Discovery of X-ray flaring activity in the arches cluster

R. Capelli, R. S. Warwick, Nico Cappelluti, S. Gillessen, P. Predehl, D. Porquet, S. Czesla

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Context. We present a study of the Arches cluster based on XMM-Newton observations performed over the past 8 years. Unexpectedly, we find that the X-ray emission associated with the cluster experienced a marked brightening in March/April 2007. Aims. We investigate the origin of both the X-ray continuum emission emanating from the star cluster and the flare. Methods. To study the time variability of the total X-ray flux, we stacked the PN and MOS data of observations performed within a time interval of a few days leading to the detection of the flaring episode. We then constructed two spectral datasets, one corresponding to the flare interval (March/April 2007) and another to the normal quiescent state of the source. Results. The X-ray light curve of the Arches cluster shows, with high significance (8.6σ), a 70% increase in the X-ray emission in the March/April 2007 timeframe followed by a decline over the following year to the pre-flare level; the short-term duration of the flare is constrained to be longer than four days. The temperature and the line-of-sight column density inferred from the flare spectrum do not differ from those measured in the normal activity state of the cluster, suggesting that the flux enhancement is thermal in origin. Conclusions. We attribute the X-ray variability to in situ stellar activity: early-type stars may be responsible for the flare via wind collisions, whereas late-type stars may contribute by means of magnetic reconnection. These two possibilities are discussed.

Original languageEnglish (US)
Article numberL2
JournalAstronomy and Astrophysics
Volume525
Issue number13
DOIs
StatePublished - Jan 1 2011
Externally publishedYes

Fingerprint

arches
arch
flares
x rays
stellar activity
intervals
stars
star clusters
XMM-Newton telescope
newton
line of sight
light curve
flaring
collision
continuums
collisions
augmentation
temperature

Keywords

  • galaxy: center
  • stars: flare
  • X-rays: stars

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Capelli, R., Warwick, R. S., Cappelluti, N., Gillessen, S., Predehl, P., Porquet, D., & Czesla, S. (2011). Discovery of X-ray flaring activity in the arches cluster. Astronomy and Astrophysics, 525(13), [L2]. https://doi.org/10.1051/0004-6361/201015758

Discovery of X-ray flaring activity in the arches cluster. / Capelli, R.; Warwick, R. S.; Cappelluti, Nico; Gillessen, S.; Predehl, P.; Porquet, D.; Czesla, S.

In: Astronomy and Astrophysics, Vol. 525, No. 13, L2, 01.01.2011.

Research output: Contribution to journalArticle

Capelli, R, Warwick, RS, Cappelluti, N, Gillessen, S, Predehl, P, Porquet, D & Czesla, S 2011, 'Discovery of X-ray flaring activity in the arches cluster', Astronomy and Astrophysics, vol. 525, no. 13, L2. https://doi.org/10.1051/0004-6361/201015758
Capelli, R. ; Warwick, R. S. ; Cappelluti, Nico ; Gillessen, S. ; Predehl, P. ; Porquet, D. ; Czesla, S. / Discovery of X-ray flaring activity in the arches cluster. In: Astronomy and Astrophysics. 2011 ; Vol. 525, No. 13.
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