J/A+A/620/A55 Magnetic flaring from PMS stars spectra (Flaccomio+, 2018) ================================================================================ A multi-wavelength view of magnetic flaring from PMS stars. Flaccomio E., Micela G., Sciortino S., Cody A.M., Guarcello M.G., Morales-Calderon M., Rebull L., Stauffer J.R. =2018A&A...620A..55F (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Stars, pre-main sequence ; Spectra, optical ; Spectra, infrared ; X-ray sources Keywords: stars: activity - stars: coronae - stars: flare - stars: pre-main sequence - stars: variables: T Tauri - HerbigAe/Be - X-rays: stars Abstract: Flares from the Sun and other stars are most prominently observed in the soft X-ray band. Most of the radiated energy, however, is released at optical/UV wavelengths. In spite of decades of investigation, the physics of flares is not fully understood. Even less is known about the powerful flares routinely observed from pre-main sequence stars, which might significantly influence the evolution of circumstellar disks. Observations of the NGC2264 star forming region were obtained in Dec. 2011, simultaneously with three telescopes, Chandra (X-rays), CoRoT (optical), and Spitzer (mIR), as part of the "Coordinated Synoptic Investigation of NGC2264" (CSI-NGC2264). Shorter Chandra and CoRoT observations were also obtained in March 2008. We analyzed the lightcurves to detect X-ray flares with an optical and/or mIR counterpart. Basic flare properties from the three datasets, such as emitted energies and peak luminosities, were then compared to constrain the spectral energy distribution of the flaring emission and the physical conditions of the emitting regions. Flares from stars with and without circumstellar disks were also compared to establish any difference that might be attributed to the presence of disks. Seventy-eight X-ray flares with an optical and/or mIR counterpart were detected. Their optical emission is found to correlate well with, and to be significantly larger than, the X-ray emission. The slopes of the correlations suggest that the difference becomes smaller for the most powerful flares. The mIR flare emission seems to be strongly affected by the presence of a circumstellar disk: flares from stars with disks have a stronger mIR emission with respect to stars without disks. This might be attributed to the reprocessing of the optical (and X-ray) flare emission by the inner circumstellar disk, providing evidence for flare-induced disk heating. Description: Tables are provided with the data to reproduce figure B.1. in the paper, showing the lightcurves of flares observed simultaneously in the Chandra X-ray band, and in the CoRoT (optical) and/or Spitzer (mIR) bands. Up to four tables are included for each of the 75 panels in the figure: the CoRoT lightcurve, the Spitzer lightcurve, and the Chandra lightcurve, binned using both a fixed bin duration (indicated in the File Summary below as "bin") and the "natural binning" Maximum-Likelihood algorithm described in the text (indicated as "blk"). For the CoRoT and Spitzer lightcurves, polynomial expressions representing the non-flaring emission during flares, derived as described in the text, are reported in the header of the relative text files, along with time intervals used to derived time-integrated flare emission. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 187 78 List of flares, deduced physical quantities, and host-star properties opt/* . 56 *Individual CoRoT spectra mir/* . 36 *Individual Spitzer spectra xbl/* . 74 Individual Chandra spectra "natural binning" xbi/* . 75 Individual Chandra spectra fixed bin duration -------------------------------------------------------------------------------- Note on opt/* and mir/*: Six header lines starting with '#' report the polynomial fit representing the non-flaring flux during the flare, as well as the column labels and units. -------------------------------------------------------------------------------- See also: J/AJ/138/1116 : A Spitzer view of NGC 2264 (Sung+, 2009) J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- Src Source number 5 A1 --- n_Src [*yzx] Note on Source (1) 7- 12 I6 --- Mon Idenfication number from Cody et al., 2014, Cat. J/AJ/147/82, CSIMon-NNNNNN in Simbad 14- 24 A11 --- Obs Chandra observation id number(s) during which the flare occurred 26- 30 F5.2 10+28J EX Total emitted X-ray energy (Chandra) 31 A1 --- u_EX Uncertainty flag on EX 33- 36 F4.2 10+25W LXpk ?=- Flare peak X-ray luminosity (Chandra) 37 A1 --- u_LXpk Uncertainty flag on LXpk 39- 43 F5.2 10+28J EOpt ?=- Optical energy (CoRoT) 44 A1 --- u_EOpt Uncertainty flag on EOpt 46- 50 F5.2 10+25W LOptpk ?=- Flare peak optical luminosity (CoRoT) 51 A1 --- u_LOptpk Uncertainty flag on LOptpk 53- 59 F7.2 10+28J EIR ?=- Infrared energy (Spitzer) 60 A1 --- u_EIR Uncertainty flag on EIR 62- 68 F7.2 10+25W LIRpk ?=- Flare peak infrared luminosity (Spitzer) 69 A1 --- u_LIRpk Uncertainty flag on LIRpk 71- 73 A3 --- Class Class 75- 79 F5.1 0.1nm EWHa ?=- H{alpha} equivalent width 81- 84 F4.2 mag AV ?=- Absorption in V band 86- 90 F5.2 10+22cm-2 NH ?=- Hydrogen column density 93- 96 A4 --- SpType MK spectral type 98-102 F5.2 mag Vmag ?=- V magnitude 106-110 F5.2 mag Rmag ?=- R magnitude 114-118 F5.2 mag Imag ?=- I magnitude 120-122 A3 --- CoRoT CoRoT light curve type 123-128 F6.3 d Prot ? Rotational period 130-143 A14 --- FOpt FileName of optical spectrum, in subdirectory opt 145-158 A14 --- FXbi FileName of Chandra spectrum fixed bin duration, in subdirectory xbi 160-173 A14 --- FXbl FileName of Chandra spectrum "natural binning", in subdirectory xbl 175-187 A13 --- FmIR FileName of Spitzer spectrum, in subdirectory mir -------------------------------------------------------------------------------- Note (1): Individual notes as follows: * = Src 405: All energies and peak luminosities are considered highly uncertain because of the large discrepancy between optical and X-ray extinction estimates (Sect. 5). y = Src 502: X-ray flare detected with 4.5 counts. No estimate of extinction was possible since AV is not available and NH could not be derived from the fit of the X-ray spectrum because of its low statistics. z = Src 536: Classified as class III on the basis of the Sung et al. (2009, Cat. J/AJ/138/1116) Spitzer photometry. Cody et al. (2014, Cat. J/AJ/147/82) indicate, however, that the star has a mIR excess. This is based on the MIPS 240m flux (not reported by Sung et al. 2009), which is, however, strongly contaminated by a nearby YSO associated with ACIS source No 541. x = Src 713: The Chandra flare falls in the gap between the last two observations - EX was multiplied by 1.497 to approximatively correct for the missing exposure time. -------------------------------------------------------------------------------- Byte-by-byte Description of file (#): opt/* -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 15 F12.6 d MJD Modified Julian Date of measurement 23- 33 F11.3 e- Flux Instrumental CoRoT flux -------------------------------------------------------------------------------- Byte-by-byte Description of file (#): mir/* -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 15 F12.6 d MJD Modified Julian Date of measurement 28- 33 F6.3 mJy Flux IRAC flux in the 3.6um or 4.5um band -------------------------------------------------------------------------------- Byte-by-byte Description of file (#): xbl/* -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 15 F12.6 d MJDb MJD of beginning of block 19- 30 F12.6 d MJDe MJD of end of block 41- 48 F8.5 ph/s/cm2 Flux ACIS-I flux in the 0.5-8.0keV band -------------------------------------------------------------------------------- Byte-by-byte Description of file (#): xbi/* -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 15 F12.6 d MJD Modified Julian Date of measurement 26- 33 F8.5 ph/s/cm2 Flux ACIS-I flux in the 0.5-8.0keV band 45- 51 F7.5 ph/s/cm2 e_Flux rms uncertainty on Flux -------------------------------------------------------------------------------- Acknowledgements: Ettore Flaccomio, ettore.flaccomio(at)inaf.it ================================================================================ (End) Patricia Vannier [CDS] 07-Sep-2018