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Cross-correlation o...
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Guha Sarkar, T.
(författare)
Cross-correlation of the H I 21-cm signal and Lyα forest: a probe of cosmology : H I 21-cm signal and Lyα
- Artikel/kapitelEngelska2011
Förlag, utgivningsår, omfång ...
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2010-10-12
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Oxford University Press (OUP),2011
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printrdacarrier
Nummerbeteckningar
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LIBRIS-ID:oai:DiVA.org:su-52881
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https://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-52881URI
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https://doi.org/10.1111/j.1365-2966.2010.17509.xDOI
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Språk:engelska
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Sammanfattning på:engelska
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Ämneskategori:ref swepub-contenttype
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Ämneskategori:art swepub-publicationtype
Anmärkningar
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Separating the cosmological redshifted 21-cm signal from foregrounds is a major challenge. We present the cross-correlation of the redshifted 21-cm emission from neutral hydrogen (HI) in the post-reionization era with the Ly-alpha forest as a new probe of the large scale matter distribution in the redshift range z=2 to 3 without the problem of foreground contamination. Though the 21-cm and the Ly-alpha forest signals originate from different astrophysical systems, they are both expected to trace the underlying dark matter distribution on large scales. The multi-frequency angular cross-correlation power spectrum estimator is found to be unaffected by the discrete quasar sampling, which only affects the noise in the estimate. We consider a hypothetical redshifted 21-cm observation in a single field of view 1.3 degrees (FWHM) centered at z=2.2 where the binned 21-cm angular power spectrum can be measured at an SNR of 3 sigma or better across the range 500 < l < 4000 . Keeping the parameters of the 21-cm observation fixed, we have estimated the SNR for the cross-correlation signal varying the quasar angular number density n of the Ly-alpha forest survey. Assuming that the spectra have SNR ~5 in pixels of length 44 km/s, we find that a 5 sigma detection of the cross-correlation signal is possible at 600 < l < 2000 with n=4 deg^{-2}. This value of n is well within the reach of upcoming Ly-alpha forest surveys. The cross-correlation signal will be a new, independent probe of the astrophysics of the diffuse IGM, the growth of structure and the expansion history of the Universe.
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Biuppslag (personer, institutioner, konferenser, titlar ...)
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Bharadwaj, Somnath
(författare)
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Choudhury, Tirthankar Roy
(författare)
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Datta, KananStockholms universitet,Institutionen för astronomi,Oskar Klein-centrum för kosmopartikelfysik (OKC)(Swepub:su)kdatt
(författare)
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Stockholms universitetInstitutionen för astronomi
(creator_code:org_t)
Sammanhörande titlar
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Ingår i:Monthly notices of the Royal Astronomical Society: Oxford University Press (OUP)410:2, s. 1130-11340035-87111365-2966
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