Publications (44)
The physics and astrophysics of X-ray outflows from Active Galactic Nuclei
Sibasish Laha, Randall Smith, Panayiotis Tzanavaris +20
The highly energetic outflows from Active Galactic Nuclei detected in X-rays are one of the most powerful mechanisms by which the central supermassive black hole (SMBH) interacts w…
Precision Fe Kalpha and Fe Kbeta Line Spectroscopy of the Seyfert 1.9 Galaxy NGC 2992 with Suzaku
Tahir Yaqoob, Kendrah D. Murphy, Richard E. Griffiths +13
We present detailed time-averaged X-ray spectroscopy in the 0.5--10 keV band of the Seyfert~1.9 galaxy NGC 2992 with the Suzaku X-ray Imaging Spectrometers (XIS). We model the comp…
X-ray Power Density Spectrum of the Narrow Line Seyfert 1 Galaxy Akn 564
Ken Pounds, Rick Edelson, Alex Markowitz +1
Beginning in 1999 January, the bright, strongly variable Narrow-Line Seyfert 1 (NLS1) galaxy Akn 564 has been observed by RXTE once every ~4.3 days. It was also monitored every ~3.…
High Temporal Resolution XMM Monitoring of PKS 2155-304
Rick Edelson, Gareth Griffiths, Alex Markowitz +3
The bright, strongly variable BL Lac object PKS 2155-304 was observed by XMM for two essentially uninterrupted periods of ~11 and 16 hr on 30-31 May 2000. The strongest variations…
An Occultation Event in Centaurus A and the Clumpy Torus Model
Elizabeth Rivers, Alex Markowitz, Richard Rothschild
We have analyzed 16 months of sustained monitoring observations of Cen A from the Rossi X-ray Timing Explorer to search for changes in the absorbing column in the line of sight to…
Spectral state transitions in Circinus ULX5
Samaresh Mondal, Agata Rozanska, Patrycja Baginska +2
We performed timing and spectral analysis of multi-epoch Suzaku, XMM-Newton and NuSTAR observations of the ultraluminous X-ray source (ULX) Circinus ULX5, to put constraints on the…
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…
Observatory Science with eXTP
Ping Zhou, Jirong Mao, Liang Zhang +97
Scheduled for launch in 2030, the enhanced X-ray Timing and Polarization (eXTP) telescope is a Chinese space-based mission aimed at studying extreme conditions and phenomena in ast…
Broadband spectroscopy using two Suzaku observation of the HMXB GX 301-2
Slawomir Suchy, Felix Fuerst, Katja Pottschmidt +5
We present the analysis of two Suzaku observations of GX 301-2 at two orbital phases after the periastron passage. Variations in the column density of the line-of-sight absorber ar…
eROSITA Detection of a Cloud Obscuration Event in the Seyfert AGN EC 04570-5206
Alex Markowitz, Mirko Krumpe, David Homan +13
Recent years have seen broad observational support for the presence of a clumpy component within the circumnuclear gas around SMBHs. In the X-ray band, individual clouds can manife…
The X-ray Power Spectral Density Function of the Seyfert Active Galactic Nucleus NGC 7469
Alex Markowitz
We present the broadband X-ray power spectral density function (PSD) of the X-ray-luminous Seyfert 1.2 NGC 7469, measured from Rossi X-ray Timing Explorer monitoring data and two X…
X-ray Spectral Variability and Rapid Variability of the Soft X-ray Spectrum Seyfert 1 Galaxies Ark 564 and Ton S180
Rick Edelson, T. J. Turner, Ken Pounds +5
The bright, soft X-ray spectrum Seyfert 1 galaxies Ark 564 and Ton S180 were monitored for 35 days and 12 days with ASCA and RXTE (and EUVE for Ton S180). The short time scale (hou…
Suzaku observations of the hard X-ray variability of MCG-6-30-15: the effects of strong gravity around a Kerr black hole
Giovanni Miniutti, Andrew C. Fabian, Naohisa Anabuki +21
Suzaku has, for the first time, enabled the hard X-ray variability of the Seyfert 1 galaxy MCG-6-30-15 to be measured. The variability in the 14-45 keV band, which is dominated by…
A Suzaku Observation of Mkn 590 Reveals a Vanishing Soft Excess
Elizabeth Rivers, Alex Markowitz, Refiz Duro +1
We have analyzed a long-look Suzaku observation of the Seyfert 1.2 Mkn~590. We aimed to measure the Compton reflection strength, Fe K complex properties and soft excess emission as…
First X-ray-Based Statistical Tests for Clumpy-Torus Models: Eclipse Events from 230 Years of Monitoring of Seyfert AGN
Alex Markowitz, Mirko Krumpe, Robert Nikutta
We present an analysis of multi-timescale variability in line-of-sight X-ray absorbing gas as a function of optical classification in a large sample of Seyfert AGN to derive the fi…
A Changing-Look Seyfert Discovered by eROSITA Reveals a Two-Component Broad-Line Region
Alex Markowitz, Mirko Krumpe, David Homan +12
Extreme sudden changes in the flow of accreting gas onto SMBHs manifest themselves via large-amplitude continuum variability and changes to broad Balmer emission profiles, driving…
The X-ray Integral Field Unit at the end of the Athena reformulation phase
Philippe Peille, Didier Barret, Edoardo Cucchetti +279
The Athena mission entered a redefinition phase in July 2022, driven by the imperative to reduce the mission cost at completion for the European Space Agency below an acceptable ta…
The Gamma-Ray Emitting Radio-Loud Narrow-Line Seyfert 1 Galaxy PKS 2004-447 I. The X-Ray View
Annika Kreikenbohm, Robert Schulz, Matthias Kadler +11
As part of the TANAMI multiwavelength progam, we discuss new X-ray observations of the -ray and radio-loud Narrow Line Seyfert galaxy (-NLS1) PKS 2004-447. The active galax…
Markarian 590: The AGN Awakens
Biswaraj Palit, Marzena Åniegowska, Alex Markowitz +3
Changing-Look AGN (CLAGN) Mkn 590 recently underwent a sudden re-ignition, marked by substantial increases in optical/UV and X-ray continuum flux since last couple of years. Swift-…
A deep X-ray view of the bare AGN Ark 120. III. X-ray timing analysis and multiwavelength variability
Andrew Lobban, Delphine Porquet, James Reeves +3
We present the spectral/timing properties of the bare Seyfert galaxy Ark 120 through a deep ~420ks XMM-Newton campaign plus recent NuSTAR observations and a ~6-month Swift monitori…
Observations of The High Mass X-ray Binary A0535+26 in Quiescence
Richard Rothschild, Alex Markowitz, Paul Hemphill +7
We have analyzed 3 observations of the High Mass X-ray Binary A0535+26 performed by the Rossi X-ray Timing Explorer (RXTE) 3, 5, and 6 months after the last outburst in 2011 Februa…
Twelve and a Half Years of Observations of Centaurus A with RXTE
Richard E. Rothschild, Alex Markowitz, Elizabeth Rivers +5
The Rossi X-ray Timing Explorer has observed the nearest radio galaxy, Centaurus A, in 13 intervals from 1966 August to 2009 February over the 3--200 keV band. Spectra accumulated…
Full Spectral Survey of Active Galactic Nuclei in the Rossi X-ray Timing Explorer Archive
Elizabeth Rivers, Alex Markowitz, Richard Rothschild
We have analyzed spectra for all active galactic nuclei in the Rossi X-ray Timing Explorer (RXTE) archive. We present long-term average values of absorption, Fe line equivalent wid…
The XMM-Newton X-ray Spectra of the Most X-ray Luminous Radio-quiet ROSAT Bright Survey-QSOs: A Reference Sample for the Interpretation of High-redshift QSO Spectra
Mirko Krumpe, Georg Lamer, Alex Markowitz +1
We present the broadband X-ray properties of four of the most X-ray luminous (L_X >= 10^{45} erg/s in the 0.5-2 keV band) radio-quiet QSOs found in the ROSAT Bright Survey. This un…
A high-density relativistic reflection origin for the soft and hard X-ray excess emission from Mrk 1044
Labani Mallick, William N. Alston, Michael L. Parker +7
We present the first results from a detailed spectral-timing analysis of a long (130 ks) XMM-Newton observation and quasi-simultaneous NuSTAR and Swift observations of the hi…
Event Horizon Telescope observations of the jet launching and collimation in Centaurus A
Michael Janssen, Heino Falcke, Matthias Kadler +236
Very-long-baseline interferometry (VLBI) observations of active galactic nuclei at millimeter wavelengths have the power to reveal the launching and initial collimation region of e…
An Expanded RXTE Survey of X-ray Variability in Seyfert 1 Galaxies
Alex Markowitz, Rick Edelson
The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogeneous samples of 2-12 keV light curves, probing h…
Tracking the Complex Absorption in NGC 2110 with Two Suzaku Observations
Elizabeth Rivers, Alex Markowitz, Richard Rothschild +6
We present spectral analysis of two Suzaku observations of the Seyfert 2 galaxy, NGC 2110. This source has been known to show complex, variable absorption which we study in depth b…
Constraining Disk-to-Corona Power Transfer Fraction, Soft X-ray Excess Origin, and Black Hole Spin Population of Type-1 AGN across Mass Scales
Labani Mallick, Ciro Pinto, John Tomsick +6
Understanding the nature of the accretion disk, its interplay with the X-ray corona, and assessing black hole spin demographics remain open challenges in astrophysics. In this pape…
Discovery of soft and hard X-ray time lags in low-mass AGNs
Labani Mallick, Daniel R. Wilkins, William N. Alston +5
The scaling relations between the black hole (BH) mass and soft lag properties for both active galactic nuclei (AGNs) and BH X-ray binaries (BHXRBs) suggest the same underlying phy…
Does the disk in the hard state of XTE J1752-223 extend to the innermost stable circular orbit?
Andrzej Zdziarski, Barbara De Marco, Michal Szanecki +2
The accreting black-hole binary XTE J1752--223 was observed in a stable hard state for 25 d by RXTE, yielding a 3--140 keV spectrum of unprecedented statistical quality. Its publis…
A Suzaku Observation of MCG-2-58-22: Constraining the Geometry of the Circumnuclear Material
Elizabeth Rivers, Alex Markowitz, Richard Rothschild
We have analyzed a Suzaku long-look of the active galactic nucleus MCG-2-58-22, a type 1.5 Seyfert with very little X-ray absorption in the line of sight and prominent features ari…
Evidence for Fe K line and soft X-ray lag in NGC 7456 ULX-1
Samaresh Mondal, Agata Rozanska, Barbara De Marco +1
We report the first detection of a Fe K line and soft X-ray lag in the ultraluminous X-ray source (ULX) NGC 7456 ULX-1. The XMM-Newton spectra show the presence of the 6.4 keV…
Discovery of a Highly Polarized Optical Microflare in the Blazar S5 0716+714 During 2014 WEBT Campaign
Gopal Bhatta, Arti Goyal, Michal Ostrowski +42
The occurrence of low-amplitude flux variations in blazars on hourly timescales, commonly known as microvariability, is still a widely debated subject in high-energy astrophysics.…
Revealing the High Energy Emission from the Obscured Seyfert Galaxy MCG -5-23-16 with Suzaku
James N. Reeves, Hisamitsu Awaki, Gulab C. Dewangan +19
We report on a 100 ks Suzaku observation of the bright, nearby (z=0.008486) Seyfert 1.9 galaxy MCG -5-23-16. The broad-band (0.4-100 keV) X-ray spectrum allows us to determine the…
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…
X-ray vs. Optical Variations in the Seyfert 1 Nucleus NGC 3516: A Puzzling Disconnectedness
Dan Maoz, Alex Markowitz, Rick Edelson +1
We present optical broadband (B and R) observations of the Seyfert 1 nucleus NGC 3516, obtained at Wise Observatory from March 1997 to March 2002, contemporaneously with X-ray 2-10…
Correlated long-term optical and X-ray variations in NGC 5548
Phil Uttley, Rick Edelson, Ian McHardy +2
We combine the long-term optical light curve of the Seyfert 1 galaxy NGC5548 with the X-ray light curve measured by the Rossi X-ray Timing Explorer over 6 years, to determine the r…
Optical and cm follow-ups of the Changing-Look event in Mkn 590
Biswaraj Palit, Abhijeet Borkar, Agata RóżaÅska +5
The Changing-Look active galactic nucleus Mkn 590 is currently in a rejuvenated state, exhibiting a contemporaneous flux rise across X-rays, UV, optical and cm wavelengths. In this…
Comparison of spectral models for disc truncation in the hard state of GX 339-4
Marta A. DzieÅak, Andrzej A. Zdziarski, MichaÅ Szanecki +3
We probe models of disc truncation in the hard spectral state of an outburst of the well-known X-ray transient GX 339--4. We test a large number of different models of disc reflect…
A 100ks XMM-Newton view of the Seyfert 1.8 ESO113-G010. I. Discovery of large X-ray variability and study of the FeKalpha line complex
Delphine Porquet, Phil Uttley, James N. Reeves +6
(Abridged) We present here a long (100ks) XMM-Newton follow-up of the Seyfert 1.8 galaxy ESO113-G010 performed in November 2005, in order to study over a longer time-scale its main…
Spectral Survey of X-Ray Bright Active Galactic Nuclei from the Rossi X-ray Timing Explorer
Elizabeth Rivers, Alex Markowitz, Richard Rothschild
Using long-term monitoring data from the Rossi X-ray Timing Explorer (RXTE), we have selected 23 active galactic nuclei (AGN) with sufficient brightness and overall observation tim…
A Clumpy Stellar Wind and Luminosity-Dependent Cyclotron Line Revealed by The First Suzaku Observation of the High-Mass X-ray Binary 4U 1538-522
Paul B. Hemphill, Richard E. Rothschild, Alex Markowitz +3
We present results from the first Suzaku observation of the high-mass X-ray binary 4U 1538-522. The broad-band spectral coverage of Suzaku allows for a detailed spectral analysis,…
The disk luminosity deficit as a tracer of receding disk during Soft-to-Hard transitions in Black Hole X-ray Binaries
Sai-En Xu, Bei You, Yi Long +4
Tracing the evolution of the thin accretion disk during the soft-to-hard state transition in black hole X-ray binaries (BHXRBs) remains difficult because conventional spectral esti…