SEAMLESS Survey: A Closer Look at Seven Local Volume Dwarf Galaxies in Diverse Environments

@misc{mutlupakdil2026seamless,
  title = {{SEAMLESS Survey: A Closer Look at Seven Local Volume Dwarf Galaxies in Diverse Environments}},
  author = {Burçin Mutlu-Pakdil and Michael G. Jones and David J. Sand and Denija Crnojević and Laura C. Hunter and Kristine Spekkens and Dennis Zaritsky and Paul Bennet and Jeffrey L. Carlin and Richard Donnerstein and Debasish Hazarika and Donghyeon J. Khim and Deepthi S. Prabhu and Cora Gillette and Grace Kelly and Harshitha Madabhushani and Annika Roberson},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.40765},
  eprint = {2610.40765},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.40765},
}

TY  - UNPB
TI  - SEAMLESS Survey: A Closer Look at Seven Local Volume Dwarf Galaxies in Diverse Environments
AU  - Burçin Mutlu-Pakdil
AU  - Michael G. Jones
AU  - David J. Sand
AU  - Denija Crnojević
AU  - Laura C. Hunter
AU  - Kristine Spekkens
AU  - Dennis Zaritsky
AU  - Paul Bennet
AU  - Jeffrey L. Carlin
AU  - Richard Donnerstein
AU  - Debasish Hazarika
AU  - Donghyeon J. Khim
AU  - Deepthi S. Prabhu
AU  - Cora Gillette
AU  - Grace Kelly
AU  - Harshitha Madabhushani
AU  - Annika Roberson
PY  - 2026
DA  - 2026/10/29
PB  - arXiv
DO  - 10.48550/arxiv.2610.40765
UR  - https://arxiv.org/abs/2610.40765
AB  - We present Hubble Space Telescope (HST) imaging of six Local Volume dwarf galaxies identified by the SEAMLESS survey - Cetus B, Hydrus A, Ursa Major C, Hydra B, Grapes, and M83-dw14 - along with Centaurus C (Cen C), discovered serendipitously in the M83-dw14 field. We report the discovery of M83-dw14 and Cen C for the first time. Our HST imaging resolves each system into individual stars, enabling measurements of tip of the red giant branch (TRGB) distances (3.6-6.5 Mpc), structural parameters, and star formation histories (SFHs). We complement these data with new HI observations from the Very Large Array for Ursa Major C, Hydra B, and M83-dw14 (also covering Cen C), and from the Green Bank Telescope for Grapes, together with existing HI limits for Cetus B and Hydrus A. With accurate TRGB distances, we place each target in its environmental context, ranging from a confirmed satellite (M83-dw14) to isolated systems (Hydrus A, Hydra B, Grapes, Cen C). Cen C (M_V=−7.96) is among the faintest isolated dwarfs known. It matches the size and luminosity of Leo T, the lowest mass gas-rich galaxy currently known, yet unlike Leo T it shows neither detected HI (log(M_HI/M_⊙)<5.3) nor recent star formation. Ursa Major C shows strongly asymmetric, spatially offset HI, suggesting that feedback may efficiently displace gas in such low-mass systems. Overall, our sample exhibits a broad range of SFHs and quenching states that does not track simply with present-day environment. This diversity is consistent with recent evidence that similarly varied SFHs occur even among isolated low-mass dwarfs, pointing to the important roles of inhomogeneous reionization, stochastic mass assembly, and internal feedback alongside environmental effects.
ER  -