J/A+A/660/A29 Spectro-phot. distances of ∼ 300000 SEGUE stars (Thomas+, 2022)
Cetus-Palca stream: A disrupted small dwarf galaxy. A prequel to the science
possible with WEAVE with precise spectro-photometric distances.
Thomas G., Battaglia G.
<Astron. Astrophys. 660, A29 (2022)>
=2022A&A...660A..29T 2022A&A...660A..29T (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, distances ; Radial velocities ;
Space velocities ; Optical
Keywords: Galaxy: halo - methods: data analysis - galaxies: dwarf -
Galaxy: kinematics and dynamics - stars: distances - catalogs
Abstract:
We present a new fully data-driven approach to derive
spectro-photometric distances based on artificial neural network. The
method was developed and tested on SEGUE data and will serve as a
reference for the Contributed Data Product (SPdist) of the WEAVE
survey. With this method, the relative precision on the distances is
of ∼13%. The catalogue of more than 300000 SEGUE stars for which we
have derived spectro-photometric distances is publicly available on
the Vizier service of the Centre de Donnees de Strasbourg. With
this catalogue of stars with distances, line-of-sight velocity, and
Gaia proper motions, we have been able to identify stars belonging to
the Cetus stellar stream in the integrals of motion space. With the
properties of the Cetus stream that we derived from them, we search
for stars from the blue horizontal and from the red giant branches
along its orbital plane. With them, we ultimately found that the Cetus
stream have a total stellar mass of ∼1.5*106M☉ and present
prominent distance gradient of 15kpc over the ∼100deg. that it covers
on the sky. Additionally, we also report the discovery of a second
structure, almost parallel to the Cetus stream, covering ∼50deg. of
the sky, that could potentially be a stellar stream formed by the
tidal disruption of a globular cluster that was orbiting around the
Cetus progenitor.
Description:
Spectro-photometric distances derived for the more than 300000 SEGUE
stars by the machne learning based algorithm.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
dist.dat 315 308692 Spectro-photometric distances
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
Byte-by-byte Description of file:dist.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- specobjID SpecobjID from SDSS/SEGUE
21- 39 I19 --- GaiaEDR3 source_id from Gaia EDR3
41- 58 I18 --- objID objID from Pan-STARRS 3pi survey
60- 82 F23.19 deg RAdeg [0.0/360.0] Right ascension (J2000)
84-106 E23.17 deg DEdeg [-19.71/84.86] Declination (J2000)
108-131 E24.17 mag MGpred [-2.82/24.93] Predicted absolute magnitude
133-154 F22.19 mag e_MGpred [0.0/14.64] Uncertainty on the predicted
absolute magnitude
156-179 F24.20 kpc Dist [0.0/192.76] Heliocentric distance using the
predicted absolute magnitude
181-204 F24.20 kpc e_Dist [0.0/116.53] Uncertainty on the
heliocentric distance
206-228 F23.19 kpc Xgc [-93.37/82.32] Galactocentric coordinate
along the X-axis
230-253 E24.17 kpc Ygc [-63.4/160.87] Galactocentric coordinate
along the Y-axis
255-277 E23.17 kpc Zgc [-86.1/173.91] Galactocentric coordinate
along the Z-axis
279-301 E23.17 km/s Vx [-7873.06/1e+20]?=1e+20 Galactocentric
velocity along the X-axis
303-308 E6.1 km/s Vy [-12449.19/1e+20]?=1e+20 Galactocentric
velocity along the Y-axis
310-315 E6.1 km/s Vz [-1e+04/1e+20]?=1e+20 Galactocentric
velocity along the Z-axis
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Acknowledgements:
Guillaume Thomas, guillaume.thomas.astro(at)gmail.com
(End) Patricia Vannier [CDS] 01-Oct-2021