Interstellar glycolamide: A comprehensive rotational study and an astronomical search in Sgr B2(N)

TL;DR

This study conducted a detailed rotational spectroscopic analysis of glycolamide, searched for it in Sgr B2(N) using ALMA and Effelsberg telescopes, and found it absent, setting upper limits on its abundance relative to related molecules.

Contribution

It provides the first comprehensive rotational spectral data for glycolamide and reports the first astronomical search for this molecule in Sgr B2(N).

Findings

Glycolamide was not detected in Sgr B2(N).

Upper limits on glycolamide's abundance were established.

Spectroscopic data for glycolamide were significantly expanded.

Abstract

Glycolamide is a glycine isomer and also one of the simplest derivatives of acetamide (e.g., one hydrogen atom is replaced with a hydroxyl group), which is a known interstellar molecule. Using a battery of state of the art rotational spectroscopic techniques in the frequency and time domain, around 1500 transitions have been newly assigned. Based on the reliable frequency predictions, we report a radioastronomical search for glycolamide in the well known high-mass star forming region Sgr B2(N) using the ALMA imaging spectral line survey ReMoCA. We also searched for glycolamide toward Sgr B2(N) with the Effelsberg radio telescope. We report the nondetection of glycolamide toward this source with an abundance at least six and five times lower than that of acetamide and glycolaldehyde, respectively. Our astrochemical model suggests that glycolamide may be present in this source at a level just below the upper limit, which was derived from the EMoCA survey. We could also not detect the molecule in the region's extended molecular envelope, which was probed with the Effelsberg telescope. We find an upper limit to its column density that is similar to the column densities obtained earlier for acetamide and glycolaldehyde with the Green Bank Telescope.