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arXiv · 2111.12592

Identification of an X-ray Pulsar in the BeXRB system IGR J18219$-$1347

B. O'Connor·E. Gogus·D. Huppenkothen·C. Kouveliotou·N. Gorgone·L. J. Townsend·A. Calamida·A. Fruchter·D. A. H. Buckley·M. G. Baring·J. A. Kennea·G. Younes·Z. Arzoumanian·E. Bellm·S. B. Cenko·K. Gendreau·J. Granot·C. Hailey·F. Harrison·D. Hartmann·L. Kaper·A. Kutyrev·P. O. Slane·D. Stern·E. Troja·A. J. van der Horst·R. A. M. J. Wijers·P. Woudt
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Abstract

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 $P_\textrm{spin}=52.46$ 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 $\Gamma$\,$\sim$\,$0.5$ and cutoff energy at $\sim$\,$13$ keV.

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B. O'Connor, E. Gogus, D. Huppenkothen, C. Kouveliotou, N. Gorgone, L. J. Townsend, A. Calamida, A. Fruchter, D. A. H. Buckley, M. G. Baring, J. A. Kennea, G. Younes, Z. Arzoumanian, E. Bellm, S. B. Cenko, K. Gendreau, J. Granot, C. Hailey, F. Harrison, D. Hartmann, L. Kaper, A. Kutyrev, P. O. Slane, D. Stern, E. Troja, A. J. van der Horst, R. A. M. J. Wijers, P. Woudt. 2021-11-24. Identification of an X-ray Pulsar in the BeXRB system IGR J18219$-$1347. https://doi.org/10.3847/1538-4357/ac5032

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