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Title: THE JETS OF TeV BLAZARS AT HIGHER RESOLUTION: 43 GHz AND POLARIMETRIC VLBA OBSERVATIONS FROM 2005 TO 2009

Abstract

We present 23 new VLBA images of the six established TeV blazars Markarian 421, Markarian 501, H 1426+428, 1ES 1959+650, PKS 2155-304, and 1ES 2344+514, obtained from 2005 to 2009. Most images were obtained at 43 GHz (7 mm), and they reveal the parsec-scale structures of three of these sources (1ES 1959+650, PKS 2155-304, and 1ES 2344+514) at factors of 2-3 higher resolution than has previously been attained. These images reveal new morphological details, including a high degree of jet bending in the inner milliarcsecond in PKS 2155-304. This establishes strong apparent jet bending on VLBI scales as a common property of TeV blazars, implying viewing angles close to the line of sight. Most of the remaining images map the linear polarization structures at a lower frequency of 22 GHz (1 cm). We discuss the transverse structures of the jets as revealed by the high-frequency and polarimetric imaging. The transverse structures include significant limb brightening in Mrk 421, and 'spine-sheath' structures in the electric vector position angle and fractional polarization distributions in Mrk 421, Mrk 501, and 1ES 1959+650. We use new measured component positions to update measured apparent jet speeds, in many cases significantly reducing the statistical error overmore » previously published results. With the increased resolution at 43 GHz, we detect new components within 0.1-0.2 mas of the core in most of these sources. No motion is apparent in these new components over the time span of our observations, and we place upper limits on the apparent speeds of the components near the core of <2c. From those limits, we conclude that {Gamma}{sub 2} < ({Gamma}{sub 1}){sup 1/2} at {approx}10{sup 5} Schwarzschild radii, where {Gamma}{sub 1} and {Gamma}{sub 2} are the bulk Lorentz factors in the TeV emitting and 43 GHz emitting regions, respectively, assuming that their velocity vectors are aligned.« less

Authors:
;  [1]
  1. Department of Physics and Astronomy, Whittier College, 13406 E. Philadelphia Street, Whittier, CA 90608 (United States)
Publication Date:
OSTI Identifier:
21471280
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 723; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/723/2/1150; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BL LACERTAE OBJECTS; GALAXIES; GHZ RANGE; POLARIZATION; SCHWARZSCHILD RADIUS; TEV RANGE; COSMIC RADIO SOURCES; ENERGY RANGE; FREQUENCY RANGE

Citation Formats

Piner, B Glenn, Pant, Niraj, and Edwards, Philip G., E-mail: gpiner@whittier.ed, E-mail: Philip.Edwards@csiro.a. THE JETS OF TeV BLAZARS AT HIGHER RESOLUTION: 43 GHz AND POLARIMETRIC VLBA OBSERVATIONS FROM 2005 TO 2009. United States: N. p., 2010. Web. doi:10.1088/0004-637X/723/2/1150.
Piner, B Glenn, Pant, Niraj, & Edwards, Philip G., E-mail: gpiner@whittier.ed, E-mail: Philip.Edwards@csiro.a. THE JETS OF TeV BLAZARS AT HIGHER RESOLUTION: 43 GHz AND POLARIMETRIC VLBA OBSERVATIONS FROM 2005 TO 2009. United States. https://doi.org/10.1088/0004-637X/723/2/1150
Piner, B Glenn, Pant, Niraj, and Edwards, Philip G., E-mail: gpiner@whittier.ed, E-mail: Philip.Edwards@csiro.a. 2010. "THE JETS OF TeV BLAZARS AT HIGHER RESOLUTION: 43 GHz AND POLARIMETRIC VLBA OBSERVATIONS FROM 2005 TO 2009". United States. https://doi.org/10.1088/0004-637X/723/2/1150.
@article{osti_21471280,
title = {THE JETS OF TeV BLAZARS AT HIGHER RESOLUTION: 43 GHz AND POLARIMETRIC VLBA OBSERVATIONS FROM 2005 TO 2009},
author = {Piner, B Glenn and Pant, Niraj and Edwards, Philip G., E-mail: gpiner@whittier.ed, E-mail: Philip.Edwards@csiro.a},
abstractNote = {We present 23 new VLBA images of the six established TeV blazars Markarian 421, Markarian 501, H 1426+428, 1ES 1959+650, PKS 2155-304, and 1ES 2344+514, obtained from 2005 to 2009. Most images were obtained at 43 GHz (7 mm), and they reveal the parsec-scale structures of three of these sources (1ES 1959+650, PKS 2155-304, and 1ES 2344+514) at factors of 2-3 higher resolution than has previously been attained. These images reveal new morphological details, including a high degree of jet bending in the inner milliarcsecond in PKS 2155-304. This establishes strong apparent jet bending on VLBI scales as a common property of TeV blazars, implying viewing angles close to the line of sight. Most of the remaining images map the linear polarization structures at a lower frequency of 22 GHz (1 cm). We discuss the transverse structures of the jets as revealed by the high-frequency and polarimetric imaging. The transverse structures include significant limb brightening in Mrk 421, and 'spine-sheath' structures in the electric vector position angle and fractional polarization distributions in Mrk 421, Mrk 501, and 1ES 1959+650. We use new measured component positions to update measured apparent jet speeds, in many cases significantly reducing the statistical error over previously published results. With the increased resolution at 43 GHz, we detect new components within 0.1-0.2 mas of the core in most of these sources. No motion is apparent in these new components over the time span of our observations, and we place upper limits on the apparent speeds of the components near the core of <2c. From those limits, we conclude that {Gamma}{sub 2} < ({Gamma}{sub 1}){sup 1/2} at {approx}10{sup 5} Schwarzschild radii, where {Gamma}{sub 1} and {Gamma}{sub 2} are the bulk Lorentz factors in the TeV emitting and 43 GHz emitting regions, respectively, assuming that their velocity vectors are aligned.},
doi = {10.1088/0004-637X/723/2/1150},
url = {https://www.osti.gov/biblio/21471280}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 723,
place = {United States},
year = {Wed Nov 10 00:00:00 EST 2010},
month = {Wed Nov 10 00:00:00 EST 2010}
}