Here we apply a technique selecting quasar candidates purely as sources with zero proper motions in the Gaia data release 2 (DR2). We demonstrate that this...
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PublicationUnidentified quasars among stationary objects from Gaia DR2
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PublicationUnravelling the nature of the dual AGN in the galaxy pair system IRAS 05589+2828 and 2MASX J06021107 + 2828382
We have studied the nuclear region of the previously detected dual AGN system in the galaxy pair IRAS 05589 + 2828 and 2MASX J06021107 + 2828382, through new...
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PublicationUnveiling the monster heart: unbeamed properties of blazar 4C 71.07
4C 71.07 is a high-redshift blazar whose optical radiation is dominated by quasar-like nuclear emission. We here present the results of a spectroscopic...
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PublicationUV and optical variability of the low luminosity quasar PG 1351+64
PG 1351+64 is a bright radio quiet quasar (z = 0.088, mV ≅ 14). IUE observations obtained within few months in 1982 - 1983 showed variations in the 1200 - 2000...
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PublicationVariability of the blazar 4C 38.41 (B3 1633+382) from GHz frequencies to GeV energies
Context. After years of modest optical activity, the quasar-type blazar 4C 38.41 (B3 1633+382) experienced a large outburst in 2011, which was detected...
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PublicationVery High Energy γ-Rays from the Universe's Middle Age: Detection of the z = 0.940 Blazar PKS 1441+25 with MAGIC
The flat-spectrum radio quasar PKS 1441+25 at a redshift of z = 0.940 is detected between 40 and 250 GeV with a significance of 25.5σ using the MAGIC telescopes...
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PublicationVery high redshift quasars and the rapid emergence of supermassive black holes
The observation of quasars at very high redshift such as Pōniuā'ena is a challenge for models of supermassive black hole (SMBH) formation. This work presents a...
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PublicationVery-High-Energy γ-Ray Observations of a Strong Flaring Activity in M 87 in 2008 February
M 87 is the only known non blazar radio galaxy to emit very high energy (VHE) gamma-rays. During a monitoring program of M 87, a rapid flare in VHE gamma-rays...
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PublicationVHE gamma-ray detection of FSRQ QSO B1420+326 and modeling of its enhanced broadband state in 2020
Context. QSO B1420+326 is a blazar classified as a flat-spectrum radio quasar (FSRQ). At the beginning of the year 2020, it was found to be in an enhanced flux...