The Luminosity Function of Ultra-Faint Trans-Neptunian Objects Detected by JWST

Abstract

We present a definitive discovery of 27 trans-Neptunian objects (TNOs) using the Near-Infrared Camera (NIRCam) aboard the James Webb Space Telescope (JWST). By employing a shift-and-stack technique and a machine learning network geared specifically to identifying false-positive detections in JWST images produced through the shift-and-stack process, we achieved a 40\% detection threshold of $m_{F150W2}=28.8$ mag (corresponding to $m_r\sim 29.8$ mag) across a sky area of $0.05{\text{deg}}^2$. This marks the deepest Solar System survey to date, reaching magnitudes that allow us to explore never-before-seen regions of the TNO size distribution. Our faintest detection has $m_{F150W2}=29.3$ mag and diameter of $\sim 10$ km (assuming 15\% albedo). Within our sample, we find that both the Cold and Hot TNO subpopulations exhibit a power-law slope. The distribution of apparent magnitudes of our nominal sample (detections at all epochs) are well fit by a single power law $dN/dm\propto 10^{\alpha m}$ with $\alpha =0.29_{-0.07}^{+0.08}$. The dynamically hot and cold subsamples in our discovery set are consistent with the same power law, suggesting that the planetesimal formation process yields similar slopes despite the differing disk conditions at the presumed $\sim 25$ and $\sim 45$~au formation regions of the two populations.

21 Figures, 7 tables. Accepted for publication at the Astronomical Journal. Redline edited version available at the DOI

References in corpus (16)

• Initial mass function of planetesimals formed by the streaming instability
• The albedo-color diversity of transneptunian objects
• The Size Distribution of Kuiper belt objects for D> 10 km
• The Kuiper Belt Luminosity Function from m(R)=21 to 26
• The Correlated Colors of Transneptunian Binaries
• OSSOS XX: The Meaning of Kuiper Belt Colors
• The Mutual Orbit, Mass, and Density of the Large Transneptunian Binary System Varda and Ilmarë
• Trans-Neptunian binaries (2018)
• Predictions of the LSST Solar System Yield: Near-Earth Objects, Main Belt Asteroids, Jupiter Trojans, and Trans-Neptunian Objects
• Fast algorithms for slow moving asteroids: constraints on the distribution of Kuiper Belt Objects
• Lightcurves and Rotational Properties of the Pristine Cold Classical Kuiper Belt Objects
• A Derivation of the Luminosity Function of the Kuiper Belt from a Broken Power-Law Size Distribution
• The hot main Kuiper belt size distribution from OSSOS
• Free Inclinations for Transneptunian Objects in the Main Kuiper Belt
• HST Images Reveal Dramatic Changes in the Core of IRC+10216
• Combined JWST and HST Deep Imaging to Characterize the Smallest Known Trans-Neptunian Objects

Cited by in corpus (1)

• Combined JWST and HST Deep Imaging to Characterize the Smallest Known Trans-Neptunian Objects