The Astrophysical Journal (Jan 2025)
Peering into the Heart of Darkness with VLBA: Radio-quiet Active Galactic Nucleus in the JWST North Ecliptic Pole Time-domain Field
- Payaswini Saikia,
- Ramon Wrzosek,
- Joseph Gelfand,
- Walter Brisken,
- William Cotton,
- S. P. Willner,
- Hansung B. Gim,
- Rogier A. Windhorst,
- Vicente Estrada-Carpenter,
- Ivan Yu. Katkov,
- Ingyin Zaw,
- Michael J. Nicandro Rosenthal,
- Hanaan Shafi,
- Kenneth Kellermann,
- James Condon,
- Anton M. Koekemoer,
- Christopher J. Conselice,
- Rafael Ortiz III,
- Christopher N. A. Willmer,
- Brenda Frye,
- Norman A. Grogin,
- Heidi B. Hammel,
- Seth H. Cohen,
- Rolf A. Jansen,
- Jake Summers,
- Jordan C. J. D’Silva,
- Simon P. Driver,
- Nor Pirzkal,
- Haojing Yan,
- Min S. Yun
Affiliations
- Payaswini Saikia
- ORCiD
- Center for Astrophysics and Space Science (CASS), New York University Abu Dhabi , PO Box 129188, Abu Dhabi, UAE ; [email protected]
- Ramon Wrzosek
- ORCiD
- Center for Astrophysics and Space Science (CASS), New York University Abu Dhabi , PO Box 129188, Abu Dhabi, UAE ; [email protected]
- Joseph Gelfand
- ORCiD
- Center for Astrophysics and Space Science (CASS), New York University Abu Dhabi , PO Box 129188, Abu Dhabi, UAE ; [email protected]
- Walter Brisken
- National Radio Astronomy Observatory , 520 Edgemont Road, Charlottesville, VA 22903, USA
- William Cotton
- ORCiD
- National Radio Astronomy Observatory , 520 Edgemont Road, Charlottesville, VA 22903, USA
- S. P. Willner
- ORCiD
- Center for Astrophysics , Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
- Hansung B. Gim
- ORCiD
- Department of Physics, Montana State University , P.O. Box 173840, Bozeman, MT 59717, USA
- Rogier A. Windhorst
- ORCiD
- School of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287-1404, USA
- Vicente Estrada-Carpenter
- ORCiD
- Institute for Computational Astrophysics and Department of Astronomy & Physics, Saint Mary’s University , 923 Robie Street, Halifax, Nova Scotia B3H 3C3, Canada
- Ivan Yu. Katkov
- ORCiD
- Center for Astrophysics and Space Science (CASS), New York University Abu Dhabi , PO Box 129188, Abu Dhabi, UAE ; [email protected]; Sternberg Astronomical Institute, M.V. Lomonosov Moscow State University , 13 Universitetsky prospect, Moscow, 119991, Russia
- Ingyin Zaw
- ORCiD
- Center for Astrophysics and Space Science (CASS), New York University Abu Dhabi , PO Box 129188, Abu Dhabi, UAE ; [email protected]
- Michael J. Nicandro Rosenthal
- ORCiD
- Department of Astronomy, University of Wisconsin-Madison , 475 North Charter Street, Madison, WI 53706, USA
- Hanaan Shafi
- ORCiD
- Center for Astrophysics and Space Science (CASS), New York University Abu Dhabi , PO Box 129188, Abu Dhabi, UAE ; [email protected]
- Kenneth Kellermann
- ORCiD
- National Radio Astronomy Observatory , 520 Edgemont Road, Charlottesville, VA 22903, USA
- James Condon
- ORCiD
- Unaffiliated , 2571 Old Lynchburg Road, North Garden, VA 22959, USA
- Anton M. Koekemoer
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Christopher J. Conselice
- ORCiD
- Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester , Oxford Road, Manchester M13 9PL, UK
- Rafael Ortiz III
- ORCiD
- School of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287-1404, USA
- Christopher N. A. Willmer
- ORCiD
- Steward Observatory, University of Arizona , 933 N Cherry Ave, Tucson, AZ, 85721-0009, USA
- Brenda Frye
- ORCiD
- Department of Astronomy/Steward Observatory, University of Arizona , 933 N Cherry Ave, Tucson, AZ, 85721-0009, USA
- Norman A. Grogin
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Heidi B. Hammel
- ORCiD
- Association of Universities for Research in Astronomy , 1331 Pennsylvania Ave NW, Suite 1475, Washington, DC 20005, USA
- Seth H. Cohen
- ORCiD
- School of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287-1404, USA
- Rolf A. Jansen
- ORCiD
- School of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287-1404, USA
- Jake Summers
- ORCiD
- School of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287-1404, USA
- Jordan C. J. D’Silva
- ORCiD
- International Centre for Radio Astronomy Research (ICRAR) and the International Space Centre (ISC), The University of Western Australia , M468, 35 Stirling Highway, Crawley, WA 6009, Australia; ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) , Australia
- Simon P. Driver
- ORCiD
- International Centre for Radio Astronomy Research (ICRAR) and the International Space Centre (ISC), The University of Western Australia , M468, 35 Stirling Highway, Crawley, WA 6009, Australia
- Nor Pirzkal
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Haojing Yan
- ORCiD
- Department of Physics and Astronomy, University of Missouri , Columbia, MO 65211, USA
- Min S. Yun
- ORCiD
- Department of Astronomy, University of Massachusetts , Amherst, MA 01003, USA
- DOI
- https://doi.org/10.3847/1538-4357/ade709
- Journal volume & issue
-
Vol. 989,
no. 1
p. 29
Abstract
We present initial results from the 4.8 GHz Very Long Baseline Array (VLBA) survey of the JWST North Ecliptic Pole Time-Domain Field (TDF). From 106 radio sources found in the Karl G. Jansky Very Large Array (VLA) observations in the TDF, we detected 12 sources (∼11% detection rate) at ∼3.3 μ Jy rms sensitivity and ∼4 mas resolution. Most detections exhibit parsec-scale emission (less than 40 pc) with high VLBA/VLA flux density ratios and brightness temperatures exceeding 10 ^5 K, confirming nonthermal active galactic nucleus (AGN) activity. Spectral indices α ≳ −0.5 correlate with higher VLBA/VLA flux ratios, consistent with synchrotron emission from AGN coronae or jets. In the majority of our sources, star formation contributes less than 50% of the total VLBA radio emission, with a few cases where the emission is almost entirely AGN driven. Although the radio emission from radio quiet AGN is thought to be primarily driven by star formation, our VLBA observations confirm that there is also often a contribution at various levels from black hole driven AGN. Eight VLBA detections have JWST/NIRCam counterparts, predominantly early-type, bulge-dominated galaxies, which we use to get an estimate of the redshift and star formation rate (SFR). Wide-field Infrared Survey Explorer colors indicate that VLBA detections are either AGN or intermediate-disk-dominated systems, while VLBA nondetections correspond to extended, star-forming galaxies. We compare SFRs derived from previous SCUBA-2 850 μ m observations with new JWST-based estimates, and discuss the observed discrepancies, highlighting JWST’s improved capability to disentangle AGN activity from star formation.
Keywords
