Discovery of a Third Harmonic Cyclotron Resonance Scattering Feature in the X-Ray Spectrum of 4U 0115+63
| dc.contributor.author | Heindl, W. A. | |
| dc.contributor.author | Coburn, W. | |
| dc.contributor.author | Gruber, D. E. | |
| dc.contributor.author | Pelling, M. R. | |
| dc.contributor.author | Rothschild, R. E. | |
| dc.contributor.author | Wilms, J. | |
| dc.contributor.author | Pottschmidt, Katja | |
| dc.contributor.author | Staubert, R. | |
| dc.date.accessioned | 2023-10-12T19:21:31Z | |
| dc.date.available | 2023-10-12T19:21:31Z | |
| dc.date.issued | 1999-08-10 | |
| dc.description.abstract | We have discovered a third harmonic cyclotron resonance scattering feature (CRSF) in observations of the recent outburst of 4U 0115+63 with the Rossi X-Ray Timing Explorer (RXTE). The spectrum in a narrow pulse phase range shows CRSFs at 12.40⁺⁰.⁶⁵₋₀.₃₅, 21.45⁺⁰.²⁵₋₀.₃₈, and 33.56⁺⁰.⁷⁰₋₀.₉₀ keV. With centroid energy ratios to the fundamental of 1.73 ± 0.08 and 2.71 ± 0.13, the CRSFs are not harmonically spaced. Strong variability of the continuum and CRSFs with pulse phase indicate a complex emission geometry near the neutron star polar cap. In addition, one RXTE observation, which spanned periastron passage, revealed a strong 2 mHz quasi-periodic oscillation (QPO). This is slower by 2 orders of magnitude than the beat-frequency QPO expected in this system and slower by a factor of more than 5 compared with other QPOs seen in accreting X-ray pulsars. | en_US |
| dc.description.sponsorship | We thank E. Smith, J. Swank, and C. Williams-Heikkila for rapidly scheduling the observations and supplying the real-time data. ASM data are provided by the RXTE/ASM teams at Massachusetts Institute of Technology and at the RXTE Science Operations Facility and Guest Observer Facility at NASA’s Goddard Space Flight Center. We also thank the anonymous referee for very useful comments and suggestions. This work was supported by NASA grants NAS5-30720 and NAG5-7339, Deutsche Forschungsgemeinschaft grant Sta 173/22, and a travel grant from the Deutscher Akademischer Austauschdienst. | en_US |
| dc.description.uri | https://iopscience.iop.org/article/10.1086/312172 | en_US |
| dc.format.extent | 5 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.identifier | doi:10.13016/m29zfv-t4xu | |
| dc.identifier.citation | Heindl, W. A., W. Coburn, D. E. Gruber, M. R. Pelling, R. E. Rothschild, J. Wilms, K. Pottschmidt, and R. Staubert. “Discovery of a Third Harmonic Cyclotron Resonance Scattering Feature in the X-Ray Spectrum of 4U 0115+63.” The Astrophysical Journal 521, no. 1 (July 6, 1999): L49. https://doi.org/10.1086/312172. | en_US |
| dc.identifier.uri | https://doi.org/10.1086/312172 | |
| dc.identifier.uri | http://hdl.handle.net/11603/30122 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | IOP Publishing | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Center for Space Sciences and Technology | |
| dc.relation.ispartof | UMBC Physics Department | |
| dc.rights | This 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. | en_US |
| dc.title | Discovery of a Third Harmonic Cyclotron Resonance Scattering Feature in the X-Ray Spectrum of 4U 0115+63 | en_US |
| dc.type | Text | en_US |
| dcterms.creator | https://orcid.org/0000-0002-4656-6881 | en_US |