Publications (32)
Magnetic Field Amplification and Flat Spectrum Radio Quasars
Xuhui Chen, Ritaban Chatterjee, Haocheng Zhang +10
We perform time-dependent, spatially-resolved simulations of blazar emission to evaluate several flaring scenarios related to magnetic-field amplification and enhanced particle acc…
Accretion Disc-Jet Decomposition from the Optical-Near Infrared Monitoring of Fermi Blazars
Garima Rajguru, Ritaban Chatterjee
We study the variability of the thermal (accretion disc) and non-thermal (jet) emission of thirteen flat spectrum radio quasars in the optical and near infrared (OIR) regime using…
Blazar Variability: A Study of Non-stationarity and the Flux-RMS Relation
Joy Bhattacharyya, Ritesh Ghosh, Ritaban Chatterjee +1
We analyze X-ray light curves of the blazars Mrk 421, PKS 2155-304, and 3C 273 using observations by the Soft X-ray Telescope on board AstroSat and archival XMM-Newton data. We use…
Probing the Jets of Blazars Using the Temporal Symmetry of Their Multi-Wavelength Outbursts
Namrata Roy, Ritaban Chatterjee, Manasvita Joshi +1
We compare the rise and decay timescales of 200 long-term (weeks-months) GeV and R-band outbursts and 25 short-term (hr-day) GeV flares in a sample of 10 bl…
A Time Resolved Study of the Broad Line Region in Blazar 3C 454.3
Jedidah C. Isler, C. Megan Urry, Paolo Coppi +6
We present multi-epoch optical observations of the blazar 3C 454.3 (z = 0.859) from 2008 August through 2011 December, using the SMARTS Consortium 1.5m+RCSpectrograph and 1.3m+ANDI…
How Plasma Properties of the Fanaroff-Riley Jet can Shape its Morphology
Priyesh Kumar Tripathi, Indranil Chattopadhyay, Raj Kishor Joshi +3
Extragalactic jets are broadly classified into two categories based on radio observations: core-brightened jets, known as Fanaroff-Riley Type I (FR I), and edge-brightened jets, cl…
Flaring Behavior of the Quasar 3C~454.3 across the Electromagnetic Spectrum
Svetlana G. Jorstad, Alan P. Marscher, Valeri M. Larionov +29
We analyze the behavior of the parsec-scale jet of the quasar 3C~454.3 during pronounced flaring activity in 2005-2008. Three major disturbances propagated down the jet along diffe…
Locating the GeV Emission Region in the Jets of Blazars from Months-Timescale Multi-Wavelength Outbursts
Saugata Barat, Ritaban Chatterjee, Kaustav Mitra
It is well-known that the -ray emission in blazars originate in the relativistic jet pointed at the observers. However, it is not clear whether the exact location of the GeV em…
The origin of the vanishing soft X-ray excess in the changing-look Active Galactic Nucleus Mrk 590
Ritesh Ghosh, Sibasish Laha, Kunal Deshmukh +3
We have studied the nature and origin of the soft X-ray excess detected in the interesting changing-look AGN (CLAGN) Mrk~590 using two decades of multi-wavelength observations from…
Similarity of the Optical-IR and Gamma-Ray Time Variability of Fermi Blazars
Ritaban Chatterjee, C. Bailyn, E. W. Bonning +6
We present the time variability properties of a sample of six blazars, AO 0235+164, 3C 273, 3C 279, PKS 1510-089, PKS 2155-304, and 3C 454.3, at optical-IR as well as gamma-ray ene…
The X-ray Spectrum and Spectral Energy Distribution of FIRST J155633.8+351758: a LoBAL Quasar with a Probable Polar Outflow
Robert C. Berrington, Michael S. Brotherton, Sarah C. Gallagher +8
We report the results of a new 60 ks Chandra X-ray Observatory Advanced CCD Imaging Spectrometer S-array (ACIS-S) observation of the reddened, radio-selected, highly polarized `FeL…
Disk-Jet Connection in the Radio Galaxy 3C 120
Ritaban Chatterjee, Alan P. Marscher, Svetlana G. Jorstad +33
We present the results of extensive multi-frequency monitoring of the radio galaxy 3C 120 between 2002 and 2007 at X-ray, optical, and radio wave bands, as well as imaging with the…
M.K. Das Gupta, the first Indian radio astronomer, and his connection with the 2020 Physics Nobel Prize
Arnab Rai Choudhuri, Ritaban Chatterjee
Half of the 2020 Nobel Prize is awarded for discovering a super-massive black hole at the centre of our Galaxy. One of the first indications of the existence of a black hole at the…
Possible Accretion Disk Origin of the Emission Variability of a Blazar Jet
Ritaban Chatterjee, Agniva Roychowdhury, Sunil Chandra +1
We analyze X-ray light curves of the blazar Mrk 421 obtained from the Soft X-ray Imaging Telescope and the Large Area X-Ray Proportional Counter instrument onboard the Indian space…
Magnetic Field Amplification and Blazar Flares
Xuhui Chen, Ritaban Chatterjee, Giovanni Fossati +1
Recent multiwavelength observations of PKS 0208-512 by SMARTS, Fermi, and Swift revealed that gamma-ray and optical light curves of this flat spectrum radio quasars are highly corr…
Sub-Day Timescale X-ray Spectral Variability of the TeV Blazars Mrk 421 and 1ES 1959+650
Susmita Das, Ritaban Chatterjee
We present X-ray spectra ( keV) of two high synchrotron-peaked blazars Mrk 421 and 1ES 1959+650 from simultaneous observations by the SXT and LAXPC instruments onboard \tex…
The Black Hole Binary V4641 Sagitarii: Activity in Quiescence & Improved Mass Determinations
Rachel K. D. MacDonald, Charles D. Bailyn, Michelle Buxton +6
We examine ~10 years of photometric data and find that the black hole X-ray binary V4641 Sgr has two optical states, passive and active, during X-ray quiescence. The passive state…
Correlated Short-Timescale Hard-Soft X-ray Variability of the Blazars Mrk 421 and 1ES 1959+650 using
Susmita Das, Ritaban Chatterjee
We study simultaneous soft ( keV) and hard ( keV) X-ray light curves at a total of eight epochs during of two TeV blazars Mrk 421 and 1ES 1959+650 ob…
Spectral Energy Distribution Modeling of Broad Emission Line Quasars: From X-ray to Radio Wavelengths
Avinanda Chakraborty, Maitreya Kundu, Suchetana Chatterjee +4
We study the differences in physical properties of quasar-host galaxies using an optically selected sample of radio loud (RL) and radio quiet (RQ) quasars (in the redshift range 0.…
Physical Inference from the gamma-ray, X-Ray and Optical Time Variability of a Large Sample of Fermi Blazars
Anwesh Majumder, Kaustav Mitra, Ritaban Chatterjee +3
We present cross-correlation studies of gamma-ray (0.1-300 GeV), X-ray (0.2-10 keV) and optical (R-band) variability of a sample of 26 blazars during 2008-2016. The light curves ar…
Moderate Correlation between the Accretion Disk and Jet Power in a Large Sample of Fermi Blazars
Garima Rajguru, Ritaban Chatterjee
We present the results of studying the accretion disk vs jet power for a large fraction of all the blazars detected by the Fermi Gamma-Ray Space Telescope. The disk power is inferr…
Optical and Near Infrared Monitoring of the Black-Hole X-ray Binary GX 339-4 During 2002-2010
Michelle M. Buxton, Charles D. Bailyn, Holly L. Capelo +4
We present the optical/infra-red lightcurve (O/IR) of the black hole X-ray binary GX 339-4 collected at the SMARTS 1.3m telescope from 2002 to 2010. During this time the source has…
The Contrasting Nature of Gamma-Ray/Optical Variability in the Blazar PKS 0208-512 During Successive Outbursts
Ritaban Chatterjee, G. Fossati, C. M. Urry +6
The Yale/SMARTS optical-near-IR monitoring program has followed the variations in emission of the Fermi-LAT monitored blazars in the southern sky with closely spaced observations s…
Location of a Sample of GeV and Optical Outbursts in the Jets of Blazars
Maitreya Kundu, Arit Bala, Saugata Barat +1
The exact location of the -ray emitting region in blazar jets has long been a matter of debate. However, the location has important implications about the emission processes, g…
Connection between the Accretion Disk and Jet in the Radio Galaxy 3C 111
Ritaban Chatterjee, Alan P. Marscher, Svetlana G. Jorstad +13
We present the results of extensive multi-frequency monitoring of the radio galaxy 3C 111 between 2004 and 2010 at X-ray (2.4--10 keV), optical (R band), and radio (14.5, 37, and 2…
RMS-Flux Relation and Disc-Jet Connection in Blazars in the Context of the Internal Shocks Model
Aritra Kundu, Ritaban Chatterjee, Kaustav Mitra +1
Recent analysis of blazar variability has revealed a proportionality between the mean flux and the root mean squared (rms) fluctuations about the mean flux. Although such rms-flux…
The Accretion Disc-Jet Connection in Blazars
Sagnick Mukherjee, Kaustav Mitra, Ritaban Chatterjee
The power spectral density (PSD) of the X-ray emission variability from the accretion disc-corona region of black hole X-ray binaries and active galactic nuclei has a broken power…
Effect of Multi-Species Plasma on Fanaroff-Riley Radio Jets
Priyesh Kumar Tripathi, Priyesh K. Tripathi, Indranil Chattopadhyay +5
The paper uses 3D magnetohydrodynamic simulations to study how different plasma compositions affect the stability and morphology of low‑power Fanaroff‑Riley I radio jets.
Implications of the Anomalous Outburst in the Blazar PKS 0208-512
Ritaban Chatterjee, Krzysztof Nalewajko, Adam D. Myers
The flat spectrum radio quasar (FSRQ) PKS 0208-512 underwent three outbursts at the optical-near-infrared (OIR) wavelengths during 2008-2011. The second OIR outburst did not have a…
An Optical-Near-Infrared Outburst with No Accompanying Gamma-Rays in the Blazar PKS 0208-512
Ritaban Chatterjee, G. Fossati, C. M. Urry +6
We report the discovery of an anomalous flare in a bright blazar, namely, PKS 0208-512, one of the targets of the Yale/SMARTS optical-near-infrared (OIR) monitoring program of Ferm…
Spectral Energy Distribution Modeling of BL Lacertae During a Large Submillimeter Outburst and Low X-Ray Polarization State
Ayon Mondal, Arijit Sar, Maitreya Kundu +2
In 2023 October-November, the blazar BL Lacertae underwent a very large-amplitude submm outburst. The usual single-zone leptonic model with the lower energy peak of the spectral en…
Short-Timescale Variability of the Blazar Mrk 421 from AstroSat and Simultaneous Multi-Wavelength Observations
Ritaban Chatterjee, Susmita Das, Archishman Khasnovis +13
We study the multi-wavelength variability of the blazar Mrk 421 at minutes to days timescales using simultaneous data at -rays from Fermi, 0.7-20 keV energies from AstroSat, an…