Near-Infrared Interferometric, Spectroscopic, and Photometric Monitoring of T Tauri Inner Disks

TL;DR

This study uses high-resolution interferometry, spectroscopy, and photometry to investigate the inner disks of 11 T Tauri stars, revealing potential correlations between disk truncation mechanisms and accretion rates, and examining inner disk variability.

Contribution

It provides the first combined interferometric, spectroscopic, and photometric analysis of T Tauri inner disks, exploring how accretion influences disk truncation and variability.

Findings

Inner disk truncation may depend on accretion rate

No strong evidence for inner disk pulsation

Variable veiling and accretion observed in some sources

Abstract

We present high angular resolution observations with the Keck Interferometer, high dispersion spectroscopic observations with Keck/NIRSPEC, and near-IR photometric observations from PAIRITEL of a sample of 11 solar-type T Tauri stars in 9 systems. We use these observations to probe the circumstellar material within 1 AU of these young stars, measuring the circumstellar-to-stellar flux ratios and angular size scales of the 2.2 micron emission. Our sample spans a range of stellar luminosities and mass accretion rates, allowing investigation of potential correlations between inner disk properties and stellar or accretion properties. We suggest that the mechanism by which the dusty inner disk is truncated may depend on the accretion rate of the source; in objects with low accretion rates, the stellar magnetospheres may truncate the disks, while sublimation may truncate dusty disks around sources with higher accretion rates. We have also included in our sample objects that are known to be highly variable (based on previous photometric and spectroscopic observations), and for several sources, we obtained multiple epochs of spectroscopic and interferometric data, supplemented by near-IR photometric monitoring, to search for inner disk variability. While time-variable veilings and accretion rates are observed in some sources, no strong evidence for inner disk pulsation is found.