Pristine IX: CFHT ESPaDOnS Spectroscopic Analysis of 115 Bright Metal-Poor Candidate Stars. (arXiv:1910.06340v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Venn_K/0/1/0/all/0/1">Kim Venn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kielty_C/0/1/0/all/0/1">Collin Kielty</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sestito_F/0/1/0/all/0/1">Federico Sestito</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Starkenburg_E/0/1/0/all/0/1">Else Starkenburg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martin_N/0/1/0/all/0/1">Nicolas Martin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aguado_D/0/1/0/all/0/1">David S. Aguado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arentsen_A/0/1/0/all/0/1">Anke Arentsen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bonifacio_P/0/1/0/all/0/1">Piercarlo Bonifacio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caffau_E/0/1/0/all/0/1">Elisabetta Caffau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hill_V/0/1/0/all/0/1">Vanessa Hill</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jablonka_P/0/1/0/all/0/1">Pascale Jablonka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lardo_C/0/1/0/all/0/1">Carmela Lardo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mashonkina_L/0/1/0/all/0/1">Lyudmilla Mashonkina</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Navarro_J/0/1/0/all/0/1">Julio F. Navarro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sneden_C/0/1/0/all/0/1">Chris Sneden</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Thomas_G/0/1/0/all/0/1">Guillaume Thomas</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Youakim_K/0/1/0/all/0/1">Kris Youakim</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gonzalez_Hernandez_J/0/1/0/all/0/1">Jonay I. Gonzalez-Hernandez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Janssen_R/0/1/0/all/0/1">Ruben Sanchez Janssen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carlberg_R/0/1/0/all/0/1">Ray Carlberg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Malhan_K/0/1/0/all/0/1">Khyati Malhan</a>
A chemo-dynamical analysis of 115 metal-poor candidate stars selected from
the narrow-band Pristine photometric survey is presented based on CFHT
high-resolution ESPaDoNS spectroscopy. We have discover 28 new bright (V < 15)
stars with [Fe/H]<-2.5 and 5 with [Fe/H]<-3.0 for success rates of 40% (28/70)
and 19% (5/27), respectively. A detailed model atmospheres analysis is carried
out for the 28 new metal-poor stars. Stellar parameters were determined from
SDSS photometric colours, Gaia DR2 parallaxes, MESA/MIST stellar isochrones,
and the initial Pristine survey metallicities, following a Bayesian inference
method. Chemical abundances are determined for 10 elements (Na, Mg, Ca, Sc, Ti,
Cr, Fe, Ni, Y, Ba). Most stars show chemical abundance patterns that are
similar to the normal metal-poor stars in the Galactic halo; however, we also
report the discoveries of a new r-process rich star, a new CEMP-s candidate
with [Y/Ba]>0, and a metal-poor star with very low [Mg/Fe]. The kinematics and
orbits for all of the highly probable metal-poor candidates are determined by
combining our precision radial velocities with Gaia DR2 proper motions. Some
stars show unusual kinematics for their chemistries, including planar orbits,
unbound orbits, and highly elliptical orbits that plunge deeply into the
Galactic bulge (Rperi < 0.5 kpc); also, eight stars have orbital energies and
actions consistent with the Gaia-Enceladus accretion event. This paper
contributes to our understanding of the complex chemo-dynamics of the
metal-poor Galaxy, and increases the number of known bright metal-poor stars
available for detailed nucleosynthetic studies.
A chemo-dynamical analysis of 115 metal-poor candidate stars selected from
the narrow-band Pristine photometric survey is presented based on CFHT
high-resolution ESPaDoNS spectroscopy. We have discover 28 new bright (V < 15)
stars with [Fe/H]<-2.5 and 5 with [Fe/H]<-3.0 for success rates of 40% (28/70)
and 19% (5/27), respectively. A detailed model atmospheres analysis is carried
out for the 28 new metal-poor stars. Stellar parameters were determined from
SDSS photometric colours, Gaia DR2 parallaxes, MESA/MIST stellar isochrones,
and the initial Pristine survey metallicities, following a Bayesian inference
method. Chemical abundances are determined for 10 elements (Na, Mg, Ca, Sc, Ti,
Cr, Fe, Ni, Y, Ba). Most stars show chemical abundance patterns that are
similar to the normal metal-poor stars in the Galactic halo; however, we also
report the discoveries of a new r-process rich star, a new CEMP-s candidate
with [Y/Ba]>0, and a metal-poor star with very low [Mg/Fe]. The kinematics and
orbits for all of the highly probable metal-poor candidates are determined by
combining our precision radial velocities with Gaia DR2 proper motions. Some
stars show unusual kinematics for their chemistries, including planar orbits,
unbound orbits, and highly elliptical orbits that plunge deeply into the
Galactic bulge (Rperi < 0.5 kpc); also, eight stars have orbital energies and
actions consistent with the Gaia-Enceladus accretion event. This paper
contributes to our understanding of the complex chemo-dynamics of the
metal-poor Galaxy, and increases the number of known bright metal-poor stars
available for detailed nucleosynthetic studies.
http://arxiv.org/icons/sfx.gif