Stellar and Circumstellar Properties of the Pre-Main Sequence Binary GV Tau from Infrared Spectroscopy

TL;DR

This study uses high-resolution infrared spectroscopy to analyze the stellar and circumstellar properties of the pre-main-sequence binary GV Tau, revealing potential binarity and complex circumstellar environments.

Contribution

First spatially resolved spectroscopic analysis of both GV Tau components, suggesting binarity and circumstellar disk features affecting molecular absorption.

Findings

GV Tau S is a radial velocity variable, indicating possible an unseen companion.

Warm molecular absorption detected toward GV Tau N, similar to that previously observed in GV Tau S.

Absorbing gas toward GV Tau N is redshifted, implying a circumbinary disk viewed edge-on.

Abstract

We report spatially resolved spectroscopy of both components of the low-mass pre-main-sequence binary GV Tau. High resolution spectroscopy in the K- and L-bands is used to characterize the stellar properties of the binary and to explore the nature of the circumstellar environment. We find that the southern component, GV Tau S, is a radial velocity variable, possibly as a result of an unseen low-mass companion. The strong warm gaseous HCN absorption reported previously toward GV Tau S (Gibb et al. 2007) was not present during the epoch of our observations. Instead, we detect warm (~500 K) molecular absorption with similar properties toward the northern infrared companion, GV Tau N. At the epoch of our observations, the absorbing gas toward GV Tau N was approximately at the radial velocity of the GV Tau molecular envelope, but it was redshifted with respect to the star by ~13 km/s. One interpretation of our results is that GV Tau N is also a binary and that most of the warm molecular absorption arises in a circumbinary disk viewed close to edge-on.