STRONG FIELD-TO-FIELD VARIATION OF Ly{alpha} NEBULAE POPULATIONS AT z {approx_equal} 2.3

Journal Article · Fri Aug 20 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/719/2/1654· OSTI ID:21457072

Yujin, Yang ^[1]; Zabludoff, Ann; Eisenstein, Daniel; Dave, Romeel ^[2]

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1. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
2. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

Understanding the nature of distant Ly{alpha} nebulae, aka 'blobs', and connecting them to their present-day descendants requires constraining their number density, clustering, and large-scale environment. To measure these basic quantities, we conduct a deep narrowband imaging survey in four different fields, Chandra Deep Field South (CDFS), Chandra Deep Field North (CDFN), and two COSMOS subfields, for a total survey area of 1.2 deg{sup 2}. We discover 25 blobs at z = 2.3 with Ly{alpha} luminosities of L{sub Ly{alpha}=} (0.7-8) x 10{sup 43} erg s{sup -1} and isophotal areas of A{sub iso} = 10-60 {open_square}arcsec. The transition from compact Ly{alpha} emitters (LAEs; A{sub iso} {approx} a few {open_square}arcsec ) to extended Ly{alpha} blobs (A {sub iso} > 10 {open_square}arcsec) is continuous, suggesting a single family perhaps governed by similar emission mechanisms. Surprisingly, most blobs (16/25) are in one survey field, the CDFS. The six brightest, largest blobs with L {sub Ly{alpha} {approx}}> 1.5x10{sup 43} erg s{sup -1} and A{sub iso} > 16 {open_square}arcsec lie only in the CDFS. These large, bright blobs have a field-to-field variance of {sigma} {sub v} {approx}> 1.5 (150%) about their number density n {approx}1.0{sup +1.8}{sub -0.6}x 10{sup -5} Mpc{sup -3}. This variance is large, significantly higher than that of unresolved LAEs ({sigma} {sub v} {approx} 0.3 or 30%), and can adversely affect comparisons of blob number densities and luminosity functions (LFs) among different surveys. Our deep, blind survey allows us to construct a reliable blob LF. We compare the statistics of our blobs with dark matter halos in a 1 h {sup -1} Gpc cosmological N-body simulation. At z = 2.3, n implies that each bright, large blob could occupy a halo of M{sub halo} {approx}>10{sup 13} M{sub sun} if most halos have detectable blobs. The predicted variance in n is consistent with that observed and corresponds to a bias of {approx}7. Blob halos lie at the high end of the halo mass distribution at z = 2.3 and are likely to evolve into the {approx}10{sup 14} M{sub sun} halos typical of galaxy clusters today. On larger scales of {approx}10 comoving Mpc, blobs cluster where compact LAEs cluster, indicating that blobs lie in coherent, highly overdense structures.

• OSTI ID: 21457072
• Journal Information: Astrophysical Journal, Vol. 719, Issue 2; Other Information: DOI: 10.1088/0004-637X/719/2/1654; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
GALACTIC EVOLUTION
GALAXIES
GALAXY CLUSTERS
HYDROGEN 1
LUMINOSITY
MASS DISTRIBUTION
NEBULAE
NONLUMINOUS MATTER
RED SHIFT
SIMULATION
UNIVERSE
DISTRIBUTION
EVOLUTION
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
MATTER
NUCLEI
ODD-EVEN NUCLEI
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SPATIAL DISTRIBUTION
STABLE ISOTOPES