1999/09/30 by E. Egami, L. Armus, Egami, E. +11
Engineering · Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Particle Accelerators and Free-Electron Lasers #Particle accelerators and beam dynamics #Physics #Spacecraft and Cryogenic Technologies #Theoretical physics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9909517
published in arXiv (Cornell University) (Cornell University) · 4 pages, 2 figures; to appear in the proceedings of "The Hy-Redshift Universe: Galaxy Formation and Evolution at High Redshift", eds. A.J.Bunker and W. J. M. van Breugel
arxiv created 1999/09/30 · openalex publication_date 1999/09/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using NICMOS on HST, we have imaged the emission-line nebulae and the line-free continuum in 4C 40.36, a ultra-steep spectrum FR II radio galaxy at z=2.269. The line-free continuum was found to be extremely compact and symmetric while the emission-line nebulae seen in H-alpha+[N II] show very clumpy structures spreading almost linearly over 16 kpc. However, this linear structure is clearly misaligned from the radio axis. The SED of the line-free continuum is very flat, suggesting that if the continuum emission is produced by a single source, it is likely to be a young bursting stellar population or scattered AGN light. However, because of the lack of a line-free optical image with a comparable spatial resolution, we cannot exclude the possibility that the observed SED is a composite of a young blue population and an old red population.