Rotational Spectroscopy and Tentative Interstellar Detection of 3-Hydroxypropanal (HOCH$_2$CH$_2$CHO) in the G+0.693-0.027 Molecular Cloud

TL;DR

This study synthesized 3-hydroxypropanal, measured its rotational spectrum, and tentatively detected it in a molecular cloud, providing insights into its presence and formation in interstellar space.

Contribution

The paper reports the first laboratory measurement of 3-hydroxypropanal's rotational spectrum and its tentative detection in an interstellar cloud, expanding knowledge of astrochemical complexity.

Findings

Tentative detection of 3-hydroxypropanal in G+0.693-0.027

Determined column density of (8.6±1.4)×10^12 cm^-2

No detection in other observed sources

Abstract

We synthesized the astrochemically relevant molecule 3-hydroxypropanal (HOCH$_2$CH$_2$CHO) and subsequently measured and analyzed its rotational spectrum in several frequency regions ranging from 130 to 485 GHz. We analyzed the ground vibrational state as well as the two perturbed lowest-lying vibrationally excited states. With the resulting rotational parameters, we searched for this molecule in the Sagittarius B2(N) and NGC 6334I hot cores, the IRAS 16293-2422B hot corino, and the G+0.693-0.027 and TMC-1 molecular clouds. Rotational emission of 3-hydroxypropanal was tentatively detected toward G+0.693-0.027 and a column density of (8.6$\pm$1.4)$\times$10$^{12}$ cm$^{-2}$ was determined. However, this molecule was not detected in the other sources that were investigated. The chemical implications of this tentative discovery are analyzed and several potential chemical formation pathways of this species are discussed.