Unveiling the Final Stages of Protostellar Evolution

Christian Flores Gonzalez^1*, Nagayoshi Ohashi¹, Michael Connelley²

¹Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan
²Institute for Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii, USA

* Presenter:Christian Flores Gonzalez, email:caflores@asiaa.sinica.edu.tw

Low-mass young stars begin their lives as deeply embedded protostars surrounded by large envelopes of gas and dust. Over time, they evolve into more visible, though still immature, young stars, dissipating their massive envelopes in the process. The time it takes for protostars to dissipate their envelopes is crucial, as it defines the timescale for stellar growth and marks a significant milestone for the age of the surrounding protoplanetary disks. Current methods for determining such ages based on bolometric temperature and near-infrared spectral index have many limitations and work only in a statistical sense. To overcome these issues, we conducted observations of 40 low-mass young stars, combining high-resolution near-infrared spectra and sub-millimeter observations. These complementary approaches allow us to estimate the stars' relative ages and the amount of remaining envelope material, providing the clearest method yet for studying the evolution of protostellar envelopes. In this talk, I will discuss these observations and the results we have obtained, highlighting what they reveal about the evolution of protostellar envelopes and how they shape the path toward disk growth and planet formation.

Keywords: protostars, young stars, infrared observations, sub-mm observations, stellar evolution