Orbital and superorbital variability and their coupling in X-ray binaries (2008)
Zdziarski, Andrzej A., Poutanen, Juri, Ibragimov, Askar, Gierlinski, Marek, Wen, Linqing
We review X-ray flux modulation from X-ray binaries on time scales corresponding to the orbital period and those at longer time scales (so called superorbital). Those modulations provide a powerful...
Reprocessing of X-rays in the outer accretion disc of the black hole binary XTE J1817--330 (2008)
Gierlinski, Marek, Done, Chris, Page, Kim
We build a simple model of the optical/UV emission from irradiation of the outer disc by the inner disc and coronal emission in black hole binaries. We apply this to the broadband Swift data from the...
RE J1034+396: The origin of the soft X-ray excess and QPO (2008)
Middleton, Matthew, Done, Chris, Ward, Martin, Gierlinski, Marek, Schurch, Nick
The X-ray quasi-periodic oscillation (QPO) seen in RE J1034+396 is so far unique amongst AGN. Here we look at the another unique feature of RE J1034+396, namely its huge soft X-ray excess, to see if...
A ~1-hour X-ray periodicity in an active galaxy RE J1034+396 (2008)
Gierlinski, Marek, Middleton, Matthew, Ward, Martin, Done, Chris
Active galactic nuclei and quasars are thought to be scaled up versions of Galactic black hole binaries, powered by accretion onto supermassive black holes with masses of 10^6-10^9 M_Sun, as opposed...
Gierlinski, Marek, Done, Chris, Page, Kim
The key aspect of the very successful truncated disc model for the low/hard X-ray spectral state in black hole binaries is that the geometrically thin disc recedes back from the last stable orbit at...
High-frequency X-ray variability as a mass estimator of stellar and supermassive black holes (2007)
Gierlinski, Marek, Nikolajuk, Marek, Czerny, Bozena
There is increasing evidence that supermassive black holes in active galactic nuclei (AGN) are scaled-up versions of Galactic black holes. We show that the amplitude of high-frequency X-ray...
Modelling the behaviour of accretion flows in X-ray binaries (2007)
Done, Chris, Gierlinski, Marek, Kubota, Aya
(abridged) We review how the recent increase in X-ray and radio data from black hole and neutron star binaries can be merged together with theoretical advances to give a coherent picture of the...
The Origin of the soft excess in AGN (2007)
Done, Chris, Gierlinski, Marek, Sobolewska, Malgosia, Schurch, Nick
We discuss various ideas for the origin of the soft X-ray excess seen in AGN. There are clear advantages to models where this arises from atomic processes in partially ionised rather than where it is...
Dependence of the orbital modulation of X-rays from 4U 1820-303 on the accretion rate (2007)
Zdziarski, Andrzej A., Gierlinski, Marek, Wen, Linqing, Kostrzewa, Zuzanna
We report the discovery, using RXTE data, of a dependence of the X-ray orbital modulation depth on the X-ray spectral state in the ultracompact atoll binary \source. This state (measured by us by the...
The superorbital variability and triple nature of the X-ray source 4U 1820-303 (2007)
Zdziarski, Andrzej A., Gierlinski, Marek, Wen, Linqing
We perform a comprehensive analysis of the superorbital modulation in the ultracompact X-ray source 4U 1820-303, consisting of a white dwarf accreting onto a neutron star. Based on RXTE data, we...
The iron K feature in Narrow Line Seyfert 1's: evidence for a P Cygni profile? (2006)
Done, C., Sobolewska, M. A., Gierlinski, Marek, Schurch, N. J.
Narrow Line Seyfert 1 galaxies are generally accreting at high fractions of the Eddington limit. They can show complex X-ray spectra, with a strong `soft excess' below 2 keV and a sharp drop at ~7...
Energy-dependent variability and the origin of the soft X-ray excess in AGN (2006)
Gierlinski, Marek, Done, Chris
The origin of the soft excess seen in many AGN below ~1 keV is still an unsolved problem. It is unlikely to represent a true continuum component as its characteristic 'temperature' shows a remarkable...
Analysing the atolls: X-ray spectral transitions of accreting neutron stars (2006)
Gladstone, Jeanette, Done, Chris, Gierlinski, Marek
We systematically analyze all the available X-ray spectra of disc accreting neutron stars (atolls and millisecond pulsars) from the RXTE database. We show that while these all have similar spectral...
X-ray spectral transitions of black holes from RXTE All-Sky Monitor (2006)
We have analysed X-ray outbursts from several Galactic black hole (GBH) transients, as seen by the ASM on board RXTE. We have used the best estimates of distance and black hole mass to find their...
Black hole spin in GRS 1915+105 (2006)
Middleton, Matthew, Done, Chris, Gierlinski, Marek, Davis, Shane
Microquasars are galactic black hole binary systems with radio jets which can sometimes be spatially resolved to show superluminal motion. The first and best known of this class of objects is GRS...
Truncated disc versus extremely broad iron line in XTE J1650-500 (2005)
Done, Chris, Gierlinski, Marek
There is growing evidence from both spectral and timing properties that there is a truncated inner accretion disc in low mass accretion rate Galactic black hole systems. The detection of extremely...
Accretion in Strong Gravity: From Galactic to Supermassive Black Holes (2005)
Done, Chris, Gierlinski, Marek
The galactic black hole binary systems give an observational template showing how the accretion flow changes as a function of increasing mass accretion rate, or L/L_Edd. These data can be synthetised...
Patterns of energy-dependent variability from Comptonization (2005)
Gierlinski, Marek, Zdziarski, Andrzej A.
We study fractional variability as a function of energy from black-hole X-ray binaries on timescales from milliseconds to hundreds of seconds. We build a theoretical model of energy-dependent...
Scaling variability from stellar to supermassive black holes (2005)
Done, Chris, Gierlinski, Marek
We investigate the correspondence between the variability seen in the stellar and supermassive black holes. Galactic Black Hole (GBH) power density spectra (PDS) are generally complex, and dependent...
GRS 1915+105: the distance, radiative processes and energy-dependent variability (2005)
Zdziarski, Andrzej A., Gierlinski, Marek, Rao, A. R., Vadawale, S. V., Mikolajewska, Joanna
We present an exhaustive analysis of five broad-band observations of GRS 1915+105 in two variability states, chi and omega, observed simultaneously by the PCA, HEXTE and OSSE. We find all the spectra...
Physics of accretion in the millisecond pulsar XTE J1751-305 (2004)
Gierlinski, Marek, Poutanen, Juri
We have undertaken an extensive study of X-ray data from the accreting millisecond pulsar XTE J1751-305 observed by RXTE and XMM-Newton during its 2002 outburst. In all aspects this source is similar...
Radiative Processes, Spectral States and Variability of Black-Hole Binaries (2004)
Zdziarski, Andrzej A., Gierlinski, Marek
We review radiative processes responsible for X-ray emission in hard (low) and soft (high) spectral states of black-hole binaries. The main process in the hard state appears to be scattering of...
Spectral transitions in X-ray Binaries (2004)
Done, Chris, Gierlinski, Marek
We systematically analyzed about a terabyte of data from Galactic binary systems to characterize how these spectra change as a function of mass accretion rate. With this volume of data we are able to...
GX 339-4: the distance, state transitions, hysteresis and spectral correlations (2004)
Zdziarski, Andrzej A., Gierlinski, Marek, Mikolajewska, Joanna, Wardzinski, Grzegorz, Smith, David M., Harmon, B. Alan, ...
We study X-ray and variability and distance of GX 339-4. We derive d>7 kpc, based on recent determination of the binary parameters. We study data from the Ginga/ASM, the CGRO/BATSE, and the RXTE/ASM,...
Is the soft excess in AGN real? (2003)
Gierlinski, Marek, Done, Chris
We systematically analyse all publicly available XMM-Newton spectra of radio-quiet PG quasars. The soft X-ray excess in these objects is well modelled by an additional, cool, Compton scattering...
Black hole accretion discs: reality confronts theory (2003)
Gierlinski, Marek, Done, Chris
Disc spectra from highly luminous black hole binaries are observed to be rather simple, despite theoretical predictions to the contrary. We collate the disc-dominated spectra from multiple...
Discovery of powerful millisecond flares from Cygnus X-1 (2003)
Gierlinski, Marek, Zdziarski, Andrzej A.
We have found a large number of very strong flares in the available XTE PCA data of Cyg X-1 (also seen in available HEXTE and BATSE data) with 13 flares satisfying our chosen threshold criterion,...
On the Nature of the X-ray Emission from the Accreting Millisecond Pulsar SAX J1808.4-3658 (2003)
Poutanen, Juri, Gierlinski, Marek
The pulse profiles of the accreting X-ray millisecond pulsar SAX J1808.4-3658 at different energies are studied. The two main emission component, the black body and the Comptonized tail that are...
The X-ray/gamma-ray spectrum of XTE J1550--564 in the very high state (2002)
Gierlinski, Marek, Done, Chris
We fit the broad-band X/gamma-ray spectrum (0.8-1000 keV) of the accreting black hole XTE J1550-564 in the very high state. The quasi-simultaneous data from ASCA, RXTE and OSSE show that the disc is...
Observing the effects of the event horizon in black holes (2002)
Done, Chris, Gierlinski, Marek
The key difference between neutron stars and black holes is the presence/absence of a solid surface. Recent attempts to detect this difference have concentrated on the quiescent luminosity, but here...
The X-ray spectrum of the atoll source 4U 1608-52 (2002)
Gierlinski, Marek, Done, Chris
The transient atoll source 4U 1608-52 had been extensively observed by the Rossi X-ray Timing Explorer RXTE during its 1998 outburst. We analyse its X-ray spectra as a function of inferred accretion...
X-ray and gamma-ray spectra and variability of the black-hole candidate GX 339-4 (2002)
Wardzinski, Grzegorz, Zdziarski, Andrzej A., Gierlinski, Marek, Grove, J. Eric, Jahoda, Keith, Johnson, W. Neil
We analyse five observations of the X-ray binary GX 339-4 by the soft gamma-ray OSSE detector on board CGRO simultaneous with either Ginga or RXTE observations. The source was bright during four of...
Poutanen, Juri, Gierlinski, Marek
The pulse profiles of the accreting X-ray millisecond pulsar SAX J1808.4-3658 at different energies are studied. The two main emission component, a black body and a power-law tail, clearly identified...
A comment on the colour-colour diagrams of Low Mass X-ray Binaries (2001)
Gierlinski, Marek, Done, Chris
Disc accreting neutron stars come in two distinct varieties, atolls and Z sources, named after their differently shaped tracks on a colour-colour diagram as the source luminosity changes. Here we...
Phase-resolved X-ray spectroscopy of the millisecond pulsar SAX J1808.4-3658 (2001)
Gierlinski, Marek, Done, Chris, Barret, Didier
We present new results based on RXTE observations of SAX J1808.4-3658. The X-ray spectrum can be fitted by a two-component model. We interpret the soft component as blackbody emission from a heated...
Phase-resolved spectra of the millisecond pulsar SAX J1808.4-3658 (2001)
Gierlinski, Marek, Done, Chris, Barret, Didier
We analyze the RXTE observations of the April 1998 outburst of SAX J1808.4-3658. We show that the soft blackbody component of the X-ray spectrum is from the hotspot on the neutron star surface, while...
Gierlinski, Marek, Maciolek-Niedzwiecki, Andrzej, Ebisawa, Ken
We present a general relativistic accretion disc model and its application to the soft-state X-ray spectra of black hole binaries. The model assumes a flat, optically thick disc around a rotating...
Accretion disk in Cyg X-1 in the soft state (1998)
Gierlinski, Marek, Zdziarski, Andrzej A.
We analyze the simultaneous ASCA/RXTE observation of Cyg X-1 in the soft state on 1996 May 30. We apply a multi-color disk model with a torque-free boundary condition in the pseudo-Newtonian...
Zdziarski, Andrzej A., Poutanen, Juri, Mikolajewska, Joanna, Gierlinski, Marek, Ebisawa, Ken, Johnson, W. Neil
We present X-ray/gamma-ray spectra of the binary GX 339-4 observed in the hard state simultaneously by Ginga and CGRO OSSE during an outburst in 1991 September. The Ginga spectra are well represented...
Thermal/non-thermal model of Cyg X-1 in the soft state (1997)
Gierlinski, Marek, Zdziarski, Andrzej A., Coppi, Paolo S., Poutanen, Juri, Ebisawa, Ken, Johnson, W. N.
We analyze X-ray/gamma-ray observations of Cyg X-1 in the soft state. We find the hybrid thermal/non-thermal model fits the data very well. The significant contribution from the non-thermal electrons...
X-ray and gamma-ray spectra of Cyg X-1 in the soft state (1997)
Gierlinski, Marek, Zdziarski, Andrzej A., Dotani, Tadayasu, Ebisawa, Ken, Jahoda, Keith, Johnson, W. Neil
We present X-ray/gamma-ray observations of Cyg X-1 in the soft state during 1996 May-June. We analyze ASCA, RXTE and OSSE data. The spectrum consists of soft X-ray blackbody emission of an optically...
X-rays and gamma-rays from accretion flows onto black holes in Seyferts and X-ray binaries (1996)
Zdziarski, Andrzej A., Johnson, W. Neil, Poutanen, Juri, Magdziarz, Pawel, Gierlinski, Marek
We review observations and theoretical models of X-ray/gamma-ray spectra of radio-quiet Seyfert galaxies and of Galactic black-hole candidates (in the hard spectral state). The observed spectra share...
Simultaneous X-ray and gamma-ray observations of Cyg X-1 in the hard state by Ginga and OSSE (1996)
Gierlinski, Marek, Zdziarski, Andrzej A., Done, Chris, Johnson, W. Neil, Ebisawa, Ken, Ueda, Yoshihiro, ...
We present four X-ray/gamma-ray spectra of Cyg X-1 observed in the hard ('low') state simultaneously by Ginga and GRO/OSSE on 1991 July 6. The 3-30 keV Ginga spectra are well represented by power...
The first simultaneous X-ray/gamma-ray observations of Cyg X-1 by Ginga and OSSE (1995)
Gierlinski, Marek, Zdziarski, Andrzej A., Johnson, W. Neil, Phlips, Bernard F., Ebisawa, Ken, Done, Chris
We present the results of 4 simultaneous observations of Cygnus X-1 by Ginga and OSSE. The X-ray/gamma-ray spectra can be described by an intrinsic continuum and a component due to Compton reflection...