Müller, S.Kühnel, M.Caballero, I.Pottschmidt, KatjaFürst, F.Kreykenbohm, I.Sagredo, M.Obst, M.Wilms, J.Ferrigno, C.Rothschild, R. E.Staubert, R.2023-09-142023-09-142012-10-18Müller, S., M. Kühnel, I. Caballero, K. Pottschmidt, F. Fürst, I. Kreykenbohm, M. Sagredo, et al. “The Reawakening of the Sleeping X-Ray Pulsar XTE J1946+274.” Astronomy & Astrophysics 546 (October 1, 2012): A125. https://doi.org/10.1051/0004-6361/201219580.https://doi.org/10.1051/0004-6361/201219580http://hdl.handle.net/11603/29693We report on a series of outbursts of the high-mass X-ray binary XTE J1946+274 in 2010/2011 observed with INTEGRAL, RXTE, and Swift. We discuss possible mechanisms resulting in the extraordinary outburst behavior of this source. The X-ray spectra can be described by standard phenomenological models, enhanced by an absorption feature of unknown origin at about 10 keV and a narrow iron Kα fluorescence line at 6.4 keV, which are variable in flux and pulse phase. We find possible evidence for a cyclotron resonance scattering feature at about 25 keV at the 93% level. The presence of a strong cyclotron line at 35 keV seen in data from the source’s 1998 outburst that was confirmed by a reanalysis of these data can be excluded. This result indicates that the cyclotron line feature in XTE J1946+274 is variable between individual outbursts.9 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.Attribution 4.0 International (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/Text