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Wyświetlanie 1-10 z 11
Tytuł:
Precursor Flares in OJ 287
Autorzy:
Chandra, S.
Sillanpää, A.
Berdyugin, A.
Reinthal, R.
Takalo, L.
Gopakumar, A.
Coggins-Hill, S. A.
Baliyan, K. S.
Salo, H.
Ganesh, S.
Lindfors, E.
Liakos, A.
Drozdz, M.
Santangelo, M. M. M.
Pihajoki, P.
Kozieł-Wierzbowska, Dorota
Provencal, J.
Valtonen, M.
Winiarski, Maciej
Nilsson, K.
Zoła, Stanisław
Ogłoza, W.
Opis:
We have studied three most recent precursor flares in the light curve of the blazar OJ 287 while invoking the presence of a precessing binary black hole in the system to explain the nature of these flares. Precursor flare timings from the historical light curves are compared with theoretical predictions from our model that incorporate effects of an accretion disk and post-Newtonian description for the binary black hole orbit. We find that the precursor flares coincide with the secondary black hole descending toward the accretion disk of the primary black hole from the observed side, with a mean z-component of approximately z_{c} = 4000 AU. We use this model of precursor flares to predict that precursor flare of similar nature should happen around 2020.96 before the next major outburst in 2022.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Refining the OJ 287 2022 impact flare arrival epoch
Autorzy:
Berdyugin, Andrei V.
Nilsson, Kari
Jelínek, Martin
Matsumoto, Katsura
Tornikoski, Merja
Mugrauer, Markus
Uemura, Makoto
Gopakumar, A.
Štrobl, Jan
Ciprini, Stefano
Drozdz, Marek
Zejmo, Michal
Reichart, Daniel E.
Kouprianov, Vladimir V.
Sillanpää, Aimo
Hudec, Rene
Lehto, Harry J.
Pursimo, Tapio
Valtonen, Mauri J.
Gomez, Jose L.
Zoła, Stanisław
Sadun, Alberto
Dey, Lankeswar
Lähteenmäki, Anne
Gupta, Alok C.
Imazawa, Ryo
Knudstrup, Emil
Opis:
The bright blazar OJ 287 routinely parades high brightness bremsstrahlung flares, which are explained as being a result of a secondary supermassive black hole (SMBH) impacting the accretion disc of a more massive primary SMBH in a binary system. The accretion disc is not rigid but rather bends in a calculable way due to the tidal influence of the secondary. Next, we refer to this phenomenon as a variable disc level. We begin by showing that these flares occur at times predicted by a simple analytical formula, based on general relativity inspired modified Kepler equation, which explains impact flares since 1888. The 2022 impact flare, namely flare number 26, is rather peculiar as it breaks the typical pattern of two impact flares per 12-yr cycle. This is the third bremsstrahlung flare of the current cycle that follows the already observed 2015 and 2019 impact flares from OJ 287. It turns out that the arrival epoch of flare number 26 is sensitive to the level of primary SMBH’s accretion disc relative to its mean level in our model. We incorporate these tidally induced changes in the level of the accretion disc to infer that the thermal flare should have occurred during 2022 July–August, when it was not possible to observe it from the Earth. Thereafter, we explore possible observational evidence for certain pre-flare activity by employing spectral and polarimetric data from our campaigns in 2004/05 and 2021/22. We point out theoretical and observational implications of two observed mini-flares during 2022 January–February.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
On the need of an ultramassive black hole in OJ 287
Autorzy:
Lähteenmäki, Anne
Valtonen, Mauri J
Pursimo, Tapio
Gomez, Jose L.
Drozdz, Marek
Nilsson, Kari
Sadun, Alberto
Gopakumar, A.
Imazawa, Ryo
Ciprini, Stefano
Berdyugin, Andrei V.
Matsumoto, Katsura
Sillanpää, Aimo
Gupta, Alok C.
Uemura, Makoto
Zoła, Stanisław
Jelínek, Martin
Davidson, James W.
Zejmo, Michal
Lehto, Harry J.
Knudstrup, Emil
Mugrauer, Markus
Hudec, Rene
Štrobl, Jan
Tornikoski, Merja
Reichart, Daniel E.
Dey, Lankeswar
Kouprianov, Vladimir V.
Opis:
The highly variable blazar OJ 287 is commonly discussed as an example of a binary black hole system. The 130 yr long optical light curve is well explained by a model where the central body is a massive black hole of 18.35 $\times$ 10$^{9}$ solar mass that supports a thin accretion disc. The secondary black hole of 0.15 $\times$ 10$^{9}$ solar mass impacts the disc twice during its 12 yr orbit, and causes observable flares. Recently, it has been argued that an accretion disc with a typical Active Galactic Nuclei (AGN) accretion rate and above mentioned central body mass should be at least six magnitudes brighter than OJ 287’s host galaxy and would therefore be observationally excluded. Based on the observations of OJ 287’s radio jet, detailed in Marscher and Jorstad (2011), and up-to-date accretion disc models of Azadi et al. (2022), we show that the V-band magnitude of the accretion disc is unlikely to exceed the host galaxy brightness by more than one magnitude, and could well be fainter than the host. This is because accretion power is necessary to launch the jet as well as to create electromagnetic radiation, distributed across many wavelengths, and not concentrated especially on the optical V-band. Further, we note that the claimed V-band concentration of accretion power leads to serious problems while interpreting observations of other AGN. Therefore, we infer that the mass of the primary black hole and its accretion rate do not need to be smaller than what is determined in the standard model for OJ 287.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Tytuł:
Primary black hole spin in OJ 287 as determined by the general relativity centenary flare
Autorzy:
Reichart, D. E.
Chavushyan, V.
Tomov, T.
Berdyugin, A.
Schweyer, T.
Naves Nogues, R.
Campos, F.
Poyner, G.
Lindfors, E.
Kidger, M.
Perri, M.
Joshi, A.
Jermak, H.
Neely, A. W.
Sonbas, E.
Er, H.
Tremosa Espasa, L.
Ogloza, W.
Keel, W. C.
Haislip, J. B.
Mugrauer, M.
Raj, A.
Filippenko, A. V.
Reinthal, R.
Soldán Alfaro, F. C.
Nelson, R. H.
Valero Pérez, J.
Okano, S.
Campas Torrent, M.
Saario, J.
Blay, P.
Zheng, W.
Valdes, J. R.
Provencal, J.
Harmanen, J.
Salto González, J.-L.
Erdem, A.
Matsumoto, K.
Piirola, V.
Gopinathan, M.
Strobl, J.
Pandey, J. C.
Valtonen, M. J.
Alicavus, F.
Caton, D. B.
Moore, J. P.
Carrillo Gómez, J.
Escartin Pérez, A.
Dębski, Bartłomiej
Ciprini, S.
Sameer
Kaur, N.
Reynolds, T.
Baliyan, K. S.
Verrecchia, F.
Zejmo, M.
Gazeas, K.
Hudec, R.
Drozdz, M.
Sakanoi, T.
Dalessio, J.
Dimitrov, D.
Hurst, G.
Gafton, E.
Sadakane, K.
Lozano de Haro, J.
Ivarsen, K. M.
Nilsson, K.
Garcia, F.
Steele, I.
Karjalainen, R.
Yoneda, M.
Takalo, L. O.
Sadegi, S.
Siwak, Michał
Gómez Pinilla, F.
Gopakumar, A.
Fallah Ramazani, V.
Kvammen, A.
Ganesh, S.
Jelinek, M.
Webb, J. R.
Pihajoki, P.
Boyd, D.
Lee, B. C.
Stocke, J. T.
LaCluyze, A. P.
Pursimo, T.
Zoła, Stanisław
Kagitani, M.
Telting, J.
Opis:
OJ 287 is a quasi-periodic quasar with roughly 12 year optical cycles. It displays prominent outbursts that are predictable in a binary black hole model. The model predicted a major optical outburst in 2015 December. We found that the outburst did occur within the expected time range, peaking on 2015 December 5 at magnitude 12.9 in the optical R-band. Based on Swift/XRT satellite measurements and optical polarization data, we find that it included a major thermal component. Its timing provides an accurate estimate for the spin of the primary black hole, x=0.313 $\pm$ 0.01. The present outburst also confirms the established general relativistic properties of the system such as the loss of orbital energy to gravitational radiation at the 2% accuracy level, and it opens up the possibility of testing the black hole no-hair theorem with 10% accuracy during the present decade.
Dostawca treści:
Repozytorium Uniwersytetu Jagiellońskiego
Artykuł
Wyświetlanie 1-10 z 11

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