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J/ApJ/688/418        X-ray flares in Orion young stars. I.       (Getman+, 2008)

X-ray flares in Orion young stars. I. Flare characteristics. Getman K.V., Feigelson E.D., Broos P.S., Micela G., Garmire G.P. <Astrophys. J., 688, 418-436 (2008)> =2008ApJ...688..418G
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; X-ray sources ; Photometry, infrared Keywords: open clusters and associations: individual (Orion Nebula Cluster) - stars: flare - stars: pre-main sequence - X-rays: stars Abstract: Pre-main-sequence (PMS) stars are known to produce powerful X-ray flares, which resemble magnetic reconnection solar flares scaled by factors up to 104. However, there are numerous puzzles, including the structure of X-ray-emitting coronae and magnetospheres, the effects of protoplanetary disks, and the effects of stellar rotation. To investigate these issues in detail, we examine 216 of the brightest flares from 161 PMS stars observed in the Chandra Orion Ultradeep Project (COUP, Getman et al. Cat. J/ApJS/160/319). The current study (Paper I) examines the flare morphologies, and provides a general comparison of COUP flare characteristics with those of other active X-ray stars and the Sun. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 103 216 Flare properties 1 table2.dat 96 216 Flare properties 2 table3.dat 116 161 COUP star properties table4.dat 55 216 Time-resolved spectroscopy analysis
See also: J/ApJ/574/258 : X-ray-emitting young stars in the Orion nebula (Feigelson+, 2002) J/PASJ/55/653 : Chandra X-ray flares in rho Ophiuchi (Imanishi+, 2003) J/ApJS/160/319 : COUP: observations and source lists (Getman+, 2005) J/ApJS/160/353 : Membership of the Orion nebula population (Getman+, 2005) J/ApJS/160/450 : X-ray emission in Orion Nebula young stars (Flaccomio+, 2005) J/A+A/474/495 : X-ray flares from Cygnus OB2 young stars (Albacete Colombo+, 2007) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 I4 --- COUP COUP source number 6 I1 --- FNo Flare number 8- 12 I5 ct NCf Net flare counts 14- 18 F5.1 ct bgf Background counts in flare 20- 23 F4.2 keV MEf X-ray median energy of flare counts 25- 30 F6.1 ks tchar1 Start time of characteristic state 32- 37 F6.1 ks tchar2 Stop time of characteristic state 39- 44 F6.1 ks tFl1 Flare start time 46- 51 F6.1 ks tFl2 Flare stop time 53- 56 F4.1 ct/ks CRchar Count rate in characteristic state 58- 63 F6.1 ct/ks CRFlpk Peak flare count rate 65- 68 F4.1 ct/ks e_CRFlpk Error in CRFlpk 70- 75 F6.1 ks tCRpk Time of maximum flare count rate 77- 82 F6.1 ks tTpk Time of maximum flare temperature 84- 89 F6.1 ks tEMpk Time of maximum flare emission measure 91- 96 F6.1 ks texp Time point for pure exponential decay (1) 98-103 F6.1 ks tsep Separation time point (2)
Note (1): Time point until which the lightcurve exhibits a pure exponential decay. Note (2): Separation time point between two distinct decay phases.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 4 I4 --- COUP COUP source number 6 I1 --- FNo Flare number 8- 12 F5.1 ks taur Rise e-folding timescale 14- 18 F5.1 ks taud1 Initial decay e-folding timescale 20- 24 F5.1 ks taud2 Full decay e-folding timescale 26- 30 F5.2 [10-7W] Lxpk Flare peak X-ray luminosity (log scale) 32- 37 F6.2 MK Tobspk Flare peak observed plasma temperature 39- 44 F6.2 10+53cm-3 EMpk Flare peak emission measure 46- 51 F6.2 MK TEMpk Plasma temperature at maximum emission measure 53- 56 F4.1 --- zeta1 Slope over the full decay 58- 61 F4.1 --- zeta2 Slope within the initial decay 63- 67 F5.1 --- zeta3 Slope within the late decay 69- 74 F6.2 10+10cm L1 Low boundary of the inferred loop length range 76- 81 F6.2 10+10cm L2 High boundary of the inferred loop length range 83- 89 F7.2 10+10cm Llim Limiting maximum loop length using Serio's law 91- 92 I2 --- Flag1 Flag for a dominant slope(s) (1) 94- 96 A3 --- Type Flare morphology (2)
Note (1): Flag defines the best or dominant slope or a combination of slopes which, in combination with decay timescales taud1 and taud2, are used to estimate loop size range; as follows: 01 = ζ1; 02 = ζ2; 03 = ζ3; 12 = ζ1, ζ2; 13 = ζ1, ζ3; 23 = ζ2, ζ3; 44 = unable to estimate loop size. Note (2): The following morphological classes are defined: typ = typical; stp = flares with step decay; srf = slow-rise-and/or-top-flat flares; dbl = double flares; inc = incomplete, interrupted by COUP observational gaps; oth = other, purely defined shapes generally due to their lower counting statistics.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 4 I4 --- COUP COUP source number (1) 6- 10 I5 ct NC Source net counts (1) 12- 14 I3 ct bg Background counts in source region (1) 16- 19 F4.2 keV ME Source's X-ray median energy (1) 21- 25 F5.2 [cm-2] NH Source's inferred column density (1) 27- 31 F5.2 mag Jmag ?=-9.99 2MASS J-band magnitude (1) 33- 37 F5.2 mag Hmag 2MASS H-band magnitude (1) 39- 43 F5.2 mag Ksmag 2MASS Ks-band magnitude (1) 45- 50 A6 --- Qual IR source and quality flag (1) 52- 56 F5.2 mag d(H-K) ?=-9.99 IR color excess (2) 58- 63 F6.3 mag 3.6mag ?=-9.999 IR 3.6 micron band magnitude 65- 70 F6.3 mag e_3.6mag ?=-9.999 Error in 3.6mag 72- 77 F6.3 mag 4.5mag ?=-9.999 IR 4.5 micron band magnitude 79- 84 F6.3 mag e_4.5mag ?=-9.999 Error in 4.5mag 86- 90 F5.2 Msun Mass ?=-9.99 Stellar mass (1) 92- 96 F5.2 10+8m Rad ?=-9.99 Stellar radius (1) 98-102 F5.2 d Per ?=-9.99 Stellar rotation period (3) 104-109 F6.2 10+8m Rcor ?=-9.99 Keplerian co-rotation radius 111-116 F6.2 0.1nm EW(CaII) ?=-99.99 Equivalent width of Ca II line (1)
Note (1): Values for these quantities are from Getman et al. (2005, Cat. J/ApJS/160/353): 3 letters for 2MASS quality flags and 3 characters for the 2MASS contamination and confusion flag. Note (2): Color excess measured from the rightmost reddening vector on the J-H vs. H-Ks color-color diagram (originating at 0.1M assuming an age of 1Myr and using PMS models of Siess et al. (2000A&A...358..593S)). Note (3): Stellar rotation periods with extended rotation data collected in Flaccomio et al. (2005, Cat. J/ApJS/160/450).
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 4 I4 --- COUP COUP source number 6 I1 --- FNo Flare number 8- 10 A3 --- Type Flare morphology (1) 12- 13 I2 --- SNo Number of time-resolved spectroscopy (TRS) segments 15- 18 I4 ct Nseg Average number of counts in TRS segment 20- 23 I4 ct Nchar Number of counts in characteristic segment 25- 29 F5.2 MK Tchar Characteristic plasma temperature 31- 36 F6.2 MK TpknCH Peak flare plasma temperature in "noCH" case (2) 38- 43 F6.2 MK TpkCH Peak flare plasma temperature in "CH" case (2) 45- 49 F5.2 --- znCH Full decay slope in "noCH" case (2) 51- 55 F5.2 --- zCH Full decay slope in "CH" case (2)
Note (1): The following morphological classes are defined: typ = typical; stp = flares with step decay; srf = slow-rise-and/or-top-flat flares; dbl = double flares; inc = incomplete, interrupted by COUP observational gaps; oth = other, purely defined shapes generally due to their lower counting statistics. Note (2): Inferred peak flare plasma temperatures and slopes of temperature- density trajectories without ("noCH") and with ("CH") account for the "characteristic" background.
History: From electronic version of the journal References: Getman et al. Paper II. 2008ApJ...688..437G
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 14-Jan-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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