7 research outputs found
Spitzer Observations of the Predicted Eddington Flare from Blazar OJ 287
Binary black hole (BH) central engine description for the unique blazar OJ
287 predicted that the next secondary BH impact-induced bremsstrahlung flare
should peak on 2019 July 31. This prediction was based on detailed general
relativistic modeling of the secondary BH trajectory around the primary BH and
its accretion disk. The expected flare was termed the Eddington flare to
commemorate the centennial celebrations of now-famous solar eclipse
observations to test general relativity by Sir Arthur Eddington. We analyze the
multi-epoch Spitzer observations of the expected flare between 2019 July 31 and
2019 September 6, as well as baseline observations during 2019 February-March.
Observed Spitzer flux density variations during the predicted outburst time
display a strong similarity with the observed optical pericenter flare from OJ
287 during 2007 September. The predicted flare appears comparable to the 2007
flare after subtracting the expected higher base-level Spitzer flux densities
at 3.55 and 4.49 m compared to the optical R-band. Comparing the 2019 and
2007 outburst lightcurves and the previously calculated predictions, we find
that the Eddington flare arrived within 4 hours of the predicted time. Our
Spitzer observations are well consistent with the presence of a nano-Hertz
gravitational wave emitting spinning massive binary BH that inspirals along a
general relativistic eccentric orbit in OJ 287. These multi-epoch Spitzer
observations provide a parametric constraint on the celebrated BH no-hair
theorem.Comment: 8 pages, 4 figures, 1 table, to appear in ApJ
Polarization and Spectral Energy Distribution in OJ 287 during the 2016/17 Outbursts
We report optical photometric and polarimetric observations of the
blazar OJ 287 gathered during 2016/17. The high level of activity,
noticed after the General Relativity Centenary flare, is argued to be
part of the follow-up flares that exhibited high levels of polarization
and originated in the primary black hole jet. We propose that the
follow-up flares were induced as a result of accretion disk
perturbations, traveling from the site of impact towards the primary
SMBH. The timings inferred from our observations allowed us to estimate
the propagation speed of these perturbations. Additionally, we make
predictions for the future brightness of OJ 287.</p
Introducing astronomy: a way to renovate school curricula
One of the most urgent tasks facing society today is to make science more attractive to the younger generation and to foster the continuous improvement of the knowledge and skills. These objectives assume ever greater importance because, firstly, young people are opting less
and less for scientific studies, secondly, we need to establish new starting points for them in order that they could better understand and improve our changing world. To achieve these aims, it is necessary to expand innovation in secondary education. In this paper, a few suggestions, which can help assess and prioritize the usefulness of astronomy-related material for improving the educational process, are presented