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Extragalactic jets are inferred to harbor dynamically important, organized magnetic fields which presumably aid in the collimation of the relativistic jet flows. We here explore by means of grid-adaptive, high resolution numerical…

天体物理学 · 物理学 2009-11-13 R. Keppens , Z. Meliani , B. van der Holst , F. Casse

High-resolution Very-Long-Baseline Interferometry observations of relativistic jets are essential to constrain fundamental parameters of jet formation models. At a distance of 249 Mpc, Cygnus A is a unique target for such studies, being the…

高能天体物理现象 · 物理学 2015-12-16 B. Boccardi , T. P. Krichbaum , U. Bach , F. Mertens , E. Ros , W. Alef , J. A. Zensus

Jets are a ubiquitous part of the accretion process, created in AGN, by a coupling between the magnetic field near the central black hole and inflowing material. We point out what advances can be achieved by new technologies, concentrating…

We report first results from KVN and VERA Array (KaVA) VLBI observations obtained in the frame of our Plasma-physics of Active Galactic Nuclei (PAGaN) project. We observed eight selected AGN at 22 and 43 GHz in single polarization (LCP)…

In large-scale optical spectroscopic surveys, there are many objects found to have multiple redshift measurements due to the weakness of their emission lines and the different automatic identification algorithms used. These include some…

星系天体物理 · 物理学 2020-08-05 Tao An , Yingkang Zhang , Sandor Frey

We report on results from new high-sensitivity, high-resolution 86GHz (3.5 millimeter) observations of the jet base in the nearby radio galaxy M87, obtained by the Very Long Baseline Array in conjunction with the Green Bank Telescope. The…

In the current paradigm, it is believed that the compact VLBI radio core of radio-loud AGNs represents the innermost upstream regions of relativistic outflows. These regions of AGN jets have generally been modeled by a conical outflow with…

高能天体物理现象 · 物理学 2017-01-11 Juan-Carlos Algaba , Masanori Nakamura , Keiichi Asada , Sang-Sung Lee

Strong observational evidence indicates that all extragalactic jets associated with AGNs move at relativistic speed up to 100 pc - 1 kpc scales from the nucleus. At larger distances, reflecting the Fanaroff-Riley radio source…

天体物理学 · 物理学 2009-11-13 P. Rossi , A. Mignone , G. Bodo , S. Massaglia , A. Ferrari

We report a measurement of transverse momentum spectra of jets detected with the ALICE detector in Pb-Pb collisions at sqrt(sNN)=2.76 TeV. Jets are reconstructed from charged particles using the anti-kt jet algorithm. The background from…

核实验 · 物理学 2019-08-21 Marta Verweij

If the transverse jet B fields observed in BL Lac objects on parsec scales represent the toroidal component of the jet B fields, this should give rise to rotation-measure gradients across the jets, due to the systematic change in the…

天体物理学 · 物理学 2007-05-23 D. C. Gabuzda , E. Murray , P. Cronin

The ATLAS collaboration has introduced and implemented a strategy for selecting and analyzing large-radius jets composed of skinny $R=0.2$ subjets in heavy ion collisions at the LHC. We show how measurements of these jets teach us about the…

高能物理 - 唯象学 · 物理学 2025-05-26 Arjun Srinivasan Kudinoor , Daniel Pablos , Krishna Rajagopal

We present 1625 new 15 GHz (2 cm) VLBA images of 295 jets associated with active galactic nuclei (AGNs) from the MOJAVE and 2 cm VLBA surveys, spanning observations between 1994 Aug 31 and 2013 Aug 20. For 274 AGNs with at least 5 VLBA…

High redshift active galactic nuclei (AGN) provide key insights into early supermassive black hole growth and cosmic evolution. This study investigates the parsec-scale properties of 86 radio-loud quasars at z $\geq$ 3 using very long…

高能天体物理现象 · 物理学 2025-02-24 Shaoguang Guo , Tao An , Yuanqi Liu , Chuanzeng Liu , Zhijun Xu , Yulia Sotnikova , Timur Mufakharov , Ailing Wang

High-resolution Very-Long-Baseline Interferometry observations of NGC 1052 show a two sided jet with several regions of enhanced emission and a clear emission gap between the two jets.This gap shrinks with increasing frequency and vanishes…

高能天体物理现象 · 物理学 2019-08-28 C. M. Fromm , Z. Younsi , A. Bazcko , Y. Mizuno , O. Porth , M. Perucho , H. Olivares , A. Nathanail , E. Angelakis , E. Ros , J. A. Zensus , L. Rezzolla

Two-dimensional (2D) jet tomography is a promising tool to study jet medium modification in high-energy heavy-ion collisions. It combines gradient (transverse) and longitudinal jet tomography for selection of events with localized initial…

高能物理 - 唯象学 · 物理学 2024-02-02 Yu-Xin Xiao , Yayun He , Long-Gang Pang , Hanzhong Zhang , Xin-Nian Wang

Extragalactic jets are a common feature of radio-loud active galaxies. The nature of the observed jets in relation to the bulk flow is still unclear. In particular it is not clear whether the observations of parsec-scale jets using the very…

高能天体物理现象 · 物理学 2015-02-13 Manel Perucho

The structure and dynamics of the M87 jet from sub-milli-arcsec to arcsecond scales are continuously examined. We analysed the VLBA archival data taken at 43 and 86 GHz to measure the size of VLBI cores. Millimeter/sub-mm VLBI cores are…

高能天体物理现象 · 物理学 2015-06-16 Masanori Nakamura , Keiichi Asada

Millimeter-VLBI images probe as deep as never before the nuclei of AGN. Global 3mm-VLBI where the VLBA is combined with sensitive European stations, gives CLEAN maps of a quality, which never before was so good. VLBI at 147 GHz yields…

天体物理学 · 物理学 2007-05-23 T. P. Krichbaum , D. A. Graham , A. Witzel , J. A. Zensus , A. Greve , H. Ungerechts , M. Grewing

We present our implementation of an automated VLBI data reduction pipeline dedicated to interferometric data imaging and analysis. The pipeline can handle massive VLBI data efficiently which makes it an appropriate tool to investigate…

天体物理仪器与方法 · 物理学 2017-12-07 M. Zhang , A. Collioud , P. Charlot

Seyfert galaxies and quasars were first discovered through optical and radio techniques, but in recent years high-energy emission, that can penetrate central gas and dust, has become essentially the defining characteristic of an AGN. AGNs…

天体物理学 · 物理学 2007-05-23 D. M. Worrall