Lyman Continuum Escape Fraction from Low-mass Starbursts at z=1.3
  We present a new constraint on the Lyman Continuum (LyC) escape fraction at
z~1.3. We obtain deep, high sensitivity far-UV imaging with the Advanced Camera
for Surveys (ACS) Solar Blind Channel (SBC) on the Hubble Space Telescope
(HST), targeting 11 star-forming galaxies at 1.2<z<1.4. The galaxies are
selected from the 3D-HST survey to have high H$\alpha$ equivalent width (EW)
with EW > 190 \AA, low stellar mass (M* < 10^10 M_sun) and U-band magnitude of
U<24.2. These criteria identify young, low metallicity star bursting
populations similar to the primordial star-forming galaxies believed to have
reionized the universe. We do not detect any LyC signal (with S/N >3) in the
individual galaxies or in the stack in the far-UV images. We place $3\sigma$
limits on the relative escape fraction of individual galaxies to be
f_{esc,rel}<[0.10-0.22] and a stacked $3\sigma$ limit of f_{esc,rel}<0.07.
Comparing to the confirmed LyC emitters from the literature, the galaxies in
our sample span similar ranges of various galaxy properties including stellar
mass, dust attenuation, and star formation rate (SFR). In particular, we
compare the distribution of H$\alpha$ and [OIII] EWs of confirmed LyC emitters
and non-detections including the galaxies in this study. Finally, we discuss if
a dichotomy seen in the distribution of H$\alpha$ EWs can perhaps distinguish
the LyC emitters from the non-detections.
