Mapping the Universe in HD

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 ($z\sim 6-10$) and earlier. We find the signal from the epoch of reionization to be strongest 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" ($z\sim 10-30$), a period in which HD could provide one of the only complementary observables to 21cm 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 ($z\gtrsim 30$) appears to be out of reach of any conceivable experiment.

19 pages, 9 figures

References in corpus (26)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Physical properties of molecular clouds for the entire Milky Way disk
• Primordial Star Formation under the Influence of Far Ultraviolet Radiation: 1540 Cosmological Halos and the Stellar Mass Distribution
• Uncertainties in H2 and HD Chemistry and Cooling and their Role in Early Structure Formation
• The First Galaxies: Assembly, Cooling and the Onset of Turbulence
• Early Cosmological HII/HeIII Regions and Their Impact on Second-Generation Star Formation
• Line-Intensity Mapping: 2017 Status Report
• An Improved Method for 21cm Foreground Removal
• The Impact of HD Cooling on the Formation of the First Stars
• An Intensity Mapping Detection of Aggregate CO Line Emission at 3 mm
• Spherical Harmonic Analyses of Intensity Mapping Power Spectra
• The role of HD cooling in primordial star formation
• Origins Space Telescope Mission Concept Study Report
• PICO: Probe of Inflation and Cosmic Origins
• Astrophysics and Cosmology with Line-Intensity Mapping
• Spitzer observations of hydrogen deuteride
• Wideband on-chip terahertz spectrometer based on a superconducting filterbank
• Cosmic rays and the primordial gas
• A New FUSE Survey of Interstellar HD
• Electric dipole rovibrational transitions in HD molecule
• Full-Array Noise Performance of Deployment-Grade SuperSpec mm-wave On-Chip Spectrometers
• Measuring the Primordial Deuterium Abundance During the Cosmic Dark Ages
• Astro 2020 Science White Paper: Fundamental Cosmology in the Dark Ages with 21-cm Line Fluctuations
• Conditions for HD Cooling in the First Galaxies Revisited: Interplay between Far-Ultraviolet and Cosmic Ray Feedback in Population III Star Formation
• CMB-HD: Astro2020 RFI Response
• Dark Cosmology: Investigating Dark Matter & Exotic Physics in the Dark Ages using the Redshifted 21-cm Global Spectrum

Cited by in corpus (5)

• Line-Intensity Mapping: Theory Review
• Forecasts and Statistical Insights for Line Intensity Mapping Cross-Correlations: A Case Study with 21cm x [CII]
• Synergizing 21 cm and sub-millimetre surveys during reionization: new empirical insights
• A statistical framework for recovering intensity mapping autocorrelations from crosscorrelations
• The Complex Magnetic Field of the Extreme Galactic Center: PRIMA Science Potential