A Ly-alpha nebula at z~3.3
  Context. Searching for high-redshift galaxies is a field of intense activity
in modern observational cosmology that will continue to grow with future
ground-based and sky observatories. Over the last few years, a lot has been
learned about the high-z Universe. Aims. Despite extensive Ly-alpha Blobs (LAB)
surveys from low to high redshifts, giant LABs over 100 kpc have been found
mostly at z~2-4. This redshift range is coincident with the transition epoch of
galactic gas-circulation processes from inflows to outflows at z~2.5-3. This
suggests that the formation of giant LABs may be related to a combination of
gas inflows and outflows. Their extreme youth makes them interesting objects in
the study of galaxy formation as they provide insight into some of the youngest
known highly star forming galaxies, with only modest time investments using
ground-based telescopes. Methods. Systematic narrow-band Ly-alpha nebula
surveys are ongoing, but they are limited in their covered redshift range and
their comoving volume. This poses a significant problem when searching for such
rare sources. To address this problem, we developed a systematic searching
tool, ATACAMA (A Tool for seArChing for lArge LyMan Alpha nebulae) designed to
find large Ly-alpha nebulae at any redshift within deep multi-wavelength
broad-band imaging. Results. We identified a Ly-alpha nebula candidate at
zphot~3.3 covering an isophotal area of 29.4sq.arcsec. Its morphology shows a
bright core and a faint core which coincides with the morphology of previously
known Ly-alpha blobs. A first estimation of the Ly-alpha equivalent width and
line flux agree with the values from the study led by several groups.
