Complex Organics Surrounding the FU Ori-Type Object V1057 Cyg Indicative of Sublimated Ices

TL;DR

This study investigates the chemical composition of five young stellar objects that experienced recent outbursts, revealing complex organic molecules and water in one source, V1057 Cyg, which shows a rich molecular spectrum indicative of sublimated ices.

Contribution

First observation of complex organic molecules in V1057 Cyg post-outburst, highlighting chemical changes due to increased luminosity in FU Ori-type objects.

Findings

V1057 Cyg shows >11 molecules including complex organics and water.

Only V1057 Cyg exhibits a rich molecular spectrum among the five sources.

Other sources' chemical inventories are limited by sensitivity.

Abstract

FU Ori and EX Lup type objects present natural experiments for understanding a critical stage in the star and planet formation process. These objects offer insight into the diversity of molecules available to forming planetary systems due to a sudden increase in accretion and central luminosity causes the disk and surrounding material to increase in temperature. This allows for volatiles to sublimate off of grains and exist in the gas-phase for tens to hundreds of years post initial outburst. While this dynamic stage may be common for solar-type protostars, observations of the chemical impact of these bursts are rare. In this article, we present observations from the NOrthern Extended Millimeter Array (NOEMA) of five Young Stellar Objects (YSOs) that have undergone outbursts within the past 100 years and catalog the volatile chemistry found within approx 1000 au of the YSO. Only one source clearly shows a line rich spectra with >11 molecules detected including complex organics and water, as is an expected spectra signature for a post-outburst source. This source is V1057 Cyg, and we present it as the northern analog to the well studied and molecule-rich FU Ori source, V883 Ori. Our conclusions on the chemical inventory of the other four sources in our sample are sensitivity limited, as V1057 Cyg contains the highest disk/envelope gas mass.