AGNS and MICROQUASARS As High-Energy γ-Ray Sources

Paredes, J. M.

doi:10.1007/s10509-005-1177-8

Cited by 6 publications

(5 citation statements)

References 29 publications

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“…One can also anticipate that additional WRG-like microquasars will possibly emerge in the near future when modern interferometers other than the existing Jansky VLA or eMERLIN, such as the Square Kilometre Array and MeerKAT, become available. Although a quantitative prediction is not straightforward, this expectation appears conceivable when considering that nearly one-third of confirmed microquasars currently known in the Galaxy 44 display compelling evidence of interaction with their ambient ISM. This includes not only co-location within a dense molecular cloud 45 , 46 but also deceleration of the relativistic ejecta 47 , direct jet collision with nearby clouds 48 , and long-distance effects due to jet impact 49 , in addition to the Cygnus X-1 jet-driven bubble mentioned above 28 .…”

Section: Discussionmentioning

confidence: 99%

A galactic microquasar mimicking winged radio galaxies

et al. 2017

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A subclass of extragalactic radio sources known as winged radio galaxies has puzzled astronomers for many years. The wing features are detected at radio wavelengths as low-surface-brightness radio lobes that are clearly misaligned with respect to the main lobe axis. Different models compete to account for these peculiar structures. Here, we report observational evidence that the parsec-scale radio jets in the Galactic microquasar GRS 1758-258 give rise to a Z-shaped radio emission strongly reminiscent of the X and Z-shaped morphologies found in winged radio galaxies. This is the first time that such extended emission features are observed in a microquasar, providing a new analogy for its extragalactic relatives. From our observations, we can clearly favour the hydrodynamic backflow interpretation against other possible wing formation scenarios. Assuming that physical processes are similar, we can extrapolate this conclusion and suggest that this mechanism could also be at work in many extragalactic cases.

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Section: Discussionmentioning

confidence: 99%

A galactic microquasar mimicking winged radio galaxies

et al. 2017

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“…This is the main fingerprint of blazar active galactic nuclei (AGN) which are well known sources of high energy gamma-rays (see e.g. Paredes 2005). 4,6,8,10,12,14,16,20,25,30,35,40,50,60,80 and 100 times 0.12 mJy beam −1 , the rms noise.…”

Section: A Blazar Candidate Counterpart For the Whipple Emission?mentioning

confidence: 99%

“…This is the main fingerprint of blazar active galactic nuclei (AGN) which are well known sources of high energy gamma-rays (see e.g. Paredes 2005).…”

Section: A Blazar Candidate Counterpart For the Whipple Emission?mentioning

confidence: 99%

Deep radio images of the HEGRA and Whipple TeV sources in the Cygnus OB2 region

Martı́

Paredes

Chandra

et al. 2007

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Context. The modern generation of Cherenkov telescopes has revealed a new population of gamma-ray sources in the Galaxy. Some of them have been identified with previously known X-ray binary systems while other remain without clear counterparts a lower energies. Our initial goal here was reporting on extensive radio observations of the first extended and yet unidentified source, namely TeV J2032+4130. This object was originally detected by the HEGRA telescope in the direction of the Cygnus OB2 region and its nature has been a matter of debate during the latest years. The situation has become more complex with the Whipple and MILAGRO telescopes new TeV detections in the same field which could be consistent with the historic HEGRA source, although a different origin cannot be ruled out. Aims. We aim to pursue our radio exploration of the TeV J2032+4130 position that we initiated in a previous paper but taking now into account the latest results from new Whipple and MILAGRO TeV telescopes. The data presented here are an extended follow up of our previous work. Methods. Our investigation is mostly based on interferometric radio observations with the Giant Metre Wave Radio Telescope (GMRT) close to Pune (India) and the Very Large Array (VLA) in New Mexico (USA). We also conducted near infrared observations with the 3.5 m telescope and the OMEGA2000 camera at the Centro Astronómico Hispano Alemán (CAHA) in Almería (Spain).Results. We present deep radio maps centered on the TeV J2032+4130 position at different wavelengths. In particular, our 49 and 20 cm maps cover a field of view larger than half a degree that fully includes the Whipple position and the peak of MILAGRO emission. Our most important result here is a catalogue of 153 radio sources detected at 49 cm within the GMRT antennae primary beam with a full width half maximum (FWHM) of 43 arc-minute. Among them, peculiar sources inside the Whipple error ellipse are discussed in detail, including a likely double-double radio galaxy and a one-sided jet source of possible blazar nature. This last object adds another alternative counterpart possibility to be considered for both the HEGRA, Whipple and MILAGRO emission. Moreover, our multi-configuration VLA images reveal the non-thermal extended emission previously reported by us with improved angular resolution. Its non-thermal spectral index is also confirmed thanks to matching beam observations at the 20 and 6 cm wavelengths.

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“…When MQ were discovered, it was the presence of extended radio jets that led to the use of the term microquasar for this kind of X-ray binaries, as they seemed to be much smaller galactic coun-terparts of active galactic nuclei (ANG -or quasars-) with jets (Geldzahler et al 1989;Fomalont & Geldzahler 1991;Mirabel et al 1992). The association between MQ and AGN was strengthened even further once the relativistic nature of the jets of MQ was revealed (Mirabel & Rodríguez 1994), and gamma-rays were proposed as coming for microquasar candidates (e.g., Paredes 2005, and references therein). Later on, MQ were also associated to gamma-ray bursts (GRB), as the engines of GRB are also based on the accretion-ejection phenomenon, and it was even proposed that MQ energetic radiation could have played a role in the Universe evolution (e.g.…”

Section: Introductionmentioning

confidence: 99%

Relativistic hydrodynamical simulations of the effects of the stellar wind and the orbit on high-mass microquasar jets

Barkov

Bosch‐Ramon

2021

Monthly Notices of the Royal Astronomical Society

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High-mass microquasar jets, produced in an accreting compact object in orbit around a massive star, must cross a region filled with stellar wind. The combined effects of the wind and orbital motion can strongly affect the jet properties on binary scales and beyond. The study of such effects can shed light on how high-mass microquasar jets propagate and terminate in the interstellar medium. We study for the first time, using relativistic hydrodynamical simulations, the combined impact of the stellar wind and orbital motion on the properties of high-mass microquasar jets on binary scales and beyond. We have performed 3-dimensional relativistic hydrodynamic simulations, using the PLUTO code, of a microquasar scenario in which a strong weakly relativistic wind from a star interacts with a relativistic jet under the effect of the binary orbital motion. The parameters of the orbit are chosen such that the results can provide insight on the jet-wind interaction in compact systems like for instance Cyg X-1 or Cyg X-3. The wind and jet momentum rates are set to values that may be realistic for these sources and lead to moderate jet bending, which together with the close orbit and jet instabilities could trigger significant jet precession and disruption. For high-mass microquasars with orbit size a ∼ 0.1 AU, and (relativistic) jet power $L_j\sim 10^{37}(\dot{M}_w/10^{-6}\, {\rm M}_\odot \, {\rm yr}^{-1})$ erg s−1, where $\dot{M}_w$ is the stellar wind mass rate, the combined effects of the stellar wind and orbital motion can induce relativistic jet disruption on scales ∼1 AU.

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AGNS and MICROQUASARS As High-Energy γ-Ray Sources

Cited by 6 publications

References 29 publications

A galactic microquasar mimicking winged radio galaxies

A galactic microquasar mimicking winged radio galaxies

Deep radio images of the HEGRA and Whipple TeV sources in the Cygnus OB2 region

Relativistic hydrodynamical simulations of the effects of the stellar wind and the orbit on high-mass microquasar jets

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