J/MNRAS/496/2422 Abundances of 42 Pisces-Eridanus stream stars (Hawkins+, 2020)
The chemical nature of the young 120-Myr-old nearby Pisces-Eridanus stellar
stream flowing through the Galactic disk.
Hawkins K., Lucey M., Curtis J.
<Mon. Not. R. Astron. Soc. 496, 2422-2435 (2020)>
=2020MNRAS.496.2422H 2020MNRAS.496.2422H (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, nearby ; Abundances ; Spectra, optical
Keywords: stars: abundances - stars: kinematics and dynamics -
Galaxy: abundances -
Abstract:
Recently, a new cylindrical-shaped stream of stars, up to 700pc long,
was discovered hiding in the Galactic disk using kinematic data
enabled by the Gaia mission. This curious stream of stars, dubbed the
Pisces-Eridanus stream, was initially thought to be as old as 1Gyr,
yet its stars shared a rotation period distribution consistent with
the 120-Myr-old Pleiades cluster. In this work, we explore the
detailed chemical nature of this stellar stream. We carried out
high-resolution spectroscopic follow-up of 42 Pisces-Eridanus stream
stars using McDonald Observatory, and combined these data with
information for 40 members observed with the low-resolution LAMOST
spectroscopic survey. Together, these data enabled us to measure the
abundance distribution of light/odd-Z (Li, C, Na, Al, Sc, V), α
(Mg, Si, Ca, Ti), Fe-peak (Cr, Mn, Fe, Co, Ni, Zn), and neutron
capture (Sr, Y, Zr, Ba, La, Nd, Eu) elements across the
Pisces-Eridanus stream. We find that the stream is (1) near solar
metallicity with [Fe/H] = -0.03 dex and (2) has a metallicity spread
of 0.07 dex (or 0.04 dex when removing outliers). We also find that
(3) the abundance of Li indicates that Pisces-Eridanus is ∼120Myr old,
consistent with the gyrochronology result. We find that (4) the stream
has a [X/Fe] abundance spreads of 0.06<σ[X/Fe]<0.20dex in most
elements, and (5) no significant abundance gradients across its major
axis except a potentially weak gradient in [Si/Fe]. These results
together show that the Pisces-Eridanus stream is a uniquely close,
young, chemically interesting laboratory for testing our understanding
of star and planet formation.
Description:
Chemical abundances derived using high-resolution optical spectra
obtained at the 2.7m McDonald Observatory with the Tull spectrograph
slit#5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 99 42 Observational properties of observed targets
table3.dat 386 42 Stellar atmospheric parameters and chemical
abundances of observed targets
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/622/A13 : VLA double-double radio galaxy candidates images
(Mahatma+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 ---- GaiaDR2 Gaia DR2 Source ID
21- 28 F8.4 deg RAdeg Gaia DR2 right ascension (ICRS) at Ep=2015.5
30- 37 F8.4 deg DEdeg Gaia DR2 declination (ICRS) at Ep=2015.5
39- 43 F5.2 mas Plx Gaia DR2 parallax
45- 48 F4.2 mas e_Plx Gaia DR2 parallax error
50- 54 F5.2 km/s RVG Gaia DR2 radial velocity
56- 59 F4.2 km/s e_RVG Gaia DR2 radial velocity error
61- 65 F5.2 km/s RV Radial velocity, this work
67- 70 F4.2 km/s e_RV Radial velocity error, this work
72- 78 F7.2 pc X Galactic X position (1)
80- 85 F6.2 pc Y Galactic Y position (1)
87- 93 F7.2 pc Z Galactic Z position (1)
95- 97 I3 pix-1 SNR Signal-to-noise ratio measured in at the
continuum level at ∼5350Å of our optical
spectra
99 A1 --- LAMOST [Y/N] whether each observed star has also been
observed in the LAMOST survey
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Note (1): Galactic Cartesian X, Y, and Z obtained in Meingast et al.
(2019, Cat. J/A+A/622/L13).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 Gaia DR2 Source ID
21- 24 I4 K Teff Effective temperature
26- 28 I3 K e_Teff rms uncertainty on Teff
30- 33 F4.2 [cm/s2] logg Surface gravity
35- 38 F4.2 [cm/s2] e_logg rms uncertainty on logg
40- 44 F5.2 [-] [Fe/H] Metallicity, [Fe/H]
46- 49 F4.2 [-] e_[Fe/H] rms uncertainty on [Fe/H]
51- 54 F4.2 km/s vmicro Micro-turbulent velocity
56- 59 F4.2 km/s e_vmicro rms uncertainty on vmicro
61- 65 F5.2 [-] [Na/Fe] Abundance [Na/Fe]
67- 70 F4.2 [-] e_[Na/Fe] rms uncertainty on [Na/Fe]
72- 73 I2 --- o_[Na/Fe] Number of Na lines
75- 80 F6.2 [-] ALi ?=-99 Li abundance
82- 87 F6.2 [-] e_ALi ?=-99 rms uncertainty on ALi
89 I1 --- o_ALi Number of Li lines
91- 95 F5.2 [-] [Mg/Fe] Abundance [Mg/Fe]
97-100 F4.2 [-] e_[Mg/Fe] rms uncertainty on [Mg/Fe]
102 I1 --- o_[Mg/Fe] Number of Mg lines
104-109 F6.2 [-] [Al/Fe] ?=-99 Abundance [Al/Fe]
111-116 F6.2 [-] e_[Al/Fe] ?=-99 rms uncertainty on [Al/Fe]
118 I1 --- o_[Al/Fe] Number of Al lines
120-124 F5.2 [-] [Si/Fe] Abundance [Si/Fe]
126-129 F4.2 [-] e_[Si/Fe] rms uncertainty on [Si/Fe]
131-132 I2 --- o_[Si/Fe] Number of Si lines
134-138 F5.2 [-] [Ca/Fe] Abundance [Ca/Fe]
140-143 F4.2 [-] e_[Ca/Fe] rms uncertainty on [Ca/Fe]
145-146 I2 --- o_[Ca/Fe] Number of Ca lines
148-152 F5.2 [-] [Ti/Fe] Abundance [Ti/Fe]
154-157 F4.2 [-] e_[Ti/Fe] rms uncertainty on [Ti/Fe]
159-160 I2 --- o_[Ti/Fe] Number of Li lines
162-166 F5.2 [-] [V/Fe] Abundance [V/Fe]
168-171 F4.2 [-] e_[V/Fe] rms uncertainty on [V/Fe]
173-174 I2 --- o_[V/Fe] Number of V lines
176-180 F5.2 [-] [Sc/Fe] Abundance [Sc/Fe]
182-185 F4.2 [-] e_[Sc/Fe] rms uncertainty on [Sc/Fe]
187-191 F5.2 --- o_[Sc/Fe] Number of Sc lines
193-197 F5.2 [-] [Cr/Fe] Abundance [Cr/Fe]
199-202 F4.2 [-] e_[Cr/Fe] rms uncertainty on [Cr/Fe]
204-208 F5.2 --- o_[Cr/Fe] Number of Cr lines
210-214 F5.2 [-] [Mn/Fe] Abundance [Mn/Fe]
216-219 F4.2 [-] e_[Mn/Fe] rms uncertainty on [Mn/Fe]
221-225 F5.2 --- o_[Mn/Fe] Number of Mn lines
227-231 F5.2 [-] [Co/Fe] Abundance [Co/Fe]
233-236 F4.2 [-] e_[Co/Fe] rms uncertainty on [Co/Fe]
238-242 F5.2 --- o_[Co/Fe] Number of Co lines
244-248 F5.2 [-] [Ni/Fe] Abundance [Ni/Fe]
250-253 F4.2 [-] e_[Ni/Fe] rms uncertainty on [Ni/Fe]
255-256 I2 --- o_[Ni/Fe] Number of Ni lines
258-262 F5.2 [-] [Cu/Fe] Abundance [Cu/Fe]
264-267 F4.2 [-] e_[Cu/Fe] rms uncertainty on [Cu/Fe]
269 I1 --- o_[Cu/Fe] Number of Cu lines
271-276 F6.2 [-] [Zn/Fe] ?=-99 Abundance [Zn/Fe]
278-283 F6.2 [-] e_[Zn/Fe] ?=-99 rms uncertainty on [Zn/Fe]
285 I1 --- o_[Zn/Fe] Number of Zn lines
287-292 F6.2 [-] [Sr/Fe] ?=-99 Abundance [Sr/Fe]
294-299 F6.2 [-] e_[Sr/Fe] ?=-99 rms uncertainty on [Sr/Fe]
301 I1 --- o_[Sr/Fe] Number of Sr lines
303-307 F5.2 [-] [Y/Fe] Abundance [Y/Fe]
309-312 F4.2 [-] e_[Y/Fe] rms uncertainty on [Y/Fe]
314-315 I2 --- o_[Y/Fe] Number of Y lines
317-322 F6.2 [-] [Zr/Fe] ?=-99 Abundance [Zr/Fe]
324-329 F6.2 [-] e_[Zr/Fe] ?=-99 rms uncertainty on [Zr/Fe]
331 I1 --- o_[Zr/Fe] Number of Zr lines
333-336 F4.2 [-] [Ba/Fe] Abundance [Ba/Fe]
338-341 F4.2 [-] e_[Ba/Fe] rms uncertainty on [Ba/Fe]
343 I1 --- o_[Ba/Fe] Number of Ba lines
345-348 F4.2 [-] [La/Fe] Abundance [La/Fe]
350-353 F4.2 [-] e_[La/Fe] rms uncertainty on [La/Fe]
355-356 I2 --- o_[La/Fe] Number of La lines
358-362 F5.2 [-] [Nd/Fe] Abundance [Nd/Fe]
364-367 F4.2 [-] e_[Nd/Fe] rms uncertainty on [Nd/Fe]
369-370 I2 --- o_[Nd/Fe] Number of Nd lines
372-377 F6.2 [-] [Eu/Fe] ?=-99 Abundance [Eu/Fe]
379-384 F6.2 [-] e_[Eu/Fe] ?=-99 rms uncertainty on [Eu/Fe]
386 I1 --- o_[Eu/Fe] Number of Eu lines
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Acknowledgements:
Keith Hawkins, keithhawkins(at)utexas.edu
(End) Patricia Vannier [CDS] 11-Jun-2020