High-Resolution Radio Imaging of Gravitational Lensing Candidates in the 1 Jansky BL Lac Sample

Abstract

While BL Lacertae objects are widely believed to be highly beamed, low-luminosity radio galaxies, many radio-selected BL Lacs have extended radio power levels and optical emission lines that are too luminous to be low-luminosity radio galaxies. Also, Stocke & Rector discovered an excess of MgII absorption systems along BL Lac sightlines compared to quasars, suggesting that gravitational lensing may be another means of creating the BL Lac phenomenon in some cases. We present a search for gravitationally-lensed BL Lacs with deep, high-resolution, two-frequency VLA radio maps of seven lensing candidates from the 1 Jansky BL Lac sample. We find that none of these objects are resolved into an Einstein ring like B 0218+357, nor do any show multiple images of the core. All of the lensing candidates that were resolved show a flat-spectrum core and very unusual, steep-spectrum extended morphology that is incompatible with a multiply lensed system. Thus, while these observations do not rule out microlensing, no macrolensing is observed.

arXiv commentAccepted, AJ

References in corpus (10)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The HST Survey of BL Lacertae Objects. I. Surface Brightness Profiles, Magnitudes, and Radii of Host Galaxies
• The Properties of the Radio-Selected 1Jy Sample of BL Lacertae Objects
• The Properties of the X-Ray-Selected EMSS Sample of BL Lac Objects
• Analysis of 6cm VLBI polarization observations of a complete sample of northern BL Lacertae Objects
• Extended radio emission in BL Lac objects - I: the images
• An Excess of Mg II Absorbers in BL Lac Objects
• The HST Survey of BL Lac Objects: Gravitational Lens Candidates and Other Unusual Sources
• HST Observations of the Host Galaxies of BL Lacertae Objects
• Bendings of radio jets in BL Lacertae objects I: EVN and MERLIN observations

Cited by in corpus (8)

• An Optical View of BL Lacertae Objects
• The Unanticipated Phenomenology of the Blazar PKS~2131$-$021: A Unique Super-Massive Black Hole Binary Candidate
• The Radio Structure of High-Energy Peaked BL Lacertae Objects
• VLBI observations of seven BL Lac objects from RGB sample
• The debeamed luminosity, sychrotron peak frequency and black hole mass of BL Lac objects
• Redshift constraints for RGB 0136+391 and PKS 0735+178 from deep optical imaging
• The parsec-scale jet of PKS 1749+096
• The nature of close companions of the BL Lac Objects 1ES 0502+675 and 1ES 1440+122