Now, a joint research study group from Northeastern University (China) and the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) has proposed using an unique probe to attempt to clarify the nature of dark matter and the early development of galaxies simultaneously.
The teams study was published in the journal Nature Astronomy on July 6.
The simulated 1-D power spectra of the 21-cm forest. Credit: Shao et al
. One way of understanding dark matter is to attempt to measure the mass of dark matter particles through cosmological observations of small structures. Discovering small-scale structures in which no star formation has ever occurred is hard, especially during the cosmic dawn. Atomic hydrogen gas in and around these dark, small structures from cosmic dawn creates 21-cm absorption lines along the lines of sight in between Earth and high-redshift radio point sources. These absorption lines are known collectively as the 21-cm forest.
The 21-cm forest probe is a theoretical concept proposed more than 20 years to probe for gas temperature levels and potentially for dark matter homes during the cosmic dawn. Up until now, researchers have actually not attempted to in fact use the probe due to various difficulties, consisting of extremely weak signals, the problem in recognizing high-redshift background sources, and the degeneracy between the mass of dark matter particles and the heating effect, which would avoid the probe from constraining either the particle mass or the heating impact from the very first galaxies.
Recently, though, a number of high-redshift radio-loud quasars have actually been discovered. In addition, building and construction on the Square Kilometre Array (SKA)– a worldwide effort to construct the worlds largest radio telescope– started last December. Both these developments recommend that using the 21-cm forest probe will quickly be possible.
Inspired by power spectrum analyses commonly used in cosmological probes, the NAOC researchers understood that the distinctive scale-dependences of the signals caused by the warm dark matter impact and the heating effect, respectively, might be used to statistically extract crucial functions to identify the 2 results.
In this research study, the researchers proposed a novel statistical solution to all at once solve the weak signal problem and the degeneracy problem, by measuring the one-dimensional (1-D) power spectrum of the 21-cm forest. The signal scale-dependence revealed by the amplitude and shape of the 1-D power spectrum makes the 21-cm forest probe a feasible and effective ways of concurrently measuring dark matter residential or commercial properties and the thermal history of the Universe.
” By measuring the one-dimensional power spectrum of the 21-cm forest, we can not only make the probe really feasible by increasing the sensitivity, but also provide a method to distinguish the impacts of warm dark matter designs and early heating procedure,” stated XU Yidong, matching author of the research study. ” We will have the ability to kill 2 birds with one stone!”
In circumstances where cosmic heating is not too extreme, SKA Phase 1s low-frequency range will can effectively constraining both dark matter particle mass and gas temperature. In cases where cosmic heating is more significant, utilizing multiple background radio sources throughout SKA Phase 2 will allow robust detection abilities.
The 21-cm forest provides a feasible ways for constraining dark matter at redshift ranges beyond the reach of other observations. By measuring the heating level, the 21-cm forest offers a way to constrain the spectral homes of the very first galaxies and the first black holes, so regarding shed light on the nature of the first intense things in the Universe. Using the 21-cm forest probe will serve as an indispensable opportunity for advancing our understanding of the early Universe and peering into the secrets of both dark matter and the first galaxies.
Because application of the 21-cm forest probe is carefully tied to observations of high-redshift background radio sources, the next step will likewise include determining more radio-bright sources at the cosmic dawn (such as radio-loud quasars and gamma-ray burst afterglows) that can be followed up in the SKA age.
Reference: “The 21-cm forest as a simultaneous probe of dark matter and cosmic heating history” by Yue Shao, Yidong Xu, Yougang Wang, Wenxiu Yang, Ran Li, Xin Zhang and Xuelei Chen, 6 July 2023, Nature Astronomy.DOI: 10.1038/ s41550-023-02024-7.
Exploring dark matter and the very first galaxies simultaneously with the 21-cm forest. This method can help constrain dark matter properties and offer insights into the thermal history of deep space. Credit: NAOC & & NEU
Exploring dark matter and the very first bright galaxies all at once: 21-cm forest probe may open secrets of early universe.
A joint research team has actually proposed an unique way to study dark matter and the formation of early galaxies using the 21-cm forest probe, a concept previously deemed theoretical. The ongoing Square Kilometre Array task and the current discovery of high-redshift radio-loud quasars have made this method practical. This brand-new approach could unlock insights into deep spaces thermal history and dark matter properties.
The mystery of the very first galaxies of deep space is an indomitable urge of human beings. The development of them is mastered by the nature of dark matter which is also among the most essential issues dealt with by fundamental physics. Understanding the nature of dark matter– for example, whether it is cold or warm– and its subsequent result on the very first galaxy formation is a big obstacle.
Exploring dark matter and the very first galaxies all at once with the 21-cm forest. A joint research team has actually proposed an unique way to study dark matter and the formation of early galaxies using the 21-cm forest probe, a principle previously considered theoretical. One way of comprehending dark matter is to attempt to determine the mass of dark matter particles through cosmological observations of small structures. The 21-cm forest provides a feasible ways for constraining dark matter at redshift varies beyond the reach of other observations. Utilizing the 21-cm forest probe will serve as an indispensable avenue for advancing our understanding of the early Universe and peering into the secrets of both dark matter and the very first galaxies.
