Cosmology from a SKA HI intensity mapping survey

Santos, Mário G.; Bull, Philip; Alonso, David; Camera, Stefano; Ferreira, Pedro G.; Bernardi, G.; Maartens, Roy; Viel, Matteo; Villaescusa-Navarro, Francisco; Abdalla, F. B.; Jarvis, Matt J.; Metcalf, R. Benton; Pourtsidou, Alkistis; Wolz, Laura

doi:10.22323/1.215.0019

Cited by 147 publications

(152 citation statements)

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“…We show the predicted sensitivity of SKA in the second and third panels of Fig. 10 at k ∼ 0.1 h Mpc −1 based on calculations of Santos et al (2015). This predicted sensitivity of the SKA is one of main drivers of the effort behind the modelling of the H I content of galaxies down to low H I mass galaxies (M H I < 10 7 h −2 M ) using a high enough resolution simulation with a physically motivated galaxy formation model to properly include these low H I mass galaxies.…”

Section: E F F E C T O F G a L A X I E S W I T H L Ow H I M A S S E Smentioning

confidence: 99%

“…We show P / P 21cm, G6 , the fluctuation between thresholds and P 21cm, G6 , in the sub-panels. The filled squares in the middle and bottom panels show the predicted constraint (noise over signal) at k ∼ 0.1 h Mpc −1 expected for the SKA1-MID (Santos et al 2015). ∼10 10 h −1 M ) in order to properly predict the 21 cm brightness temperature signal.…”

Section: S U M M a Rymentioning

confidence: 99%

“…Jonas 2007) in the Southern hemisphere, FAST (Five-hundred-meter Aperture Spherical Telescope) 1 and APERTIF (APERture Tile In Focus) 2 in the Northern hemisphere. In addition, the BINGO (the BAO in Neutral Gas Observations; Battye et al 2012), CHIME (the Canadian Hydrogen Intensity Mapping Experiment; Bandura et al 2014) and SKA are expected to detect the distribution of neutral hydrogen at 0.5 < z < 3 in the Universe using the 21 cm intensity mapping technique which does not require individual H I-selected galaxies to be resolved Wyithe & Loeb (2007); Wolz et al (2014); Santos et al (2015). There have been several theoretical models predicting the H I intensity during the post-reionization era.…”

Section: Introductionmentioning

confidence: 99%

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The spatial distribution of neutral hydrogen as traced by low H i mass galaxies

Kim

Wyithe

Baugh

et al. 2016

Mon. Not. R. Astron. Soc.

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The formation and evolution of galaxies with low neutral atomic hydrogen (HI) masses, M HI <10 8 h −2 M , are affected by host dark matter halo mass and photoionisation feedback from the UV background after the end of reionization. We study how the physical processes governing the formation of galaxies with low HI mass are imprinted on the distribution of neutral hydrogen in the Universe using the hierarchical galaxy formation model, GALFORM. We calculate the effect on the correlation function of changing the HI mass detection threshold at redshifts 0 z 0.5. We parameterize the clustering as ξ(r) = (r/r 0 ) −γ and we find that including galaxies with M HI <10 8 h −2 M increases the clustering amplitude r 0 and slope γ compared to samples of higher HI masses. This is due to these galaxies with low HI masses typically being hosted by haloes with masses greater than 10 12 h −1 M , and is in contrast to optically selected surveys for which the inclusion of faint, blue galaxies lowers the clustering amplitude. We show the HI mass function for different host dark matter halo masses and galaxy types (central or satellite) to interpret the values of r 0 and γ of the clustering of HI-selected galaxies. We also predict the contribution of low HI mass galaxies to the 21cm intensity mapping signal. We calculate that a dark matter halo mass resolution better than ∼10 10 h −1 M at redshifts higher than 0.5 is required in order to predict converged 21cm brightness temperature fluctuations.

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Section: E F F E C T O F G a L A X I E S W I T H L Ow H I M A S S E Smentioning

confidence: 99%

Section: S U M M a Rymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The spatial distribution of neutral hydrogen as traced by low H i mass galaxies

Kim

Wyithe

Baugh

et al. 2016

Mon. Not. R. Astron. Soc.

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“…We assume a total of N f = 254 feeds, 190 of which come from the SKA MID array and 64 from the MeerKAT array. The effective area of the elements is taken as A eff = 140 m 2 [63], and the sky area as S 21 = 15000 sq.deg.. We combine the two frequency bands B1 and B2, such that the survey probes redshifts 0.00 < z < 3.06, and the antenna temperature is taken as T ant = 20 K for the higher frequency B2 band and T ant = 28 K for the lower frequency B1 band. Finally we assume a maximum baseline of D max = 1000 m, dual-polarization feeds (n p = 2), and the same total observing time as CHIME, t 0 = 10 4 hrs.…”

Section: Skamentioning

confidence: 99%

Measuring cosmic velocities with 21 cm intensity mapping and galaxy redshift survey cross-correlation dipoles

Hall

Bonvin

2017

Phys. Rev. D

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We investigate the feasibility of measuring the effects of peculiar velocities in large-scale structure using the dipole of the redshift-space cross-correlation function. We combine number counts of galaxies with brightness-temperature fluctuations from 21 cm intensity mapping, demonstrating that the dipole may be measured at modest significance ( 2σ) by combining the upcoming radio survey CHIME with the future redshift surveys of DESI and Euclid. More significant measurements ( 10σ) will be possible by combining intensity maps from the SKA with these of DESI or Euclid, and an even higher significance measurement ( 100σ) may be made by combining observables completely internally to the SKA. We account for effects such as contamination by wide-angle terms, interferometer noise and beams in the intensity maps, non-linear enhancements to the power spectrum, stacking multiple populations, sensitivity to the magnification slope, and the possibility that number counts and intensity maps probe the same tracers. We also derive a new expression for the covariance matrix of multi-tracer redshift-space correlation function estimators with arbitrary orientation weights, which may be useful for upcoming surveys aiming at measuring redshift-space clustering with multiple tracers.

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“…Since the galaxy population hosting the HI emitting regions is a biased tracer of the underlying dark matter distribution, so too is the integrated HI signal, and redshift information is trivially obtained by the frequency of the emission. By making low-resolution maps over a substantial fraction of the sky, for many channels over a wide band, intensity mapping (IM) surveys are therefore able to rapidly reconstruct the large-scale redshift-space matter distribution over extremely large cosmological volumes, out to high redshift (Santos et al 2015).…”

Section: Intensity Mappingmentioning

confidence: 99%

Synergy between the Large Synoptic Survey Telescope and the Square Kilometre Array

Bacon¹,

Bridle²,

Abdalla³

et al. 2015

Proceedings of Advancing Astrophysics With the Square Kilometre Array — PoS(AASKA14)

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We provide an overview of the science benefits of combining information from the Square Kilometre Array (SKA) and the Large Synoptic Survey Telescope (LSST). We first summarise the capabilities and timeline of the LSST and overview its science goals. We then discuss the science questions in common between the two projects, and how they can be best addressed by combining the data from both telescopes. We describe how weak gravitational lensing and galaxy clustering studies with LSST and SKA can provide improved constraints on the causes of the cosmological acceleration. We summarise the benefits to galaxy evolution studies of combining deep optical multi-band imaging with radio observations. Finally, we discuss the excellent match between one of the most unique features of the LSST, its temporal cadence in the optical waveband, and the time resolution of the SKA.Advancing Astrophysics with the Square Kilometre Array

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Cosmology from a SKA HI intensity mapping survey

Cited by 147 publications

References 59 publications

The spatial distribution of neutral hydrogen as traced by low H i mass galaxies

The spatial distribution of neutral hydrogen as traced by low H i mass galaxies

Measuring cosmic velocities with 21 cm intensity mapping and galaxy redshift survey cross-correlation dipoles

Synergy between the Large Synoptic Survey Telescope and the Square Kilometre Array

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