J/A+A/639/A64 Extended Meingast 1 source catalogue (Ratzenboeck+, 2020)
Extended stellar systems in the solar neighborhood.
IV. Meingast 1: the most massive stellar stream in the solar neighborhood.
Ratzenboeck S., Meingast S., Alves J., Moeller T., Bomze I.
<Astron. Astrophys. 639, A64 (2020)>
=2020A&A...639A..64R 2020A&A...639A..64R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Positional data
Keywords: methods: statistical - open clusters and associations: Meingast 1 -
stars: luminosity function, mass function - stars: massive -
stars: low-mass - white dwarfs
Abstract:
Nearby stellar streams carry unique information on the dynamical
evolution and disruption of stellar systems in the Galaxy, the mass
distribution in the disk, and they provide unique targets for planet
formation and evolution studies. Recently, Meingast 1, a 120°
stellar stream with a length of at least 400pc, was discovered.
We aim to revisit the Meingast 1 stream to search for new members
within its currently known 400pc extent, using Gaia DR2 data and an
innovative machine learning approach.
We used a bagging classifier of one-class support vector machines with
Gaia DR2 data to perform a 5D search (positions and proper motions)
for new stream members. The ensemble was created by randomly sampling
2.4 million hyper-parameter realizations admitting classifiers that
fulfill a set of prior assumptions. We used the variable prediction
frequency resulting from the multitude of classifiers to estimate a
stream membership criterion, which we used to select high-fidelity
sources. We used the HR diagram and the Cartesian velocity
distribution as test and validation tools.
We find about 2000 stream members with high fidelity, or about an
order of magnitude more than previously known, unveiling the
stream's population across the entire stellar mass spectrum, from B
stars to M stars, including white dwarfs. We find that, apart from
being slightly more metal poor, the HRD of the stream is
indistinguishable from that of the Pleiades cluster. For the mass
range at which we are mostly complete, ∼0.2M☉<M≲4M☉, we
find a normal IMF, allowing us to estimate the total mass of stream to
be about 2000M☉, making this relatively young stream by far the
most massive one known. In addition, we identify several white dwarfs
as potential stream members.
The nearby Meingast 1 stream, due to its richness, age, and distance,
is a new fundamental laboratory for star and planet formation and
evolution studies for the poorly studied and gravitationally unbound
star formation mode. We also demonstrate that one-class support vector
machines can be effectively used to unveil the full stellar
populations of nearby stellar systems with Gaia data.
Description:
This provided table contains the extended source selection for the
Meingast 1 stream as presented in the associated paper. We provide
basic Gaia DR2 information which including source identifiers,
Galactic Cartesian positions, proper motions, as well as the
determined stability score and two quality filter criteria for each
source.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 122 4269 Meingast 1 extended source selection
--------------------------------------------------------------------------------
See also:
J/A+A/621/L3 : Hyades tidal tails with Gaia DR2 (Meingast+, 2019)
J/A+A/622/L13 : Stellar stream in Gaia DR2 discovery (Meingast+, 2019)
J/A+A/624/L11 : Coma Berenices neighbor moving group (Fuernkranz+, 2019)
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR2 Gaia DR2 unique source identifier
21- 31 F11.7 deg RAdeg Right ascension (ICRS) at Ep=2015.5
33- 43 F11.7 deg DEdeg Declination (ICRS) at Ep=2015.5
45- 56 F12.7 pc X Galactic Cartesian X position
58- 69 F12.7 pc Y Galactic Cartesian Y position
71- 82 F12.7 pc Z Galactic Cartesian Z position
84- 94 F11.7 mas/yr pmRA* Gaia DR2 proper motion in RA direction,
pmRA*cosDE
96-106 F11.7 mas/yr pmDE Gaia DR2 proper motion in DE direction
108-118 F11.7 % Stab Source fidelity measure
120 I1 --- Q1 [0/1] Employed quality filter 1
122 I1 --- Q2 [0/1] Employed quality filter 2
--------------------------------------------------------------------------------
Acknowledgements:
Sebastian Ratzenboeck, sebastian.ratzenboeck(at)univie.ac.at
References:
Meingast & Alves, Paper I 2019A&A...621L...3M 2019A&A...621L...3M, Cat. J/A+A/621/L3
Meingast et al., Paper II 2019A&A...622L..13M 2019A&A...622L..13M, Cat. J/A+A/622/L13
Furnkranz et al., Paper III 2019A&A...624L..11F 2019A&A...624L..11F, Cat. J/A+A/624/L11
(End) Patricia Vannier [CDS] 01-Jul-2020