GIARPS High-resolution Observations of T Tauri stars (GHOsT)

III. A pilot study of stellar and accretion properties^★

¹ INAF-Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
e-mail: juan.alcala@inaf.it
² INAF-Osservatorio Astronomico di Roma, Via di Frascati 33, 00078 Monte Porzio Catone, Italy
³ INAF-Osservatorio Astrofisico di Catania, via S. Sofia 78, 95123 Catania, Italy
⁴ INAF-Osservatorio Astronomico di Padova – Via dell’Osservatorio 8, 36012, Asiago (VI), Italy
⁵ Fundación Galileo Galilei – INAF – Telescopio Nazionale Galileo, 38700, Breña Baja, Santa Cruz de Tenerife, Spain
⁶ European Southern Observatory, Karl Schwarzschild Str. 2, 85748 Garching, Germany

Received: 26 March 2021
Accepted: 6 June 2021

Abstract

The mass-accretion rate, Ṁ_acc, is a crucial parameter for the study of the evolution of accretion disks around young low-mass stellar objects (YSOs) and for planet formation studies. The Taurus star forming region (SFR) is rich in pre-main sequence stars, most of them of the T Tauri class. A variety of methodologies have been used in the past to measure mass accretion in samples of YSOs in Taurus, but despite being a general benchmark for star formation studies, a comprehensive and systematic analysis of the Taurus T Tauri population, where the stellar and accretion properties are derived homogeneously and simultaneously, is still missing. As part of the GIARPS High-resolution Observations of T Tauri stars (GHOsT) project, here we present a pilot study of the stellar and accretion properties of seven YSOs in Taurus using the spectrograph GIARPS at the Telescopio Nazionale Galileo. Contemporaneous low-resolution spectroscopic and photometric ancillary observations allow us to perform an accurate flux calibration of the high-resolution spectra. The simultaneity of the high-resolution, wide-band spectroscopic observations, from the optical to the near-infrared (NIR), the veiling measurements in such wide spectral range, and many well-calibrated emission line diagnostics allows us to derive the stellar and accretion properties of the seven YSOs in a homogeneous and self-consistent way. The procedures and methodologies presented here will be adopted in future works for the analysis of the complete GHOsT data set. We discuss the accretion properties of the seven YSOs in comparison with the 90% complete sample of YSOs in the Lupus SFR and investigate possibilities for the origin of the continuum excess emission in the NIR.