JINAbase—A Database for Chemical Abundances of Metal-poor Stars

Abstract

Reconstructing the chemical evolution of the Milky Way is crucial for understanding the formation of stars, planets, and galaxies throughout cosmic time. Different studies associated with element production in the early universe and how elements are incorporated into gas and stars are necessary to piece together how the elements evolved. These include establishing chemical abundance trends, as set by metal-poor stars, comparing nucleosynthesis yield predictions with stellar abundance data, and theoretical modeling of chemical evolution. To aid these studies, we have collected chemical abundance measurements and other information such as stellar parameters, coordinates, magnitudes, and radial velocities, for extremely metal-poor stars from the literature. The database, JINAbase, contains 1658 unique stars, 60% of which have [Fe/H] −2.5. This information is stored in an SQL database, together with a user-friendly queryable web application a) . Objects with unique chemical element signatures (e.g., r-process stars, s-process and CEMP stars) are labeled or can be classified as such. The web application enables fast selection of customized comparison samples from the literature for the aforementioned studies and many more. Using the multiple entries for three of the most well studied metal-poor stars, we evaluate systematic uncertainties of chemical abundances measurements. We provide a brief guide on the selection of chemical elements for model comparisons for nonspectroscopists who wish to learn about metal-poor stars and the details of chemical abundances measurements.

Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III

“…Our full abundance results are tabulated in Table 6 (Appendix B) and Figures 2 and 4. We compare the results to halo stars in small grey points (Abohalima & Frebel 2018), and to other UFD measurements in the literature. The UFD literature compilation includes Bootes I (Feltzing et al 2009;Norris et al 2010;Gilmore et al 2013;Ishigaki et al 2014;Frebel et al 2016 (Frebel et al 2010).…”

The Lanthanide Fraction Distribution in Metal-poor Stars: A Test of Neutron Star Mergers as the Dominant r-process Site

“…We collect the neutron-capture element abundances of these stars from the literature. Second, we use the JINAbase database of metal-poor star abundances (Abohalima & Frebel 2018). This is a large inhomogeneous literature compilation with an ambiguous selection function, but it is intended to be complete for literature stars with [Fe/H] < −2.5 prior to 2015.…”

Evidence for an Aspherical Population III Supernova Explosion Inferred from the Hyper-metal-poor Star HE 1327–2326∗

“…The [Zn/Fe] = 0.80 ± 0.25 obtained in this work for HE 1327−2326 at [Fe/H] = −5.20 ± 0.20 is shown by the blue star and black error bars. Abundance values are extracted from the JINAbase (Abohalima & Frebel 2018). model, large Zn and other iron-peak elemental abundances cannot be obtained (Tominaga 2009;Nomoto et al 2013;Grimmett et al 2018) because a weak explosion energy is required to achieve the extensive fallback (necessary for producing a low iron abundance). On the other hand, in the aspherical bipolar jet explosion model, the high entropy environment along the jets enables large [Zn/Fe] ratios since more Zn is ejected.…”