Measuring the mass accretion rates of Herbig Ae/Be stars with X-shooter

Abstract

We present the results of our observations of eight magnetic Herbig Ae/Be stars obtained with the X-shooter spectrograph mounted on UT2 at the VLT. X-shooter provides a simultaneous, medium-resolution and high-sensitivity spectrum over the entire wavelength range from 300 to 2500 nm. We estimate the mass accretion rates M_acc of the targets from 13 different spectral diagnostics using empiric calibrations derived previously for T Tauri-type stars and brown dwarfs. We have estimated the mass accretion rates of our targets, which range from 2x10^-9 to 2x10^-7 M_sun/yr. Furthermore, we have found accretion rate variability with amplitudes of 0.10-0.40 dex taking place on time scales from one day to tens of days. Additional future night-to-night observations need to be carried out to investigate the character of M_acc variability in details. Our study shows that the majority of the calibrational relations can be applied to Herbig Ae/Be stars, but several of them need to be re-calibrated on the basis of new spectral data for a larger number of Herbig Ae/Be stars.

19 pages, 13 figures, nine tables, accepted for publication in Astronomische Nachrichten

References in corpus (11)

• UV excess measures of accretion onto young very low-mass stars and brown dwarfs
• Accretion Rates in Herbig Ae stars
• Parameters of Herbig Ae/Be and Vega-type stars
• A search for strong, ordered magnetic fields in Herbig Ae/Be stars
• Accretion rates and accretion tracers of Herbig Ae/Be stars
• The magnetic field of the pre-main sequence Herbig Ae star HD 190073
• Optical spectroscopic variability of Herbig Ae/Be stars
• On the difference between Herbig Ae and Herbig Be stars
• A study of the magnetic field in the photospheric and circumstellar components of Herbig Ae stars
• Accretion properties of T Tauri stars in sigma Ori
• Characterising the magnetic fields of the Herbig Ae/Be stars HD97048, HD150193, HD176386, and MWC480

Cited by in corpus (19)

• A spectroscopic survey of Herbig Ae/Be stars with X-Shooter I: Stellar parameters and accretion rates
• Gaia DR2 study of Herbig Ae/Be stars
• Temperaments of young stars: Rapid mass-accretion rate changes in T Tauri and Herbig Ae stars
• Abundant refractory sulfur in protoplanetary disks
• Fingerprints of giant planets in the photospheres of Herbig stars
• The accretion rates and mechanisms of Herbig Ae/Be stars
• NIR Spectroscopy of the HAeBe Star HD 100546: III. Further Evidence of an Orbiting Companion?
• Shadows and cavities in protoplanetary disks: HD163296, HD141569A, and HD150193A in polarized light
• Protoplanetary Disk Heating and Evolution Driven by the Spiral Density Waves
• Accretion variability of Herbig Ae/Be stars observed by X-Shooter. HD 31648 and HD 163296
• Resolving structure of the disk around HD100546 at 7 mm with ATCA
• High-resolution Br-gamma spectro-interferometry of the transitional Herbig Ae/Be star HD 100546: a Keplerian gaseous disc inside the inner rim
• The prevalence of weak magnetic fields in Herbig Ae stars: The case of PDS2
• On the Mass Accretion Rates of Herbig Ae/Be Stars. Magnetospheric Accretion or Boundary Layer?
• Pre-main sequence accretion in the low metallicity Galactic star-forming region Sh 2-284
• Near Infrared High Resolution Spectroscopy and Spectro-astrometry of Gas in Disks around Herbig Ae/Be Stars
• Time-monitoring Observations of Br$\gamma$ Emission from Young Stars
• UX Ori Stars Eclipses by Large-Scale Disc Perturbations
• Chemical abundances of the high-latitude Herbig Ae Star PDS2