@article{04848f878f014ccdb2f9a7f78776ef97,
title = "A Study of Two Diffuse Dwarf Galaxies in the Field",
abstract = "We present optical long-slit spectroscopy and far-ultraviolet to mid-infrared spectral energy distribution fitting of two diffuse dwarf galaxies, LSBG-285 and LSBG-750, which were recently discovered by the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). We measure redshifts using Hα line emission and find that these galaxies are at comoving distances of ≈25 and ≈41 Mpc, respectively, after correcting for the local velocity field. They have effective radii of r eff = 1.2 and 1.8 kpc and stellar masses of M ∗ ≈ (2-3) ×107 M o. There are no massive galaxies () within a comoving separation of at least 1.5 Mpc from LSBG-285 and 2 Mpc from LSBG-750. These sources are similar in size and surface brightness to ultradiffuse galaxies, except they are isolated, star-forming objects that were optically selected in an environmentally blind survey. Both galaxies likely have low stellar metallicities [Z ∗/Z o] < -1.0 and are consistent with the stellar mass-metallicity relation for dwarf galaxies. We set an upper limit on LSBG-750's rotational velocity of ∼50 km s-1, which is comparable to dwarf galaxies of similar stellar mass with estimated halo masses <1011 M o. We find tentative evidence that the gas-phase metallicities in both of these diffuse systems are high for their stellar mass, though a statistically complete, optically selected galaxy sample at very low surface brightness will be necessary to place these results into context with the higher surface brightness galaxy population.",
keywords = "galaxies: dwarf, galaxies: general",
author = "Greco, {Johnny P.} and Goulding, {Andy D.} and Greene, {Jenny E.} and Strauss, {Michael A.} and Song Huang and Kim, {Ji Hoon} and Yutaka Komiyama",
note = "Funding Information: The Hyper Suprime-Cam (HSC) Collaboration includes the astronomical communities of Japan and Taiwan, as well as Princeton University. The HSC instrumentation and software were developed by the National Astronomical Observatory of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA), and Princeton University. Funding was contributed by the FIRST program from the Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. Funding Information: We thank the anonymous referee for their careful reading of our paper and their useful comments and suggestions. We thank Gonzalo Aniano for making his convolution kernels publicly available and for his assistance with generating additional WISE kernels. We thank Amy Reines for sharing her dwarf galaxy catalog. J.P.G. is grateful to Adrian Price-Whelan and Viraj Pandya for useful conversations. J.P.G. was supported by the National Science Foundation under grant No. AST 1713828. Funding Information: The spectra presented in this work are based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnolog{\'i}a e Innovaci{\'o}n Productiva (Argentina), and Minist{\'e}rio da Ci{\^e}ncia, Tecnologia e Inova{\c c}{\~a}o (Brazil). Publisher Copyright: {\textcopyright} 2018. The American Astronomical Society. All rights reserved..",
year = "2018",
month = oct,
day = "20",
doi = "10.3847/1538-4357/aae0f4",
language = "English (US)",
volume = "866",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",
}