학술논문
PEARLS: Discovery of Point-Source Features Within Galaxies in the North Ecliptic Pole Time Domain Field
Document Type
Working Paper
Author
Ortiz III, Rafael; Windhorst, Rogier A.; Cohen, Seth H.; Willner, S. P.; Jansen, Rolf A.; Carleton, Timothy; Kamieneski, Patrick S.; Rutkowski, Michael J.; Smith, Brent; Summers, Jake; McCabe, Tyler J.; O'Brien, Rosalia; Diego, Jose M.; Yun, Min S.; D'Silva, Jordan C. J.; Li, Juno; Gim, Hansung B.; Hathi, Nimish P.; Holwerda, Benne W.; Zitrin, Adi; Cheng, Cheng; McLeod, Noah J.; Conselice, Christopher J.; Driver, Simon P.; Yan, Haojing; Coe, Dan; Frye, Brenda; Grogin, Norman; Koekemoer, Anton; Marshall, Madeline A.; Pirzkal, Nor; Robotham, Aaron; Ryan, Jr., Russell E.; Willmer, Christopher N. A.; Keel, William; Hammel, H. B.; Hyun, M.; Im, M.; Milam, S. N.
Source
Subject
Language
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.
Comment: 17 pages, 9 figures, 2 tables
Comment: 17 pages, 9 figures, 2 tables