The infrared color evolution of active nuclei

Abstract

view Abstract Citations (14) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Infrared Color Evolution of Active Nuclei Baan, Willem A. Abstract The far-infrared color evolution is studied for galaxies with a nuclear starburst or an AGN. The nuclear source heats the surrounding dust to an effective blackbody temperature (T_d_ = 50-100 K). The color and luminosity evolution for such galaxies is simulated by letting the central heating source and the resulting warm dust emission (the primary source) decay exponentially in combination with a slower decaying secondary IR emission source. Secondary spectral components can be nonthermal or (hot or cold) thermal in nature and may be associated with the nuclear activity or with the rest of the galaxy. The evolving far-infrared (FIR) galaxy traverses the FIR color diagrams in a rather systematic fashion, and an FIR galaxy can be modeled very effectively with an appropriate mixture of primary and secondary luminosity contributions. The secondary components must have an initial strength of 0.1-0.005 relative to the primary source. Superluminous FIR sources with dominant nuclear sources lie at the start of the simulated evolutionary tracks in the color-color diagrams. While these sources evolve across the color diagram they will reveal more of their nuclear characteristics and eventually they may appear to the observer as normal Seyferts or quasars. The group of powerful FIR sources also incorporates the OH megamaser galaxies. A luminosity function is constructed for the family of nuclear FIR sources. A single distribution of nuclear FIR sources can account for the observed luminosity function at high L_IR_. Another distribution of nonnuclear sources is required to explain the low-luminosity end. Publication: The Astrophysical Journal Pub Date: July 1988 DOI: 10.1086/166508 Bibcode: 1988ApJ...330..743B Keywords: Active Galactic Nuclei; Color-Color Diagram; Infrared Sources (Astronomy); Seyfert Galaxies; Far Infrared Radiation; Infrared Spectra; Interstellar Matter; Luminosity; Starburst Galaxies; Astrophysics; GALAXIES: NUCLEI; INFRARED: SOURCES; INTERSTELLAR: GRAINS full text sources ADS | data products SIMBAD (10) NED (6)