Galaxy And Mass Assembly (GAMA): detection of low-surface-brightness galaxies from SDSS data
Williams, Baldry, Kelvin et al. 2016, published in MNRAS, Vol. 463, 2746 (link:
ADS).
Abstract
We report on a search for new low-surface-brightness galaxies (LSBGs)
using Sloan Digital Sky Survey (SDSS) data within the GAMA equatorial
fields. The search method consisted of masking objects detected with
SDSS photo, combining gri images weighted to maximise the expected
signal-to-noise ratio (SNR), and smoothing the images. The processed
images were then run through a detection algorithm that finds all
pixels above a set threshold and groups them based on their proximity
to one another. The list of detections was cleaned of contaminants
such as diffraction spikes and the faint wings of masked objects. From
these, selecting potentially the brightest in terms of total flux, a
list of 343 LSBGs was produced having been confirmed using VISTA
Kilo-degree Infrared Galaxy Survey (VIKING) imaging. The photometry of
this sample was refined using the deeper VIKING Z band as the
aperture-defining band. Measuring their g-i and J-K colours shows
that most are consistent with being at redshifts less than 0.2. The
photometry is carried out using an AUTO aperture for each detection
giving surface brightnesses of μr ≥ 25 mag
arcsec-2 and magnitudes of r > 19.8 mag. None of these
galaxies are bright enough to be within the GAMA main survey limit but
could be part of future deeper surveys to measure the low-mass end of
the galaxy stellar mass function.
Data:
Data on 343 detected galaxies
(columns as per Table 2 of paper).
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