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تسجيل مستخدم جديدThe Einstein ring GAL-CLUS-022058s: a Lensed Ultrabright Submillimeter Galaxy at z=1.4796
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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$_{870 mu m}= 54pm 8$ 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 $mu_{rm L} =18pm 4$. 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 $f = 0.34pm 0.07$. 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.
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