Searching for Low-mass Stellar and Sub-stellar objects in the JWST North Ecliptic Pole Time-Domain Field
Abstract
The James Webb Space Telescope (JWST) North Ecliptic Pole (NEP) Time-Domain Field (TDF) is a 14' diameter region of the sky selected to be ideal for ultra-deep (mAB 29 mag) time-domain science with JWST (Jansen & Windhorst 2018), that is being developed as a community field. Located within JWST's northern Continuous Viewing Zone, it can be observed year-round, is devoid of detector saturating stars, has low Galactic foreground extinction, and will be targeted by GTO program 1176 (Windhorst) with NIRCam and NIRISS. It is the only region in the sky where JWST can observe a clean extragalactic deep survey field of this size at arbitrary cadence and orientation, enabling a wide range of new and exciting time-domain science, including high redshift transient searches and monitoring (e.g., SNe), variability studies from Active Galactic Nuclei (AGN) to brown dwarf atmospheres, as well as proper motions of extreme scattered Kuiper Belt Objects and comets beyond the distance of Neptune, and of nearby Galactic brown dwarfs, low-mass stars, and ultracool white dwarfs. In anticipation of JWST's launch in 2021, a wealth of ancillary data across the electromagnetic spectrum (X-ray-radio) has already been collected. This includes deep ( 0.9 muJy rms) VLA 3GHz radio observations (B+A configuration) and LBT/LBC Ugrz (mAB 26 mag) and MMT/MMIRS YJHKs (mAB 24.5-22 mag) photometry of the entire JWST NEP TDF, as well as HST/WFC3+ACS UV-Visible observations of the central r< 5'. Since a major science driver for this field is the study of AGN activity, and since Galactic late-type stars and brown dwarfs are often identified within samples of AGN candidates, we here report on an analysis of the 3GHz radio and LBT/LBC and MMT/MMIRS visible-near-IR observations to search for such late-type stellar and substellar sources. We also aim to study their properties, with particular emphasis on the possible detection of faint radio-emission (coronal, auroral, flares) of either individual objects or (through stacking) of the populations. We furthermore report on the progress of HST-GO-15278, the final two visits of which executed flawlessly, and preliminary analysis thereof.
- Publication:
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American Astronomical Society Meeting Abstracts #234
- Pub Date:
- June 2019
- Bibcode:
- 2019AAS...23420810T