SIMBAD references

2014ApJS..214...23S - Astrophys. J., Suppl. Ser., 214, 23 (2014/October-0)

Infrared spectra and photometry of complete samples of palomar-green and two micron all sky survey quasars.


Abstract (from CDS):

As a step toward a comprehensive overview of the infrared (IR) diagnostics of the central engines and host galaxies of quasars at low redshift, we present Spitzer Space Telescope spectroscopic (5-40 µm) and photometric (24, 70, and 160 µm) measurements of all Palomar-Green (PG) quasars at z < 0.5 and Two Micron All Sky Survey (2MASS) quasars at z < 0.3. We supplement these data with Herschel measurements at 160 µm. The sample is composed of 87 optically selected PG quasars and 52 near-IR-selected 2MASS quasars. Here we present the data, measure the prominent spectral features, and separate emission due to star formation from that emitted by the dusty circumnuclear torus. We find that the mid-IR (5-30 µm) spectral shape for the torus is largely independent of quasar IR luminosity with scatter in the spectral energy distribution (SED) shape of ≲ 0.2 dex. Except for the silicate features, no large difference is observed between PG (unobscured–silicate emission) and 2MASS (obscured–silicate absorption) quasars. Only mild silicate features are observed in both cases. When in emission, the peak wavelength of the silicate feature tends to be longer than 9.7 µm, possibly indicating effects on grain properties near the active galactic nucleus. The IR color is shown to correlate with the equivalent width of the aromatic features, indicating that the slope of the quasar mid- to far-IR SED is to first order driven by the fraction of radiation from star formation in the IR bands.

Abstract Copyright:

Journal keyword(s): galaxies: active - galaxies: starburst - infrared: galaxies

VizieR on-line data: <Available at CDS (J/ApJS/214/23): table1.dat table2.dat table3.dat table4.dat>

Simbad objects: 139

goto Full paper

goto View the reference in ADS

To bookmark this query, right click on this link: simbad:2014ApJS..214...23S and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact