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- Istituto Nazionale di Fisica Nucleare, Sezione di MilanoIT369 papers
- Brera Astronomical ObservatoryIT367 papers
- National Institute for AstrophysicsIT354 papers
- University of Milano-BicoccaIT255 papers
- University of MilanIT233 papers
- Centre National de la Recherche ScientifiqueFR220 papers
- Istituto Nazionale di Fisica Nucleare, Sezione di Milano BicoccaIT216 papers
- University of PaduaIT178 papers
- Osservatorio Astronomico di PadovaIT153 papers
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- Astronomical Observatory of RomeIT117 papers
11 papers · 2 filters
Radio-loud AGNs at high redshifts and the cosmic microwave background
G. Ghisellini, A. Celotti, F. Tavecchio +2
We discuss how the interaction between the electrons in a relativistic jet and the Cosmic Microwave Background (CMB) affects the observable properties of radio-loud AGN at early ep…
Spectroscopy of Optically Selected BL Lac Objects and their gamma-ray emission
A. Sandrinelli, A. Treves, R. Falomo +4
We present Very Large Telescope optical spectroscopy of nine BL Lac objects of unknown redshift belonging to the list of optically selected radio loud BL Lacs candidates. We explor…
Black-hole mass estimates for a homogeneous sample of bright flat-spectrum radio quasars
Gianluca Castignani, Francesco Haardt, Andrea Lapi +3
We have selected a complete sample of flat-spectrum radio quasars (FSRQs) from the WMAP 7-yr catalog within the SDSS area, all with measured redshift, and have compared the black h…
NuSTAR detection of the blazar B2 1023+25 at redshift 5.3
T. Sbarrato, G. Tagliaferri, G. Ghisellini +19
B2 1023+25 is an extremely radio-loud quasar at z=5.3 which was first identified as a likely high-redshift blazar candidate in the SDSS+FIRST quasar catalog. Here we use the Nuclea…
Can supermassive black hole seeds form in galaxy mergers?
A. Ferrara, F. Haardt, R. Salvaterra
It has been recently suggested that supermassive black holes at z = 5-6 might form from super-fast (\dot M > 10^4 Msun/yr) accretion occurring in unstable, massive nuclear gas disk…
The role of relativistic jets in the heaviest and most active supermassive black holes at high redshift
G. Ghisellini, F. Haardt, R. Della Ceca +2
In powerful radio-quiet active galactic nuclei (AGN), black holes heavier than one billion solar masses form at a redshift ~1.5-2. Supermassive black holes in jetted radio-loud AGN…