We report on observations of the candidate Be/X-ray binary IGR J18219−1347 with \textit{Swift}/XRT, \textit{NuSTAR}, and \textit{NICER} during Type-I outbursts in March and June 2020. Our timing analysis revealed the spin period of a neutron star with Pspin=52.46 s. This periodicity, combined with the known orbital period of 72.4 d, indicates that the system is a BeXRB. Furthermore, by comparing the infrared counterpart's spectral energy distribution to known BeXRBs, we confirm this classification and set a distance of approximately 10−15 kpc for the source. The source's broadband X-ray spectrum (1.5−50 keV) is described by an absorbed power-law with photon index Γ\,∼\,0.5 and cutoff energy at ∼\,13 keV.
@article{arxiv.2111.12592,
title = {Identification of an X-ray Pulsar in the BeXRB system IGR J18219$-$1347},
author = {B. O'Connor and E. Gogus and D. Huppenkothen and C. Kouveliotou and N. Gorgone and L. J. Townsend and A. Calamida and A. Fruchter and D. A. H. Buckley and M. G. Baring and J. A. Kennea and G. Younes and Z. Arzoumanian and E. Bellm and S. B. Cenko and K. Gendreau and J. Granot and C. Hailey and F. Harrison and D. Hartmann and L. Kaper and A. Kutyrev and P. O. Slane and D. Stern and E. Troja and A. J. van der Horst and R. A. M. J. Wijers and P. Woudt},
journal= {arXiv preprint arXiv:2111.12592},
year = {2022}
}