• 제목/요약/키워드: galaxies: clusters: individual (XMM-LSS02182-05102)

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DISCOVERY OF A STRONG LENSING GALAXY EMBEDDED IN A CLUSTER AT z = 1.62

  • WONG, KENNETH C.;TRAN, KIM-VY H.;SUYU, SHERRY H.;MOMCHEVA, IVELINA G.;BRAMMER, GABRIEL B.;BRODWIN, MARK;GONZALEZ, ANTHONY H.;HALKOLA, ALEKSI;KACPRZAK, GLENN G.;KOEKEMOER, ANTON M.;PAPOVICH, CASEY J.;RUDNICK, GREGORY H.
    • 천문학논총
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    • 제30권2호
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    • pp.389-392
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    • 2015
  • We identify a strong lensing galaxy in the cluster IRC 0218 that is spectroscopically confirmed to be at z = 1.62, making it the highest-redshift strong lens galaxy known. The lens is one of the two brightest cluster galaxies and lenses a background source galaxy into an arc and a counterimage. With Hubble Space Telescope (HST) grism and Keck/LRIS spectroscopy, we measure the source redshift to be $z_S=2.26$. Using HST imaging, we model the lens mass distribution with an elliptical power-law profile and account for the effects of the cluster halo and nearby galaxies. The Einstein radius is $^{\theta}E=0.38^{+0.02{\prime}{\prime}}_{-0.01}$ ($3.2^{+0.2}_{-0.1}kpc$) and the total enclosed mass is $M_{tot}(<^{\theta}_E)=1.8^{+0.2}_{-0.1}{\times}10^{11}M_{\odot}$. We estimate that the cluster environment contributes ~ 10% of this total mass. Assuming a Chabrier IMF, the dark matter fraction within $^{\theta}E$ is $f^{Chab}_{DM}=0.3^{+0.1}_{-0.3}$, while a Salpeter IMF is marginally inconsistent with the enclosed mass ($f^{Salp}_{DM}=-0.3^{+0.2}_{-0.5}$).