Salvato in:
| Autori principali: | , , , , , , , , , , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2026
|
| Soggetti: | |
| Accesso online: | https://arxiv.org/abs/2603.10111 |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866917331098140672 |
|---|---|
| author | Coley, Joel B. Ballhausen, Ralf Brumback, McKinley Corbet, Robin H. D. Diez, Camille M. Fuerst, Felix Islam, Nazma Jaisawal, Gaurava K. Kretschmar, Peter Malacaria, Christian Pottschmidt, Katja Pradhan, Pragati |
| author_facet | Coley, Joel B. Ballhausen, Ralf Brumback, McKinley Corbet, Robin H. D. Diez, Camille M. Fuerst, Felix Islam, Nazma Jaisawal, Gaurava K. Kretschmar, Peter Malacaria, Christian Pottschmidt, Katja Pradhan, Pragati |
| contents | We report on a pair of X-ray Multi-Mirror Mission (XMM-Newton) observations of the Supergiant X-ray binary 4U 1909+07, which were performed on 2021 October 3 and 2021 October 8, respectively. We measure the neutron star rotation period in each observation to be $\sim$602.62 s. This continues a long spin-up trend that has persisted since 2001 where the neutron star spin period was found to be $\sim$604.66 s. In our timing analysis, we observe strong variations in the amplitude of the 1--10 keV pulse profile as a function of time, and for the first time we find a low flux interval extending for a single pulse period in which pulsations are no longer detected. We interpret this low flux interval as a pulse dropout similar to those observed in Vela X-1 and GX 301-2, which were each explained by a low-density cavity in the wind driving the propeller effect. In our time-resolved spectral analysis, we observed the spectral continuum, which can be described as an absorbed power law modified by a high-energy cutoff, to significantly soften during the pulse-dropout phase. No evidence of an increasing absorption column density was found. The observed softening in 4U 1909+07 also supports an interpretation that the observed pulse dropout may be driven by the propeller effect, but the quasi-spherical settling accretion regime cannot be ruled out. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2603_10111 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | XMM-Newton Observations of Flares and a Possible Pulse Dropout in the Supergiant X-ray binary 4U 1909+07 Coley, Joel B. Ballhausen, Ralf Brumback, McKinley Corbet, Robin H. D. Diez, Camille M. Fuerst, Felix Islam, Nazma Jaisawal, Gaurava K. Kretschmar, Peter Malacaria, Christian Pottschmidt, Katja Pradhan, Pragati High Energy Astrophysical Phenomena We report on a pair of X-ray Multi-Mirror Mission (XMM-Newton) observations of the Supergiant X-ray binary 4U 1909+07, which were performed on 2021 October 3 and 2021 October 8, respectively. We measure the neutron star rotation period in each observation to be $\sim$602.62 s. This continues a long spin-up trend that has persisted since 2001 where the neutron star spin period was found to be $\sim$604.66 s. In our timing analysis, we observe strong variations in the amplitude of the 1--10 keV pulse profile as a function of time, and for the first time we find a low flux interval extending for a single pulse period in which pulsations are no longer detected. We interpret this low flux interval as a pulse dropout similar to those observed in Vela X-1 and GX 301-2, which were each explained by a low-density cavity in the wind driving the propeller effect. In our time-resolved spectral analysis, we observed the spectral continuum, which can be described as an absorbed power law modified by a high-energy cutoff, to significantly soften during the pulse-dropout phase. No evidence of an increasing absorption column density was found. The observed softening in 4U 1909+07 also supports an interpretation that the observed pulse dropout may be driven by the propeller effect, but the quasi-spherical settling accretion regime cannot be ruled out. |
| title | XMM-Newton Observations of Flares and a Possible Pulse Dropout in the Supergiant X-ray binary 4U 1909+07 |
| topic | High Energy Astrophysical Phenomena |
| url | https://arxiv.org/abs/2603.10111 |