Filament hunting: integrated H I 21 cm emission from filaments inferred by galaxy surveys

Robin Kooistra, Marta B. Silva, Saleem Zaroubi

OnderzoeksoutputAcademicpeer review

6 Citaten (Scopus)
218 Downloads (Pure)

Samenvatting

Large-scale filaments, with lengths that can reach tens of Mpc, are the most prominent features in the cosmic web. These filaments have only been observed indirectly through the positions of galaxies in large galaxy surveys or through absorption features in the spectra of high-redshift sources. In this study, we propose to go one step further and directly detect intergalactic medium filaments through their emission in the H I 21 cm line. We make use of high-resolution cosmological simulations to estimate the intensity of this emission in low-redshift filaments and use it to make predictions for the direct detectability of specific filaments previously inferred from galaxy surveys, in particular the Sloan Digital Sky Survey. Given the expected signal of these filaments, our study shows that H I emission from large filaments can be observed by current and next-generation radio telescopes. We estimate that gas in filaments of length l ≳ 15 h-1 Mpc with relatively small inclinations to the line of sight (≲ 10°) can be observed in ˜40-100 h with telescopes such as Giant Metrewave Radio Telescope or Expanded Very Large Array, potentially providing large improvements over our knowledge of the astrophysical properties of these filaments. Due to their large field of view and sufficiently long integration times, upcoming H I surveys with the Apertif and Australian Square Kilometre Array Pathfinder instruments will be able to detect large filaments independently of their orientation and curvature. Furthermore, our estimates indicate that a more powerful future radio telescope like Square Kilometre Array can be used to map most of these filaments, which will allow them to be used as a strong cosmological probe.
Originele taal-2English
Pagina's (van-tot)857-869
Aantal pagina's13
TijdschriftMonthly Notices of the Royal Astronomical Society
Volume468
Nummer van het tijdschrift1
DOI's
StatusPublished - 1-jun.-2017

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