GLOSTAR -- Radio Source Catalog I: $28^{\circ}< \textit{l} < 36^{\circ}$
  and $|b| < 1^{\circ}$
  The GLOSTAR survey will study the star formation in the Galactic plane
between $-2^{\circ}< \textit{l}< 85^{\circ}$ and $|b| < 1^{\circ}$ with
unprecedented sensitivity in both, flux density ($\sim$ 40 $\mu Jy$
beam$^{-1}$) and range of angular scales ($\sim$ 1."5 to the largest radio
structures in the Galaxy). In this paper we present the first results obtained
from a radio continuum map of a 16 square degree sized region of the Galactic
plane centered on $\textit{l} = 32^{\circ}$ and $b = 0^{\circ}$ ($28^{\circ} <
\textit{l} < 36^{\circ}$ and $|b| < 1^{\circ}$). This map has a resolution of
18" and sensitivity of $\sim$ 60-150 $\mu Jy$ beam$^{-1}$. We present data
acquired with the VLA in D-configuration. Two 1 GHz wide sub-bands were
observed simultaneously and centred at 4.7 and 6.9 GHz. These data were
calibrated and imaged using the $\textit{Obit}$ software package. The source
extraction has been performed using the BLOBCAT software package and verified
through a combination of visual inspection and cross-matching with other radio
and mid-infrared surveys. The final catalog consists of 1575 discrete radio
sources and 27 large scale structures (including W43 and W44). By
cross-matching with other catalogs and calculating the spectral indices
($S(\nu) \propto \nu^\alpha$), we have classified 231 continuum sources as HII
regions, 37 as ionization fronts, and 46 as planetary nebulae. The longitude
and latitude distribution and negative spectral indices are all consistent with
the vast majority of the unclassified sources being extragalactic background
sources. We present a catalog of 1575 radio continuum sources and discuss their
physical properties, emission nature and relation with previously reported.
These first GLOSTAR results have increased the number of reliable HII regions
in this part of the Galaxy by a factor of four.
