X-Shooter spectroscopy of young stellar objects: II. Impact of chromospheric emission on accretion rate estimates

Abstract

Context. The lack of knowledge of photospheric parameters and the level of chromospheric activity in young low-mass pre-main sequence stars introduces uncertainties when measuring mass accretion rates in accreting (Class II) Young Stellar Objects. A detailed investigation of the effect of chromospheric emission on the estimates of mass accretion rate in young low-mass stars is still missing. This can be undertaken using samples of young diskless (Class III) K and M-type stars. Aims. Our goal is to measure the chromospheric activity of Class III pre main sequence stars to determine its effect on the estimates of accretion luminosity (Lacc) and mass accretion rate (Macc) in young stellar objects with disks. Methods. Using VLT/X-Shooter spectra we have analyzed a sample of 24 non-accreting young stellar objects of spectral type between K5 and M9.5. We identify the main emission lines normally used as tracers of accretion in Class II objects, and we determine their fluxes in order to estimate the contribution of the chromospheric activity to the line luminosity. Results. We have used the relationships between line luminosity and accretion luminosity derived in the literature for Class II objects to evaluate the impact of chromospheric activity on the accretion rate measurements. We find that the typical chromospheric activity would bias the derived accretion luminosity by Lacc,noise< 10-3Lsun, with a strong dependence with the Teff of the objects. The noise on Macc depends on stellar mass and age, and the typical values of log(Macc,noise) range between -9.2 to -11.6Msun/yr. Conclusions. Values of Lacc< 10-3Lsun obtained in accreting low-mass pre main sequence stars through line luminosity should be treated with caution as the line emission may be dominated by the contribution of chromospheric activity.

accepted for publication in Astronomy & Astrophysics

References in corpus (15)

• UV excess measures of accretion onto young very low-mass stars and brown dwarfs
• Accretion in the Rho-Oph pre-main sequence stars
• Probing T Tauri Accretion and Outflow with 1 Micron Spectroscopy
• A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages
• Characterizing Young Brown Dwarfs using Low Resolution Near-IR Spectra
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. XI. Lupus Observed With IRAC and MIPS
• Lithium Depletion of Nearby Young Stellar Associations
• Distance and Kinematics of the TW Hydrae Association from Parallaxes
• FLAMES spectroscopy of low-mass stars in the young clusters sigma Ori and lambda Ori
• Discovery of an M9.5 Candidate Brown Dwarf in the TW Hydrae Association - DENIS J124514.1-442907
• Optical Spectroscopic Classification and Membership of Young M Dwarfs in Star-Forming Regions
• Stars and brown dwarfs in the sigma Orionis cluster: the Mayrit catalogue
• Doppler Images and Chromospheric Variability of TWA 6
• SSPMJ1102-3431 brown dwarf characterization from accurate proper motion and trigonometric parallax
• Circumstellar discs in the young sigma Orionis cluster

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