CLEAR: High-ionization [Ne v] λ3426 Emission-line Galaxies at 1.4 < z < 2.3

Nikko J. Cleri; Guang Yang; Casey Papovich; Jonathan R. Trump; Bren E. Backhaus; Vicente Estrada-Carpenter; Steven L. Finkelstein; Mauro Giavalisco; Taylor A. Hutchison; Zhiyuan Ji; Intae Jung; Jasleen Matharu; Ivelina Momcheva; Grace M. Olivier; Raymond Simons; Benjamin Weiner

doi:10.3847/1538-4357/acc1e6

The Astrophysical Journal (Jan 2023)

CLEAR: High-ionization [Ne v] λ3426 Emission-line Galaxies at 1.4 < z < 2.3

Nikko J. Cleri,
Guang Yang,
Casey Papovich,
Jonathan R. Trump,
Bren E. Backhaus,
Vicente Estrada-Carpenter,
Steven L. Finkelstein,
Mauro Giavalisco,
Taylor A. Hutchison,
Zhiyuan Ji,
Intae Jung,
Jasleen Matharu,
Ivelina Momcheva,
Grace M. Olivier,
Raymond Simons,
Benjamin Weiner

Affiliations

Nikko J. Cleri: ORCiD; Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA; Department of Physics, University of Connecticut , Storrs, CT 06269, USA
Guang Yang: ORCiD; Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA; Kapteyn Astronomical Institute, University of Groningen , P.O. Box 800, 9700 AV Groningen, The Netherlands; SRON Netherlands Institute for Space Research , Postbus 800, 9700 AV Groningen, The Netherlands
Casey Papovich: ORCiD; Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA
Jonathan R. Trump: ORCiD; Department of Physics, University of Connecticut , Storrs, CT 06269, USA
Bren E. Backhaus: ORCiD; Department of Physics, University of Connecticut , Storrs, CT 06269, USA
Vicente Estrada-Carpenter: ORCiD; Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA; Department of Astronomy & Physics, Saint Mary’s University , 923 Robie Street, Halifax, NS B3H 3C3, Canada
Steven L. Finkelstein: ORCiD; Department of Astronomy, The University of Texas , Austin, TX 78712 USA
Mauro Giavalisco: ORCiD; Department of Astronomy, University of Massachusetts Amherst , 710 N. Pleasant Street, Amherst, MA 01003, USA
Taylor A. Hutchison: ORCiD; Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA; Astrophysics Science Division, NASA Goddard Space Flight Center , 8800 Greenbelt Road, Greenbelt, MD 20771, USA
Zhiyuan Ji: ORCiD; Department of Astronomy, University of Massachusetts Amherst , 710 N. Pleasant Street, Amherst, MA 01003, USA
Intae Jung: ORCiD; Department of Physics, The Catholic University of America , Washington, DC 20064, USA; Astrophysics Science Division, Goddard Space Flight Center , Greenbelt, MD 20771, USA; Center for Research and Exploration in Space Science and Technology , NASA/GSFC, Greenbelt, MD 20771, USA
Jasleen Matharu: ORCiD; Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA; Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen , Rådmandsgade 62, DK-2200 Copenhagen, Denmark
Ivelina Momcheva: ORCiD; Max-Planck-Institut für Astronomie , Königstuhl 17, D-69117 Heidelberg, Germany; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD, 21218 USA
Grace M. Olivier: ORCiD; Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA ; [email protected]; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA
Raymond Simons: ORCiD; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD, 21218 USA
Benjamin Weiner: ORCiD; MMT/Steward Observatory, 933 N. Cherry Street, University of Arizona , Tucson, AZ 85721, USA

DOI: https://doi.org/10.3847/1538-4357/acc1e6
Journal volume & issue: Vol. 948, no. 2
p. 112

Abstract

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We analyze a sample of 25 [Ne v ] ( λ 3426) emission-line galaxies at 1.4 < z < 2.3 using Hubble Space Telescope/Wide Field Camera 3 G102 and G141 grism observations from the CANDELS Ly α Emission at Reionization (CLEAR) survey. [Ne v ] emission probes extremely energetic photoionization (creation potential of 97.11 eV) and is often attributed to energetic radiation from active galactic nuclei (AGNs), shocks from supernovae, or an otherwise very hard ionizing spectrum from the stellar continuum. In this work, we use [Ne v ] in conjunction with other rest-frame UV/optical emission lines ([O ii ] λ λ 3726, 3729, [Ne iii ] λ 3869, H β , [O iii ] λ λ 4959, 5007, H α +[N ii ] λ λ 6548, 6583, [S ii ] λ λ 6716, 6731), deep (2–7 Ms) X-ray observations (from Chandra), and mid-infrared imaging (from Spitzer) to study the origin of this emission and to place constraints on the nature of the ionizing engine. The majority of the [Ne v ]-detected galaxies have properties consistent with ionization from AGNs. However, for our [Ne v ]-selected sample, the X-ray luminosities are consistent with local ( z ≲ 0.1) X-ray-selected Seyferts, but the [Ne v ] luminosities are more consistent with those from z ∼ 1 X-ray-selected QSOs. The excess [Ne v ] emission requires either reduced hard X-rays or a ∼0.1 keV excess. We discuss possible origins of the apparent [Ne v ] excess, which could be related to the “soft (X-ray) excess” observed in some QSOs and Seyferts and/or be a consequence of a complex/anisotropic geometry for the narrow-line region, combined with absorption from a warm, relativistic wind ejected from the accretion disk. We also consider implications for future studies of extreme high-ionization systems in the epoch of reionization ( z ≳ 6) with the James Webb Space Telescope.

Published in The Astrophysical Journal

ISSN: 1538-4357 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/0004-637X

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