Abstract
Hydrogen deuteride (HD) is prevalent in a wide variety of astrophysical environments, and measuring its large-scale distribution at different epochs can, in principle, provide information about the properties of these environments. In this paper we explore the prospects for accessing this distribution using line-intensity mapping of emission from the lowest rotational transition in HD, focusing on observations of the epoch of reionization () and earlier. We find the signal from the epoch of reionization to be most promising, through cross correlations within existing [CII] intensity mapping surveys. While the signal we predict is out of reach for current-generation projects, planned future improvements should be able to detect reionization-era HD without any additional observations, and would help to constrain the properties of the star-forming galaxies thought to play a key role in reionization. We also investigate several avenues for measuring HD during “cosmic dawn” (), a period in which HD could provide one of the only complementary observables to 21 cm intensity maps. We conclude that existing and planned facilities are poorly matched to the specifications desirable for a significant detection, though such a measurement may be achievable with sustained future effort. Finally, we explain why HD intensity mapping of the intergalactic medium during the cosmic dark ages () appears to be out of reach of any conceivable experiment.
3 More- Received 13 May 2021
- Accepted 9 March 2022
DOI:https://doi.org/10.1103/PhysRevD.105.083009
© 2022 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Observing the Cosmic Dawn with Hydrogen Deuteride
Published 15 April 2022
Researchers have developed a new approach that could make it easier to watch the birth of the Universe’s first stars.
See more in Physics