skip to main content


Title: Large-scale clustering of Lymanα emission intensity from SDSS/BOSS

Here we present a tentative detection of the large-scale structure of Ly α emission in the Universe at redshifts z = 2–3.5 by measuring the cross-correlation of Ly α surface brightness with quasars in Sloan Digital Sky Survey/Baryon Oscillation Spectroscopic Survey. We use a million spectra targeting luminous red galaxies at z < 0.8, after subtracting a best-fitting model galaxy spectrum from each one, as an estimate of the high-redshift Ly α surface brightness. The quasar–Ly α emission cross-correlation is detected on scales 1 ~ 15h ₋1 Mpc, with shape consistent with a ΛCDM model with Ω m =0.30± 0.10 0.07. The predicted amplitude of this cross- correlation is proportional to the product of the mean Lyα surface brightness, {μ α}, the amplitude of mass density fluctuations, and the quasar and Lyα emission bias factors. Using published cosmological observations to constrain the amplitude of mass fluctuations and the quasar bias factor, we infer the value of the product {μ α} (b α /3) = (3.9±0.9)×10 ₋21 erg s ₋1 cm ₋2 °A ₋1 arcsec ₋2, where b α is the Lyα emission linear bias factor. If the dominant sources of Lyα emission we measure are star forming galaxies, we infermore » a total mean star formation rate density of ρSFR = (0.28 ± 0.07)(3/b α ) yr ₋1 Mpc ₋3 at z = 2 ₋ 3.5. For b α = 3, this value is a factor of 21 ₋ 35 above previous estimates relying on individually detected Lyα emitters, although it is consistent with the total star-formation density derived from dust-corrected, continuum UV surveys. Our observations therefore imply that 97% of the Lyα emission in the Universe at these redshifts is undetected in previous surveys of Lyα emitters. Our detected Lyα emission is also much greater, by at least an order of magnitude, than that measured from stacking analyses of faint halos surrounding previously detected Lyα emitters, but we speculate that it arises from similar low surface brightness Lyα halos surrounding all luminous star-forming galaxies. We also detect a redshift space anisotropy of the quasar-Lyα emission cross-correlation, finding evidence at the 3.0σ level that it is radially elongated, contrary to the prediction for linear gravitational evolution, but consistent with distortions caused by radiative-transfer effects, as predicted by Zheng et al. (2011). Lastly, our measurements represent the first application of the intensity mapping technique to optical observations.« less
 [1] ;  [2] ;  [3] ;  [3] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [3] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [9] ;  [14] ;  [15] ;  [16] more »;  [10] ;  [17] ;  [10] ;  [18] ;  [19] ;  [19] ;  [20] ;  [21] ;  [9] « less
  1. Carnegie Mellon Univ., Pittsburgh, PA (United States); Univ. of Oxford (United Kingdom). Dept. of Astrophysics
  2. Catalan Inst. for Research and Advanced Studies (ICREA), Barcelona (Spain); Univ. of Barcelona, Barcelona (Spain). Inst. of Sciences of the Cosmos
  3. Univ. of Utah, Salt Lake City, UT (United States). Dept. of Physics and Astronomy
  4. Carnegie Mellon Univ., Pittsburgh, PA (United States)
  5. Univ. of Chicago, IL (United States)
  6. Harvard Univ., Cambridge, MA (United States)
  7. Apache Point Observatory, Sunspot, NM (United States)
  8. Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences
  9. Alternative Energies and Atomic Energy Commission (CEA), Saclay (France)
  10. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  11. CNRS/IN2P3. Univ. Paris (France). Observatoire de Paris. AstroParticule et Cosmologie (APC)
  12. Max Planck Inst. fur Astronomie, Heidelberg (Germany)
  13. Univ. of Wyoming, Laramie, WY (United States)
  14. National Inst. for Astrophysics (INAF), Trieste (Italy). Trieste Astronomical Observatory
  15. Univ. of Paris at CNRS, Paris (France). Inst. of Astrophysics
  16. Aix-Marseille Univ.and CNRS, Marseille (France). Astrophysics Lab.
  17. Sejong Univ., Seoul (Korea, Republic of)
  18. Pennsylvania State Univ., University Park, PA (United States)
  19. Brookhaven National Lab. (BNL), Upton, NY (United States)
  20. National Inst. for Astrophysics (INAF), Trieste (Italy). Trieste Astronomical Observatory; Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy)
  21. Ohio State Univ., Columbus, OH (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0035-8711; KA2301020
Grant/Contract Number:
SC0012704; AC02-98CH10886; NNX14AC89G; AST-1208891; AYA2012- 33938; AST-1009781; AST- 1109730; OCI-0749212; AC02-05CH11231
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 457; Journal Issue: 4; Journal ID: ISSN 0035-8711
Royal Astronomical Society
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; cosmology: observations
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1379081