GraphNPE recovers a significantly lower central density for Boötes I consistent with a core while Draco remains marginally cuspy, and demonstrates that higher-order velocity moments reduce bias in dynamical modeling.
A MegaCam Survey of Outer Halo Satellites. III. Photometric and Structural Parameters
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
We present structural parameters from a wide-field homogeneous imaging survey of Milky Way satellites carried out with the MegaCam imagers on the 3.6m Canada-France-Hawaii Telescope (CFHT) and 6.5m Magellan-Clay telescope. Our survey targets an unbiased sample of "outer halo" satellites (i.e., substructures having Galactocentric distances greater than 25 kpc) and includes classical dSph galaxies, ultra-faint dwarfs, and remote globular clusters. We combine deep, panoramic $gr$ imaging for 44 satellites and archival $gr$ imaging for 14 additional objects (primarily obtained with the DECam instrument as part of the Dark Energy Survey), to measure photometric and structural parameters for 58 outer halo satellites. This is the largest and most uniform analysis of Milky Way satellites undertaken to date and represents roughly three quarters ($58/81 \simeq$72\%) of all known outer halo satellites. We use a maximum-likelihood method to fit four density laws to each object in our survey: exponential, Plummer, King and Sersic models. We examine systematically the isodensity contour maps and color magnitude diagrams for each of our program objects, present a comparison with previous results, and tabulate our best-fit photometric and structural parameters, including ellipticities, position angles, effective radii, Sersic indices, absolute magnitudes, and surface brightness measurements. We investigate the distribution of outer halo satellites in the size-magnitude diagram, and show that the current sample of outer halo substructures spans a wide range in effective radius, luminosity and surface brightness, with little evidence for a clean separation into star cluster and galaxy populations at the faintest luminosities and surface brightnesses.
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2026 4roles
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Koposov 2 is an ancient, extremely metal-poor, compact stellar system best explained as a dissolving globular cluster, not a dwarf galaxy.
Photometric analysis yields metallicity distributions for 3917 stars across 12 faint Milky Way satellites, showing average [Fe/H] ~ -2.3 dex, 170 EMP candidates, and no gradients in ultra-faint systems.
Using Jeans analysis of Leo II stellar kinematics, the paper constrains the fuzzy dark matter mass m_a and self-interaction parameter f_a, finding 95% CL lower limits on m_a in the (1-10)×10^{-22} eV range for |f_a^{-1}| ≲ 10^{-14} GeV^{-1}.
citing papers explorer
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Dark Matter in Draco and Bo\"otes I: Hints of a Core in an Ultra-Faint Dwarf from Simulation-Based Inference
GraphNPE recovers a significantly lower central density for Boötes I consistent with a core while Draco remains marginally cuspy, and demonstrates that higher-order velocity moments reduce bias in dynamical modeling.
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The Hubble Missing Globular Clusters Survey IV. Ultra-faint compact satellites of the Milky Way. The case of Koposov 2
Koposov 2 is an ancient, extremely metal-poor, compact stellar system best explained as a dissolving globular cluster, not a dwarf galaxy.
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The Pristine Dwarf Galaxy Survey -- VII. The metallicity distributions of 12 Milky Way faint satellites
Photometric analysis yields metallicity distributions for 3917 stars across 12 faint Milky Way satellites, showing average [Fe/H] ~ -2.3 dex, 170 EMP candidates, and no gradients in ultra-faint systems.
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Constraints on Self-Interacting Fuzzy Dark Matter from the Stellar Kinematics of the Dwarf Galaxy Leo II
Using Jeans analysis of Leo II stellar kinematics, the paper constrains the fuzzy dark matter mass m_a and self-interaction parameter f_a, finding 95% CL lower limits on m_a in the (1-10)×10^{-22} eV range for |f_a^{-1}| ≲ 10^{-14} GeV^{-1}.