The Faint Satellite System of NGC 253: Insights into Low-Density Environments and No Satellite Plane

Burçin Mutlu-Pakdil; David J. Sand; Denija Crnojević; Paul Bennet; Michael G. Jones; Kristine Spekkens; Ananthan Karunakaran; Dennis Zaritsky; Nelson Caldwell; Catherine E. Fielder; Puragra Guhathakurta; Anil C. Seth; Joshua D. Simon; Jay Strader; Elisa Toloba

arXiv · 2401.14457

The Faint Satellite System of NGC 253: Insights into Low-Density Environments and No Satellite Plane

Burçin Mutlu-Pakdil·David J. Sand·Denija Crnojević·Paul Bennet·Michael G. Jones·Kristine Spekkens·Ananthan Karunakaran·Dennis Zaritsky·Nelson Caldwell·Catherine E. Fielder·Puragra Guhathakurta·Anil C. Seth·Joshua D. Simon·Jay Strader·Elisa Toloba

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Abstract

We have conducted a systematic search around the Milky Way (MW) analog NGC 253 (D=3.5 Mpc), as a part of the Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) - a Magellan+Megacam survey to identify dwarfs and other substructures in resolved stellar light around MW-mass galaxies outside of the Local Group. In total, NGC 253 has five satellites identified by PISCeS within 100 kpc with an absolute V-band magnitude $M_V<-7$. We have additionally obtained deep Hubble Space Telescope imaging of four reported candidates beyond the survey footprint: Do III, Do IV, and dw0036m2828 are confirmed to be satellites of NGC 253, while SculptorSR is found to be a background galaxy. We find no convincing evidence for the presence of a plane of satellites surrounding NGC 253. We construct its satellite luminosity function, which is complete down to $M_V$$\lesssim$$-8$ out to 100 kpc and $M_V$$\lesssim$$-9$ out to 300 kpc, and compare it to those calculated for other Local Volume galaxies. Exploring trends in satellite counts and star-forming fractions among satellite systems, we find relationships with host stellar mass, environment, and morphology, pointing to a complex picture of satellite formation, and a successful model has to reproduce all of these trends.

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Burçin Mutlu-Pakdil, David J. Sand, Denija Crnojević, Paul Bennet, Michael G. Jones, Kristine Spekkens, Ananthan Karunakaran, Dennis Zaritsky, Nelson Caldwell, Catherine E. Fielder, Puragra Guhathakurta, Anil C. Seth, Joshua D. Simon, Jay Strader, Elisa Toloba. 2024-01-25. The Faint Satellite System of NGC 253: Insights into Low-Density Environments and No Satellite Plane. https://arxiv.org/abs/2401.14457

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