2008/03/29 by Moire K. M. Prescott, M. K. M. Prescott, N. Kashikawa +5 · 3 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Emission nebula #Galaxies: Formation, Evolution, Phenomena #Galaxy #Nebula #Physics #Radio Astronomy Observations and Technology #Redshift #Stars #Universe #astro-ph
paper · pdf · doi:10.1086/588606
published as Astrophys.J. 678 (2008) L77-80 · Accepted for publication in ApJL; 8 pages, 4 figures, emulateapj format
arxiv created 2008/03/29 · openalex publication_date 2008/04/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Large nebulae (≳ 50 kpc) emitting strongly in Lyα (also known as Lyα "blobs") are likely signposts of ongoing massive galaxy formation. The relative rarity of these sources and their discovery in well-studied galaxy overdensities suggest that they may be associated with regions of high galaxy density. One of the largest Lyα nebulae, discovered at a redshift of z ≈ 2.7 via its strong mid-infrared emission, provides an unbiased test of this association. We have carried out a deep intermediate-band imaging survey for Lyα-emitting galaxies (LAEs) within a 30' × 26' field of view around this Lyα nebula. This is the first study of the environment of a Lyα nebula found without a priori knowledge of its surroundings. We find that the nebula is located in an overdense region, at least 20 × 50 h 70 −1 comoving Mpc in size, showing a factor of ~3 LAE number density enhancement relative to the edge of the field. Given the predicted number of such overdensities, we rule out the possibility of a chance coincidence at the ≲1% level. This study, in conjunction with previous work, provides strong confirmation of the association between the largest Lyα nebulae and overdense regions of the universe.