The GENJI Programme: Gamma-Ray Emitting Notable AGN Monitoring by Japanese VLBI

Nagai, Hiroshi; Kino, Motoki; Niinuma, Kotaro; Akiyama, Kazunori; Hada, Kazuhiro; Koyama, Shoko; Orienti, M.; Hiura, Koichiro; Sawada-Satoh, Satoko; Honma, Mareki; Giovannini, G.; Giroletti, M.; Shibata, Katsunori M.; Saito, Kazuo

doi:10.1093/pasj/65.2.24

Cited by 24 publications

(9 citation statements)

References 59 publications

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“…Delay and bandpass solutions were derived using J2202+4216 and applied to all sources. The aforementioned amplitude issue was circumvented by scaling the observed flux density of J2202+4216 based on independent VLBI K-band measurements from the GENJI monitoring project (Nagai et al 2013).…”

Section: Data Reductionmentioning

confidence: 99%

VLBI observations of the G25.65+1.05 water maser superburst

Burns

Orosz

Bayandina

et al. 2019

Monthly Notices of the Royal Astronomical Society

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This paper reports observations of a 22 GHz water maser ‘superburst’ in the G25.65+1.05 massive star-forming region, conducted in response to an alert from the Maser Monitoring Organisation (M2O). Very long baseline interferometry (VLBI) observations using the European VLBI Network (EVN) recorded a maser flux density of 1.2 × 104 Jy. The superburst was investipgated in the spectral, structural, and temporal domains and its cause was determined to be an increase in maser path length generated by the superposition of multiple maser emitting regions aligning in the line of sight to the observer. This conclusion was based on the location of the bursting maser in the context of the star-forming region, its complex structure, and its rapid onset and decay.

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Section: Data Reductionmentioning

confidence: 99%

VLBI observations of the G25.65+1.05 water maser superburst

Burns

Orosz

Bayandina

et al. 2019

Monthly Notices of the Royal Astronomical Society

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“…The source is also known as a γ-ray emitter (cf. Nagai et al 2013, and references therein). Lister et al (2013) found a maximum apparent jet speed of 15.4c.…”

Section: +018 (4c+0128)mentioning

confidence: 99%

Pagan Ii: The Evolution of Agn Jets on Sub-Parsec Scales

Trippe

Kang

et al. 2015

Journal of The Korean Astronomical Society

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Abstract:We report first results from KVN and VERA Array (KaVA) VLBI observations obtained in the frame of our P lasma-physics of Active Galactic N uclei (PAGaN) project. We observed eight selected AGN at 22 and 43 GHz in single polarization (LCP) between March 2014 and April 2015. Each source was observed for 6 to 8 hours per observing run to maximize the uv coverage. We obtained a total of 15 deep high-resolution images permitting the identification of individual circular Gaussian jet components and three spectral index maps of BL Lac, 3C 111 and 3C 345 from simultaneous dual-frequency observations. The spectral index maps show trends in agreement with general expectations -flat core and steep jetswhile the actual value of the spectral index for jets shows indications for a dependence on AGN type. We analyzed the kinematics of jet components of BL Lac and 3C 111, detecting superluminal proper motions with maximum apparent speeds of about 5c. This constrains the lower limits of the intrinsic component velocities to ∼ 0.98c and the upper limits of the angle between jet and line of sight to ∼20• . In agreement with global jet expansion, jet components show systematically larger diameters d at larger core distances r, following the global relation d ≈ 0.2r, albeit within substantial scatter.

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“…In radio, NGC 1275 was regularly monitored with the Metsähovi 14 m single-dish telescope with additional VLBI observations of the VERA stations at 43 GHz (Nagai et al 2012) and the MOJAVE program at 15 GHz (discussed in Section 2.5). Moreover, the GENJI program (Nagai et al 2013) started a dense VLBI monitoring of NGC 1275 at 22 GHz in November 2010 (during the second MAGIC observation campaign). All radio data show the same trend of a flux slowly increasing with time from the component C3 during the period of interest.…”

Section: Other Multi-frequency Datamentioning

confidence: 99%

Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energyγ-rays

Aleksić¹,

Ansoldi²,

Antonelli³

et al. 2014

A&A

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Aims. The radio galaxy NGC 1275, recently identified as a very high energy (VHE, >100 GeV) γ-ray emitter by MAGIC, is one of the few non-blazar active galactic nuclei detected in the VHE regime. The purpose of this work is to better understand the origin of the γ-ray emission and locate it within the galaxy. Methods. We studied contemporaneous multifrequency observations of NGC 1275 and modeled the overall spectral energy distribution. We analyzed unpublished MAGIC observations carried out between October 2009 and February 2010, and the previously published observations taken between August 2010 and February 2011. We studied the multiband variability and correlations by analyzing data of Fermi-LAT in the 100 MeV-100 GeV energy band, as well as Chandra (X-ray), KVA (optical), and MOJAVE (radio) data taken during the same period. Results. Using customized Monte Carlo simulations corresponding to early MAGIC stereoscopic data, we detect NGC 1275 also in the earlier MAGIC campaign. The flux level and energy spectra are similar to the results of the second campaign. The monthly light curve above 100 GeV shows a hint of variability at the 3.6σ level. In the Fermi-LAT band, both flux and spectral shape variabilities are reported. The optical light curve is also variable and shows a clear correlation with the γ-ray flux above 100 MeV. In radio, three compact components are resolved in the innermost part of the jet. One of these components shows a similar trend as the Fermi-LAT and KVA light curves. The γ-ray spectra measured simultaneously with MAGIC and Fermi-LAT from 100 MeV to 650 GeV can be well fitted either by a log-parabola or by a power-law with a subexponential cutoff for the two observation campaigns. A single-zone synchrotron-self-Compton model, with an electron spectrum following a power-law with an exponential cutoff, can explain the broadband spectral energy distribution and the multifrequency behavior of the source. However, this model suggests an untypical low bulk-Lorentz factor or a velocity alignment closer to the line of sight than the parsec-scale radio jet.

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The GENJI Programme: Gamma-Ray Emitting Notable AGN Monitoring by Japanese VLBI

Cited by 24 publications

References 59 publications

VLBI observations of the G25.65+1.05 water maser superburst

VLBI observations of the G25.65+1.05 water maser superburst

Pagan Ii: The Evolution of Agn Jets on Sub-Parsec Scales

Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energyγ-rays

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