TY - JOUR

T1 - Millimetre-wave spectroscopy of 2-hydroxyprop-2-enal and an astronomical search with ALMA

AU - Koucky, J.

AU - Kolesnikova, L.

AU - Lukova, K.

AU - Vavra, K.

AU - Kania, P.

AU - Coutens, A.

AU - Loison, J-C

AU - Jorgensen, J. K.

AU - Belloche, A.

AU - Urban, S.

PY - 2022/10/21

Y1 - 2022/10/21

N2 - Context. Several sugar-like molecules have been found in the interstellar medium (ISM). The molecule studied in this work, 2-hydroxyprop-2-enal, is among the candidates to be searched for, as it is a dehydration product of C-3 sugars and contains structural motifs that are typical for some interstellar molecules. Furthermore, it has recently been predicted that it is more abundant in the ISM than its tentatively detected isomer 3-hydroxypropenal.Aims. So far, only low-frequency microwave data of 2-hydroxyprop-2-enal have been published. The aim of this work is to deepen our knowledge about the millimetre-wave spectrum of 2-hydroxyprop-2-enal, enabling its detailed search towards astronomical objects. In particular, we target the solar-type protostar IRAS 16293-2422 and the star-forming region Sagittarius (Sgr) B2(N).Methods. The rotational spectrum of 2-hydroxyprop-2-enal was measured and analysed in the frequency regions of 128-166 GHz and 285-329 GHz. The interstellar exploration towards IRAS 16293-2422 was based on the Atacama Large Millimeter/submillimeter Array (ALMA) data of the Protostellar Interferometric Line Survey (PILS). We also used the imaging spectral line survey ReMoCA performed with ALMA towards Sgr B2(N) to search for 2-hydroxyprop-2-enal in the ISM. We modelled the astronomical spectra under the assumption of local thermodynamic equilibrium (LTE).Results. We provide laboratory analysis of hundreds of rotational transitions of 2-hydroxyprop-2-enal in the ground state and the lowest lying excited vibrational state. We report its non-detection towards IRAS 16293 B. The 2-hydroxyprop-2-ena1/3-hydroxypropenal abundance ratio is estimated to beConclusions. Despite the non-detections of 2-hydroxyprop-2-enal, the results of this work represent a significant improvement on previous investigations in the microwave region and meet the requirements for further searches for this molecule in the ISM.

AB - Context. Several sugar-like molecules have been found in the interstellar medium (ISM). The molecule studied in this work, 2-hydroxyprop-2-enal, is among the candidates to be searched for, as it is a dehydration product of C-3 sugars and contains structural motifs that are typical for some interstellar molecules. Furthermore, it has recently been predicted that it is more abundant in the ISM than its tentatively detected isomer 3-hydroxypropenal.Aims. So far, only low-frequency microwave data of 2-hydroxyprop-2-enal have been published. The aim of this work is to deepen our knowledge about the millimetre-wave spectrum of 2-hydroxyprop-2-enal, enabling its detailed search towards astronomical objects. In particular, we target the solar-type protostar IRAS 16293-2422 and the star-forming region Sagittarius (Sgr) B2(N).Methods. The rotational spectrum of 2-hydroxyprop-2-enal was measured and analysed in the frequency regions of 128-166 GHz and 285-329 GHz. The interstellar exploration towards IRAS 16293-2422 was based on the Atacama Large Millimeter/submillimeter Array (ALMA) data of the Protostellar Interferometric Line Survey (PILS). We also used the imaging spectral line survey ReMoCA performed with ALMA towards Sgr B2(N) to search for 2-hydroxyprop-2-enal in the ISM. We modelled the astronomical spectra under the assumption of local thermodynamic equilibrium (LTE).Results. We provide laboratory analysis of hundreds of rotational transitions of 2-hydroxyprop-2-enal in the ground state and the lowest lying excited vibrational state. We report its non-detection towards IRAS 16293 B. The 2-hydroxyprop-2-ena1/3-hydroxypropenal abundance ratio is estimated to beConclusions. Despite the non-detections of 2-hydroxyprop-2-enal, the results of this work represent a significant improvement on previous investigations in the microwave region and meet the requirements for further searches for this molecule in the ISM.

KW - astrochemistry

KW - ISM: molecules

KW - line: identification

KW - ISM: individual objects: IRAS 16293-2422

KW - ISM: individual objects: Sagittarius B2

KW - astronomical databases: miscellaneous

KW - COMPLEX ORGANIC-MOLECULES

KW - ROTATIONAL SPECTRUM

KW - MICROWAVE DETECTION

KW - IRAS 16293-2422

KW - SGR B2(N)

KW - ACRYLONITRILE

KW - HYDROXYACETONE

KW - MALONALDEHYDE

KW - PROTOSTELLAR

KW - DETECTIONS

U2 - 10.1051/0004-6361/202244376

DO - 10.1051/0004-6361/202244376

M3 - Journal article

VL - 666

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

M1 - A158

ER -