# An unbiased spectral line survey observation toward the low-mass star-forming region L1527

## TL;DR

This paper presents an extensive spectral line survey of the low-mass star-forming region L1527, revealing the chemical composition and abundance of various molecules, especially carbon-chain species, near a protostar.

## Contribution

It provides the first comprehensive spectral line survey of L1527 in the 3 mm band, identifying 69 molecular species and offering insights into WCCC chemistry.

## Key findings

- Identified 69 molecular species, including 27 carbon-chain species.
- Detected abundant unsaturated organic molecules near the protostar.
- Established a detailed chemical template for WCCC sources.

## Abstract

An unbiased spectral line survey toward a solar-type Class 0/I protostar, IRAS04368+2557, in L1527 has been carried out in the 3 mm band with the Nobeyama 45 m telescope. L1527 is known as a warm carbon-chain chemistry (WCCC) source, which harbors abundant unsaturated organic species such as C$_n$H ($n = 3,\ 4,\ 5,\ldots$) in a warm and dense region near the protostar. The observation covers the frequency range from 80 to 116 GHz. A supplementary observation has also been conducted in the 70 GHz band to observe fundamental transitions of deuterated species. In total, 69 molecular species are identified, among which 27 species are carbon-chain species and their isomers, including their minor isotopologues. This spectral line survey provides us with a good template of the chemical composition of the WCCC source.