Fornasini, Francesca M.Francesca M.FornasiniTomsick, John A.John A.TomsickHong, JaeSubJaeSubHongGiommi, PaoloPaoloGiommiPerri, MatteoMatteoPerriPuccetti, SimonettaSimonettaPuccetti2020-09-172020-09-172017-04-01https://hdl.handle.net/20.500.13025/5218The Astrophysical Journal Supplement Series, Volume 229, Issue 2, article id. 33, <NUMPAGES>39</NUMPAGES> pp. (2017).We present a catalog of hard X-ray sources in a square-degree region surveyed by the Nuclear Spectroscopic Telescope Array (NuSTAR) in the direction of the Norma spiral arm. This survey has a total exposure time of 1.7 Ms, and the typical and maximum exposure depths are 50 ks and 1 Ms, respectively. In the area of deepest coverage, sensitivity limits of 5 10<SUP>-14</SUP> and 4 10<SUP>-14</SUP> erg s<SUP>-1</SUP> cm<SUP>-2</SUP> in the 3--10 and 10--20 keV bands, respectively, are reached. Twenty-eight sources are firmly detected, and 10 are detected with low significance; 8 of the 38 sources are expected to be active galactic nuclei. The three brightest sources were previously identified as a low-mass X-ray binary, high-mass X-ray binary, and pulsar wind nebula. Based on their X-ray properties and multiwavelength counterparts, we identify the likely nature of the other sources as two colliding wind binaries, three pulsar wind nebulae, a black hole binary, and a plurality of cataclysmic variables (CVs). The CV candidates in the Norma region have plasma temperatures of &ap;10--20 keV, consistent with the Galactic ridge X-ray emission spectrum but lower than the temperatures of CVs near the Galactic center. This temperature difference may indicate that the Norma region has a lower fraction of intermediate polars relative to other types of CVs compared to the Galactic center. The NuSTAR logN--logS distribution in the 10--20 keV band is consistent with the distribution measured by Chandra at 2--10 keV if the average source spectrum is assumed to be a thermal model with kT &ap; 15 keV, as observed for the CV candidates.binaries generalGalaxy disknovaecataclysmic variablesX-rays binariesX-rays stars10.3847/1538-4365/aa61fchttp://adsabs.harvard.edu/abs/2017ApJS..229...33F2017ApJS..229...33F