Hidden depths in the local Universe: The Stellar Stream Legacy Survey

March 2023 • 2023A&A...671A.141M

Authors • Martínez-Delgado, David • Cooper, Andrew P. • Román, Javier • Pillepich, Annalisa • Erkal, Denis • Pearson, Sarah • Moustakas, John • Laporte, Chervin F. P. • Laine, Seppo • Akhlaghi, Mohammad • Lang, Dustin • Makarov, Dmitry • Borlaff, Alejandro S. • Donatiello, Giuseppe • Pearson, William J. • Miró-Carretero, Juan • Cuillandre, Jean-Charles • Domínguez, Helena • Roca-Fàbrega, Santi • Frenk, Carlos S. • Schmidt, Judy • Gómez-Flechoso, María A. • Guzman, Rafael • Libeskind, Noam I. • Dey, Arjun • Weaver, Benjamin A. • Schlegel, David • Myers, Adam D. • Valdes, Frank G.

Abstract • Context. Mergers and tidal interactions between massive galaxies and their dwarf satellites are a fundamental prediction of the Lambda-cold dark matter cosmology. These events are thought to provide important observational diagnostics of non-linear structure formation. Stellar streams in the Milky Way and Andromeda are spectacular evidence for ongoing satellite disruption. However, constructing a statistically meaningful sample of tidal streams beyond the Local Group has proven a daunting observational challenge, and the full potential for deepening our understanding of galaxy assembly using stellar streams has yet to be realised.
Aims: Here we introduce the Stellar Stream Legacy Survey, a systematic imaging survey of tidal features associated with dwarf galaxy accretion around a sample of ∼3100 nearby galaxies within z ∼ 0.02, including about 940 Milky Way analogues.
Methods: Our survey exploits public deep imaging data from the DESI Legacy Imaging Surveys, which reach surface brightness as faint as ∼29 mag arcsec⁻² in the r band. As a proof of concept of our survey, we report the detection and broad-band photometry of 24 new stellar streams in the local Universe.
Results: We discuss how these observations can yield new constraints on galaxy formation theory through comparison to mock observations from cosmological galaxy simulations. These tests will probe the present-day mass assembly rate of galaxies, the stellar populations and orbits of satellites, the growth of stellar halos, and the resilience of stellar disks to satellite bombardment.

Links

• PREPRINT http://arxiv.org/abs/2104.06071
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2023A%26A...671A.141M
• POSTSCRIPT https://www.aanda.org/10.1051/0004-6361/202245011/postscript
• ELECTR https://doi.org/10.1051%2F0004-6361%2F202245011
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2023A%26A...671A.141M
• PDF https://www.aanda.org/10.1051/0004-6361/202245011/pdf
• DATA https://irsa.ipac.caltech.edu/bibdata/2023/M/2023A&A...671A.141M.html