X‐ray spectroscopy of early‐type stars: The present and the future

Rauw, Grégor; Nazé, Yaël; Oskinova, L. M.

doi:10.1002/asna.200710918

Cited by 4 publications

(3 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Small changes in flux (of the order of one sigma) can be spotted from time to time. They are similar to those recorded at optical wavelengths (Eversberg et al 1998;Rauw et al 2010), with double peaks where the blue to red ratio slightly changes. Their small amplitude and the low signal to noise of the data however prevent us from making a detailed analysis: this must await the advent of more sensitive observatories.…”

Section: X-ray Linessupporting

confidence: 86%

A DETAILED X-RAY INVESTIGATION OF ζ Puppis. II. THE VARIABILITY ON SHORT AND LONG TIMESCALES

Nazé

Oskinova

Gosset

2013

ApJ

View full text Add to dashboard Cite

Stellar winds are a crucial component of massive stars, but their exact properties still remain uncertain. To shed some light on this subject, we have analyzed an exceptional set of X-ray observations of ζ Puppis, one of the closest and brightest massive stars. The sensitive light curves that were derived reveal two major results. On the one hand, a slow modulation of the X-ray flux (with a relative amplitude of up to 15% over 16 hr in the 0.3-4.0 keV band) is detected. Its characteristic timescale cannot be determined with precision, but amounts from one to several days. It could be related to corotating interaction regions, known to exist in ζ Puppis from UV observations. Hour-long changes, linked to flares or to the pulsation activity, are not observed in the last decade covered by the XMM observations; the 17 hr tentative period, previously reported in a ROSAT analysis, is not confirmed either and is thus transient, at best. On the other hand, short-term changes are surprisingly small (<1% relative amplitude for the total energy band). In fact, they are compatible solely with the presence of Poisson noise in the data. This surprisingly low level of short-term variability, in view of the embedded wind-shock origin, requires a very high fragmentation of the stellar wind, for both absorbing and emitting features (>10 5 parcels, comparing with a two-dimensional wind model). This is the first time that constraints have been placed on the number of clumps in an O-type star wind and from X-ray observations.

show abstract

Section: X-ray Linessupporting

confidence: 86%

A DETAILED X-RAY INVESTIGATION OF ζ Puppis. II. THE VARIABILITY ON SHORT AND LONG TIMESCALES

Nazé

Oskinova

Gosset

2013

ApJ

View full text Add to dashboard Cite

show abstract

“…The individual EPIC images were exposure corrected, the stray-light features from Cyg X-3 (lower right corner) were excluded, and the out-of-time events from the bright central source (Cyg OB2 #8a) were removed before the images were combined. A preliminary version of this figure was published by Rauw et al (2008).…”

Section: Xmm-newton Observations Of Cyg Ob2mentioning

confidence: 99%

A multi-epochXMM-Newtoncampaign on the core of the massive Cygnus OB2 association

Rauw

2011

A&A

Self Cite

View full text Add to dashboard Cite

Context. Cyg OB2 is one of the most massive associations of O-type stars in our Galaxy. Despite the large interstellar reddening towards Cyg OB2, many studies, spanning a wide range of wavelengths, have been conducted to more clearly understand this association. X-ray observations provide a powerful tool to overcome the effect of interstellar absorption and study the most energetic processes associated with the stars in Cyg OB2. Aims. We analyse XMM-Newton data to investigate the X-ray and UV properties of massive O-type stars as well as low-mass pre-main sequence stars in Cyg OB2. Methods. We obtained six XMM-Newton observations of the core of Cyg OB2. In our analysis, we pay particular attention to the variability of the X-ray bright OB stars, especially the luminous blue variable candidate Cyg OB2 #12. Results. We find that X-ray variability is quite common among the stars in Cyg OB2. Whilst short-term variations are restricted mostly to low-mass pre-main sequence stars, one third of the OB stars display long-term variations. The X-ray flux of Cyg OB2 #12 varies by 37%, over timescales from days to years, whilst its mean log L X L bol amounts to −6.10. Conclusions. These properties suggest that Cyg OB2 #12 is either an interacting-wind system or displays a magnetically confined wind. Two other X-ray bright O-type stars (MT91 516 and CPR2002 A11) display variations that suggest they are interacting wind binary systems.

show abstract

“…The general properties of the X-ray emission of early-type stars are well explained by a model in which X-rays originate in shocks produced by instabilities in the radiatively driven winds of these massive stars (e.g., Lucy and White 1980;Owocki et al 1988). However, high-resolution X-ray spectroscopy with Chandra and XMM-Newton has revealed a somewhat more complex scenario, where at least for some of these massive stars magnetic fields also likely play a significant role (see e.g., Rauw et al 2008;Güdel and Nazé 2009;Testa 2010, for reviews of recent findings) .…”

Section: Abundances In X-ray Plasmas In Massive Starsmentioning

confidence: 99%

Element Abundances in X-ray Emitting Plasmas in Stars

Testa

2010

Space Sci Rev

View full text Add to dashboard Cite

Studies of element abundances in stars are of fundamental interest for their impact in a wide astrophysical context, from our understanding of galactic chemistry and its evolution, to their effect on models of stellar interiors, to the influence of the composition of material in young stellar environments on the planet formation process. We review recent results of studies of abundance properties of X-ray emitting plasmas in stars, ranging from the corona of the Sun and other solar-like stars, to premain sequence low-mass stars, and to early-type stars. We discuss the status of our understanding of abundance patterns in stellar X-ray plasmas, and recent advances made possible by accurate diagnostics now accessible thanks to the high resolution X-ray spectroscopy with Chandra and XMM-Newton.

show abstract

X‐ray spectroscopy of early‐type stars: The present and the future

Cited by 4 publications

References 23 publications

A DETAILED X-RAY INVESTIGATION OF ζ Puppis. II. THE VARIABILITY ON SHORT AND LONG TIMESCALES

A DETAILED X-RAY INVESTIGATION OF ζ Puppis. II. THE VARIABILITY ON SHORT AND LONG TIMESCALES

A multi-epochXMM-Newtoncampaign on the core of the massive Cygnus OB2 association

Element Abundances in X-ray Emitting Plasmas in Stars

Contact Info

Product

Resources

About