Revisiting the spectral energy distribution of I Zw 1 under the CaFe
  Project
  The CaFe Project involves the study of the properties of the low ionization
emission lines (LILs) pertaining to the broad-line region (BLR) in active
galaxies. These emission lines, especially the singly-ionized iron (Fe II) in
the optical and the corresponding singly-ionized calcium (Ca II) in the
near-infrared (NIR) are found to show a strong correlation in their emission
strengths, i.e. with respect to the broad H$\beta$ emission line, the latter
also belonging to the same category of LILs. The origin of this correlation is
attributed to the similarity in the physical conditions necessary to emit these
lines - especially in terms of the strength of the ionization from the central
continuum source and the local number density of available matter in these
regions. In this paper, we focus on the issue of the spectral energy
distribution (SED) characteristic to a prototypical Type-1 Narrow-line Seyfert
galaxy (NLS1) - I Zw 1. We extract the continuum from quasi-simultaneous
spectroscopic measurements ranging from the near-UV ($\sim$1200A) to the
near-infrared ($\sim$24000A) to construct the SED and supplement it with
archival X-ray measurements available for this source. Using the
photoionization code CLOUDY, we assess and compare the contribution of the
prominent "Big Blue Bump" seen in our SED versus the SED used in our previous
work, wherein the latter was constructed from archival, multi-epoch photometric
measurements. Following the prescription from our previous work, we constrain
the physical parameter space to optimize the emission from these LILs and
discuss the implication of the use of a "better" SED.
