Image: arxiv.org
The Story
The objects are best understood through ordinary dwarf-galaxy physics plus environmental history. Their small masses make gas retention difficult, while a prior passage through M101 could have removed or disrupted their fuel for star formation. Their present-day positions outside the apparent virial region do not rule out that history, because simulations predict backsplash systems. The interpretation is plausible, not yet confirmed.
- A prior close passage by M101 could have stripped or disrupted the dwarfs’ star-forming gas before their outward journey.
- The galaxies’ quenched populations, positions, and model fits are consistent with a backsplash origin, especially for two objects.
- Dwarf-galaxy star formation is inefficient because processes such as photoelectric heating can heat the gas needed for collapse.
Deeper Insight
The anomaly may expose limits in how dwarf-galaxy formation and satellite populations are modeled rather than simply reveal a completed backsplash case. M101 already has an unusual satellite luminosity gap, and dwarf-galaxy counts, locations, and internal structure remain difficult for cosmological models to reproduce. The three objects could therefore test star-formation physics, halo demographics, or distance and membership assumptions as much as they test backsplash predictions.
- M101’s unusually large gap in satellite magnitudes is not explained by standard halo-abundance matching, leaving the system’s satellite population itself anomalous.
- Dwarf-galaxy observations continue to present tensions involving halo numbers, spatial distributions, internal structure, and the diversity of galaxy properties.
- Baryonic feedback can alter both which low-mass halos form visible galaxies and the central structure of those halos, complicating simple expectations about star formation.
Sources · 10
Featured · Primary source · arxiv.org
Discovery of Isolated, Quenched, and Likely Backsplash Dwarf Galaxies near M101
Discovery of Isolated, Quenched, and Likely Backsplash Dwarf Galaxies near M101 # Discovery of Isolated, Quenched, and Likely Backsplash Dwarf Galaxies near M101 Julian Shapiro The Dalton School, 108 E 89th St, New York, NY 10128, USA [ (%5B) ###### Abstract I report the discovery of three faint, se
Read sourcePrimary source · ar5iv.labs.arxiv.org
[2206.05295] Baryonic solutions and challenges for cosmological models of dwarf galaxies
[2206.05295] Baryonic solutions and challenges for cosmological models of dwarf galaxies # Baryonic solutions and challenges for cosmological models of dwarf galaxies Laura V. Sales Department of Physics and Astronomy, University of California, Riverside, CA 92507, USA e-mail: [email protected] Andrew
Read sourceAnalysis · ui.adsabs.harvard.edu
Discovery of Isolated, Quenched, and Likely Backsplash Dwarf Galaxies near M101 - ADS
Discovery of Isolated, Quenched, and Likely Backsplash Dwarf Galaxies near M101 - ADS Now on home page ## ADS |-- ## Discovery of Isolated, Quenched, and Likely Backsplash Dwarf Galaxies near M101 - Shapiro, Julian I report the discovery of three faint, semi-resolved quiescent dwarf galaxies, two of
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