J/ApJ/920/51 Stars of the LMS-1 stream with sp. obs. (Malhan+, 2021)
Evidence of a dwarf galaxy stream populating the inner Milky Way halo.
Malhan K., Yuan Z., Ibata R.A., Arentsen A., Bellazzini M., Martin N.F.
<Astrophys. J., 920, 51 (2021)>
=2021ApJ...920...51M 2021ApJ...920...51M
ADC_Keywords: Associations, stellar; Milky Way; Abundances, [Fe/H]; Surveys;
Spectra, optical
Keywords: Milky Way stellar halo ; Stellar streams ; Milky Way formation ;
Surveys ; Galaxy stellar content ; Galaxy structure
Abstract:
Stellar streams produced from dwarf galaxies provide direct evidence
of the hierarchical formation of the Milky Way. Here, we present the
first comprehensive study of the LMS-1 stellar stream, that we detect
by searching for wide streams in the Gaia EDR3 data set using the
STREAMFINDER algorithm. This stream was recently discovered by Yuan et
al. We detect LMS-1 as a 60° long stream to the north of the
galactic bulge, at a distance of ∼20kpc from the Sun, together with
additional components that suggest that the overall stream is
completely wrapped around the inner Galaxy. Using spectroscopic
measurements from the Large Sky Area Multi-Object Fiber Spectroscopic
Telescope, the Sloan Digital Sky Survey, and the Apache Point
Observatory Galactic Evolution Experiment, we infer that the stream is
very metal-poor (<[Fe/H]≥-2.1) with a significant metallicity
dispersion (σ[Fe/H]=0.4), and it possesses a large radial
velocity dispersion (σv=20±4km/s). These estimates together
imply that LMS-1 is a dwarf galaxy stream. The orbit of LMS-1 is close
to polar, with an inclination of 75° to the galactic plane. Both
the orbit and metallicity of LMS-1 are remarkably similar to the
globular clusters NGC 5053, NGC 5024, and the stellar stream Indus.
These findings make LMS-1 an important contributor to the stellar
population of the inner Milky Way halo.
Description:
To detect LMS-1, we process the Gaia EDR3 catalog using the
STREAMFINDER algorithm (Malhan & Ibata 2018MNRAS.477.4063M 2018MNRAS.477.4063M &
Malhan+ 2018MNRAS.481.3442M 2018MNRAS.481.3442M).
To measure the metallicity ([Fe/H]) of LMS-1 stars, we made the
selection of the northern part of the structure as shown in the top
panel of Figure 3 and cross-matched these sources with public
spectroscopic surveys (LAMOST DR6, SDSS/SEGUE DR10 and APOGEE DR14);
see Table 1.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
13 14 30.00 +17 56 00.0 LMS-1 = NAME LMS-1 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 47 63 Stars of LMS-1 with spectroscopic observations
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See also:
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/A+A/511/L10 : Abundances and space velocities of 94 stars (Nissen+, 2010)
J/A+A/531/A165 : MILES atmospheric parameters (Prugniel+, 2011)
J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)
J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/ApJ/804/109 : Equivalent widths of RGB stars in NGC 5053 (Boberg+, 2015)
J/AJ/150/187 : Abundances and stellar param. of LAMOST stars (Lee+, 2015)
J/ApJ/824/5 : Chemical abundances in NGC 5024 (M53) (Boberg+, 2016)
J/A+A/585/A64 : New atmospheric param. of MILES cool stars (Sharma+, 2016)
J/A+A/601/A41 : Palomar 5 abundance analysis (Koch+, 2017)
J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)
J/ApJS/238/16 : LAMOST-DR3 very metal-poor star catalog (Li+, 2018)
J/ApJ/866/22 : Spectroscopic analysis of Tuc III stream (Li+, 2018)
J/A+A/627/A138 : XSL atmospheric parameters (Arentsen+, 2019)
J/MNRAS/482/5138 : Gal. GC mean proper motions & velocities (Baumgardt+, 2019)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/MNRAS/485/4726 : An all-sky view of the Orphan Stream (Koposov+, 2019)
J/MNRAS/486/2995 : GD-1 stellar stream (Malhan+, 2019)
J/ApJS/245/34 : Abund. for 6 million stars from LAMOST DR5 (Xiang+, 2019)
J/ApJ/889/63 : Properties of Sgr Stars (Hayes+, 2020)
J/AJ/160/181 : Chemical abundances in red giants with Magellan (Ji+, 2020)
J/A+A/638/A104 : Gaia DR2 cand. RR Lyrae of Sgr stream & dwarf (Ramos+, 2020)
J/ApJ/891/39 : LAMOST very metal-poor stars of the Gal. halo (Yuan+, 2020)
J/ApJ/914/123 : Gaia DR2 and EDR3 stars with sp. follow-up (Ibata+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 I1 --- Survey [1/3] Source survey (1)
3- 12 F10.6 deg RAdeg [195/246] Right ascension (J2000)
14- 22 F9.6 deg DEdeg [13/33] Declination (J2000)
24- 30 F7.2 km/s Vlos [-201.5/109.6] Line of sight velocity
32- 36 F5.2 km/s e_Vlos [0.1/34] Vlos uncertainty
38- 42 F5.2 [Sun] [Fe/H] [-3.1/-0.6]? Metallicity
44- 47 F4.2 [Sun] e_[Fe/H] [0/0.4]? [Fe/H] uncertainty
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Note (1): Source survey as follows:
1 = APOGEE DR14 (Majewski+ 2017AJ....154...94M 2017AJ....154...94M); 1 occurrence
2 = LAMOST DR6 (Zhao+ 2012RAA....12..723Z 2012RAA....12..723Z); 49 occurrences
3 = SDSS/SEGUE DR10 (Yanny+ 2009, J/AJ/137/4377); 13 occurrences
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Acknowledgements:
Rodrigo Ibata [rodrigo.ibata at astro.unistra.fr]
(End) Emmanuelle Perret [CDS] 21-Feb-2024