A Joint NICER and XMM-Newton View of the “Magnificent” Thermally Emitting X-Ray Isolated Neutron Star RX J1605.3+3249

Research output: Contribution to journalJournal article – Annual report year: 2019Researchpeer-review


  • Author: Malacaria, Christian

    NASA Marshall Space Flight Center, United States

  • Author: Bogdanov, Slavko

    Columbia University, United States

  • Author: Ho, Wynn C. G.

    Haverford College, United States

  • Author: Enoto, Teruaki

    Kyoto University, Japan

  • Author: Ray, Paul S.

    U.S. Naval Research Laboratory , United States

  • Author: Arzoumanian, Zaven

    NASA Goddard Space Flight Center, United States

  • Author: Cazeau, Thoniel

    NASA Goddard Space Flight Center, United States

  • Author: Gendreau, Keith C.

    NASA Goddard Space Flight Center, United States

  • Author: Guillot, Sebastien

    Universite de Toulouse, France

  • Author: Güver, Tolga

    Istanbul University, Turkey

  • Author: Jaisawal, Gaurava K.

    Astrophysics and Atmospheric Physics, National Space Institute, Technical University of Denmark, Elektrovej, 2800, Kgs. Lyngby, Denmark

  • Author: Wolff, Michael T.

    U.S. Naval Research Laboratory , United States

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Thermally emitting X-ray isolated neutron stars (NSs) represent excellent targets for testing cooling surface emission and atmosphere models, which are used to infer the physical parameters of the NS. Among the seven known members of this class, RX J1605.3+3249 is the only one that still lacks confirmation of its spin period. Here we analyze NICER and XMM-Newton observations of RX J1605.3+3249, in order to address its timing and spectral behavior. Contrary to a previous tentative detection, but in agreement with the recent work by Pires et al., we find no significant pulsation with a pulsed fraction higher than 1.3% (3σ) for periods above 150 ms. We also find a limit of 2.6% for periods above 2 ms, despite searches in different energy bands. The X-ray spectrum can be fit by either a double-blackbody model or by a single-temperature magnetized atmosphere model, both modified by a Gaussian absorption line at ∼0.44 keV. The origin of the absorption feature as a proton cyclotron line or as an atomic transition in the NS atmosphere is discussed. The predictions of the best-fit X-ray models extended to IR, optical, and UV bands, are compared with archival data. Our results are interpreted in the framework of a fallback disk scenario.
Original languageEnglish
Article number74
JournalAstrophysical Journal
Issue number2
Number of pages11
Publication statusPublished - 2019
CitationsWeb of Science® Times Cited: No match on DOI

    Research areas

  • Stars: individual (RX J1605.3+3249), Stars: neutron, X-rays: stars

ID: 189371967