1997/12/11 by I. Aretxaga, R. J. Terlevich, Aretxaga, I. +4
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9712155
4 pages, Latex, uses paspconf.sty. Also available at http://www.mpa-garching.mpg.de/~itziar. To appear in in "The Young Universe", eds. S. D'Odorico et al., A.S.P. Conf. Ser
arxiv created 1997/12/11 · openalex publication_date 1997/12/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Three high-redshift (z=2) and high luminosity (MB < -28 mag for Ho = 50, qo=0.5) QSOs, two radio-quiet one radio-loud, were imaged in R, I and K bands. The luminosities, colours and sizes of the hosts overlap with those of actively star-forming galaxies in the local Universe. These properties give support to the young host galaxy interpretation of the extended light around QSOs at high-redshift. The rest-frame UV and UV-optical colours are inconsistent with the hypothesis of a scattered halo of light from the active nucleus by a simple optically-thin scattering process produced by dust or hot electrons. If the UV light is indeed stellar, star formation rates of hundreds of solar masses per year are implied, an order of magnitude larger than in field galaxies at similar redshifts and above. This might indicate that the QSO phenomenon is preferentially accompanied by enhanced galactic activity at high-redshift.