The Einstein ring GAL-CLUS-022058s: a Lensed Ultrabright Submillimeter
  Galaxy at z=1.4796
  We report an ultra-bright lensed submillimeter galaxy at $z_{spec}=1.4796$,
identified as a result of a full-sky cross-correlation of the AllWISE and
Planck compact source catalogs aimed to search for bright submillimeter
galaxies at $z \sim 1.5-2.8$. APEX/LABOCA observations of the candidate galaxy
reveal a source with flux (S$_{870 \mu m}= 54\pm 8$ mJy). The position of the
APEX source coincides with the position of the AllWISE mid-IR source, and with
the Einstein ring GAL-CLUS-022058s, observed with the HST. Archival VLT/FORS
observations reveal the redshift of this Einstein ring, $z_{spec}=1.4796$, and
detection of the CO(5-4) line at $z_{spec} = 1.4802$ with APEX/nFLASH230
confirms the redshift of the submillimeter emission. The lensed source appears
to be gravitationally magnified by a massive foreground galaxy cluster lens at
$z = 0.36$. We use Lenstool to model the gravitational lensing, which is near
to a "fold arc" configuration for an elliptical mass distribution of the
central halo, where four images of the lensed galaxy are seen; the mean
magnification is $\mu_{\rm L} =18\pm 4$. We have determined an intrinsic
rest-frame infrared luminosity of $L_{IR} \approx 10^{12} L_\odot $ and a
likely star formation rate of $\sim 70-170$ $M_\odot\ yr^{-1}$. The molecular
gas mass is $M_{mol} \sim 2.6 \times 10^{10} M_\odot$ and the gas fraction is
$f = 0.34\pm 0.07$. We also obtain a stellar mass log$(M_\ast/M_\odot) = 10.7
\pm 0.1$ and a specific star formation rate log$(sSFR/Gyr^{-1})=0.15 \pm 0.03$.
This galaxy lies on the so-called main sequence of star-forming galaxies at
this redshift.
