First light measurements with the XMM-Newton reflection grating spectrometers:
 Evidence for an inverse first ionisation potential effect and 
 anomalous Ne abundance   in the Coronae of HR 1099

Brinkman, A. C.; Behar, E.; Güdel, M.; Audard, M.; Boggende, A. J. F. den; Branduardi‐Raymont, G.; Cottam, J.; Erd, C.; Herder, J. W. den; Jansen, F.; Kaastra, J. S.; Kahn, S. M.; Mewe, R.; Paerels, F.; Peterson, J. R.; Rasmussen, Andrew; Sakelliou, I.; Vries, C. de

doi:10.1051/0004-6361:20000047

Cited by 169 publications

(171 citation statements)

References 24 publications

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“…Such a Ne abundance enhancement is reminiscent of a similar anomaly observed in a subset of solar flares (Murphy et al 1991;Schmelz 1993). Large Ne abundance enhancements are a common feature of active stellar coronae (Güdel et al 2001;Huenmoerder et al 2001) and an inverse FIP effect is observed in very active coronae Drake et al 2001) where the abundances (relative to oxygen) increase with increasing first ionization potential (FIP). The emitting volume of the different plasma components could be constrained if their electron densities were known.…”

Section: Obsmentioning

confidence: 82%

The corona of V390 Aurigae (HD 33798)

Gondoin

2003

A&A

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Abstract. V390 Aurigae (HD 33798) is a rapidly rotating, lithium rich, late-type giant whose distinctive characteristics include a high X-ray luminosity observed by the XMM-Newton space observatory. Series of lines of highly ionized Fe and several Lyman lines of hydrogen-like ions and triplet lines of helium-like ions are visible in the reflection grating spectra, most notably from O and Ne. X-ray emission from plasma at high temperature (T > 10 7 K) indicates intense flaring activity on this star. Analysis results suggest a scenario where the corona of V390 Aurigae is dominated by large magnetic structures similar in size to interconnecting loops between solar active regions but significantly hotter. The interaction of these structures could explain the permanent flaring activity on large scales that is responsible for heating plasma to high temperatures. The intense activity on V390 Aurigae is related to its evolutionary position at the bottom of the red giant branch. It is anticipated that the rotation of the star will spin-down in the future, thus decreasing the efficiency of its α − Ω dynamo with the suppressing of large scale magnetic structures in its corona.

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Section: Obsmentioning

confidence: 82%

The corona of V390 Aurigae (HD 33798)

Gondoin

2003

A&A

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“…The abundance trends found in other systems show that low-FIP species are subsolar, while high-FIP elements (neon) have enhanced abundance Drake et al 2001;Audard, Gü del, & Mewe 2001;Brinkman et al 2001;Güdel et al 2001aGüdel et al , 2001b. However, we find that the lowest FIP elements have intermediate abundances, as does the high-FIP element Ar, relative to the other elements.…”

Section: Discussionmentioning

confidence: 97%

The Coronae of AR Lacertae

Huenemoerder

Canizares

Drake

et al. 2003

ApJ

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We observed the coronally active eclipsing binary AR Lac with the High Energy Transmission Grating on Chandra for a total of 97 ks, spaced over five orbits, at quadratures and conjunctions. Contemporaneous and simultaneous EUV spectra and photometry were also obtained with the Extreme Ultraviolet Explorer. Significant variability in both X-ray and EUV fluxes were observed, dominated by at least one X-ray flare and one EUV flare. We saw no evidence of primary or secondary eclipses, but exposures at these phases were short and intrinsic variability compromised detection of any geometric modulation. X-ray flux modulation was largest at high temperature, indicative of flare heating of coronal plasma rather than changes in emitting volume or global emission measure. Analysis of spectral line widths interpreted in terms of Doppler broadening suggests that both binary stellar components are active. On the basis of line fluxes obtained from total integrated spectra, we have modeled the emission measure and abundance distributions. The EUV spectral line fluxes were particularly useful for constraining the parameters of the '' cool '' ( 2 Â 10 6 K) plasma. A strong maximum was found in the differential emission measure, characterized by two apparent peaks at log T ¼ 6:9 and 7.4, together with a weak but significant cooler maximum near log T ¼ 6:2 and a moderately strong hot tail from log T ¼ 7:6 8:2. Coronal abundances have a broad distribution and show no simple correlation with first ionization potential. While the resulting model spectrum generally agrees very well with the observed spectrum, there are some significant discrepancies, especially among the many Fe L lines. Both the emission measure and abundance distributions are qualitatively similar to prior determinations from other X-ray and ultraviolet spectra, indicating some long-term stability in the overall coronal structure.

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“…However, a reverse pattern called the "inverse FIP effect" (IFIP) is observed in active stars (e.g. Brinkman et al 2001;Audard et al 2003). As can be seen in Fig.…”

Section: Fip Effectmentioning

confidence: 95%

A multi-wavelength view of AB Doradus outer atmosphere

Lalitha

Fuhrmeister

Wolter

et al. 2013

A&A

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Aims. We study the chromosphere and corona of the ultra-fast rotator AB Dor A at high temporal and spectral resolution using simultaneous observations with XMM-Newton in the X-rays, VLT/UVES in the optical, and the ATCA in the radio. Our optical spectra have a resolving power of ∼50 000 with a time cadence of ∼1 min. Our observations continuously cover more than one rotational period and include both quiescent periods and three flaring events of different strengths. Methods. From the X-ray observations we investigated the variations in coronal temperature, emission measure, densities, and abundance. We interpreted our data in terms of a loop model. From the optical data we characterised the flaring chromospheric material using numerous emission lines that appear in the course of the flares. A detailed analysis of the line shapes and line centres allowed us to infer physical characteristics of the flaring chromosphere and to coarsely localise the flare event on the star. Results. We specifically used the optical high-cadence spectra to demonstrate that both turbulent and Stark broadening are present during the first ten minutes of the first flare. Also, in the first few minutes of this flare, we find short-lived (one to several minutes) emission subcomponents in the Hα and Ca ii K lines, which we interpret as flare-connected shocks owing to their high intrinsic velocities. Combining the space-based data with the results of our optical spectroscopy, we derive flare-filling factors. Finally, comparing X-ray, optical broadband, and line emission, we find a correlation for two of the three flaring events, while there is no clear correlation for one event. Also, we do not find any correlation of the radio data to any other observed data.

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First light measurements with the XMM-Newton reflection grating spectrometers: Evidence for an inverse first ionisation potential effect and anomalous Ne abundance in the Coronae of HR 1099

Cited by 169 publications

References 24 publications

The corona of V390 Aurigae (HD 33798)

The corona of V390 Aurigae (HD 33798)

The Coronae of AR Lacertae

A multi-wavelength view of AB Doradus outer atmosphere

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