMFINDER algorithm
(Malhan & Ibata 2018MNRAS.477.4063M 2018MNRAS.477.4063M & Malhan+ 2018MNRAS.481.3442M 2018MNRAS.481.3442M) in
an almost identical way to the procedure described in
Ibata+ (2019ApJ...872..152I 2019ApJ...872..152I).
Objects:
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RA (ICRS) DE Designation(s)
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02 22 00.00 +00 00 00.0 Sagittarius stream = NAME Sgr Stream
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 263438 STREAMFINDER stars in the Sagittarius Stream
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See also:
III/279 : RAVE 5th data release (Kunder+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/ApJ/850/96 : PS1 3π RRab stars within Sgr stream (Hernitschek+, 2017)
J/MNRAS/481/1195 : GaiaDR2 RR Lyrae stars as standard candles (Muraveva+, 2018)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/ApJ/874/138 : Gaia & LAMOST DR4 M giant members of Sgr stream (Li+, 2019)
J/ApJ/885/131 : High-mass SFR plx & proper motion with VLBI (Reid+, 2019)
J/A+A/635/L3 : Cand. member stars of the Sagittarius stream (Antoja+, 2020)
J/A+A/638/A104 : Gaia DR2 cand. RR Lyrae of Sgr stream & dwarf (Ramos+, 2020)
J/A+A/666/A64 : Sagittarius stream with eDR3 (Ramos+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 F10.6 deg RAdeg [0/360] Gaia DR2 right ascension (ICRS)
at Ep=2015.5
12- 21 F10.6 deg DEdeg [-50/46] Gaia DR2 declination (ICRS)
at Ep=2015.5
23- 28 F6.3 mas/yr pmRA [-3.7/1.3] Gaia DR2 proper motion in right
ascension, µa(*cos(δ))
30- 35 F6.3 mas/yr pmDE [-4.2/0.4] Proper motion in declination,
µδ
37- 42 F6.3 mag Gmag0 [12.9/19.5] Gaia DR2 G-band magnitude corrected
for extinction (1)
44- 48 F5.3 mag Bp-Rp0 [0.6/2.1] Bp-Rp color index, (GBP-GRP)0 (1)
50- 55 F6.3 kpc Dist [11.4/100] Distance estimate dSF provided
by STREAMFINDER
57- 64 F8.3 deg GLON [-180/180] Sagittarius galactic longitude,
Λ☉ (2)
66- 72 F7.3 deg GLAT [-20/15] Sagittarius galactic latitude,
B☉ (2)
74- 79 F6.3 mas/yr pmGLON [-4/0.8] Proper motion in RA, µΛ (2)
81- 86 F6.3 mas/yr pmGLAT [-4/0.05] Proper motion in DE, µB (2)
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Note (1): Magnitudes were corrected for extinction using the
Schlegel+ (1998ApJ...500..525S 1998ApJ...500..525S) maps, adopting the recalibration by
Schlafly & Finkbeiner (2011ApJ...737..103S 2011ApJ...737..103S), with RV=3.1.
See Section 2.
Note (2): Gaia DR2 coordinates and proper motions rotated into the Sagittarius
coordinate system.
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Acknowledgements:
Rodrigo Ibata [rodrigo.ibata at astro.unistra.fr]
(End) Emmanuelle Perret [CDS] 21-Feb-2024