Short-Timescale monitoring of the X-ray, UV and broad double-peak
  emission line of the nucleus of NGC 1097
  Recent studies have suggested that the short-timescale ($\lesssim7$ days)
variability of the broad ($\sim$10,000 km s$^{-1}$) double-peaked H$\alpha$
profile of the LINER nucleus of NGC1097 could be driven by a variable X-ray
emission from a central radiatively inefficient accretion flow (RIAF). To test
this scenario, we have monitored the NGC1097 nucleus in X-ray and UV continuum
with Swift and the H$\alpha$ flux and profile in the optical spectrum using
SOAR and Gemini-South from 2012 August to 2013 February. During the monitoring
campaign, the H$\alpha$ flux remained at a very low level --- 3 times lower
than the maximum flux observed in previous campaigns and showing only limited
($\sim 20\%$) variability. The X-ray variations were small, only $\sim 13\%$
throughout the campaign, while the UV did not show significant variations. We
concluded that the timescale of the H$\alpha$ profile variation is close to the
sampling interval of the optical observations, which results in only marginal
correlation between the X-ray and H$\alpha$ fluxes. We have caught the AGN in
NGC1097 in a very low activity state, in which the ionizing source was very
weak and capable of ionizing just the innermost part of the gas in the disk.
Nonetheless, the data presented here still support the picture in which the gas
that emits the broad double-peaked Balmer lines is illuminated/ionized by a
source of high-energy photons which is located interior to the inner radius of
the line-emitting part of the disk.
