Abstract
Abstract We present the first systematic study of the stellar populations of ultra-diffuse galaxies (UDGs) in the field, integrating the large area search and characterization of UDGs by the SMUDGes survey with the twelve-band optical photometry of the S-PLUS survey. Based on Bayesian modeling of the optical colors of UDGs, we determine the ages, metallicities, and stellar masses of 100 UDGs distributed in an area of ∼330 deg2 in the Stripe 82 region. We find that the stellar masses and metallicities of field UDGs are similar to those observed in clusters and follow the trends previously defined in studies of dwarf and giant galaxies. However, field UDGs have younger luminosity-weighted ages than do UDGs in clusters. We interpret this result to mean that field UDGs have more extended star formation histories, including some that continue to form stars at low levels to the present time. Finally, we examine stellar population scaling relations that show that UDGs are, as a population, similar to other low surface brightness galaxies.
Highlights
Ultra-diffuse galaxies (UDGs) are a recently defined class of low surface brightness (LSB) galaxy initially found in large numbers in the Coma Cluster
Bayesian SED fitter (BSF) is written in the Python programming language based on the PYMC3 statistical package (Salvatier et al 2016), which allows for the construction of general Bayesian models while abstracting the complex issues related to the actual modeling and sampling
We perform the first systematic study of the stellar populations of field UDGs combining the deep and large area search of UDGs performed by the SMUDGes survey (Zaritsky et al 2019) with the multiband capabilities of the S-PLUS survey (Mendes de Oliveira et al 2019)
Summary
Ultra-diffuse galaxies (UDGs) are a recently defined class of low surface brightness (LSB) galaxy initially found in large numbers in the Coma Cluster (van Dokkum et al 2015). A key challenge in developing a unified understanding of UDGs and their relation to other galaxies is that the data so far come from disparate studies, with different selection criteria, and mostly focus on high density environments. These deficits are exacerbated by the difficulties posed in observing such LSB galaxies. Photometric information, such as broadband colors (e.g., Prole et al 2019), are available for many UDGs but are of limited value in determining the properties of the stellar populations, while spectroscopy, which can provide the necessary information, is only available for a small number of galaxies (e.g., Martínez-Delgado et al 2016; Kadowaki et al 2017; Ferré-Mateu et al 2018; Gu et al 2018; Ruiz-Lara et al 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
