Probing X-Ray Timing and Spectral Variability in the Blazar PKS 2155-304 over a Decade of XMM-Newton Observations

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19630%2F25%3AA0000473" target="_blank" >RIV/47813059:19630/25:A0000473 - isvavai.cz</a>

Result on the web

<a href="https://iopscience.iop.org/article/10.3847/1538-4357/adb0c9" target="_blank" >https://iopscience.iop.org/article/10.3847/1538-4357/adb0c9</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/adb0c9" target="_blank" >10.3847/1538-4357/adb0c9</a>

Result language

angličtina

Original language name

Probing X-Ray Timing and Spectral Variability in the Blazar PKS 2155-304 over a Decade of XMM-Newton Observations

Original language description

Blazars, a class of active galactic nuclei (AGN) powered by supermassive black holes, are known for their remarkable variability across multiple timescales and wavelengths. Despite significant advancements in our understanding of AGN central engines, thanks to both ground- and space-based telescopes, the details of the mechanisms driving this variability remain elusive. The primary objective of this study is to constrain the X-ray variability properties of the TeV blazar PKS 2155-304. We conducted a comprehensive X-ray spectral and timing analysis, focusing on both long-term and intraday variability (IDV), using data from 22 epochs of XMM-Newton observations collected over 15 yr (2000-2014). For the timing analysis, we estimated the fractional variability, variability amplitude, minimum variability timescales, flux distribution, and power spectral density. In the spectral analysis, we fitted the X-ray spectra using power-law, log-parabola, and broken power-law models to determine the best-fitting parameters. We observed moderate IDV in the majority of the light curves (LCs). Seven out of the 22 observations showed a clear bimodal flux distribution, indicating the presence of two distinct flux states. Our analysis revealed a variable power spectral slope. Most hardness ratio plots did not show significant variation with flux, except for two observations, where the hardness ratio changed considerably with flux. The fitted X-ray spectra favored the broken power-law model for the majority of observations, indicating a break in the spectral profiles. The findings of this work shed light on the IDV of blazars, providing insights into the nonthermal jet processes that drive the observed flux variations.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GA23-07043S" target="_blank" >GA23-07043S: Black Hole Magnetosphere</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Volume of the periodical

981

Issue of the periodical within the volume

2

Country of publishing house

GB - UNITED KINGDOM

Number of pages

24

Pages from-to

„118-1“-„118-24“

UT code for WoS article

001436916100001

EID of the result in the Scopus database

2-s2.0-105000124548