Metallicity and Age of the Stellar Stream around the Disk Galaxy NGC 5907

September 2016 • 2016AJ....152...72L

Authors • Laine, Seppo • Grillmair, Carl J. • Capak, Peter • Arendt, Richard G. • Romanowsky, Aaron J. • Martínez-Delgado, David • Ashby, Matthew L. N. • Davies, James E. • Majewski, Stephen R. • Brodie, Jean P. • GaBany, R. Jay • Arnold, Jacob A.

Abstract • Stellar streams have become central to studies of the interaction histories of nearby galaxies. To characterize the most prominent parts of the stellar stream around the well-known nearby (d = 17 Mpc) edge-on disk galaxy NGC 5907, we have obtained and analyzed new, deep gri Subaru/Suprime-Cam and 3.6 μm Spitzer/Infrared Array Camera observations. Combining the near-infrared 3.6 μm data with visible-light images allows us to use a long wavelength baseline to estimate the metallicity and age of the stellar population along an ∼60 kpc long segment of the stream. We have fitted the stellar spectral energy distribution with a single-burst stellar population synthesis model and we use it to distinguish between the proposed satellite accretion and minor/major merger formation models of the stellar stream around this galaxy. We conclude that a massive minor merger (stellar mass ratio of at least 1:8) can best account for the metallicity of -0.3 inferred along the brightest parts of the stream.


IPAC Authors


Carl Grillmair

Associate Scientist


Seppo Laine

Associate Scientist