Abstract
We have investigated the properties (e.g., age, metallicity) of the stellar
populations of a ring-like tidal stellar stream (or streams) around the edge-on
galaxy SPRC047 (z = 0.031) using spectral energy distribution (SED) fits to
integrated broad-band aperture flux densities. We used visual images in six
different bands and Spitzer/IRAC 3.6 micron data. We have attempted to derive
best-fit stellar population parameters (metallicity, age) in three
non-contiguous segments of the stream. Due to the very low surface brightness
of the stream, we have performed a deconvolution with a Richardson-Lucy type
algorithm of the low spatial resolution 3.6 micron IRAC image, thereby reducing
the effect of the point-spread-function (PSF) aliased "emission" from the
bright edge-on central galaxy at the locations of our three stream segments.
Our SED fits that used several different star formation history priors, from an
exponentially decaying star formation burst to continuous star formation,
indicate that the age-metallicity-dust degeneracy is not resolved, most likely
because of inadequate wavelength coverage and low signal-to-noise ratios of the
low surface brightness features. We also discuss how future deep
visual-near-infrared observations, combined with absolute flux calibration
uncertainties at or below the 1 per cent level, complemented by equally well
absolute flux calibrated observations in ultraviolet and mid-infrared bands,
would improve the accuracy of broad-band SED fitting results for low surface
brightness targets, such as stellar streams around nearby galaxies that are not
resolved into stars.