Open AccessEvidence for cold accretion onto a massive galaxy at high redshift?
Author(s) -
Smith Daniel J. B.,
Jarvis Matt J.
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society: letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.067
H-Index - 122
eISSN - 1745-3933
pISSN - 1745-3925
DOI - 10.1111/j.1745-3933.2007.00318.x
Subject(s) - physics , astrophysics , galaxy , redshift , halo , surface brightness , astronomy , hubble ultra deep field , luminosity , accretion (finance) , hubble deep field
In this Letter we report on the discovery of a z = 2.83 Lyman α Blob (LAB) found in our wide‐field narrow‐band survey within the Spitzer First Look Survey region. The blob is extended over at least 95 kpc and has a total Lyman α luminosity of 2.1 × 10 44 erg s −1 . It is only the sixth LAB known of this scale (>50 kpc), and is associated with an embedded continuum source in g ′, R , i ′, K and 4.5‐μm bands. The LAB's optical spectrum shows clumpy structures and tantalising hints of a sharp red cut‐off and shear within the Lyman α emission line. Studies of the LAB's surface brightness profile and of the continuum counterpart's spectral energy distribution indicate that the profuse Lyman α emission is consistent with being powered by cold gas accreting onto a massive dark matter halo.