# Radio Emission From a $z =$ 10.3 Black Hole in UHZ1

**Authors:** Daniel J. Whalen, Muhammad A. Latif, Mar Mezcua  
**arXiv:** [2308.03837](https://arxiv.org/abs/2308.03837)  
**Date:** 2023-08-07  
**Summary page:** https://www.summarizepaper.com/en/paper/2308.03837v1/

## Key points

- Recent discovery of a 4 $\times$ 10$^7$ M$_{\odot}$ black hole in UHZ1 at $z =$ 10.3
- Suggests that the seeds of the first quasars may have been direct-collapse black holes (DCBHs) from the collapse of supermassive primordial stars at $z \sim$ 20
- Discovery made using data from James Webb Space Telescope (JWST) NIRcam and Chandra X-ray observations
- Estimates of radio flux for UHZ1 across a frequency range of 0.1 - 10 GHz presented by Daniel J. Whalen, Muhammad A. Latif, and Mar Mezcua
- Square Kilometer Array (SKA) and next-generation Very Large Array (ngVLA) have potential to detect radio emission from this black hole with integration times of 10 - 100 hours and just 1 - 10 hours respectively
- Possibility to observe this object with VLA currently by increasing integration times
- Detection of radio emission would confirm its nature as a black hole and test new synergies between near-infrared (NIR) and radio observatories
- Discovery could open up opportunities for studying quasars in the redshift range of $z \sim$ 5 - 15 in the coming decade
- Importance of multi-wavelength observations in understanding early cosmic structures and formation mechanisms of supermassive black holes in the early universe

## Summary

The recent discovery of a 4 $\times$ 10$^7$ M$_{\odot}$ black hole (BH) in UHZ1 at $z =$ 10.3, just 450 Myr after the big bang, suggests that the seeds of the first quasars may have been direct-collapse black holes (DCBHs) from the collapse of supermassive primordial stars at $z \sim$ 20. This finding was made using data from the James Webb Space Telescope (JWST) NIRcam and Chandra X-ray observations. Daniel J. Whalen, Muhammad A. Latif, and Mar Mezcua present estimates of radio flux for UHZ1 across a frequency range of 0.1 - 10 GHz and find that both Square Kilometer Array (SKA) and next-generation Very Large Array (ngVLA) have the potential to detect radio emission from this black hole with integration times of 10 - 100 hours and just 1 - 10 hours respectively. The authors suggest that it may even be possible to observe this object with VLA currently by increasing integration times. The detection of radio emission from UHZ1 would not only confirm its nature as a black hole but also serve as an exciting test for new synergies between near-infrared (NIR) and radio observatories. This discovery could open up opportunities for studying quasars in the redshift range of $z \sim$ 5 - 15 in the coming decade. Overall, this study highlights the importance of multi-wavelength observations in understanding early cosmic structures and provides valuable insights into the formation mechanisms of supermassive black holes in the early universe.