THE LACK OF TORUS EMISSION FROM BL LACERTAE OBJECTS: AN INFRARED VIEW OF UNIFICATION WITH WISE

Journal Article · Wed Feb 15 04:00:00 EST 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/745/2/L27· OSTI ID:22048071

Plotkin, Richard M; Markoff, Sera ^[1]; Anderson, Scott F ^[2]; Brandt, W N; Jianfeng, Wu ^[3]; Shemmer, Ohad ^[4]

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1. Astronomical Institute 'Anton Pannekoek', University of Amsterdam, Science Park 904, 1098 XH, Amsterdam (Netherlands)
2. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States)
3. Department of Astronomy and Astrophysics, Pennsylvania Sate University, 525 Davey Laboratory, University Park, PA 16802 (United States)
4. Department of Physics, University of North Texas, Denton, TX 76203 (United States)

We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number ({approx}10{sup 2}) of BL Lac objects-low-luminosity active galactic nuclei (AGNs) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions. In other BL Lac objects, however, the jet is not strong enough to completely dilute the rest of the AGN emission. We do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. The lack of observable torus emission is consistent with suggestions that BL Lac objects are fed by radiatively inefficient accretion disks. Implications for the 'nature versus nurture' debate for FR I and FR II radio galaxies are briefly discussed. Our study supports the notion that, beyond orientation, accretion rate plays an important role in AGN unification.

• OSTI ID: 22048071
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 745; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
ASTROPHYSICS
BL LACERTAE OBJECTS
COSMIC DUST
ENERGY SPECTRA
GALAXY NUCLEI
INFRARED SPECTRA
INFRARED SURVEYS
JETS
LUMINOSITY
ORIENTATION
PHOTON EMISSION
RADIO GALAXIES