Bridging integrated-light and resolved-star studies of Local Group dwarf spheroidals
4 affiliations
- 1Instituto de Astrofísica de Canarias
- 2Institute of Space Sciences (ICE, CSIC)
- 3Amateur astronomer
- 4Parc Astronòmic Muntanyes de Prades
Abstract
Low-mass galaxies beyond the Local Group can only be studied through their integrated light, yet it remains unclear whether structural parameters inferred from integrated light are directly comparable to those obtained from resolved-star studies. Using new deep imaging obtained with small-aperture amateur telescopes, we analyse the classical dwarf spheroidals Leo II, Sculptor, and Fornax, whose stellar distributions have been extensively characterised through resolved-star studies. We find that the radial light distributions and effective radii inferred from integrated light are in excellent agreement with those derived from resolved stars, showing that resolved-star and integrated-light analyses can be placed within a common observational framework applicable across a broad range of distances. The two approaches are highly complementary: resolved-star analyses trace galaxies to very large radii but are limited by stellar crowding in their central regions, whereas integrated-light observations are insensitive to crowding and allow the inner stellar distribution to be traced to substantially smaller radii. The integrated-light analysis extends the structural analysis to radii up to an order of magnitude smaller than previous star-counting studies while significantly reducing the scatter in the measured profiles.
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BibTeX
@article{sergio2026bridging,
title = {{Bridging integrated-light and resolved-star studies of Local Group dwarf spheroidals}},
author = {Guerra Arencibia Sergio and Trujillo Ignacio and Montes Mireia and Ruiz Cejudo Ignacio and Marrero-de la Rosa Carlos and Fontana Vicente and Roig Aleix},
journal = {Astronomy \& Astrophysics},
year = {2026},
month = oct,
doi = {10.1051/0004-6361/202662063},
url = {https://doi.org/10.1051/0004-6361/202662063},
note = {CC BY},
}
RIS
TY - JOUR
TI - Bridging integrated-light and resolved-star studies of Local Group dwarf spheroidals
AU - Guerra Arencibia Sergio
AU - Trujillo Ignacio
AU - Montes Mireia
AU - Ruiz Cejudo Ignacio
AU - Marrero-de la Rosa Carlos
AU - Fontana Vicente
AU - Roig Aleix
PY - 2026
DA - 2026/10/24
JO - Astronomy & Astrophysics
DO - 10.1051/0004-6361/202662063
UR - https://doi.org/10.1051/0004-6361/202662063
AB - Low-mass galaxies beyond the Local Group can only be studied through their integrated light, yet it remains unclear whether structural parameters inferred from integrated light are directly comparable to those obtained from resolved-star studies. Using new deep imaging obtained with small-aperture amateur telescopes, we analyse the classical dwarf spheroidals Leo II, Sculptor, and Fornax, whose stellar distributions have been extensively characterised through resolved-star studies. We find that the radial light distributions and effective radii inferred from integrated light are in excellent agreement with those derived from resolved stars, showing that resolved-star and integrated-light analyses can be placed within a common observational framework applicable across a broad range of distances. The two approaches are highly complementary: resolved-star analyses trace galaxies to very large radii but are limited by stellar crowding in their central regions, whereas integrated-light observations are insensitive to crowding and allow the inner stellar distribution to be traced to substantially smaller radii. The integrated-light analysis extends the structural analysis to radii up to an order of magnitude smaller than previous star-counting studies while significantly reducing the scatter in the measured profiles.
SN - 0004-6361
SN - 1432-0746
ER -