Title:A Lya blob survey at z~3.15 in the GOODS South field
Author(s):Kentaro Sumikawa
Abstract:
Spatially extended Lya-emitting objects that are faint and compact in continuum, so-called Lya "blobs" (LABs), are candidate for proto galaxies. Searching for LABs is important to understand formation and evolution of galaxies. However, LABs surveys have never been carried out much in blank fields. We carried out a survey for LABs at z~3.15 in GOODS South field, using intermediate-band (IA) imaging data taken with the Suprime-Cam on Subaru Telescope.
Our survey covers a field of view of 34'x27' and, using 15 IA filters, the whole wavelength range of 4150-8750A. Each filter has a bandwidth of ~200-340A, so that we can obtain low-resolution (R~23) SEDs in the rest-UV wavelengths. In this study, we carry out a survey for LABs in the IA505 (central wavelength ~5060A) corresponding to the redshift range of 3.05 We find one LAB candidate. This object has a total Lya luminosity of ~5.7x10^42 erg/s and a spatial extent of at least ~20 kpc. The Lya line is clearly detected in IA505, but no clear continuum is detected, either in blue side or in red side of the Lya. The blue side continuum is clearly undetected (fainter than 2-sigma level), while the red side shows a marginal detection of the flat continuum with ~2-sigma level.
We will present the results in other redshift ranges, together with the result in IA505.