We present the largest publicly available catalog of interacting dwarf galaxies. It includes 177 nearby merging dwarf galaxies of stellar mass M ∗ < 1010 M o and redshifts z < 0.02. These galaxies are selected by visual inspection of publicly available archival imaging from two wide-field optical surveys (SDSS-III and the Legacy Survey), and they possess low-surface-brightness features that are likely the result of an interaction between dwarf galaxies. We list UV and optical photometric data that we use to estimate stellar masses and star formation rates. So far, the study of interacting dwarf galaxies has largely been done on an individual basis, and lacks a sufficiently large catalog to give statistics on the properties of interacting dwarf galaxies, and their role in the evolution of low-mass galaxies. We expect that this public catalog can be used as a reference sample to investigate the effects of the tidal interaction on the evolution of star formation, and the morphology/structure of dwarf galaxies. Our sample is overwhelmingly dominated by star-forming galaxies, and they are generally found significantly below the red sequence in the color-magnitude relation. The number of early-type galaxies is only 3 out of 177. We classify them, according to observed low-surface-brightness features, into various categories including shells, stellar streams, loops, antennae, or simply interacting. We find that dwarf-dwarf interactions tend to prefer the low-density environment. Only 41 out of the 177 candidate dwarf-dwarf interaction systems have giant neighbors within a sky-projected distance of 700 kpc and a line-of-sight radial velocity range ±700 km s-1, and compared to the LMC-SMC, they are generally located at much larger sky-projected distances from their nearest giant neighbors.
Bibliographical noteFunding Information:
P.S. acknowledges the support by the Samsung Science & Technology Foundation under Project Number SSTF-BA1501-0. S.-J.Y. acknowledges support from the Center for Galaxy Evolution Research (No. 2010-0027910) through the NRF of Korea and from the Yonsei University Observatory—KASI Joint Research Program (2018). P.C.-C. was supported by CONICYT (Chile) through Programa Nacional de Becas de Doctorado 2014 folio 21140882.
This study is based on the archival images and spectra from the Sloan Digital Sky Survey and Legacy Survey Data. Full acknowledgments for these surveys can be found at https://www.sdss.org/collaboration/#acknowledgements and http://legacysurvey.org/acknowledgment/, respectively. Funding for the SDSS has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS website is http://www.sdss.org/. The Legacy Surveys imaging of the DESI footprint is supported by the Director, Office of Science, Office of High Energy Physics of the U.S. Department of Energy under Contract No. DE-AC02-05CH1123, by the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility under the same contract; and by the U.S. National Science Foundation, Division of Astronomical Sciences under Contract No. AST-0950945 to NOAO. We also made use of the GALEX all-sky survey imaging data. The GALEX is operated for NASA by the California Institute of Technology under NASA contract NAS5-98034. We also acknowledge the use of NASA’s Astrophysics Data System Bibliographic Services and the NASA/IPAC Extragalactic Database (NED). We also made use of archival data from the Canada–France–Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de lÚnivers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science