Resolved Infrared Spectroscopy of Two High-Redshift Radio Galaxies

December 2001 • 2001ApJ...563...63C

Authors • Carson, Jennifer E. • Larkin, James E. • McLean, Ian S. • Graham, James R. • Becklin, E. E. • Figer, Donald F. • Gilbert, Andrea M. • Levenson, N. A. • Teplitz, Harry I. • Wilcox, Mavourneen K.

Abstract • We report on the rest-frame optical-line emission from the extended gas in two high-redshift radio galaxies, 4C 48.48 at z=2.343 and 4C 40.36 at z=2.265. These are among the first observations to obtain rest-frame optical spectra for distinct knots of gas within a high-redshift radio galaxy. Although the dominant ionization mechanism in both sources is photoionization by the central AGNs, we find evidence of another mechanism within the off-nuclear emission of each source. We measure [O II], [Ne III] and [O III] for several regions in 4C 48.48; these measurements indicate shock ionization in one region. We measure seven lines in 4C 40.36 and compare the on- and off-nuclear emission from the two strongest, Hα and [O III] we find that [O III]/Hα is at least a factor of 4 weaker off-nucleus, suggesting star formation in the extended region.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2001ApJ...563...63C
• NED https://ned.ipac.caltech.edu/uri/NED::InRefcode/2001ApJ...563...63C
• ELECTR https://doi.org/10.1086%2F323833