4 research outputs found
Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III
We present the first detailed elemental abundances in the ultra-faint
Magellanic satellite galaxies Carina II (Car II) and Carina III (Car III). With
high-resolution Magellan/MIKE spectroscopy, we determined abundances of nine
stars in Car II including the first abundances of an RR Lyrae star in an
ultra-faint dwarf galaxy; and two stars in Car III. The chemical abundances
demonstrate that both systems are clearly galaxies and not globular clusters.
The stars in these galaxies mostly display abundance trends matching those of
other similarly faint dwarf galaxies: enhanced but declining [alpha/Fe] ratios,
iron-peak elements matching the stellar halo, and unusually low neutron-capture
element abundances. One star displays a low outlying [Sc/Fe] = -1.0. We detect
a large Ba scatter in Car II, likely due to inhomogeneous enrichment by
low-mass AGB star winds. The most striking abundance trend is for [Mg/Ca] in
Car II, which decreases from +0.4 to -0.4 and indicates clear variation in the
initial progenitor masses of enriching core-collapse supernovae. So far, the
only ultra-faint dwarf galaxies displaying a similar [Mg/Ca] trend are likely
satellites of the Large Magellanic Cloud. We find two stars with [Fe/H] < -3.5,
whose abundances likely trace the first generation of metal-free Population III
stars and are well-fit by Population III core-collapse supernova yields. An
appendix describes our new abundance uncertainty analysis that propagates
line-by-line stellar parameter uncertainties.Comment: 21 pages + appendix, 9 figures, 6 tables, accepted to Ap
Recommended from our members
Probing the Fundamental Nature of Dark Matter with the Large Synoptic Survey Telescope
Astrophysical and cosmological observations currently provide the only
robust, empirical measurements of dark matter. Future observations with Large
Synoptic Survey Telescope (LSST) will provide necessary guidance for the
experimental dark matter program. This white paper represents a community
effort to summarize the science case for studying the fundamental physics of
dark matter with LSST. We discuss how LSST will inform our understanding of the
fundamental properties of dark matter, such as particle mass, self-interaction
strength, non-gravitational couplings to the Standard Model, and compact object
abundances. Additionally, we discuss the ways that LSST will complement other
experiments to strengthen our understanding of the fundamental characteristics
of dark matter. More information on the LSST dark matter effort can be found at
https://lsstdarkmatter.github.io/
Probing the Fundamental Nature of Dark Matter with the Large Synoptic Survey Telescope
94 pages, 22 figures, 1 tableAstrophysical and cosmological observations currently provide the only robust, empirical measurements of dark matter. Future observations with Large Synoptic Survey Telescope (LSST) will provide necessary guidance for the experimental dark matter program. This white paper represents a community effort to summarize the science case for studying the fundamental physics of dark matter with LSST. We discuss how LSST will inform our understanding of the fundamental properties of dark matter, such as particle mass, self-interaction strength, non-gravitational couplings to the Standard Model, and compact object abundances. Additionally, we discuss the ways that LSST will complement other experiments to strengthen our understanding of the fundamental characteristics of dark matter. More information on the LSST dark matter effort can be found at https://lsstdarkmatter.github.io/
Dark Matter Science in the Era of LSST
Astrophysical observations currently provide the only robust, empirical measurements of dark matter. In the coming decade, astrophysical observations will guide other experimental efforts, while simultaneously probing unique regions of dark matter parameter space. This white paper summarizes astrophysical observations that can constrain the fundamental physics of dark matter in the era of LSST. We describe how astrophysical observations will inform our understanding of the fundamental properties of dark matter, such as particle mass, self-interaction strength, non-gravitational interactions with the Standard Model, and compact object abundances. Additionally, we highlight theoretical work and experimental/observational facilities that will complement LSST to strengthen our understanding of the fundamental characteristics of dark matter