This work is based on observations made with the APEX Telescope. APEX is a collaboration between the Max-Planck-Institut für Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory.

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The nomenclature about Ly $\alpha$ blobs is still a bit confused. A Ly $\alpha$ blob (or LAB) refers clearly to an extended or resolved region of Ly $\alpha$ emission. However, the evidence for extension depends on the quality of the optical image. In the prototype region SA 22, there is a list of several tens of LABs down to an extension of ${\sim}5\hbox{$^{\prime\prime}$ }$ (see e.g. Table 1 of Geach et al. 2005). In the J2143-4423 region, extensions are published only to $\sim$ $7\hbox{$^{\prime\prime}$ }$ ( $\sim$ 50 kpc), for four blobs, B1, B5, B6, B7 (see Table 4 of Palunas et al. 2004). However, other unresolved Ly $\alpha$ emitters are also labeled B2, B4, B8 and B9 (Francis et al. 1997,1996; Colbert et al. 2006; Palunas et al. 2004). To avoid confusion, we will call extended objects of the first group 50 kpc-Ly $\alpha$ blobs.

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... model

See http://www.lesia.obspm.fr/~lellouch/mars/

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... temperatures

See http://www-mars.lmd.jussieu.fr/

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