Evropská jižní observatoř

Kategorie: Kosmologie, Zpět na celou fotogalerii.

Popis (v anglickém jazyce):

The image displayed was obtained in the near-infrared J-band, where the lensing galaxy in HE 1104-1805 is quite faint, but still well visible and measurable after `deconvolution'.

The observed, infrared colour, i.e. the difference in brightness of its image in the J- and K-bands (the (J-K) index ), is compatible with that of a high-redshift elliptical galaxy, at a distance corresponding to a redshift somewhere between z = 1 and z = 1.8.

The brightest of the two quasar images (`A'; the upper one in ESO PR Photo 21/97) shows absorption lines in its spectrum which have been red-shifted at z = 1.66. Since the lensing galaxy is situated at a small angular distance from this component, it is quite likely that these spectral lines are produced by this galaxy.

Thus, the gravitational deflector in HE 1104-1805 is most probably an elliptical galaxy at redshift z = 1.66. This corresponds to a recession velocity of about 200,000 km/sec and a distance that, depending on the adopted Hubble relation, is of the order of 6,000 - 9,000 million light-years.

Odkaz na další informace na www.eso.org (stránka v AJ)