High resolution WFPC2 imaging of IRAS 09104+4109

Abstract

With an infrared luminosity of L_(IR) = 6 x 10^(12) L_☉, IRAS 09104+4109 is one of the most luminous objects detected in the IRAS survey. First identified with a faint, R ~ 18 mag, galaxy at z = 0.442 by Kleinmann et al.(1988), IRAS 09104+4109 emits more than 99% of its bolometric luminosity longward of ⋋ ~ 1µm. Like most Ultraluminous Infrared Galaxies (ULIRGs), IRAS 09104+4109 has very strong emission lines. The nucleus exhibits a Seyfert type 2 spectrum, with strong, narrow lines over a wide range of ionization (Kleinmann et al.,1988; Soifer et al.,1996). Two-dimensional, ground-based spectrophotometry shows a "plume" of [OIII] emission-line gas extending almost 500 from the nucleus, along with a strong, blueshifted (ΔV ~ 1200 km s^(−1)) nuclear component (Crawford & Vanderriest, 1996). Although the dominant energy source in most ULIRGs is still a matter of some debate, the highly polarized spectrum (~ 18%), broad (10^4 km s^(−1)), (presumably reflected) MgII emission line, and double-lobed, core-jet radio structure, indicate a quasar at the heart of IRAS 09104+4109 (Hines & Wills, 1993). Recent calculations by Hines et al. (1999) suggest that the buried quasar in IRAS 09104+4109 can account for all of the bolometric luminosity of the system.