A Search for Double-peaked narrow emission line Galaxies and AGNs in the LAMOST DR1

TL;DR

This paper reports the discovery of 20 double-peaked narrow emission line galaxies and AGNs in LAMOST DR1, highlighting potential origins and emphasizing the need for follow-up observations to understand their physical mechanisms.

Contribution

It introduces a new search method using multi-Gaussian fitting to identify double-peaked NEL galaxies and AGNs in LAMOST DR1, including 10 new discoveries.

Findings

20 double-peaked NEL galaxies and AGNs identified

10 are newly discovered, 10 previously published

Possible origins include jet interactions, galaxy interactions, and black hole binaries

Abstract

LAMOST has released more than two million spectra, which provide the opportunity to search for double-peaked narrow emission line (NEL) galaxies and AGNs. The double-peaked narrow-line profiles can be well modeled by two velocity components, respectively blueshifted and redshifted with respect to the systemic recession velocity. This paper presents 20 double-peaked NEL galaxies and AGNs found from LAMOST DR1 using a search method based on multi-gaussian fit of the narrow emission lines. Among them, 10 have already been published by other authors, either listed as genuine double-peaked NEL objects or as asymmetric NEL objects, the remaining 10 being first discoveries. We discuss some possible origins for double-peaked narrow-line features, as interaction between jet and narrow line regions, interaction with companion galaxies and black hole binaries. Spatially resolved optical imaging and/or follow-up observations in other spectral bands are needed to further discuss the physical mechanisms at work.