Zobrazeno 1 - 10
of 1 018
pro vyhledávání: '"Papadakis, I"'
Recently, nearby active galactic nuclei (AGN) have been subject to long X-rays/UV/optical monitoring campaigns. These campaigns reveal a strong correlation between the various UV and optical bands, with time lags increasing with wavelength. In a seri
Externí odkaz:
http://arxiv.org/abs/2403.12208
Autor:
Papadakis, I. E., Binas-Valavanis, V.
Publikováno v:
A&A 685, A50 (2024)
We study the X-ray power spectrum of Active Galactic Nuclei (AGN) to investigate whether Seyfert I and II power spectra are similar or not, whether the AGN variability depends on black hole mass and accretion rate, and to compare the AGN power spectr
Externí odkaz:
http://arxiv.org/abs/2402.15373
Autor:
Gliozzi, M., Williams, J. K., Akylas, A., Papadakis, I. E., Shuvo, O. I., Halavatkar, A., Alt, A.
The black hole mass MBH is crucial in constraining the growth of supermassive BHs within their host galaxies. Since direct measurements of MBH with dynamical methods are restricted to a limited number of nearly quiescent nearby galaxies and a small m
Externí odkaz:
http://arxiv.org/abs/2312.14098
We study the connection between the variations in the far ultra-violet (FUV), near ultra-violet (NUV) and X-ray band emission from NGC 4051 using 4-days long AstroSat observations performed during 5-9 June 2016. NGC 4051 showed rapid variability in a
Externí odkaz:
http://arxiv.org/abs/2311.02722
In this paper, we present an updated version of our model (KYNXiltr) which considers thermal reverberation of a standard Novikov-Thorne accretion disc illuminated by an X-ray point-like source. Previously, the model considered only two cases of black
Externí odkaz:
http://arxiv.org/abs/2309.05392
Autor:
Blinov, D., Maharana, S., Bouzelou, F., Casadio, C., Gjerløw, E., Jormanainen, J., Kiehlmann, S., Kypriotakis, J. A., Liodakis, I., Mandarakas, N., Markopoulioti, L., Panopoulou, G. V., Pelgrims, V., Pouliasi, A., Romanopoulos, S., Skalidis, R., Anche, R. M., Angelakis, E., Antoniadis, J., Medhi, B. J., Hovatta, T., Kus, A., Kylafis, N., Mahabal, A., Myserlis, I., Paleologou, E., Papadakis, I., Pavlidou, V., Papamastorakis, I., Pearson, T. J., Potter, S. B., Ramaprakash, A. N., Readhead, A. C. S., Reig, P., Słowikowska, A., Tassis, K., Zensus, J. A.
Publikováno v:
A&A 677, A144 (2023)
Optical polarimeters are typically calibrated using measurements of stars with known and stable polarization parameters. However, there is a lack of such stars available across the sky. Many of the currently available standards are not suitable for m
Externí odkaz:
http://arxiv.org/abs/2307.06151
Autor:
Kumar, Shrabani, Dewangan, G. C., Singh, K. P., Gandhi, P., Papadakis, I. E., Tripathi, P., Mallick, L.
$\require{mediawiki-texvc}$ We study accretion disk emission from eight Seyfert $1 - 1.5$ active galactic nuclei (AGN) using far ultra-violet ($1300-1800$ ${\AA}$) slit-less grating spectra acquired with AstroSat/UVIT. We correct for the Galactic and
Externí odkaz:
http://arxiv.org/abs/2303.11882
Autor:
Kumari, Kavita, Dewangan, G. C., Papadakis, I. E., Beard, Max W. J., McHardy, I. M., Singh, K. P., Bhattacharya, D., Bhattacharyya, S., Chandra, S.
We study accretion disk-corona connection in Seyfert 1 galaxies using simultaneous UV/X-ray observations of NGC 4593 (July 14-18, 2016) and NGC 7469 (October 15-19, 2017) performed with AstroSat. We use the X-ray (0.5-7.0 keV) data acquired with the
Externí odkaz:
http://arxiv.org/abs/2303.01556
Autor:
Paolillo, M., Papadakis, I. E., Brandt, W. N., Bauer, F. E., Lanzuisi, G., Allevato, V., Shemmer, O., Zheng, X. C., De Cicco, D., Gilli, R., Luo, B., Thomas, M., Tozzi, P., Vito, F., Xue, Y. Q.
Publikováno v:
A&A 673, A68 (2023)
We study the ensemble X-ray variability properties of Active Galactic Nuclei (AGN) over a large range of timescales (20 ks $\leq T\leq$ 14 yrs), redshift ($0\leq z \lesssim 3$), luminosities ($10^{40}$ erg s$^{-1}\leq L_X\leq 10^{46}$ erg s$^{-1}$) a
Externí odkaz:
http://arxiv.org/abs/2302.08524
We study the Fourier time-lags due to the Comptonization of disc-emitted photons in a spherical, uniform, and stationary X-ray corona, which located on the rotational axis of the black hole. We use Monk, a general relativistic Monte-Carlo radiative t
Externí odkaz:
http://arxiv.org/abs/2212.02734