Misc,
The VLT LBG Redshift Survey - V. Characterising the z = 3.1 Lyman Alpha Emitter Population
(2015)cite arxiv:1501.01215Comment: 20 pages, 13 figures, submitted to MNRAS.
Abstract
We present a survey of Ly$\alpha$ emitting galaxies in the fields of the VLT
LBG Redshift Survey, incorporating the analysis of narrow band number counts,
the rest frame UV luminosity function and the two-point correlation function of
Ly$\alpha$ emitters at $z\approx3.1$. Our photometric sample consists of 750
LAE candidates, over an area of 1.07 deg$^2$, with estimated equivalent widths
of $\gtrsim65$ \AA, from 5 fields based on deep Subaru Suprime-Cam imaging
data. Added to this we have obtained spectroscopic follow-up observations,
which successfully detected Ly$\alpha$ emission in 35 galaxies. Based on the
spectroscopic results, we refined our photometric selection constraints, with
the resulting sample having a success rate of $78\pm18\%$. We calculate the
narrow band number counts for our photometric sample and find these to be
consistent with previous studies of LAEs at this redshift. We find the $R$-band
continuum luminosity function to be $\sim10\times$ lower than the equivalent
luminosity function of LBGs at this redshift. The results are consistent with
the LAE fraction of the LBG population being constant or marginally increasing
to fainter magnitudes at $R<26$. Finally, we calculate the LAE auto-correlation
function and find a low clustering amplitude compared to the $z\sim3$ LBG
population. We calculate a clustering length of $2.87\pm0.70~h^-1Mpc$,
which corresponds to a clustering bias of $b=2.13\pm0.47$ and a median halo
mass of $M_DM=10^11.0\pm0.6~h^-1~M_ødot$. Overall, we conclude
that LAEs inhabit primarily low mass halos, but are a relatively small
component of the galaxy population found in such halos.
