J/A+A/311/211 X-ray flare of CF Tuc (=HD 5303) (Kuerster+ 1996)
Forty days in the life of CF Tucana (=HD 5303).
The longest stellar X-ray flare observed with ROSAT
Kuerster M., Schmitt J.H.M.M.
<Astron. Astrophys. 311, 211 (1996)>
=1996A&A...311..211K 1996A&A...311..211K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, flare
Keywords: stars: flare - binaries: eclipsing - stars: coronae -
stars: activity - stars: late-type - stars: rotation -
stars: individual: CF Tuc
Abstract:
Solar abundance fits to the quiescent spectra 1-3 and 20-35 were made
with a two-component thermal plasma (model 1a) whereas sub-solar
abundance fits to the quiescent spectra were made with a one-component
thermal plasma (model 2a). Modifications of these models were used for
the flare spectra 4-19 in order to account for the `quiescent
background'. Thus solar abundance fits to the flare spectra were made
with a thermal plasma of two variable components plus two components
kept constant at the average quiescent values T_qu,cool=2.46*10^6K,
EM_qu,cool=0.49*1053cm-3, T_qu,hot =17.8*10^6K,
EM_qu,hot=1.95*1053cm-3, and z=1.00 (model 1b). Sub-solar abundance
fits to the flare spectra were made with a plasma of one variable
component plus one component kept constant at the average quiescent
values T_qu=13.0*10^6K, EM_qu=5.20*1053cm-3, and z=0.10 (model 2b).
In both cases the mean values of spectra 3, and 20-35 were used to
account for the quiescent emission.
Objects:
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RA (2000) DE Name
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00 53 04.8 -74 39 07 HD 5303 = CF Tuc
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2 171 35 Raymond-Smith model fits with solar and
sub-solar metal abundances, z=1.0 and z=0.1.
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1- 2 I2 --- Sq Number of the spectrum
4- 7 A4 --- State Emission state as inferred from the light
curve (1)
9- 20 F12.4 d HJD Heliocentric Julian day
22- 24 F3.1 10+19cm-2 NH1 Hydrogen column density, model 1 (2)
26- 28 F3.1 10+19cm-2 e(NH1)u Error in NH1, upper limit
30- 32 F3.1 10+19cm-2 e(NH1)l Error in NH1, lower limit
34- 37 F4.2 10+53cm-3 EMcool Emission measure of the cooler plasma
component, model 1 (2)
39- 42 F4.2 10+53cm-3 e(EMcool)u Error in EMcool, upper limit
44- 47 F4.2 10+53cm-3 e(EMcool)l Error in EMcool, lower limit
49- 52 F4.2 10+6K Tcool temperature of the cooler plasma
component, model 1 (2)
54- 57 F4.2 10+6K e(Tcool)u Error in Tcool, upper limit
59- 62 F4.2 10+6K e(Tcool)l Error in Tcool, lower limit
64- 68 F5.2 10+53cm-3 EMhot Emission measure of the hotter plasma
component, model 1 (2)
70- 73 F4.2 10+53cm-3 e(EMhot)u Error in EMhot, upper limit
75- 78 F4.2 10+53cm-3 e(EMhot)l Error in EMhot, lower limit
80- 83 F4.1 10+6K Thot Temperature of the hotter plasma
component, model 1 (2)
85- 89 F5.1 10+6K e(Thot)u Error in Thot, upper limit
91- 94 F4.1 10+6K e(Thot)l Error in Thot, lower limit
96- 99 F4.2 --- Chi21 Reduced chi-square of the fit, model 1 (2)
101-102 I2 --- f_Chi21 Number of degrees of freedom of chi2
104-107 F4.2 10+19cm-2 NH2 Hydrogen column density, model 2 (3)
109-112 F4.2 10+19cm-3 e(NH2)u Error in NH2, upper limit
114-117 F4.2 10+19cm-3 e(NH2)l Error in NH2, lower limit
119-123 F5.2 10+53cm-3 EM Emission measure, model 2 (3)
125-128 F4.2 10+53cm-3 e(EM)u Error in EM, upper limit
130-133 F4.2 10+53cm-3 e(EM)l Error in EM, lower limit
135-138 F4.1 10+6K T Temperature, model 2 (3)
140-143 F4.1 10+6K e(T)u Error in T, upper limit
145-147 F3.1 10+6K e(T)l Error in T, lower limit
149-152 F4.2 --- Chi22 Reduced chi-square of the fit, model 2 (3)
154-155 I2 --- f_Chi22 Number of degrees of freedom
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Note (1): qu/f = high-level quiescent emission or possible flare,
qu = low-level quiescent emission,
f-r = flare rise,
f-p = flare peak,
d-r = rapid flare decay,
d-h = decay halt,
d-s = slow flare decay.
Note (2): Model 1: 2-component model (1a/1b) with metallicity z=1.0
Note (3): Model 2: 1-component model (2a/2b) with z=0.1
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Courtesy: Martin Kuerster,
(End) Patricia Bauer [CDS] 01-Mar-1996