Metallicity Distribution Function of the Eridanus II Ultra-faint Dwarf Galaxy from Hubble Space Telescope Narrowband Imaging

  title={Metallicity Distribution Function of the Eridanus II Ultra-faint Dwarf Galaxy from Hubble Space Telescope Narrowband Imaging},
  author={Sal Wanying Fu and Daniel R. Weisz and Else Starkenburg and Nicolas F. Martin and Alexander P. Ji and Ekta Patel and Michael Boylan-Kolchin and Patrick C{\^o}t{\'e} and Andrew E. Dolphin and Nicolas Longeard and Mario L. Mateo and Nathan Ross Sandford},
  journal={The Astrophysical Journal},
We use deep narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope (HST) to construct the metallicity distribution function (MDF) of Local Group ultra-faint dwarf galaxy Eridanus II (Eri II). When combined with archival F475W and F814W data, we measure metallicities for 60 resolved red giant branch stars as faint as m F475W ∼ 24 mag, a factor of ∼4× more stars than current spectroscopic MDF determinations. We find that Eri II has a mean metallicity of [Fe/H] = −2.50 −0.07+0.07… 


Pristine dwarf galaxy survey – I. A detailed photometric and spectroscopic study of the very metal-poor Draco II satellite
We present a detailed study of the faint Milky Way satellite Draco II (Dra II) from deep CFHT/MegaCam broad-band g and i photometry and narrow-band metallicity-sensitive CaHK observations, along with
Stellar Metallicities from SkyMapper Photometry I: A Study of the Tucana II Ultra-faint Dwarf Galaxy
We present a study of the ultra-faint Milky Way dwarf satellite galaxy Tucana II using deep photometry from the 1.3 m SkyMapper telescope at Siding Spring Observatory, Australia. The SkyMapper filter
Variable stars in Local Group galaxies – V. The fast and early evolution of the low-mass Eridanus II dSph galaxy
We present a detailed study of the variable star population of Eridanus II (Eri II), an ultra-faint dwarf galaxy that lies close to the Milky Way virial radius. We analyse multi-epoch g, r, i
The Milky Way Tomography with SDSS. II. Stellar Metallicity
Using effective temperature and metallicity derived from SDSS spectra for ~60,000 F- and G-type main-sequence stars (0.2 < g − r < 0.6), we develop polynomial models for estimating these parameters
The Pristine Survey – VIII. The metallicity distribution function of the Milky Way halo down to the extremely metal-poor regime
The Pristine survey uses narrow-band photometry to derive precise metallicities down to the extremely metal-poor regime ([Fe/H] < -3), and currently consists of over 4 million FGK-type stars over a
Chemical Abundance Analysis of Three α-poor, Metal-poor Stars in the Ultrafaint Dwarf Galaxy Horologium I
We present chemical abundance measurements of three stars in the ultrafaint dwarf galaxy Horologium I, a Milky Way satellite discovered by the Dark Energy Survey. Using high-resolution spectroscopic
Narrowband Ca Photometry for Dwarf Spheroidal Galaxies. I. Chemostructural Study on Draco, Sextans, and Canes Venatici I
A few dozen dwarf satellite galaxies of the Milky Way have been discovered, which are often viewed as the remaining building blocks of our Galaxy. The follow-up spectroscopy showed that dwarf
The MUSE-Faint survey
Aims. It has been shown that the ultra-faint dwarf galaxy Eridanus 2 may host a stellar cluster in its centre. If this cluster is shown to exist, it can be used to set constraints on the mass and
Farthest Neighbor: The Distant Milky Way Satellite Eridanus II
We present Magellan/IMACS spectroscopy of the recently discovered Milky Way satellite Eridanus II (Eri II). We identify 28 member stars in Eri II, from which we measure a systemic radial velocity of
The role of faint population III supernovae in forming CEMP stars in ultra-faint dwarf galaxies
CEMP-no stars, a subset of carbon enhanced metal poor (CEMP) stars ([C/Fe] ≥ 0.7 and [Fe/H] . −1) have been discovered in ultra-faint dwarf (UFD) galaxies, with Mvir ≈ 108 M and M∗ ≈ 103 − 104 M at z