TY - JOUR
T1 - X-ray timing and spectral variability properties of blazars S5 0716 + 714, OJ 287, Mrk 501, and RBS 2070
AU - Mohorian, Maksym
AU - Bhatta, Gopal
AU - Adhikari, Tek P.
AU - Dhital, Niraj
AU - Pánis, Radim
AU - Dinesh, Adithiya
AU - Chaudhary, Suvas C.
AU - Bachchan, Rajesh K.
AU - Stuchlík, Zdeněk
PY - 2022/3/1
Y1 - 2022/3/1
N2 - The X-ray emission from blazars has been widely investigated using several space telescopes. In this work, we explored statistical properties of the X-ray variability in the blazars S5 0716+714, OJ 287, Mkn 501, and RBS 2070 using the archival observations from the XMM-Newton telescope between the period 2002-2020. Several methods of timing and spectral analyses, including fractional variability, minimum variability time-scale, power spectral density analyses, and countrate distribution, were performed. In addition, we fitted various spectral models to the observations, as well as estimated hardness ratio. The results show that the sources are moderately variable within the intraday time-scale. Three of the four sources exhibited a clear bi-modal pattern in their countrate distribution, revealing possible indication of two distinct countrate states, that is, hard and soft countrate states. The slope indices of the power spectral density were found to be centred around 0.5. Furthermore, the spectra of the sources were fitted with single power law, broken power law, log-parabolic, and blackbody + log-parabolic models (the latter only for OJ 287). We conclude that for most of the observations log-parabolic model was the best fit. The power-spectral-density analysis revealed the variable nature of PSD slopes in the source light curves. The results of this analysis could indicate the non-stationary nature of the blazar processes on intraday time-scales. The observed features can be explained within the context of current blazar models, in which the non-thermal emission mostly arises from kilo-pc scale relativistic jets.
AB - The X-ray emission from blazars has been widely investigated using several space telescopes. In this work, we explored statistical properties of the X-ray variability in the blazars S5 0716+714, OJ 287, Mkn 501, and RBS 2070 using the archival observations from the XMM-Newton telescope between the period 2002-2020. Several methods of timing and spectral analyses, including fractional variability, minimum variability time-scale, power spectral density analyses, and countrate distribution, were performed. In addition, we fitted various spectral models to the observations, as well as estimated hardness ratio. The results show that the sources are moderately variable within the intraday time-scale. Three of the four sources exhibited a clear bi-modal pattern in their countrate distribution, revealing possible indication of two distinct countrate states, that is, hard and soft countrate states. The slope indices of the power spectral density were found to be centred around 0.5. Furthermore, the spectra of the sources were fitted with single power law, broken power law, log-parabolic, and blackbody + log-parabolic models (the latter only for OJ 287). We conclude that for most of the observations log-parabolic model was the best fit. The power-spectral-density analysis revealed the variable nature of PSD slopes in the source light curves. The results of this analysis could indicate the non-stationary nature of the blazar processes on intraday time-scales. The observed features can be explained within the context of current blazar models, in which the non-thermal emission mostly arises from kilo-pc scale relativistic jets.
KW - accretion, accretion discs
KW - radiation mechanisms: non-thermal
KW - methods: data analysis
KW - BL Lacertae objects: individual: RBS 2070, OJ 287, Mrk 501, S5 0716 + 714
KW - X-rays: galaxies
UR - http://www.scopus.com/inward/record.url?scp=85125124920&partnerID=8YFLogxK
U2 - 10.1093/mnras/stab3738
DO - 10.1093/mnras/stab3738
M3 - Article
AN - SCOPUS:85125124920
SN - 0035-8711
VL - 510
SP - 5280
EP - 5301
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -