J/MNRAS/502/4170 Action-space clustering on stellar stream data (Reino+, 2021)
Galactic potential constraints from clustering in action space of combined
stellar stream data.
Reino S., Rossi E.M., Sanderson R.E., Sellentin E., Helmi A.,
Koppelman H.H., Sharma S.
<Mon. Not. R. Astron. Soc., 502, 4170-4193 (2021)>
=2021MNRAS.502.4170R 2021MNRAS.502.4170R (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, halo ; Stars, distances ; Radial velocities ;
Optical
Keywords: methods: numerical - Galaxy: fundamental parameters -
Galaxy: kinematics and dynamics - Galaxy: structure - dark matter
Abstract:
Stream stars removed by tides from their progenitor satellite galaxy
or globular cluster act as a group of test particles on neighbouring
orbits, probing the gravitational field of the Milky Way. While
constraints from individual streams have been shown to be susceptible
to biases, combining several streams from orbits with various
distances reduces these biases. We fit a common gravitational
potential to multiple stellar streams simultaneously by maximizing the
clustering of the stream stars in action space. We apply this
technique to members of the GD-1, Palomar 5 (Pal 5), Orphan, and Helmi
streams, exploiting both the individual and combined data sets. We
describe the Galactic potential with a Stackel model, and vary up to
five parameters simultaneously. We find that we can only constrain the
enclosed mass, and that the strongest constraints come from the GD-1,
Pal 5, and Orphan streams whose combined data set yields
M(<20kpc)=2.96+0.25-0.26x1011M☉. When including the Helmi
stream in the data set, the mass uncertainty increases to
M(<20kpc)=3.12+3.21-0.46x1011M☉.
Description:
The goal of this work is to use the action-space clustering method on
real data of known stream stars. For this purpose we compiled data
from seven different literature sources (Willett et al.
2009ApJ...697..207W 2009ApJ...697..207W, Cat. J/ApJ/697/207; Koposov et al.
2010ApJ...712..260K 2010ApJ...712..260K, 2019MNRAS.485.4726K 2019MNRAS.485.4726K, Cat. J/MNRAS/485/4726; Ibata
et al. 2017ApJ...842..120I 2017ApJ...842..120I, Cat. J/ApJ/842/120; Li et al.
2017RAA....17...62L 2017RAA....17...62L, Cat. J/other/RAA/17.62; Koppelman et al.
2019A&A...625A...5K 2019A&A...625A...5K; Price-Whelan et al. 2019AJ....158..223P 2019AJ....158..223P, Cat.
J/AJ/158/223) to obtain a data set containing full 6D phase-space
information for stars in the GD-1, Helmi, Orphan, and Pal 5 streams.
When complete 6D information for individual stars was not available,
we made use of the stream's track: the measurements of the stream's
mean phase-space position as a function of a coordinate aligned with
the stream. We fit the tracks with a simple polynomial function in
order to find the stars' missing 6D phase-space components, based on
their location along the stream.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
streams.dat 77 723 Stream catalogue
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/842/120 : Large spectrosc. survey of Palomar 5 stellar stream
(Ibata+, 2017)
J/MNRAS/485/4726 : An all-sky view of the Orphan Stream (Koposov+, 2019)
J/other/RAA/17.62 : Candidate members of 4 stellar streams (Li+, 2017)
J/AJ/158/223 : RR Lyrae members of the Pal 5 stellar stream
(Price-Whelan+, 2019)
J/ApJ/697/207 : Cold stellar stream orbit fit (Willett+, 2009)
Byte-by-byte Description of file: streams.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 Gaia DR2 source identifier
21- 26 A6 --- Stream Stream name
28- 41 A14 --- Ref Reference in literature (1)
43- 54 F12.9 kpc Dist Heliocentric distance
56- 66 F11.6 km/s RV Heliocentric radial velocity
68- 77 F10.6 km/s e_RV ? Error on RV (2)
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Note (1): Reference as follows:
Ibata17 = Ibata et al. (2017ApJ...842..120I 2017ApJ...842..120I, Cat. J/ApJ/842/120)
radial velocities, the distances are estimated from fits to
tracks
Koposov10 = Koposov et al. (2010ApJ...712..260K 2010ApJ...712..260K) radial velocities, the
distances are estimated from fits to tracks
Koposov19 = Koposov et al. (2019MNRAS.485.4726K 2019MNRAS.485.4726K, Cat. J/MNRAS/485/4726)
distances, radial velocities are estimated from fits to
tracks
Koposov19&Li17 = Koposov et al. (2019MNRAS.485.4726K 2019MNRAS.485.4726K, Cat. J/MNRAS/485/4726)
distances, Li et al. (2017RAA....17...62L 2017RAA....17...62L,
Cat. J/other/RAA/17.62) radial velocities
Koppelman19 = Koppelman et al. (2019A&A...625A...5K 2019A&A...625A...5K) members
Li17 = Li et al. (2017RAA....17...62L 2017RAA....17...62L, Cat. J/other/RAA/17.62)
radial velocities, the distances are estimated from fits to
tracks
PriceWhelan19 = Price-Whelan et al. (2019AJ....158..223P 2019AJ....158..223P, Cat. J/AJ/158/223)
distances, radial velocities are estimated from fits to
tracks
Willett09 = Willet et al. (2009ApJ...697..207W 2009ApJ...697..207W, Cat. J/ApJ/697/207)
radial velocities, the distances are estimated from fits to
tracks
Note (2): Error missing for the stars for which radial velocity was estimated
from tracks
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 31-Oct-2023