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

IV. Accretion properties of the Taurus-Auriga young association^★,★★

¹ INAF – Osservatorio Astronômico di Roma, Via Frascati 33, 00078 Monte Porzio Catone, Italy
e-mail: manuele.gangi@inaf.it
² INAF – Osservatorio Astrofísico di Catania, Via S. Sofia 78, 95123 Catania, Italy
³ INAF – Osservatorio Astronomico di Capodimonte – Salita Moiariello 16, 80131 Napoli, Italy
⁴ European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
⁵ ASI – Agenzia Spaziale Italiana, Via del Politecnico, 00133 Roma, Italy
⁶ Fundación Galileo Galilei – INAF – Telescopio Nazionale Galileo, 38700 Breña Baja, Santa Cruz de Tenerife, Spain
⁷ INAF – Osservatorio Astronomico di Padova, via dell’Osservatorio 8, 36012 Asiago (VI), Italy

Received: 17 May 2022
Accepted: 31 August 2022

Abstract

Aims. In the framework of the GIARPS High-resolution Observations of T Tauri stars (GHOsT) project, we study the accretion properties of 37 classical T Tauri stars of the Taurus-Auriga star-forming region (SFR) with the aim of characterizing their relation with the properties of the central star, with jets and disk winds, and with the global disk structure, in synergy with complementary ALMA millimeter observations.

Methods. We derive the stellar parameters, optical veiling, the accretion luminosity (L_acc), and the mass accretion rate (Ṁ_acc) in a homogeneous and self-consistent way using high-resolution spectra acquired at the Telescopio Nazionale Galileo with the HARPS-N and GIANO spectrographs that are flux-calibrated based on contemporaneous low-resolution spectroscopic and photometric ancillary observations.

Results. The L_acc–L_*, Ṁ_acc–M_* and Ṁ_acc–M_disk relations of the Taurus sample are provided and compared with those of the coeval SFRs of Lupus and Chamaeleon I. We analyzed possible causes for the observed large spreads in the relations. We find that (i) a proper modeling in deriving the stellar properties in highly spotted stars can reduce the spread of the Ṁ_acc–M_* relation, (ii) transitional disks tend to have lower Ṁ_acc at a given M_*, (iii) stars in multiple systems have higher Ṁ_acc at the same M_disk, (iv) the Ṁ_acc versus disk surface density has a smaller spread than the Ṁ_acc–M_disk, indicating that opacity effects might be important in the derivation of M_disk. Finally, the luminosities of the [O i] 630 nm narrow low-velocity component and high-velocity component (HVC) and the deprojected HVC peak velocity were found to correlate with the accretion luminosity. We discuss these correlations in the framework of the currently accepted models of jets and winds.

Conclusions. Our results demonstrate the potential of contemporaneous optical and near-infrared high-resolution spectroscopy to simultaneously provide precise measurements of the stellar wind and accretion wind properties of young stars.