PEARLS: Discovery of Point-Source Features Within Galaxies in the North Ecliptic Pole Time Domain Field
Abstract
The first public 0.9-4.4{\mu}m NIRCam images of the North Ecliptic Pole (NEP) Time Domain Field (TDF) uncovered galaxies displaying point-source features in their cores as seen in the longer wavelength filters. We visually identified a sample of 66 galaxies (~1 galaxy per arcmin2) with point-like cores and have modeled their two-dimensional light profiles with GalFit, identifying 16 galactic nuclei with measurable point-source components. GalFit suggests the visual sample is a mix of both compact stellar bulge and point-source galaxy cores. This core classification is complemented by spectral energy distribution (SED) modeling to infer the sample's active galactic nucleus (AGN) and host-galaxy parameters. For galaxies with measurable point-source components, the median fractional AGN contribution to their 0.1-30.0{\mu}m flux is 0.44, and 14/16 are color-classified AGN. We conclude that near-infrared point-source galaxy cores are signatures of AGN. In addition, we define an automated sample-selection criterion to identify these point-source features. These criteria can be used in other extant and future NIRCam images to streamline the search for galaxies with unresolved IR-luminous AGN. The James Webb Space Telescope's superb angular resolution and sensitivity at infrared wavelengths is resurrecting the morphological identification of AGN.
Cite
@article{arxiv.2404.10709,
title = {PEARLS: Discovery of Point-Source Features Within Galaxies in the North Ecliptic Pole Time Domain Field},
author = {Rafael Ortiz and Rogier A. Windhorst and Seth H. Cohen and S. P. Willner and Rolf A. Jansen and Timothy Carleton and Patrick S. Kamieneski and Michael J. Rutkowski and Brent Smith and Jake Summers and Tyler J. McCabe and Rosalia O'Brien and Jose M. Diego and Min S. Yun and Jordan C. J. D'Silva and Juno Li and Hansung B. Gim and Nimish P. Hathi and Benne W. Holwerda and Adi Zitrin and Cheng Cheng and Noah J. McLeod and Christopher J. Conselice and Simon P. Driver and Haojing Yan and Dan Coe and Brenda Frye and Norman Grogin and Anton Koekemoer and Madeline A. Marshall and Nor Pirzkal and Aaron Robotham and Russell E. Ryan, and Christopher N. A. Willmer and William Keel and H. B. Hammel and M. Hyun and M. Im and S. N. Milam},
journal= {arXiv preprint arXiv:2404.10709},
year = {2024}
}
Comments
17 pages, 9 figures, 2 tables