Detection Of Possible Glycine Precursor Molecule Methylamine Towards The Hot Molecular Core G358.93−0.03 MM1

The search for the simplest amino acid, glycine (NH₂CH₂COOH), in the interstellar medium (ISM), has become a never-ending story for astrochemistry and astrophysics researchers because that molecule plays a possible connection between the Universe and the origin of life.

In the last forty years, all searches for NH₂CH₂COOH in the ISM at millimeter and submillimeter wavelengths have failed. Since the detection of NH₂CH₂COOH in the ISM was extremely difficult, we aimed to search for the possible precursors of NH₂CH₂COOH. Earlier, many laboratory experiments have suggested that methylamine (CH₃NH₂) plays an important role in the ISM as a possible precursor of NH₂CH₂COOH.

After spectral analysis using the local thermodynamic equilibrium (LTE) model, we identified the rotational emission lines of CH₃NH₂ towards the hot molecular core G358.93−0.03 MM1 using the Atacama Large Millimeter/Submillimeter Array (ALMA). The column density of CH₃NH₂ towards the G358.93−0.03 MM1 was estimated to be (1.10±0.31)×1017 cm⁻² with an excitation temperature of 180.8±25.5 K. The fractional abundance of CH₃NH₂ with respect to H₂ towards the G358.93−0.03 MM1 was (8.80±2.60)×10⁻⁸. The column density ratio of CH₃NH₂ and NH₂CN towards G358.93−0.03 MM1 was (1.86±0.95)×10².

The estimated fractional abundance of CH₃NH₂ towards the G358.93−0.03 MM1 agrees fairly well with the previous three-phase warm-up chemical modelling abundance of CH₃NH₂. We also discussed the possible formation mechanism of CH₃NH₂, and we find that CH₃NH₂ is most probably formed via the reactions of radical CH₃ and radical NH₂ on the grain surface of G358.93−0.03 MM1.

Arijit Manna, Sabyasachi Pal

Comments: Published in New Astronomy
Subjects: Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2402.16798 [astro-ph.GA] (or arXiv:2402.16798v1 [astro-ph.GA] for this version)
https://doi.org/10.48550/arXiv.2402.16798
Focus to learn more
Journal reference: New Astron, 109, 102199, (2024)
Related DOI:
https://doi.org/10.1016/j.newast.2024.102199
Focus to learn more
Submission history
From: Arijit Manna
[v1] Mon, 26 Feb 2024 18:11:03 UTC (1,806 KB)
https://arxiv.org/abs/2402.16798
Astrobiology, Astrochemistry,