### Abstract

We present the highly significant detection of a quasi-periodic fbx modulation with a period of 22.2min seen in the X-ray data of the Sgr A* flare of 2004 August 31. This flaring event, which lasted a total of about three hours, was detected simultaneously by EPIC on XMM-Newton and the NICMOS near-infrared camera on the HST. Given the inherent difficulty in, and the lack of readily available methods for quantifying the probability of a periodic signal detected over only several cycles in a data set where red noise can be important, we developed a general method for quantifying the likelihood that such a modulation is indeed intrinsic to the source and does not arise from background fluctuations. We here describe this Monte Carlo based method, and discuss the results obtained by its application to other XMM-Newton data sets. Under the simplest hypothesis that we witnessed a transient event that evolved, peaked and decayed near the marginally stable orbit of the supermassive black hole, this result implies that for a mass of 3.5 × 10^{6} M, the central object must have an angular momentum corresponding to a spin parameter of a 0.22.

Original language | English (US) |
---|---|

Article number | 066 |

Pages (from-to) | 420-426 |

Number of pages | 7 |

Journal | Journal of Physics: Conference Series |

Volume | 54 |

Issue number | 1 |

DOIs | |

State | Published - Dec 1 2006 |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Journal of Physics: Conference Series*,

*54*(1), 420-426. [066]. https://doi.org/10.1088/1742-6596/54/1/066

**Periodic modulations in an X-ray flare from sagittarius A*.** / Bélanger, G.; Terrier, R.; De Jager, O. C.; Goldwurm, A.; Melia, Fulvio.

Research output: Contribution to journal › Article

*Journal of Physics: Conference Series*, vol. 54, no. 1, 066, pp. 420-426. https://doi.org/10.1088/1742-6596/54/1/066

}

TY - JOUR

T1 - Periodic modulations in an X-ray flare from sagittarius A*

AU - Bélanger, G.

AU - Terrier, R.

AU - De Jager, O. C.

AU - Goldwurm, A.

AU - Melia, Fulvio

PY - 2006/12/1

Y1 - 2006/12/1

N2 - We present the highly significant detection of a quasi-periodic fbx modulation with a period of 22.2min seen in the X-ray data of the Sgr A* flare of 2004 August 31. This flaring event, which lasted a total of about three hours, was detected simultaneously by EPIC on XMM-Newton and the NICMOS near-infrared camera on the HST. Given the inherent difficulty in, and the lack of readily available methods for quantifying the probability of a periodic signal detected over only several cycles in a data set where red noise can be important, we developed a general method for quantifying the likelihood that such a modulation is indeed intrinsic to the source and does not arise from background fluctuations. We here describe this Monte Carlo based method, and discuss the results obtained by its application to other XMM-Newton data sets. Under the simplest hypothesis that we witnessed a transient event that evolved, peaked and decayed near the marginally stable orbit of the supermassive black hole, this result implies that for a mass of 3.5 × 106 M, the central object must have an angular momentum corresponding to a spin parameter of a 0.22.

AB - We present the highly significant detection of a quasi-periodic fbx modulation with a period of 22.2min seen in the X-ray data of the Sgr A* flare of 2004 August 31. This flaring event, which lasted a total of about three hours, was detected simultaneously by EPIC on XMM-Newton and the NICMOS near-infrared camera on the HST. Given the inherent difficulty in, and the lack of readily available methods for quantifying the probability of a periodic signal detected over only several cycles in a data set where red noise can be important, we developed a general method for quantifying the likelihood that such a modulation is indeed intrinsic to the source and does not arise from background fluctuations. We here describe this Monte Carlo based method, and discuss the results obtained by its application to other XMM-Newton data sets. Under the simplest hypothesis that we witnessed a transient event that evolved, peaked and decayed near the marginally stable orbit of the supermassive black hole, this result implies that for a mass of 3.5 × 106 M, the central object must have an angular momentum corresponding to a spin parameter of a 0.22.

UR - http://www.scopus.com/inward/record.url?scp=33947633444&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33947633444&partnerID=8YFLogxK

U2 - 10.1088/1742-6596/54/1/066

DO - 10.1088/1742-6596/54/1/066

M3 - Article

AN - SCOPUS:33947633444

VL - 54

SP - 420

EP - 426

JO - Journal of Physics: Conference Series

JF - Journal of Physics: Conference Series

SN - 1742-6588

IS - 1

M1 - 066

ER -