A new strong-lensing galaxy at z=0.066: Another elliptical galaxy with a
  lightweight IMF
  We report the discovery of a new low-redshift galaxy-scale gravitational
lens, identified from a systematic search of publicly available MUSE
observations. The lens galaxy, 2MASXJ04035024-0239275, is a giant elliptical at
$z$ = 0.06604 with a velocity dispersion of $\sigma$ = 314 km s$^{-1}$. The
lensed source has a redshift of 0.19165 and forms a pair of bright images
either side of the lens centre. The Einstein radius is 1.5 arcsec, projecting
to 1.8 kpc, which is just one quarter of the galaxy effective radius. After
correcting for an estimated 19 per cent dark matter contribution, we find that
the stellar mass-to-light ratio from lensing is consistent with that expected
for a Milky Way initial mass function (IMF). Combining the new system with
three previously-studied low-redshift lenses of similar $\sigma$, the derived
mean mass excess factor (relative to a Kroupa IMF) is $\langle\alpha\rangle$ =
1.09$\pm$0.08. With all four systems, the intrinsic scatter in $\alpha$ for
massive elliptical galaxies can be limited to $<0.32$, at 90 per cent
confidence.
