Neon and [CII] 158 micron Emission Line Profiles in Dusty Starbursts and Active Galactic Nuclei

TL;DR

This study analyzes the emission line profiles of [NeII], [NeIII], and [CII] in 379 extragalactic sources, revealing that line widths are generally consistent across classifications, with some variations in [NeIII].

Contribution

It provides a comprehensive dataset of high-resolution mid-infrared and far-infrared emission line profiles for a large sample of dusty starbursts and AGN, including intrinsic line widths and classifications.

Findings

[CII] line widths do not vary significantly across classifications.

[NeIII] lines are broader in AGN compared to starbursts.

Identified objects with unusually broad lines or redshift differences.

Abstract

The sample of 379 extragalactic sources is presented that have mid-infrared, high resolution spectroscopy with the Spitzer Infrared Spectrograph (IRS) and also spectroscopy of the [CII] 158 um line with the Herschel Photodetector Array Camera and Spectrometer (PACS). The emission line profiles of [NeII] 12.81 um, [NeIII] 15.55 um, and [CII] 158 um are presented, and intrinsic line widths are determined (full width half maximum of Gaussian profiles after instrumental correction). All line profiles together with overlays comparing positions of PACS and IRS observations are made available in the Cornell Atlas of Spitzer IRS Sources (CASSIS). Sources are classified from AGN to starburst based on equivalent widths of the 6.2 um polycyclic aromatic hydrocarbon feature. It is found that intrinsic line widths do not change among classification for [CII], with median widths of 207 km per s for AGN, 248 km per s for composites, and 233 km per s for starbursts. The [NeII] line widths also do not change with classification, but [NeIII] lines are progressively broader from starburst to AGN. A small number of objects with unusually broad lines or unusual redshift differences in any feature are identified.