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- 1156]295 (1)
- 1606]106) – radio continuum: galaxies (1)
- 1ES 2344+514 (1)
- 3C 270) – galaxies : jets – galaxies : nuclei – radio continuum : galaxies (1)
- 3C 270) – galaxies : jets – galaxies : nuclei – radio continuum (1)
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- Accretion (1)
- Accretion disks – galaxies : active – galaxies : individual (NGC 4261 (1)
- BL Lacertae objects: general – BL Lacertae objects: individual (OJ287) – galaxies: active – galaxies: jets – polarization – radio continuum: galaxies Online-only material: color figures (1)
- BL Lacertae objects: general – galaxies: active – galaxies: jets – radio continuum: galaxies Online-only material: color figures (1)
- BL Lacertae objects: general – galaxies: active – galaxies: jets – radio continuum: galaxies Online-only material: color figures (1)
- BL Lacertae objects: individual (1ES 1959+650 (1)
- BL Lacertae objects: individual (Markarian 421) — galaxies: active — galaxies: jets — radio continuum: galaxies (1)
- BL Lacertae objects: individual (Markarian 501) – galaxies: active – galaxies: jets – radio continuum: galaxies (1)
- CTA 26 (1)
- Galaxies : active ¬– galaxies : individual (NGC 4261 (1)
- Galaxies: active — galaxies: jets — quasars: individual (3C 279) — radiation mechanisms: nonthermal — radio continuum: galaxies (1)
- Galaxies: jets – quasars: individual (0202]149 (1)
- Ice/ocean interactions (1)
- Iron oxide (1)
- Liquid crystals (1)
- Machine-readable tables (1)
- Magnetic field (1)
- Nanorods (1)
- PKS 2155 304) — galaxies: active — galaxies: jets — radio continuum: galaxies (1)
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- TeV blazars; VLBI; active galactic nuclei (1)
Articles 1 - 17 of 17
Full-Text Articles in Physics
Parsec-Scale Structure And Kinematics Of Faint Tev Hbls, B. Glenn Piner, Philip G. Edwards
Parsec-Scale Structure And Kinematics Of Faint Tev Hbls, B. Glenn Piner, Philip G. Edwards
Physics
We present new multi-epoch Very Long Baseline Array (VLBA) observations of a set of TeV blazars drawn from our VLBA program to monitor all TeV-detected high-frequency peaked BL Lac objects (HBLs) at parsec scales. Most of these sources are faint in the radio, so they have not been well observed with VLBI by other surveys. Our previous measurements of apparent jet speeds in TeV HBLs showed apparent jet speeds that were subluminal or barely superluminal, suggesting jets with velocity structures at the parsec-scale. Here we present apparent jet speed measurements for eight new TeV HBLs, which for the first time …
The Giant Radio Array For Neutrino Detection, Jordan C. Hanson, Olivier Martineau-Huynh, Kumiko Kotera, Mauricio Bustamente, Didier Charrier, Sijbrand De Jong, Krijn D. De Vries, Ke Fang, Zhaoyang Feng, Chad Finley, Quanbu Gou, Junhua Gu, Hongbo Hu, Kohta Murase, Valentin Niess, Foteini Oikonomou, Nicolas Renault-Tinacci, Julia Schmid, Charles Timmermans, Zhen Wang, Xiangping Wu, Jianli Zhang, Yi Zhang
The Giant Radio Array For Neutrino Detection, Jordan C. Hanson, Olivier Martineau-Huynh, Kumiko Kotera, Mauricio Bustamente, Didier Charrier, Sijbrand De Jong, Krijn D. De Vries, Ke Fang, Zhaoyang Feng, Chad Finley, Quanbu Gou, Junhua Gu, Hongbo Hu, Kohta Murase, Valentin Niess, Foteini Oikonomou, Nicolas Renault-Tinacci, Julia Schmid, Charles Timmermans, Zhen Wang, Xiangping Wu, Jianli Zhang, Yi Zhang
Physics
High-energy neutrino astronomy will probe the working of the most violent phenomena in the Universe. The Giant Radio Array for Neutrino Detection (GRAND) project consists of an array of ∼ 105 radio antennas deployed over ∼ 200 000 km2 in a mountainous site. It aims at detecting high-energy neutrinos via the measurement of air showers induced by the decay in the atmosphere of τ leptons produced by the interaction of cosmic neutrinos under the Earth surface. Our objective with GRAND is to reach a neutrino sensitivity of 5 × 10−11E−2 GeV−1 cm−2 s …
Radar Absorption, Basal Reflection, Thickness And Polarization Measurements From The Ross Ice Shelf, Antarctica, Jordan C. Hanson, Steven W. Barwick, Eric C. Berg, Dave Z. Besson, Thorin J. Duffin, Spencer R. Klein, Stuart A. Kleinfelder, Corey Reed, Mahshid Roumi, Thorsten Stezelberger, Joulien Tatar, James A. Walker, Liang Zou
Radar Absorption, Basal Reflection, Thickness And Polarization Measurements From The Ross Ice Shelf, Antarctica, Jordan C. Hanson, Steven W. Barwick, Eric C. Berg, Dave Z. Besson, Thorin J. Duffin, Spencer R. Klein, Stuart A. Kleinfelder, Corey Reed, Mahshid Roumi, Thorsten Stezelberger, Joulien Tatar, James A. Walker, Liang Zou
Physics
Radio-glaciological parameters from the Moore’s Bay region of the Ross Ice Shelf, Antarctica, have been measured. The thickness of the ice shelf in Moore’s Bay was measured from reflection times of radio-frequency pulses propagating vertically through the shelf and reflecting from the ocean, and is found to be 576 ± 8 m. Introducing a baseline of 543 ± 7m between radio transmitter and receiver allowed the computation of the basal reflection coefficient, R, separately from englacial loss. The depth-averaged attenuation length of the ice column, 〈L〉 is shown to depend linearly on frequency. The best fit (95% confidence level) is …
First-Epoch Vlba Imaging Of 20 New Tev Blazars, B. Glenn Piner, Philip G. Edwards
First-Epoch Vlba Imaging Of 20 New Tev Blazars, B. Glenn Piner, Philip G. Edwards
Physics
We present Very Long Baseline Array (VLBA) images of 20 TeV blazars not previously well studied on the parsec scale. All 20 of these sources are high-frequency peaked BL Lac objects (HBLs). Observations were made between August and December of 2013 at a frequency of 8.4 GHz. These observations represent the first epoch of a VLBA monitoring campaign on these blazars, and they significantly increase the fraction of TeV HBLs studied with high-resolution imaging. The peak very long baseline interferometry (VLBI) flux densities of these sources range from ~10 to ~100 mJy bm–1, and parsec-scale jet structure is detected in …
Magnetically Actuated Liquid Crystals, Serkan Zorba, Mingsheng Wang, Le He, Yadong Yin
Magnetically Actuated Liquid Crystals, Serkan Zorba, Mingsheng Wang, Le He, Yadong Yin
Physics
Ferrimagnetic inorganic nanorods have been used as building blocks to construct liquid crystals with optical properties that can be instantly and reversibly controlled by manipulating the nanorod orientation using considerably weak external magnetic fields (1 mT). Under an alternating magnetic field, they exhibit an optical switching frequency above 100 Hz, which is comparable to the performance of commercial liquid crystals based on electrical switching. By combining magnetic alignment and lithography processes, it is also possible to create patterns of different polarizations in a thin composite film and control over the transmittance of light in particular areas. Developing such magnetically responsive …
The Parsec-Scale Structure Of The Newer Tev Blazars, Glenn Piner
The Parsec-Scale Structure Of The Newer Tev Blazars, Glenn Piner
Physics
We expand our previous studies of the parsec-scale structure of TeV blazars by presenting first- epoch images from VLBA monitoring of ten newer TeV HBLs. All ten sources were successfully detected and imaged, and all showed a one-sided core-jet structure. Many display a morphology common to TeV HBLs: a short, collimated jet followed by a transition to low surface brightness extended emission with a much broader opening angle. The newly detected TeV HBLs tend to be fainter in the radio; the median core flux density was 22 mJy, and the median brightness temperature was 8 × 109 K. The brightness …
Magnetic Tuning Of Plasmonic Excitation Of Gold Nanorods, Serkan Zorba, Mingsheng Wang, Chuanbo Gao, Le He, Jinzhong Zhang, Chi Tang, Yadong Yin
Magnetic Tuning Of Plasmonic Excitation Of Gold Nanorods, Serkan Zorba, Mingsheng Wang, Chuanbo Gao, Le He, Jinzhong Zhang, Chi Tang, Yadong Yin
Physics
By using gold nanorods as an example, we report the dynamic and reversible tuning of the plasmonic property of anisotropically shaped colloidal metal nanostructures by controlling their orientation using external magnetic fields. The magnetic orientational control enables instant and selective excitation of the plasmon modes of AuNRs through the manipulation of the field direction relative to the directions of incidence and polarization of light.
Dark Matter And Dark Energy As Inertial Effects, Serkan Zorba
Dark Matter And Dark Energy As Inertial Effects, Serkan Zorba
Physics
A disk-shaped universe (encompassing the observable universe) rotating globally with an angular speed equal to the Hubble constant is postulated. It is shown that dark energy and dark matter are cosmic inertial effects resulting from such a cosmic rotation, corresponding to centrifugal (dark energy), and a combination of centrifugal and the Coriolis forces (dark matter), respectively. The physics and the cosmological and galactic parameters obtained from the model closely match those attributed to dark energy and dark matter in the standard Λ-CDM model.
Erratic Jet Wobbling In The Bl Lacertae Object Oj287 Revealed By Sixteen Years Of 7mm Vlba Observations, B. Glenn Piner, Alan P. Marscher, Svetlana G. Jorstad, Jose L. Gomez, Manel Perucho, Maria Rioja, Richard Dodson
Erratic Jet Wobbling In The Bl Lacertae Object Oj287 Revealed By Sixteen Years Of 7mm Vlba Observations, B. Glenn Piner, Alan P. Marscher, Svetlana G. Jorstad, Jose L. Gomez, Manel Perucho, Maria Rioja, Richard Dodson
Physics
No abstract provided.
The Jets Of Tev Blazars At Higher Resolution: 43 Ghz And Polarimetric Vlba Observations From 2005-2009, B. Glenn Piner, Philip G. Edwards
The Jets Of Tev Blazars At Higher Resolution: 43 Ghz And Polarimetric Vlba Observations From 2005-2009, B. Glenn Piner, Philip G. Edwards
Physics
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, 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 two to three higher resolution than has previously been attained. Most of the remaining images map the linear polarization structures at a lower frequency of 22 GHz. We discuss the transverse structures of the jets as revealed by the high-frequency …
Significant Limb-Brightening In The Inner Parsec Of Markarian 501, Glenn Piner
Significant Limb-Brightening In The Inner Parsec Of Markarian 501, Glenn Piner
Physics
We present three 43 GHz images and a single 86 GHz image of Markarian 501 from VLBA observations in 2005. The 86 GHz image shows a partially resolved core with a flux density of about 200 mJy and a size of about 300 Schwarzschild radii, similar to recent results by Giroletti et al. Extreme limb-brightening is found in the inner parsec of the jet in the 43 GHz images, providing strong observational support for a “spine–layer” structure at this distance from the core. The jet is well-resolved transverse to its axis, allowing Gaussian model components to be fit to each …
Vlba Polarization Observations Of Markarian 421 After A Gamma-Ray High State, B. Glenn Piner, Philip G. Edwards
Vlba Polarization Observations Of Markarian 421 After A Gamma-Ray High State, B. Glenn Piner, Philip G. Edwards
Physics
We present four high dynamic range, dual-circular polarization, Very Long Baseline Array (VLBA) observations at 22 GHz of Mrk 421, taken throughout the year following the source's unprecedented gamma-ray high state in early 2001. Previous VLBI observations of this source had shown only subluminal apparent motions in the parsec-scale jet and no apparent connection between jet components and gamma-ray flares, so we examined whether the larger gamma-ray flares of 2001 had produced a component that could be followed on the parsec-scale VLBA images. These four new VLBA observations are combined with data from our earlier 1999 paper and archival VLBA …
The Parsec-Scale Structure And Jet Motions Of The Tev Blazars 1es 1959+650, Pks 2155-304, And 1es 2344+514, B. Glenn Piner, Philip G. Edwards
The Parsec-Scale Structure And Jet Motions Of The Tev Blazars 1es 1959+650, Pks 2155-304, And 1es 2344+514, B. Glenn Piner, Philip G. Edwards
Physics
As part of our study of the VLBI properties of TeV blazar jets, we present here a series of high-resolution 15 GHz Very Long Baseline Array (VLBA) images of the parsec-scale jets of the TeV blazars 1ES 1959+650, PKS 2155-304, and 1ES 2344+514, with linear resolutions of ~0.5 pc. Each of these sources was observed with the VLBA at three or four epochs during 1999 and 2000. There is a notable lack of any strong moving components on the VLBI images (in contrast to the rapid superluminal motions seen in EGRET blazars), and the structure of the VLBI jet can …
The Speed And Orientation Of The Parsec-Scale Jet In 3c 279, B. Glenn Piner, Stephen C. Unwind, Ann E. Wehrle, Alma C. Zook, C. Megan Urry, Diane M. Gilmore
The Speed And Orientation Of The Parsec-Scale Jet In 3c 279, B. Glenn Piner, Stephen C. Unwind, Ann E. Wehrle, Alma C. Zook, C. Megan Urry, Diane M. Gilmore
Physics
A high degree of relativistic beaming is inferred for the jets of blazars on the basis of several lines of evidence, but the intrinsic speed and angle of the jet to the line of sight for individual sources are difficult to measure. We have calculated inverse Compton Doppler factors for 3C 279 using the collection of VLBI data (including high-resolution space VLBI data at low frequencies) recently published by us (as Wehrle et al. and Piner et al.) and the collection of multiwavelength spectra recently published by Hartman et al. From the Doppler factor and superluminal apparent speed, we then …
Orientation And Speed Of The Parsec-Scale Jet In Ngc4261 (3c270), B. Glenn Piner, Dayton L. Jones, Ann E. Wehrle
Orientation And Speed Of The Parsec-Scale Jet In Ngc4261 (3c270), B. Glenn Piner, Dayton L. Jones, Ann E. Wehrle
Physics
NGC 4261 (3C 270) is an elliptical galaxy containing a 300 pc–scale nuclear disk of gas and dust imaged by the Hubble Space Telescope (HST), around a central supermassive black hole. Previous VLBI observations of NGC 4261 revealed a gap in emission in the radio counterjet, presumably due to free-free absorption in the inner parsec of the accretion disk. Here we present three 8 GHz VLBA observations of NGC 4261 that allow us to monitor the location and depth of the gap and check for motions in the jet and counterjet. The separation between the brightest peak and …
In The Shadow Of The Accretion Disk: Higher Resolution Imaging Of The Central Parsec In Ngc 4261, B. Glenn Piner, Dayton L. Jones, Ann E. Wehrle, David L. Meier
In The Shadow Of The Accretion Disk: Higher Resolution Imaging Of The Central Parsec In Ngc 4261, B. Glenn Piner, Dayton L. Jones, Ann E. Wehrle, David L. Meier
Physics
The physical conditions in the inner parsec of accretion disks believed to orbit the central black holes in active galactic nuclei can be probed by imaging the absorption (by ionized gas in the disk) of background emission from a radio counterjet. We report high angular resolution VLBI observations of the nearby (~40 Mpc) radio galaxy NGC 4261 that confirm free-free absorption of radio emission from a counterjet by a geometrically thin, nearly edge-on disk at 1.6, 4.8, and 8.4 GHz. The angular width and depth of the absorption appears to increase with decreasing frequency, as expected. We derive an average …
Geodetic Vlbi Observations Of Egret Blazars, B. Glenn Piner, Kerry A. Kingham
Geodetic Vlbi Observations Of Egret Blazars, B. Glenn Piner, Kerry A. Kingham
Physics
We present VLBI observations of the EGRET quasars 0202+149, CTA 26, and 1606+106, as well as additional analysis of VLBI observations of 1156+295 presented in a previous letter. We have produced 8 and 2 GHz VLBI images at 11 epochs, 8 epochs, and 12 epochs, spanning the years 1989-1996, of 0202+149, CTA 26, and 1606+106, respectively. The VLBI data have been taken from the Washington VLBI correlator's geodetic database. We have measured the apparent velocities of the jet components and find that CTA 26 and 1606+106 are superluminal sources, with average apparent speeds of 8.9 and 2.9 h-1c …