相关论文: Model simulation of optical light curves for blaza…

Light curves for more than century optical photometric observations of the blazar OJ 287 reveals strong flares with a quasi-period of about 12 years. For a long time, this period has been interpreted by processes in a binary black hole…

The optical light curve of the Be/neutron star binary AX J0049.4-7323 has been investigated using data from the MACHO and OGLE-II projects. This X-ray source, whose neutron star has a very slow rotation rate (P_pulse=755.5 sec), shows…

We present a long term optical $R$ band light curve analysis of the gravitationally lensed blazar AO 0235+164 in the time span 1982 - 2019. Several methods of analysis lead to the result that there is a periodicity of ~8.13 years present in…

We have studied long-term optical, ultraviolet (UV) and X-ray observations of OJ 287 collected with the UVOT and XRT instruments mounted on board the Swift satellite to quantify spectral and temporal variability patterns observed during…

A super-massive black hole (SMBH) binary in the core of the blazar OJ 287 has been invoked in previous works to explain its observed optical flare quasi-periodicity. Following this picture, we investigate a hadronic origin for the X-ray and…

In February 2017, the blazar OJ~287 underwent a period of intense multiwavelength activity. It reached a new historic peak in the soft X-ray (0.3-10 keV) band, as measured by Swift-XRT. This event coincides with a very-high-energy (VHE)…

We have obtained simultaneous optical and near infrared observations of 4U 1543-47 during its 2002 outburst. The most striking feature of the outburst light curve is the secondary maximum which appears after the object transitions into the…

OJ 287 is a well-studied binary black hole system, that occasionally exhibits bright X-ray and optical flares. Here we present a detailed spectral study of its second brightest X-ray flare observed during 2019-2020 using archival Swift and…

We present a multi-wavelength spectral and temporal investigation of OJ 287 emission during its strong optical-to-X-ray activity between July 2016 - July 2017. The daily $\gamma$-ray fluxes from \emph{Fermi}-LAT are consistent with no…

We report the study of a huge optical intraday flare on November 12, 2021, at 2 am UT, in the blazar OJ287. In the binary black hole model it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our…

We present a detailed investigation of the flaring activity observed from a BL Lac object, S5 0716+714 , during its brightest ever optical state in the second half of January 2015. Observed almost simultaneously in the optical, X-rays and…

Quasi-periodic fluctuations in the light curves of blazars can provide insight into the underlying emission process. This type of flux modulation hints at periodic physical processes that result in emission. CTA 102, a flat spectrum radio…

In 2021 BL Lacertae underwent an extraordinary activity phase, which was intensively followed by the Whole Earth Blazar Telescope (WEBT) Collaboration. We present the WEBT optical data in the BVRI bands acquired at 36 observatories around…

Context. OJ287 is a quasar with a quasi-periodic optical light curve, with the periodicity observed for over 120 years. This has lead to a binary black hole model as a common explanation of the quasar. The radio jet of OJ287 has been…

Context. The blazar AO 0235+164, located at redshift $z=0.94$, has displayed interesting and repeating flaring activity in the past, the latest episodes occurring in 2008 and 2015. In 2020, the source brightened again, starting a new…

We present the results of optical (R band) photometric and polarimetric monitoring and Very Long Baseline Array (VLBA) imaging of the blazar S5 0716+714 along with Fermi gamma-ray data during a multi-waveband outburst in 2011 October. We…

Based on our dedicated Swift monitoring program, MOMO, OJ 287 is one of the best-monitored blazars in the X-ray--UV--optical regime. Here, we report results from our accompanying, dense, multi-frequency (1.4--44 GHz) radio monitoring of OJ…

We present a comprehensive analysis of the time-resolved spectral energy distributions (SEDs) of the blazar OJ 287 over a 15-year period (2008-2023), using multi-wavelength data. In the $\gamma$-ray band, multiple flaring episodes were…

We present the results of polarimetric ($R$ band) and multicolor photometric ($BVRIJHK$) observations of the blazar AO 0235+16 during an outburst in 2006 December. The data reveal a short timescale of variability (several hours), which…

OJ287 is a BL Lac object at redshift z=0.306 that has shown double-peaked bursts at regular intervals of ~12 yr during the last ~ 40 yr. Due to this behavior, it has been suggested that OJ287 might host a close supermassive binary black…