85 citations · 385 across the 29 of their papers we have counts for
32 papers
25 Years of Mrk 421 with XMM-Newton: Unveiling Structured Jets and Energy-Dependent Escape
Tek P. Adhikari, Gopal Bhatta, Sangeetha Kizhakkekalam +4
We present a long-term X-ray spectral and timing analysis of the TeV blazar Mrk~421 based on nearly a quarter century of archival \textit{XMM-Newton}/pn observations obtained betwe…
15-Year X-ray Study Links Variable Mass Accretion to Changing Look Behavior in AGN NGC 7582
Santanu Mondal, V. Jithesh, Neeraj Kumari +1
Changing Look Active Galactic Nuclei (CLAGN) are a subclass of AGN that exhibit spectral state transitions in both optical/UV and X-ray bands on timescales of days to years. In thi…
Tidal Grinding of Dwarf Galaxies in Cluster Environments
Sanjaya Paudel, Suk-Jin Yoon, Tek Prasad Adhikari +4
Dwarf elliptical galaxies (dEs) dominate galaxy clusters and provide key constraints on environmentally driven galaxy evolution. Here we examine whether the projected shapes of dEs…
NICER Perspective on TeV Blazar Mrk~421: X-ray Variability and Particle Acceleration
Sangeetha Kizhakkekalam, Gopal Bhatta, Navaneeth P K +1
Mrk~421 is one of the most fascinating blazars, widely studied across the electromagnetic spectrum using observations at various wavebands, from radio to the TeV gamma ray bands. W…
A constant pressure model for the warm absorber in Mrk 509
Krzysztof Hryniewicz, Agata Różańska, Tek Prasad Adhikari +3
We present the analysis of 900 ks high-resolution RGS XMM-Newton observations of the nearby Seyfert galaxy Mrk 509 with the use of a self-consistent warm absorber (WA) model. We pe…
Deterministic and Stochastic Study of the X-ray Emission from the TeV Blazar Mrk~421
Radim Pánis, Gopal Bhatta, Tek P. Adhikari +6
We present a comprehensive timing analysis of X-ray data from the {\it XMM-Newton} satellite, examining 50 light curves covering 17 years of observations of the blazar Mrk~421. Thi…
Changing Look AGN: A study of Optical/UV and the Highly Ionized Fe K X-ray Line Flux Variations Using Photo-Ionization Simulations
Tek P. Adhikari, Santanu Mondal, Zhicheng He +2
Significant variability in broad emission line strengths of active galactic nuclei (AGN) over months to years has been observed, often accompanied by intrinsic continuum changes. S…
Exploring the central region of NGC 1365 in the ultraviolet domain
Kshama Sara Kurian, C. S. Stalin, Dominika Wylezalek +6
Active galactic nuclei (AGN) feedback and its impact on their host galaxies are critical to our understanding of galaxy evolution. Here, we present a combined analysis of new high…
Probing X-ray Timing and Spectral Variability in the Blazar PKS 2155-304 Over a Decade of XMM-Newton Observations
Gopal Bhatta, Suvas C. Chaudhary, Niraj Dhital +5
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…
Constraining X-ray variability of the blazar 3C 273 using XMM-Newton observations over two decades
Adithiya Dinesh, Gopal Bhatta, Tek P. Adhikari +5
Blazars exhibit relentless variability across diverse spatial and temporal frequencies. The study of long- and short-term variability properties observed in the X-ray band provides…
Dusty plasma in active galactic nuclei
Bożena Czerny, Michal Zajaček, Mohammad-Hassan Naddaf +10
Since many years we know that dust in the form of the dusty-molecular torus is responsible for the obscuration in active galactic nuclei (AGN) at large viewing angles and thus for…
Variable mass accretion and failed wind explain changing look phenomena in NGC 1365
Santanu Mondal, Tek P. Adhikari, Krzysztof Hryniewicz +2
Changing look active galactic nuclei (CLAGNs) show complex nature in their X-ray spectral shape and line of sight column density variation. The physical mechanisms responsible for…
X-ray timing and spectral variability properties of blazars S5 0716+714, OJ 287, Mrk 501, and RBS 2070
Maksym Mohorian, Gopal Bhatta, Tek P. Adhikari +6
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 blazar…
Emission lines from X-ray illuminated accretion disc in black hole binaries
Santanu Mondal, Tek P. Adhikari, Chandra B. Singh
X-ray flux from the inner hot region around central compact object in a binary system illuminates the upper surface of an accretion disc and it behaves like a corona. This region c…
The multi-phase environment in the centre of Centaurus A
A. Borkar, T. P. Adhikari, A. Różańska +6
We study the multi-phase medium in the vicinity of the active galactic nucleus Centaurus A (Cen A). Combined high-resolution observations with the ALMA and Chandra observatories in…
Incoherent fast variability of X-ray obscurers. The case of NGC 3783
B. De Marco, T. P. Adhikari, G. Ponti +22
Context. Obscuration events caused by outflowing clumps or streams of high column density, low ionisation gas, heavily absorbing the X-ray continuum, have been witnessed in a numbe…
What shapes the Absorption Measure Distribution in AGN outflows
T. P. Adhikari, A. Różańska, K. Hryniewicz +2
The Absorption Measure Distribution (AMD) in the X-ray outflows of Seyfert active galactic nuclei (AGN) describes the distribution of absorbing column density as a function of ioni…
Modelling of the quasar main sequence in the optical plane
Swayamtrupta Panda, Bożena Czerny, Tek P. Adhikari +4
The concept of the quasar main sequence is very attractive since it stresses correlations between various parameters and implies the underlying simplicity. In the optical plane def…
Intermediate-line Emission in AGNs: The Effect of Prescription of the Gas Density
T. P. Adhikari, K. Hryniewicz, A. Różańska +2
The requirement of intermediate line component in the recently observed spectra of several AGNs points to possibility of the existence of a physically separate region between broad…
Absorption Measure Distribution in AGN
T. P. Adhikari, A. Różańska, K. Hryniewicz +1
The most common observed feature of the X-ray outflows in active galactic nuclei (AGN) is their broad ionization distribution spanning up to 5 orders of magnitude in ionizat…
Ultra Luminous X-ray sources - new distance indicators?
Agata Rozanska, Karol Bresler, Bartosz Beldycki +2
In this paper we fit the NuSTAR and XMM-Newton data of three sources: NGC7793~P13, NGC5907~ULX1, and Circinus~ULX5. Our single model contains emission form non-spherical system: ne…
On the Intermediate Line Region in AGNs
T. P. Adhikari, A. Rozanska, K. Hryniewicz +2
In this paper we explore the intermediate line region (ILR) by using the photoionisation simulations of the gas clouds present at different radial distances from the center, corres…
Multi-phase environment of compact galactic nuclei: the role of the Nuclear Star Cluster
A. Różańska, D. Kunneriath, B. Czerny +2
We study the conditions for the onset of Thermal Instability in the innermost regions of compact galactic nuclei, where the properties of the interstellar environment are governed…
The appearance of non-spherical systems. Application to LMXB
A. Rozanska, B. Beldycki, J. Madej +2
We study the appearance of the neutron star - accretion disk system as seen by a distant observer in the UV/X-ray domain. The observed intensity spectra are computed assuming non-s…