Very deep near IR view of "AXAF Deep Field"

In order to be able to see such obscured and/or "evolved" galaxies in the early Universe, and to look for hitherto unknown galaxies beyond the limits of "deep-field" imaging in visible spectral bands, it is necessary to employ other observing techniques. The astronomers must search for such objects on large-field, very long-exposure sky images obtained in the near-infrared and far IR region of the electromagnetic spectrum. North is up and east is left. The reproduction is "negative", with dark objects on a light sky, in order to better show the faintest objects.

Technical note : This K-band image is the result of 510 min of integration time with ISAAC at VLT ANTU. The 3-sigma magnitude limit is about K = 23.5 per arcsec 2. A J-band image was also obtained during 200 min of integration, with a 3-sigma limit of J = 25 per arcsec 2. The seeing FWHM (Full Width at Half Maximum) is 0.65 arcsec for both bands.