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

Clark, Peter [Southampton U.; Portsmouth U., ICG] (ORCID:0000000265767400)·Callow, Joseph [Portsmouth U., ICG] (ORCID:0000000208049533)·Graur, Or [Portsmouth U., ICG; New York U.; Amer. Museum Natural Hist.] (ORCID:0000000243916137)·Filippenko, Alexei V. [UC, Berkeley, Astron. Dept.] (ORCID:0000000334600103)·Brink, Thomas G. [UC, Berkeley, Astron. Dept.] (ORCID:0000000159552502)·Zheng, WeiKang [UC, Berkeley, Astron. Dept.] (ORCID:0000000226366508)·Aguilar, Jessica [LBL, Berkeley] (ORCID:000000030822452X)·Ahlen, Steven [Boston U.] (ORCID:0000000160987247)·BenZvi, Segev [Rochester U.] (ORCID:0000000155374710)·Bianchi, Davide [Milan U.; Brera Observ.] (ORCID:0000000197120006)·Brooks, David [University Coll. London] (ORCID:0000000284585047)·Claybaugh, Todd [LBL, Berkeley] (ORCID:0000000250246987)·Cuceu, Andrei [LBL, Berkeley] (ORCID:0000000221690595)·de la Macorra, Axel [UNAM, Mexico] (ORCID:0000000217691640)·Dey, Arjun [Natl. Solar Observ., Tucson] (ORCID:0000000249284003)·Doel, Peter [University Coll. London] (ORCID:0000000263974457)·Fawcett, Victoria A. [European Southern Observ.] (ORCID:000000031251532X)·Forero-Romero, Jaime E. [Andes U., Bogota] (ORCID:0000000228903725)·Gaztañaga, Enrique [Barcelona, IEEC; Portsmouth U., ICG; ICE, Bellaterra] (ORCID:0000000196320815)·Gontcho A. Gontcho, Satya [LBL, Berkeley; Virginia U.] (ORCID:000000033142233X)·Gutierrez, Gaston [Fermilab] (ORCID:0000000308250517)·Ishak, Mustapha [U. Texas, Dallas] (ORCID:000000026024466X)·Jimenez, Jorge [Barcelona, IFAE] (ORCID:0000000185283473)·Joyce, Dick [Natl. Solar Observ., Tucson] (ORCID:0000000302015241)·Juneau, Stephanie [Natl. Solar Observ., Tucson] (ORCID:0000000200002394)·Kisner, Theodore [LBL, Berkeley] (ORCID:0000000335107134)·Kremin, Anthony [LBL, Berkeley] (ORCID:0000000163567424)·Landriau, Martin [LBL, Berkeley] (ORCID:0000000318388528)·Le Guillou, Laurent [LPNHE, Paris] (ORCID:0000000171788868)·Manera, Marc [Barcelona, IFAE; Barcelona, Autonoma U.] (ORCID:0000000349628934)·Meisner, Aaron [Natl. Solar Observ., Tucson] (ORCID:0000000211257384)·Miquel, Ramon [ICREA, Barcelona; Barcelona, IFAE] (ORCID:0000000266104836)·Moustakas, John [Siena Coll., Loudonville] (ORCID:0000000227334559)·Nadathur, Seshadri [Portsmouth U., ICG] (ORCID:0000000190703102)·Percival, Will J. [Waterloo U.; Perimeter Inst. Theor. Phys.] (ORCID:0000000206445727)·Pérez-Ràfols, Ignasi [Barcelona, Polytechnic U.] (ORCID:0000000169790125)·Prada, Francisco [Granada U., Theor. Phys. Astrophys.] (ORCID:0000000171458674)·Rossi, Graziano [Sejong U.]·Sanchez, Eusebio [Madrid, CIEMAT] (ORCID:0000000296468198)·Schlegel, David [LBL, Berkeley] (ORCID:0000000250425088)·Schubnell, Michael [Michigan U.; KEK, Tsukuba; Hiroshima Shudo U.] (ORCID:0000000195042059)·Silber, Joseph Harry [LBL, Berkeley] (ORCID:0000000234610320)·Sprayberry, David [Natl. Solar Observ., Tucson]·Tarlé, Gregory [Michigan U.; KEK, Tsukuba; Hiroshima Shudo U.] (ORCID:0000000317040781)·Weaver, Benjamin A. [Natl. Solar Observ., Tucson]·Zhou, Rongpu [LBL, Berkeley] (ORCID:0000000153814372)·Zou, Hu [Unlisted] (ORCID:0000000266843997)
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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 RG=5 −3+5×10−6 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.

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BibTeXRIS

Clark, Peter [Southampton U.; Portsmouth U., ICG] (ORCID:0000000265767400), Callow, Joseph [Portsmouth U., ICG] (ORCID:0000000208049533), Graur, Or [Portsmouth U., ICG; New York U.; Amer. Museum Natural Hist.] (ORCID:0000000243916137), Filippenko, Alexei V. [UC, Berkeley, Astron. Dept.] (ORCID:0000000334600103), Brink, Thomas G. [UC, Berkeley, Astron. Dept.] (ORCID:0000000159552502), Zheng, WeiKang [UC, Berkeley, Astron. Dept.] (ORCID:0000000226366508), Aguilar, Jessica [LBL, Berkeley] (ORCID:000000030822452X), Ahlen, Steven [Boston U.] (ORCID:0000000160987247), BenZvi, Segev [Rochester U.] (ORCID:0000000155374710), Bianchi, Davide [Milan U.; Brera Observ.] (ORCID:0000000197120006), Brooks, David [University Coll. London] (ORCID:0000000284585047), Claybaugh, Todd [LBL, Berkeley] (ORCID:0000000250246987), Cuceu, Andrei [LBL, Berkeley] (ORCID:0000000221690595), de la Macorra, Axel [UNAM, Mexico] (ORCID:0000000217691640), Dey, Arjun [Natl. Solar Observ., Tucson] (ORCID:0000000249284003), Doel, Peter [University Coll. London] (ORCID:0000000263974457), Fawcett, Victoria A. [European Southern Observ.] (ORCID:000000031251532X), Forero-Romero, Jaime E. [Andes U., Bogota] (ORCID:0000000228903725), Gaztañaga, Enrique [Barcelona, IEEC; Portsmouth U., ICG; ICE, Bellaterra] (ORCID:0000000196320815), Gontcho A. Gontcho, Satya [LBL, Berkeley; Virginia U.] (ORCID:000000033142233X), Gutierrez, Gaston [Fermilab] (ORCID:0000000308250517), Ishak, Mustapha [U. Texas, Dallas] (ORCID:000000026024466X), Jimenez, Jorge [Barcelona, IFAE] (ORCID:0000000185283473), Joyce, Dick [Natl. Solar Observ., Tucson] (ORCID:0000000302015241), Juneau, Stephanie [Natl. Solar Observ., Tucson] (ORCID:0000000200002394), Kisner, Theodore [LBL, Berkeley] (ORCID:0000000335107134), Kremin, Anthony [LBL, Berkeley] (ORCID:0000000163567424), Landriau, Martin [LBL, Berkeley] (ORCID:0000000318388528), Le Guillou, Laurent [LPNHE, Paris] (ORCID:0000000171788868), Manera, Marc [Barcelona, IFAE; Barcelona, Autonoma U.] (ORCID:0000000349628934), Meisner, Aaron [Natl. Solar Observ., Tucson] (ORCID:0000000211257384), Miquel, Ramon [ICREA, Barcelona; Barcelona, IFAE] (ORCID:0000000266104836), Moustakas, John [Siena Coll., Loudonville] (ORCID:0000000227334559), Nadathur, Seshadri [Portsmouth U., ICG] (ORCID:0000000190703102), Percival, Will J. [Waterloo U.; Perimeter Inst. Theor. Phys.] (ORCID:0000000206445727), Pérez-Ràfols, Ignasi [Barcelona, Polytechnic U.] (ORCID:0000000169790125), Prada, Francisco [Granada U., Theor. Phys. Astrophys.] (ORCID:0000000171458674), Rossi, Graziano [Sejong U.], Sanchez, Eusebio [Madrid, CIEMAT] (ORCID:0000000296468198), Schlegel, David [LBL, Berkeley] (ORCID:0000000250425088), Schubnell, Michael [Michigan U.; KEK, Tsukuba; Hiroshima Shudo U.] (ORCID:0000000195042059), Silber, Joseph Harry [LBL, Berkeley] (ORCID:0000000234610320), Sprayberry, David [Natl. Solar Observ., Tucson], Tarlé, Gregory [Michigan U.; KEK, Tsukuba; Hiroshima Shudo U.] (ORCID:0000000317040781), Weaver, Benjamin A. [Natl. Solar Observ., Tucson], Zhou, Rongpu [LBL, Berkeley] (ORCID:0000000153814372), Zou, Hu [Unlisted] (ORCID:0000000266843997). 2026-05-09. Early results in the search for extreme coronal line emitters with the Dark Energy Spectroscopic Instrument. https://doi.org/10.1093/mnras/stag887

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