neutronstars

Publications

NEUTRONSTARS CoE started operating in 2026. Since the starting date, … papers have been published.
6549793 1 apa 50 default 1 217 https://neutronstars.fi/wp-content/plugins/zotpress/
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Ahlberg, V., Veledina, A., Churazov, E., & Khabibullin, I. (2026). From reflection to scattering: polarimetric signatures of funnel-type outflows. Modeling obscured ultraluminous X-ray sources (arXiv:2605.29487). arXiv. https://doi.org/10.48550/arXiv.2605.29487
Zhou, M., Wang, P., Liu, H., Ducci, L., Tsygankov, S. S., Zhao, Q., Poutanen, J., Ji, L., Suleimanov, V. F., Mushtukov, A. A., Liu, Q., Diez, C. M., Rodríguez, L. A., Grinberg, V., & Santangelo, A. (2025). Probing the emission geometry of the X-ray pulsar 2S 1417$-$624 during a weak outburst with NICER, IXPE, and NuSTAR (arXiv:2508.16417). arXiv. https://doi.org/10.48550/arXiv.2508.16417
Salganik, A., Kong, L., Forsblom, S. V., Zhou, M., Liu, H., Zhao, Q., Tsygankov, S. S., Santangelo, A., & Poutanen, J. (2026). First detection of X-ray polarization from the long-period X-ray pulsar 4U 1954+319. Astronomy & Astrophysics, 710, A36. https://doi.org/10.1051/0004-6361/202558439
Díaz Teodori, M. A., Bobrikova, A., Gnarini, A., Ursini, F., Forsblom, S. V., Poutanen, J., Salganik, A., Bianchi, S., Capitanio, F., Cocchi, M., Fabiani, S., Farinelli, R., Kaaret, P., Kajava, J. J. E., Matt, G., Ng, M., Ravi, S., Soffitta, P., Tarana, A., & Zane, S. (2026). X-Ray Polarization from the Atoll 4U 1735−44 Suggests a Low Inclination. The Astrophysical Journal, 1002(2), 143. https://doi.org/10.3847/1538-4357/ae5a8e
Zhao, Q.-C., Tao, L., Tsygankov, S. S., Poutanen, J., Feng, H., Zhang, S.-N., Li, H., Ge, M., Zhang, L., & Mushtukov, A. A. (2026). Discovery of energy-dependent phase variations in the polarization angle of Cen X-3. Astronomy & Astrophysics, 708, A94. https://doi.org/10.1051/0004-6361/202556184
Hu, Y., Xiao, H., Tsygankov, S. S., Ji, L., Poutanen, J., & Huang, R. (2026). Temporal evolution of the circumstellar disk orientation in the transient X-ray pulsar GRO J1008-57 (arXiv:2605.19211). arXiv. https://doi.org/10.48550/arXiv.2605.19211
Liu, Q., Kong, L., Ji, L., Ducci, L., Dai, X., Santangelo, A., Cai, C., Cui, S., Ge, M., Zhang, S., Zhang, S.-N., Tao, L., Feng, H., Wang, W., Suleimanov, V., Tsygankov, S., Poutanen, J., & Mushtukov, A. (2026). NICER detection of a new candidate cyclotron line in the bursting X-ray pulsar GRO J1744-28 (arXiv:2606.04664). arXiv. https://doi.org/10.48550/arXiv.2606.04664
Suleimanov, V. F., Poutanen, J., & Werner, K. (2026). Neutron star atmospheres composed of fusion ashes. Astronomy & Astrophysics, 710, A169. https://doi.org/10.1051/0004-6361/202659003
Mao, Y.-H., Dorsman, B., Watts, A. L., Salmi, T., Poutanen, J., & Li, X.-D. (2026). Pulse profile modelling of accreting millisecond pulsars with disc occultation and its impact on parameter inference (arXiv:2606.14493). arXiv. https://doi.org/10.48550/arXiv.2606.14493
Salganik, A., Tsygankov, S. S., Molkov, S. V., Xiao, H., Zhao, Q., Ji, L., Mushtukov, A. A., Lapshov, I. Y., Lutovinov, A. A., Tkachenko, A. Y., Feng, H., Zhang, S.-N., Li, X.-B., Zhang, S., & Poutanen, J. (2026). Detection and luminosity-dependent evolution of the high-energy hump in the Be/X-ray pulsar 1A 1118-61 (arXiv:2606.16805). arXiv. https://doi.org/10.48550/arXiv.2606.16805
Dorsman, B., Salmi, T., Watts, A. L., Ng, M., Bobrikova, A., Loktev, V., Poutanen, J., & Wilms, J. (2026). Pulse profile modelling of the accretion-powered millisecond pulsar SAX J1808.4−3658 using NICER data from its 2019 and 2022 outbursts. Monthly Notices of the Royal Astronomical Society, Volume 545, Issue 2, 545(2), staf1983. https://doi.org/10.1093/mnras/staf1983
Kiuru, O. (2026). Evaluation of QED cross sections in strong magnetic fields. arXiv.2603.26545. https://doi.org/10.48550/arXiv.2603.26545
Kiuru, O., Nättilä, J., Paatelainen, R., & Vuorinen, A. (2026). QED cross sections in strong magnetic fields. arXiv.2603.25491. https://doi.org/10.48550/arXiv.2603.25491