Early results in the search for extreme coronal line emitters with the Dark Energy Spectroscopic Instrument

2026/01/31 by Peter Clark, Joseph Callow, Or Graur +44 · 1 voice
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae

paper · doi:10.1093/mnras/stag887

openalex publication_date 2026/05/08 · openalex created_date 2026/05/10 · openalex updated_date 2026/07/29

Abstract

ABSTRACT Here, we present the results of our search through the early data release (EDR) of the Dark Energy Spectroscopic Instrument (DESI) for extreme coronal line emitters (ECLEs) – a rare classification of galaxies displaying strong, high-ionization iron coronal emission lines within their spectra. With the requirement of a strong X-ray continuum to generate the coronal emission, ECLEs have been linked to both active galactic nuclei (AGNs) and tidal disruption events (TDEs). We focus our search on identifying TDE-linked ECLEs. We identify three such objects within the EDR sample, highlighting DESI’s effectiveness for discovering new nuclear transients, and determine a galaxy-normalized TDE-linked ECLE rate of R_G=5~⁺⁵_-3× 10^-6~galaxy^-1~yr^-1 at a median redshift of z = 0.2 – broadly consistent with previous work. Additionally, we identify more than 200 AGNs displaying coronal emission lines, which serve as the primary astrophysical contaminants in searches for TDE-related events. We also include an outline of the custom python code developed for this search.

Citations

• Classification parameters for the emission-line spectra of extragalactic objects
• THE WIDE-FIELD INFRARED SURVEY EXPLORER (WISE): MISSION DESCRIPTION AND INITIAL ON-ORBIT PERFORMANCE
• The Two Micron All Sky Survey (2MASS)
• Galactic Stellar and Substellar Initial Mass Function
• Correcting for the Effects of Interstellar Extinction
• Sifting for Sapphires: Systematic Selection of Tidal Disruption Events in iPTF
• Overview of the DESI Legacy Imaging Surveys
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• The Karl G. Jansky Very Large Array Sky Survey (VLASS). Science case and survey design
• The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar, and APOGEE-2 Data
• The Spectroscopic Data Processing Pipeline for the Dark Energy Spectroscopic Instrument
• DESI 2024 VI: cosmological constraints from the measurements of baryon acoustic oscillations
• DESI 2024 VII: cosmological constraints from the full-shape modeling of clustering measurements
• Nine tidal disruption event candidates in eROSITA-DE DR1 discovered through supersoft X-ray selection
• RX J1420.4+5334 - another tidal disruption event?
• ASTRA-DESI DR1 Release v0.12

Discussions

• New paper thread! You can read it on MNRAS here: doi.org/10.1093/mnra... or on arXiv if you prefer: arxiv.org/abs/2601.20964 This is a 'quite' a long paper, so I'll give you the highlights here 😎 [bsky, 2 points, 1 comments]

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