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تسجيل مستخدم جديدThe Stellar Mass, Star Formation Rate and Dark Matter Halo Properties of LAEs at $zsim2$
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We present average stellar population properties and dark matter halo masses of $z sim 2$ lya emitters (LAEs) from SED fitting and clustering analysis, respectively, using $simeq$ $1250$ objects ($NB387le25.5$) in four separate fields of $simeq 1$ deg$^2$ in total. With an average stellar mass of $10.2, pm, 1.8times 10^8 {mathrm M_odot}$ and star formation rate of $3.4, pm, 0.4 {mathrm M_odot} {rm yr^{-1}}$, the LAEs lie on an extrapolation of the star-formation main sequence (MS) to low stellar mass. Their effective dark matter halo mass is estimated to be $4.0_{-2.9}^{+5.1} times 10^{10} {mathrm M_odot}$ with an effective bias of $1.22^{+0.16}_{-0.18}$ which is lower than that of $z sim 2$ LAEs ($1.8, pm, 0.3$), obtained by a previous study based on a three times smaller survey area, with a probability of $96%$. However, the difference in the bias values can be explained if cosmic variance is taken into account. If such a low halo mass implies a low HI gas mass, this result appears to be consistent with the observations of a high lya escape fraction. With the low halo masses and ongoing star formation, our LAEs have a relatively high stellar-to-halo mass ratio (SHMR) and a high efficiency of converting baryons into stars. The extended Press-Schechter formalism predicts that at $z=0$ our LAEs are typically embedded in halos with masses similar to that of the Large Magellanic Cloud (LMC); they will also have similar SHMRs to the LMC, if their SFRs are largely suppressed after $z sim 2$ as some previous studies have reported for the LMC itself.
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