Double-peaked Narrow Emission-line Galaxies in LAMOST Survey

TL;DR

This study systematically searches for galaxies with double-peaked narrow emission lines in LAMOST data, identifying candidates potentially related to galaxy mergers or dual active nuclei, and analyzes their origins using IFU data.

Contribution

It provides a large sample of double-peaked emission-line galaxies and demonstrates the use of IFU data to determine their kinematic origins.

Findings

Identified 325 candidate galaxies with double-peaked lines.

33 objects show signs of recent interactions or dual cores.

MaNGA data suggests rotation and disturbance as the origin for a key candidate.

Abstract

We outline a full-scale search for galaxies exhibiting double-peaked profiles of promi- nent narrow emission lines, motivated by the prospect of finding objects related to merging galaxies, and even dual active galactic nuclei candidates as by-product, from the Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) Data Re- lease 4. We assemble a large sample of 325 candidates with double-peaked or strong asymmetric narrow emission lines, with 33 objects therein appearing optically resolved dual-cored structures, close companions or signs of recent interaction on the Sloan Dig- ital Sky Survey images. A candidate from LAMOST (J074810.95+281349.2) is also stressed here based on the kinematic and spatial decompositions of the double-peaked narrow emission line target, with analysis from the cross-referenced Mapping Nearby Galaxies at the Apache Point Observatory (MaNGA) survey datacube. MaNGA en- ables us to constrain the origin of double peaks for these sources, and with the IFU data we infer that the most promising origin of double-peaked profiles for LAMOST J074810.95+281349.2 is the `Rotation Dominated + Disturbance' structure.