Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.
False-color picture of the ionized hydrogen gas surrounding the radio galaxy 1138-262 (Lyman-alpha). The size of this cloud is about 5 times larger than the optical extent of the Milky Way Galaxy. A contour plot, as observed with VLT ANTU + FORS1 in a narrow-band filter around the wavelength of the redshifted Lyman-alpha line, is superposed on a false-color representation of the same image. The contour levels are a geometric progression in steps of 2 1/2. The image has not been flux calibrated, so the first contour level is arbitrary. The field measures 35 x 25 arcsec 2, corresponding to about 910, 000 x 650, 000 light-years (280 x 200 kpc). The linear scale is indicated at the lower left. North is up and East is left. Narrow and broad-band imaging was carried out on April 12 and 13, 1999, with the ESO VLT ANTU (UT1), using the FORS1 multi-mode instrument in imaging mode. Release date July 30, 1999.
