A Detailed Study of the Rise Phase of a Long Duration X-Ray Flare in the Young Star TWA 11B

Fabio Reale, Fabio Reale, Crespo-Chacón, López-Santiago, Micela

Risultato della ricerca: Article

7 Citazioni (Scopus)

Abstract

We analyzed a long duration flare observed in a serendipitous XMM-Newton detection of the M star CD-39 7717B (TWA 11B), member of the young stellar association TW Hya (~8 Myr). Only the rise phase (with a duration of ~35 ks) and possibly the flare peak were observed. We took advantage of the high count rate of the X-ray source to carry out a detailed analysis of its spectrum during the whole exposure. After a careful analysis, we interpreted the rise phase as resulting from the ignition of a first group of loops (event A) which triggered a subsequent two-ribbon flare (event B). Event A was analyzed using a single-loop model, while a two-ribbon model was applied for event B. Loop semi-lengths of ~4 R * were obtained. Such large structures had been previously observed in very young stellar objects (~1-4 Myr). This is the first time that they have been inferred in a slightly more evolved star. The fluorescent iron emission line at 6.4 keV was detected during event B. Since TWA 11B seems to have no disk, the most plausible explanation found for its presence in the X-ray spectrum of this star is collisional- or photo-ionization. As far as we are concerned, this is only the third clear detection of Fe photospheric fluorescence in stars other than the Sun.
Lingua originaleEnglish
pagine (da-a)78-87
Numero di pagine10
RivistaTHE ASTROPHYSICAL JOURNAL
Volume712
Stato di pubblicazionePublished - 2010

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flares
stars
x rays
ribbons
M stars
XMM-Newton telescope
newton
ignition
photoionization
iron
fluorescence

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cita questo

A Detailed Study of the Rise Phase of a Long Duration X-Ray Flare in the Young Star TWA 11B. / Reale, Fabio; Reale, Fabio; Crespo-Chacón; López-Santiago; Micela.

In: THE ASTROPHYSICAL JOURNAL, Vol. 712, 2010, pag. 78-87.

Risultato della ricerca: Article

Reale, F, Reale, F, Crespo-Chacón, López-Santiago & Micela 2010, 'A Detailed Study of the Rise Phase of a Long Duration X-Ray Flare in the Young Star TWA 11B', THE ASTROPHYSICAL JOURNAL, vol. 712, pagg. 78-87.
Reale, Fabio ; Reale, Fabio ; Crespo-Chacón ; López-Santiago ; Micela. / A Detailed Study of the Rise Phase of a Long Duration X-Ray Flare in the Young Star TWA 11B. In: THE ASTROPHYSICAL JOURNAL. 2010 ; Vol. 712. pagg. 78-87.
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abstract = "We analyzed a long duration flare observed in a serendipitous XMM-Newton detection of the M star CD-39 7717B (TWA 11B), member of the young stellar association TW Hya (~8 Myr). Only the rise phase (with a duration of ~35 ks) and possibly the flare peak were observed. We took advantage of the high count rate of the X-ray source to carry out a detailed analysis of its spectrum during the whole exposure. After a careful analysis, we interpreted the rise phase as resulting from the ignition of a first group of loops (event A) which triggered a subsequent two-ribbon flare (event B). Event A was analyzed using a single-loop model, while a two-ribbon model was applied for event B. Loop semi-lengths of ~4 R * were obtained. Such large structures had been previously observed in very young stellar objects (~1-4 Myr). This is the first time that they have been inferred in a slightly more evolved star. The fluorescent iron emission line at 6.4 keV was detected during event B. Since TWA 11B seems to have no disk, the most plausible explanation found for its presence in the X-ray spectrum of this star is collisional- or photo-ionization. As far as we are concerned, this is only the third clear detection of Fe photospheric fluorescence in stars other than the Sun.",
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T1 - A Detailed Study of the Rise Phase of a Long Duration X-Ray Flare in the Young Star TWA 11B

AU - Reale, Fabio

AU - Reale, Fabio

AU - Crespo-Chacón, null

AU - López-Santiago, null

AU - Micela, null

PY - 2010

Y1 - 2010

N2 - We analyzed a long duration flare observed in a serendipitous XMM-Newton detection of the M star CD-39 7717B (TWA 11B), member of the young stellar association TW Hya (~8 Myr). Only the rise phase (with a duration of ~35 ks) and possibly the flare peak were observed. We took advantage of the high count rate of the X-ray source to carry out a detailed analysis of its spectrum during the whole exposure. After a careful analysis, we interpreted the rise phase as resulting from the ignition of a first group of loops (event A) which triggered a subsequent two-ribbon flare (event B). Event A was analyzed using a single-loop model, while a two-ribbon model was applied for event B. Loop semi-lengths of ~4 R * were obtained. Such large structures had been previously observed in very young stellar objects (~1-4 Myr). This is the first time that they have been inferred in a slightly more evolved star. The fluorescent iron emission line at 6.4 keV was detected during event B. Since TWA 11B seems to have no disk, the most plausible explanation found for its presence in the X-ray spectrum of this star is collisional- or photo-ionization. As far as we are concerned, this is only the third clear detection of Fe photospheric fluorescence in stars other than the Sun.

AB - We analyzed a long duration flare observed in a serendipitous XMM-Newton detection of the M star CD-39 7717B (TWA 11B), member of the young stellar association TW Hya (~8 Myr). Only the rise phase (with a duration of ~35 ks) and possibly the flare peak were observed. We took advantage of the high count rate of the X-ray source to carry out a detailed analysis of its spectrum during the whole exposure. After a careful analysis, we interpreted the rise phase as resulting from the ignition of a first group of loops (event A) which triggered a subsequent two-ribbon flare (event B). Event A was analyzed using a single-loop model, while a two-ribbon model was applied for event B. Loop semi-lengths of ~4 R * were obtained. Such large structures had been previously observed in very young stellar objects (~1-4 Myr). This is the first time that they have been inferred in a slightly more evolved star. The fluorescent iron emission line at 6.4 keV was detected during event B. Since TWA 11B seems to have no disk, the most plausible explanation found for its presence in the X-ray spectrum of this star is collisional- or photo-ionization. As far as we are concerned, this is only the third clear detection of Fe photospheric fluorescence in stars other than the Sun.

KW - astrofisica

KW - fisica stellare

KW - flares

KW - stars: activity

KW - stars: coronae

KW - stars: flare

KW - stars: individual: CD-39 7717B TWA 11B

KW - stars: pre-main sequence

UR - http://hdl.handle.net/10447/51569

UR - http://adsabs.harvard.edu/abs/2010ApJ...712...78L

M3 - Article

VL - 712

SP - 78

EP - 87

JO - THE ASTROPHYSICAL JOURNAL

JF - THE ASTROPHYSICAL JOURNAL

SN - 0004-637X

ER -