Rob Fender

Linking jet emission and X-ray properties in the peculiar neutron star X-ray binary Circinus X-1 (2009)

Soleri, Paolo, Tudose, Valeriu, Fender, Rob, Van Der Klis, Michiel, Jonker, Peter G.

We present the results of simultaneous X-ray and radio observations of the peculiar Z-type neutron star X-ray binary Cir X-1, observed with the Rossi X-ray timing explorer satellite and the Australia...

Internal shocks model for microquasar jets (2008)

Jamil, Omar, Fender, Rob, Kaiser, Christian

We present an internal shocks model to investigate particle acceleration and radiation production in microquasar jets. The jet is modelled with discrete ejecta at various time intervals. These ejecta...

A Global Study of X-ray Binaries (2008)

Dunn, Robert, Fender, Rob, Koerding, Elmar, Cabanac, Clement, Belloni, Tomaso

We present preliminary results on a global study of X-ray binaries using 14 Ms of data from the Rossi X-ray Timing Explorer satellite. Our initial study on GX 339-4 is recapped as an introduction to...

High energy astrophysics with the next generation of radio astronomy facilities (2008)

Fender, Rob

High energy astrophysics has made good use of combined high energy (X-ray, gamma-ray) and radio observations to uncover connections between outbursts, accretion, particle acceleration and kinetic...

MAXI, LOFAR and Microquasars - All-sky monitoring of X-ray binaries in X-rays and radio (2008)

Fender, Rob

In this paper I will discuss future synergies between the Japanese MAXI X-ray all-sky monitor, to be placed on the International Space Station in 2009, and the next-generation radio astronomy array...

A transient radio jet in an erupting dwarf nova (2008)

Koerding, Elmar, Rupen, Michael, Knigge, Christian, Fender, Rob, Dhawan, Vivek, Templeton, Matthew, ...

Astrophysical jets seem to occur in nearly all types of accreting objects: from supermassive black holes to young stellar objects. Based on X-ray binaries, a unified scenario describing the disc/jet...

LOFAR Transients and the Radio Sky Monitor (2008)

Fender, Rob, Wijers, Ralph, Stappers, Ben

The study of transient and variable low-frequency radio sources is a key goal for LOFAR, with an extremely broad science case ranging from relativistic jets sources to pulsars, exoplanets, radio...

Multiwavelength observations of the black hole candidate Swift J1753.5-0127 (2008)

Soleri, Paolo, Altamirano, Diego, Fender, Rob, Casella, Piergiorgio, Tudose, Valeriu, Maitra, Dipankar, ...

We present preliminary results from the analysis of simultaneous multiwavelength observations of the black hole candidate Swift J1753.5-0127. The source is still continuing its outburst started in...

Simultaneous X-ray/radio observations of Cir X-1 (2008)

Soleri, Paolo, Tudose, Valeriu, Fender, Rob, Van Der Klis, Michiel

We analysed simultaneous X-ray/radio observations of Circinus X-1 collected respectively with RXTE and ATCA in 2000 October and 2002 December and identified radio flares close to phase 0.0 and 0.5 of...

Searching for the signatures of jet-ISM interactions in X-ray binaries (2008)

Miller-Jones, James, Kaiser, Christian, Maccarone, Tom, Fender, Rob, Kapińska, Anna, Gunn, Katherine, ...

Jets from X-ray binaries are continuously injecting matter and energy into the surrounding interstellar medium (ISM). However, there exist to date relatively few cases where jet-ISM interactions have...

Broadband X-ray Spectra of GX 339-4 and the Geometry of Accreting Black Holes in the Hard State (2008)

Tomsick, John A., Kalemci, Emrah, Kaaret, Philip, Markoff, Sera, Corbel, Stephane, Migliari, Simone, ...

A major question in the study of black hole binaries involves our understanding of the accretion geometry when the sources are in the hard state. In this state, the X-ray energy spectrum is dominated...

The power of jets: New clues from radio circular polarization and X-rays (2007)

Heino Falcke, Thomas Beckert, Sera Markoff, Elmar Körding, Geoffrey C. Bower, Rob Fender

Jets are ubiquitous in accreting black holes. Often ignored, they may be a major contributor to the emitted spectral energy distribution for sub-Eddington black holes. For example, recent...

Eight powers of ten: similarities in black hole accretion on all mass scales (2007)

Fender, Rob, Koerding, Elmar, Belloni, Tomaso, Uttley, Phil, McHardy, Ian, Tzioumis, Tasso

In this paper we discuss the recent advances in the quantitative comparison of accretion, and the accretion:jet coupling, in accreting black holes in both X-ray binaries (where M ~ 10Msun) and Active...

A highly polarised radio jet during the 1998 outburst of the black hole transient XTE J1748-288 (2007)

Brocksopp, Catherine, Miller-Jones, James, Fender, Rob, Stappers, Ben

XTE J1748-288 is a black hole X-ray transient which went into outburst in 1998 June. The X-ray lightcurves showed canonical morphologies, with minor variations on the ``Fast Rise Exponential Decay''...

Jet-dominated advective systems of all mass scales (2006)

Koerding, Elmar, Fender, Rob

We show that the radio emission of black hole (BH) and neutron star (NS) X-ray binaries (XRBs) follows the analytical prediction of a jet model where the jet carries a constant fraction of the...

A link between radio loudness and X-ray/optical properties of AGN (2006)

Jester, Sebastian, Koerding, Elmar, Fender, Rob

We have found empirically that the radio loudness of AGN can be understood as function of both the X-ray and optical luminosity. This way of considering the radio loudness was inspired by the...

The LOFAR Transients Key Project (2006)

Fender, Rob, Braun, Robert, Stappers, Ben, Wijers, Ralph, Wise, Michael, Coenen, Thijs, ...

LOFAR, the Low Frequency Array, is a new radio telescope under construction in the Netherlands, designed to operate between 30 and 240 MHz. The Transients Key Project is one of the four Key Science...

RXTE observations of the first transient Z source XTE J1701-462: shedding new light on mass accretion in luminous neutron star LMXBs (2006)

Homan, Jeroen, Van Der Klis, Michiel, Wijnands, Rudy, Belloni, Tomaso, Fender, Rob, Klein-Wolt, Marc, ...

(Abridged) We report on ten weeks of RXTE observations of the X-ray transient XTE J1701-462. Comparisons with other sources suggest it had all the characteristics of the neutron star Z sources (the...

Accretion states and radio loudness in Active Galactic Nuclei: analogies with X-ray binaries (2006)

Koerding, Elmar, Jester, Sebastian, Fender, Rob

Hardness-intensity diagrams (HIDs) have been used with great success to study the accretion states and their connection to radio jets in X-ray binaries (XRBs). The analogy between XRBs and active...

Jet-dominated advective systems: radio and X-ray luminosity dependence on the accretion rate (2006)

Koerding, Elmar, Fender, Rob, Migliari, Simone

We present a novel method to measure the accretion rate of radio emitting X-ray binaries (XRBs) and active galactic nuclei (AGN) independently of the X-ray luminosity. The radio emission of the jet...

A ULX microquasar in NGC 5408? (2006)

Soria, Roberto, Fender, Rob, Hannikainen, Diana, Read, Andrew, Stevens, Ian

We studied the radio source associated with the ultraluminous X-ray source in NGC 5408 (L_X ~ 10^{40} erg/s). The radio spectrum is steep (index ~ -1), consistent with optically-thin synchrotron...

Accretion states and radio loudness in active galactic nuclei: analogies with X-ray binaries (2006)

Koerding, Elmar G., Jester, Sebastian, Fender, Rob

Hardness-intensity diagrams (HIDs) have been used with great success to study the accretion states and their connection to radio jets in x-ray binaries (XRBs). The analogy between XRBs and active...

Jet-dominated advective systems: radio and x-ray luminosity dependence on the accretion rate (2006)

Koerding, Elmar, Fender, Rob, Migliari, Simone

We present a novel method to measure the accretion rate of radio emitting x-ray binaries (XRBs) and active galactic nuclei (AGN) independently of the x-ray luminosity. The radio emission of the jet...

Accretion states and radio loudness in active galactic nuclei: analogies with X-ray binaries (2006)

Körding, Elmar G., Jester, Sebastian, Fender, Rob

Hardness-intensity diagrams (HIDs) have been used with great success to study the accretion states and their connection to radio jets in X-ray binaries (XRBs). The analogy between XRBs and active...

Accretion modes and jet production in black hole X-ray binaries (2005)

Gallo, Elena, Fender, Rob

We review our current understanding of the radio properties of black hole X-ray binaries in connection with the X-ray spectral states, and discuss them in the framework of the recently proposed...

A unified model for black hole X-ray binary jets ? (2005)

Fender, Rob, Belloni, Tomaso, Gallo, Elena

We have recently put forward a 'unified' semi-empirical model for the coupling between accretion and jet production in galactic black hole X-ray binaries (published in MNRAS, 2004). In this paper we...

Energisation of interstellar media and cosmic ray production by jets from X-ray binaries (2005)

Fender, Rob, Maccarone, Tom, Van Kesteren, Zdenko

Drawing on recent estimates of the power of jets from X-ray binary systems as a function of X-ray luminosity, combined with improved estimates of the relevant Log(N)-Log(L_X) luminosity functions, we...

Black hole X-ray binary jets (2005)

Gallo, Elena, Fender, Rob, Kaiser, Christian

Relativistic jets powered by stellar mass black holes in X-ray binaries appear to come in two types: steady outflows associated with hard X-ray states and large scale discrete ejections associated...

Letter to Nature: A dark jet dominates the power output of the stellar black hole Cygnus X-1 (2005)

Gallo, Elena, Fender, Rob, Kaiser, Christian, Russell, David, Morganti, Rafella, Oosterloo, Tom, ...

Black holes undergoing accretion are thought to emit the bulk of their power in the X-ray band by releasing the gravitational potential energy of the infalling matter1. At the same time, they are...

The radio spectrum of a quiescent stellar mass black hole (2004)

Gallo, Elena, Fender, Rob, Hynes, Rob

Observations of V404 Cyg performed with the Westerbork Synthesis Radio Telescope at four frequencies, over the interval 1.4-8.4 GHz, have provided us with the first broadband radio spectrum of a...

GRS 1915+105 and the disc-jet coupling in accreting black hole systems (2004)

Fender, Rob, Belloni, Tomaso

GRS 1915+105—the first stellar-scale, highly relativistic jet source identified—is a key system for our understanding of the disc-jet coupling in accreting black hole systems. Comprehending the...

Correlation between Hard X-ray Peak Flux and Soft X-ray Peak Flux in the Outburst Rise of Low Mass X-ray Binaries (2004)

Yu, Wenfei, Van Der Klis, Michiel, Fender, Rob

We have analyzed {\it Rossi} X-ray timing explorer (RXTE) pointed observations of the outbursts of black hole and neutron star soft X-ray transients in which an initial low/hard state or `island'...

GRS 1915+105 and the Disc-Jet Coupling in Accreting Black Hole Systems (2004)

Fender, Rob, Belloni, Tomaso

GRS 1915+105 - the first stellar-scale, highly relativistic jet source identified - is a key system for our understanding of the disc-jet coupling in accreting black hole systems. Comprehending the...

An ultra-relativistic outflow from a neutron star accreting gas from a companion (2004)

Fender, Rob, Wu, Kinwah, Johnston, Helen, Tzioumis, Tasso, Jonker, Peter, Spencer, Ralph, ...

Collimated relativistic outflows, or jets, are amongst the most energetic and relativistic phenomena in the Universe. They are associated with supermassive black holes in distant active galactic...

Letter to Nature: An ultra-relativistic outflow from a neutron star accreting gas from a companion. (2004)

Fender, Rob, Wu, Kinwah, Johnston, Helen, Tzioumis, Tasso, Jonker, Peter, Spencer, Ralph, ...

Collimated relativistic outflows—also known as jets—are amongst the most energetic phenomena in the Universe. They are associated with supermassive black holes in distant active galactic nuclei1,...

A transient large-scale relativistic radio jet from GX 339-4 (2003)

Gallo, Elena, Corbel, Stephane, Fender, Rob, Maccarone, Tom, Tzioumis, Tasso

We report on the formation and evolution of a large-scale, synchrotron-emitting jet from the black hole candidate and X-ray binary system GX 339-4. In 2002 May, the source moved from a low/hard to a...

High energy emission from microquasars (2003)

Fender, Rob, Maccarone, Tom

The microquasar phenomenon is associated with the production of jets by X-ray binaries and, as such, may be associated with the majority of such systems. In this chapter we briefly outline the...

Chandra Detections of Two Quiescent Black Hole X-Ray Transients (2003)

Tomsick, John A., Corbel, Stephane, Fender, Rob, Miller, Jon M., Orosz, Jerome A., Rupen, Michael P., ...

Using the Chandra X-ray Observatory, we have detected the black hole transients V4641 Sgr and XTE J1859+226 in their low luminosity, quiescent states. The 0.3-8 keV luminosities are...

Evidence of a decrease of kHz QPO peak separation towards low frequencies in 4U 1728-34 (GX 354-0) (2003)

Migliari, Simone, Van Der Klis, Michiel, Fender, Rob

We have produced the colour-colour diagram of all the observations of 4U 1728-34 available in the Rossi X-ray Timing Explorer public archive (from 1996 to 2002) and found observations filling in a...

Simultaneous radio and X-ray observations of the low-mass X-ray binary GX 13+1 (2003)

Homan, Jeroen, Wijnands, Rudy, Rupen, Michael P., Fender, Rob, Hjellming, Robert M., Di Salvo, Tiziana, ...

We present the results of two simultaneous X-ray/radio observations of the low-mass X-ray binary GX 13+1, performed in July/August 1999 with the Rossi X-ray Timing Explorer and the Very Large Array....

Circularly polarised radio emission from GRS 1915+105 and other X-ray binaries (2003)

Fender, Rob

I report the detection of circular polarisation, associated with relativistic ejections, from the `microquasar' GRS 1915+105. I further compare detections and limits of circular polarisation and...

Disc-jet coupling in an atoll-type neutron star X-ray binary: 4U 1728-34 (GX 354-0) (2003)

Migliari, Simone, Fender, Rob, Rupen, Michael, Jonker, Peter, Klein-Wolt, Marc, Hjellming, Robert, ...

We have analysed 12 simultaneous radio (VLA) and X-ray (RXTE) observations of the atoll-type X-ray binary 4U 1728-34, performed in two blocks in 2000 and 2001. We have found that the strongest and...

A universal radio/X-ray correlation in low/hard state black hole binaries (2003)

Gallo, Elena, Fender, Rob, Pooley, Guy

We present a comprehensive study of (quasi-)simultaneous radio:X-ray observations of stellar black hole binaries during the spectrally hard X-ray state, finding evidence for a strong correlation...

Hard X-ray Flares Preceding Soft X-ray Outbursts in Aquila X-1: A Link between Neutron Star and Black Hole State Transitions (2003)

Yu, Wenfei, Klein-Wolt, Marc, Fender, Rob, Van Der Klis, Michiel

We have analyzed {\it Rossi X-ray Timing Explorer} (RXTE) data of the neutron star transient Aquila X-1 obtained during its outbursts in May/June 1999 and September/October 2000. We find that in the...

Jets from X-ray binaries (2003)

Fender, Rob

Relativistic outflows, or `Jets', represent one of the most obvious, important and yet poorly-explained phenomena associated with accreting relativistic objects, including X-ray binaries. In the past...

The connection between radio-quiet active galactic nuclei and the high/soft state of X-ray binaries (2003)

Maccarone, Thomas J., Gallo, Elena, Fender, Rob

A large sample of active galactic nuclei (AGN) studied here shows a `quenching' of the radio emission that occurs when the luminosity is from a few per cent to about 10 per cent of the Eddington...

X-Ray Jet Emission from the Black Hole X-Ray Binary XTE J1550-564 with Chandra in 2000 (2002)

Tomsick, John A., Corbel, Stephane, Fender, Rob, Miller, Jon M., Orosz, Jerome A., Tzioumis, Tasso, ...

We have discovered an X-ray jet due to material ejected from the black hole X-ray transient XTE J1550-564. The discovery was first reported by Corbel et al. (Science, 298, 196 and astro-ph/0210224),...

Iron Emission Lines from Extended X-ray Jets in SS 433: Reheating of Atomic Nuclei (2002)

Migliari, Simone, Fender, Rob, Mendez, Mariano

Powerful relativistic jets are among the most ubiquitous and energetic observational consequences of accretion around supermassive black holes in active galactic nuclei and neutron stars and...

Exploring the Role of Jets in the Radio/X-ray Correlations of GX 339-4 (2002)

Sera Markoff, Michael Nowak, Stephane Corbel, Rob Fender, Heino Falcke

The Galactic black hole candidate X-ray binary GX 339 4 spends most of its time in the low/hard state, making it an ideal candidate for modeling the assumedly low accretion phase. The radio emission...

The Power of Jets: New Clues from Radio Circular Polarization and X-rays (2001)

Falcke, Heino, Beckert, Thomas, Markoff, Sera, Koerding, Elmar, Bower, Geoffrey C., Fender, Rob

Jets are ubiquitous in accreting black holes. Often ignored, they may be a major contributor to the emitted spectral energy distribution for sub-Eddington black holes. For example, recent...

Relativistic outflows from X-ray binaries (a.k.a. `Microquasars') (2001)

Fender, Rob

In this review I summarise the observational connections between accretion and relativistic outflows -- jets -- in X-ray binaries. I argue that jets are likely to be a fairly ubiquitous property of...

Secular and orbital variability of Cir X-1 observed in optical spectra (2001)

Johnston, Helen M., Wu, Kinwah, Fender, Rob, Cullen, Jason G.

We have observed variations in the optical emission lines from the X-ray binary Circinus X-1. These variations may be attributed both to orbital variations and to long term secular changes in line...

A relativistic jet from Cygnus X-1 in the low/hard X-ray state (2001)

Stirling, Alastair, De La Force, Chris, Spencer, Ralph, Garrett, Mike, Fender, Rob, Ogley, Richard

We present the detection of a radio-emitting jet from the black-hole candidate and X-ray binary source Cygnus X-1. Evidence of a bright core with a slightly extended structure was found on...

Microquasars: hard X-ray/gamma-ray emission (2001)

Fender, Rob

I review some of the basic observational details of jets from X-ray binaries, or `microquasars'. It is shown that in both (Z and Atoll) NS and BHC systems radio emission, and therefore jet formation,...

Gamma-ray Emission from Jets in Galactic Microquasars (2001)

Sera Markoff, Heino Falcke, Rob Fender, Peter L. Biermann

Strong evidence exists for the presence of powerful jets in the Low/Hard state of black hole candidate X-ray binaries, earning them the additional nomenclature "microquasars ". In several...

Energetics of jets from X-ray binaries (2000)

Fender, Rob

I discuss the energetics of synchrotron-emitting outflows, increasingly found to be present in many different classes of X-ray binary systems. It is shown that the outflow is likely to be comparable...

A jet model for the broadband spectrum of XTE J1118+480: Synchrotron emission from radio to X-rays in the Low/Hard spectral state (2000)

Markoff, Sera, Falcke, Heino, Fender, Rob

Observations have revealed strong evidence for powerful jets in the Low/Hard states of black hole candidate X-ray binaries. Correlations, both temporal and spectral, between the radio -- infrared and...

Correlated X-ray Spectral and Timing Behavior of the Black Hole Candidate XTE J1550-564: A New Interpretation of Black Hole States (2000)

Homan, Jeroen, Wijnands, Rudy, Van Der Klis, Michiel, Belloni, Tomaso, Van Paradijs, Jan, Klein-Wolt, Marc, ...

We present an analysis of RXTE data of the X-ray transient XTE J1550-564. The source went through several states, which were divided into spectrally soft and hard states. These states showed up as...

Relativistic Jets from X-ray binaries (1999)

Fender, Rob

In this review I summarise the status of observational research into relativistic jets from X-ray binaries, highlighting four areas in particular: (i) How relativistic are the jets ?, (ii) The disc :...

High resolution optical and infrared spectroscopic observations of Cir X-1 (1999)

Johnston, Helen, Fender, Rob, Wu, Kinwah

We present new optical and infrared (IR) observations of Cir X-1 taken near apastron. Both sets of spectra show asymmetric emission lines. Archival optical observations show that an asymmetric...