Publications (140)
High-resolution radio imaging of TGSSJ1530+1049, a radio galaxy in a dense environment at z=4
K. Ã. Gabányi, S. Frey, L. I. Gurvits +10
High-redshift radio galaxies can provide insights into the structure formation and galaxy evolution at earlier cosmological epochs. TGSSJ1530+1049 was selected as a candidate high-…
Mapping the neutral atomic hydrogen gas outflow in the restarted radio galaxy 3C 236
R. Schulz, R. Morganti, K. Nyland +3
The energetic feedback that is generated by radio jets in active galactic nuclei (AGNs) has been suggested to be able to produce fast outflows of atomic hydrogen (HI) gas that can…
Highly polarised microstructure from the repeating FRB 20180916B
K. Nimmo, J. W. T. Hessels, A. Keimpema +7
Fast radio bursts (FRBs) are bright, coherent, short-duration radio transients of as-yet unknown extragalactic origin. FRBs exhibit a wide variety of spectral, temporal and polarim…
VLBI observation of the newly discovered z=5.18 quasar SDSS J0131-0321
K. E. Gabanyi, D. Cseh, S. Frey +4
Few high-redshift, radio-loud quasars are known to date. The extremely luminous, radio-bright quasar, SDSS J013127.34-032100.1 was recently discovered at a redshift of . We…
A search for AGN in the most extreme UV-selected starbursts using the European VLBI Network
R. Alexandroff, R. A. Overzier, Z. Paragi +7
We have used the European VLBI Network (EVN) to observe a sample of Lyman Break Analogs (LBAs), nearby (z < 0.3) galaxies with properties similar to the more distant Lyman Break Ga…
The Intriguing Parsec-Scale Radio Structure in the "Offset AGN" KISSR 102
P. Kharb, D. Lena, Z. Paragi +4
We report the detection of an intriguing parsec-scale radio source in the "offset AGN" candidate, KISSR 102. The elliptical host galaxy includes two optical nuclei at a projected s…
Localizations of Fast Radio Bursts on milliarcsecond scales
B. Marcote, Z. Paragi
Fast Radio Bursts (FRBs) are transient sources that emit a single radio pulse with a duration of only a few milliseconds. Since the discovery of the first FRB in 2007, tens of simi…
Detailed Radio View on Two Stellar Explosions and Their Host Galaxy: XRF080109/SN2008D and SN2007uy in NGC2770
A. J. van der Horst, A. P. Kamble, Z. Paragi +16
The galaxy NGC2770 hosted two core-collapse supernova explosions, SN2008D and SN2007uy, within 10 days of each other and 9 years after the first supernova of the same type, SN1999e…
Revealing Hanny's Voorwerp: radio observations of IC 2497
G. I. G. Jozsa, M. A. Garrett, T. A. Oosterloo +7
We present multi-wavelength radio observations in the direction of the spiral galaxy IC 2497 and the neighbouring emission nebula known as "Hanny's Voorwerp". Our WSRT continuum ob…
A Hyperactive FRB Pinpointed in an SMC-Like Satellite Host Galaxy
M. Bhardwaj, M. P. Snelders, J. W. T. Hessels +24
Precise localizations of fast radio bursts (FRBs) are essential for uncovering their host galaxies and immediate environments. We present the milliarcsecond-precision European VLBI…
First e-VLBI observations of GRS 1915+105
A. Rushton, R. E. Spencer, M. Strong +10
We present results from the first successful open call e-VLBI science run, observing the X-ray binary GRS 1915+105. e-VLBI science allows the rapid production of VLBI radio maps, w…
High-resolution radio observations of TeV candidate sources
J. KÅmÃves, K. Ã. Gabányi, S. Frey +3
Radio-loud active galactic nuclei (AGN) with their jets pointed close to our line of sight constitute the majority of extragalactic -ray sources and significantly contribute to…
Probing the Active Massive Black Hole Candidate in the Center of NGC 404 with VLBI
Z. Paragi, S. Frey, P. Kaaret +3
Recently Nyland et al. (2012) argued that the radio emission observed in the center of the dwarf galaxy NGC 404 originates in a low-luminosity active galactic nucleus (LLAGN) power…
Transient Relativistic Ejections and Stationary Core in XTE J1752-223
J. Yang, Z. Paragi, S. Corbel +3
The Galactic X-ray transient XTE J1752-223 was shown to have properties of black hole binary candidates. As reported in our previous paper, we identified transient and decelerating…
Burst timescales and luminosities link young pulsars and fast radio bursts
K. Nimmo, J. W. T. Hessels, F. Kirsten +45
Fast radio bursts (FRBs) are extragalactic radio flashes of unknown physical origin. Their high luminosities and short durations require extreme energy densities, like those found…
VLBI imaging of extremely high redshift quasars at 5 GHz
Z. Paragi, S. Frey, L. I. Gurvits +5
We present very long baseline interferometry (VLBI) images of ten very high redshift (z>3) quasars at 5 GHz. The sources 0004+139, 0830+101, 0906+041, 0938+119 and 1500+045 were ob…
e-VLBI observations of SN2001em - an off-axis GRB candidate
Z. Paragi, M. A. Garrett, B. Paczynski +5
Studying transient phenomena with the Very Long Baseline Interferometry (VLBI) technique faces severe difficulties because the turnaround time of the experiments from the observati…
The Repeating Fast Radio Burst FRB 121102 as Seen on Milliarcsecond Angular Scales
B. Marcote, Z. Paragi, J. W. T. Hessels +26
The millisecond-duration radio flashes known as Fast Radio Bursts (FRBs) represent an enigmatic astrophysical phenomenon. Recently, the sub-arcsecond localization (~ 100mas precisi…
Four dual AGN candidates observed with the VLBA
K. Ã. Gabányi, T. An, S. Frey +4
According to hierarchical structure formation models, merging galaxies are expected to be seen in different stages of their coalescence. However, currently there are no straightfor…
Unveiling multiple AGN activity in galaxy mergers
A. De Rosa, S. Bianchi, T. Bogdanovic +13
In this paper we present an overview of the MAGNA (Multiple AGN Activity) project aiming at a comprehensive study of multiple supemassive black hole systems. With the main goal to…
The proper motion and changing jet morphology of Cygnus X-3
J. C. A. Miller-Jones, C. M. Sakari, V. Dhawan +4
We present analysis of 25 years' worth of archival VLA, VLBA and EVN observations of the X-ray binary Cygnus X-3. From this, we deduce the source proper motion, allowing us to pred…
Unveiling recurrent jets of the ULX Holmberg II X-1: evidence for a massive stellar-mass black hole?
D. Cseh, P. Kaaret, S. Corbel +10
We report on the discovery of an apparent triple radio structure hidden inside the radio bubble of the ultraluminous X-ray source Holmberg II X-1. The morphology is consistent with…
From compact jets to extended lobes: radio morphologies of distant quasars at z > 4
K. Ã. Gabányi, M. Kunert-Bajraszewska, A. Krauze +9
High-redshift quasars play an essential role in studying the growth and evolution of supermassive black holes and active galactic nuclei (AGN). Radio-loud quasars additionally enab…
A suspected Dark Lens revealed with the e-EVN
Z. Paragi, S. Frey, B. Campbell +1
The e-VLBI technique offers a unique opportunity for users to probe the milliarcsecond (mas) scale structure of unidentified radio sources, and organise quick follow-up observation…
Periodic activity from a fast radio burst source
FRB Collaboration, M. Amiri, B. C. Andersen +70
Fast radio bursts (FRBs) are bright, millisecond-duration radio transients originating from extragalactic distances. Their origin is unknown. Some FRB sources emit repeat bursts, r…
The SFXC software correlator for Very Long Baseline Interferometry: Algorithms and Implementation
A. Keimpema, M. M. Kettenis, S. V. Pogrebenko +13
In this paper a description is given of the SFXC software correlator, developed and maintained at the Joint Institute for VLBI in Europe (JIVE). The software is designed to run on…
Broadband monitoring tracing the evolution of the jet and disk in the black hole candidate X-ray binary MAXI J1659-152
A. J. van der Horst, P. A. Curran, J. C. A. Miller-Jones +31
MAXI J1659-152 was discovered on 2010 September 25 as a new X-ray transient, initially identified as a gamma-ray burst, but was later shown to be a new X-ray binary with a black ho…
Milliarcsecond-scale radio structure of the most distant BL Lac object candidate at redshift 6.57
S. Frey, Y. Zhang, K. Perger +7
The existence of accreting supermassive black holes up to billions of solar masses at early cosmological epochs (in the context of this work, redshifts z>=6) requires very fast gro…
Probing the polarization characteristics of SS433 on mas scales
Z. Paragi, R. C. Vermeulen, D. C. Homan +5
We present a status report of dedicated circular polarization (CP) global VLBI observations of SS433. The total intensity image of the source is presented. We do not detect linear…
Apertif, Phased Array Feeds for the Westerbork Synthesis Radio Telescope
W. A. van Cappellen, T. A. Oosterloo, M. A. W. Verheijen +87
We describe the APERture Tile In Focus (Apertif) system, a phased array feed (PAF) upgrade of the Westerbork Synthesis Radio Telescope which has transformed this telescope into a h…
A mildly relativistic radio jet from the otherwise normal Type Ic Supernova 2007gr
Z. Paragi, G. B. Taylor, C. Kouveliotou +11
The class of type Ic supernovae have drawn increasing attention since 1998 owing to their sparse association (only four so far) with long duration gamma-ray bursts. Although both p…
The most distant radio quasars at the highest resolution
S. Frey, Z. Paragi, . L. I. Gurvits +2
There are about 50 quasars known at redshifts z>5.7 to date. Only three of them are detected in the radio (J0836+0054, z=5.77; J1427+3312, z=6.12; J1429+5447, z=6.21). The highest-…
SS433: outflows here and there
Z. Paragi, I. Fejes, R. C. Vermeulen +3
We summarize the results of VLBA and global VLBI observations of SS433 between 1995 and 2000. With these observations we resolve the inner jet of the source and identify an absorpt…
Revealing HI gas in emission and absorption on pc to kpc scales in a galaxy at z ~ 0.017
N. Gupta, R. Srianand, J. S. Farnes +6
We present a detailed study of the quasar-galaxy pair: J1243+4043 - UGC07904. The sight line of the background quasar ( = 1.5266) passes through a region of the galaxy (=…
Two in one? A possible dual radio-emitting nucleus in the quasar SDSS J1425+3231
S. Frey, Z. Paragi, T. An +1
The radio-emitting quasar SDSS J1425+3231 (z=0.478) was recently found to have double-peaked narrow [O III] optical emission lines. Based on the analysis of the optical spectrum, P…
Swift J1644+5734: the EVN view
Z. Paragi, J. Yang, S. Komossa +5
A small fraction of Tidal Disruption Events (TDE) produce relativistic jets, evidenced by their non-thermal X-ray spectra and transient radio emission. Here we present milliarcseco…
Revisiting dual AGN candidates with spatially resolved LBT spectroscopy -- The impact of spillover light contamination
B. Husemann, J. Heidt, A. De Rosa +5
The merging of supermassive black holes (SMBHs) is a direct consequence of our hierarchical picture of galaxy evolution. It is difficult to track the merging process of SMBHs durin…
Probing the origin of the off-pulse emission from the pulsars B0525+21 and B2045-16
B. Marcote, Y. Maan, Z. Paragi +1
Pulsars typically exhibit radio emission in the form of narrow pulses originated from confined regions of their magnetospheres. A potential presence of magnetospherically originate…
Into the central 10 pc of the most distant known radio quasar. VLBI imaging observations of J1429+5447 at z=6.21
S. Frey, Z. Paragi, L. I. Gurvits +2
Context: There are about 60 quasars known at redshifts z>5.7 to date. Only three of them are detected in the radio above 1 mJy flux density at 1.4 GHz frequency. Among them, J1429+…
Is an obscured AGN at the centre of the disk galaxy IC 2497 responsible for Hanny's Voorwerp?
H. Rampadarath, M. A. Garrett, T. Muxlow +3
We present the results of VLBI and MERLIN observations of the massive disk galaxy IC 2497. Optical observations of IC 2497 revealed the existence of a giant emission nebula "Hanny'…
A decelerating jet observed by the EVN and VLBA in the X-ray transient XTE J1752-223
J. Yang, C. Brocksopp, S. Corbel +3
The recently discovered Galactic X-ray transient XTE J1752-223 entered its first known outburst in 2010, emitting from the X-ray to the radio regimes. Its general X-ray properties…
VLBI observations of the radio quasar J2228+0110 at z=5.95 and other field sources in multiple-phase-centre mode
H. -M. Cao, S. Frey, L. I. Gurvits +5
A patch of sky in the SDSS Stripe 82 was observed at 1.6 GHz with Very Long Baseline Interferometry (VLBI) using the European VLBI Network (EVN). The data were correlated at the EV…
High-resolution double morphology of the most distant known radio quasar at z=6.12
S. Frey, L. I. Gurvits, Z. Paragi +1
Context: The highest redshift quasars at z>~6 receive considerable attention since they provide strong constraints on the growth of the earliest supermassive black holes. They also…
Evolution of the radio - X-ray coupling throughout an entire outburst of Aquila X-1
J. C. A. Miller-Jones, G. R. Sivakoff, D. Altamirano +18
The 2009 November outburst of the neutron star X-ray binary Aquila X-1 was observed with unprecedented radio coverage and simultaneous pointed X-ray observations, tracing the radio…
High-resolution radio imaging of the gamma-ray blazar candidate J1331+2932
A. Gemes, K. Ã. Gabányi, S. Frey +3
Active galactic nuclei are the most luminous persistent (non-transient, even if often variable) objects in the Universe. They are bright in the entire electromagnetic spectrum. Bla…
LOFT as a discovery machine for jetted Tidal Disruption Events
E. M. Rossi, I. Donnarumma, R. Fender +5
This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT f…
A close-pair binary in a distant triple supermassive black-hole system
R. P. Deane, Z. Paragi, M. J. Jarvis +8
Galaxies are believed to evolve through merging, which should lead to multiple supermassive black holes in some. There are four known triple black hole systems, with the closest pa…
High-resolution images of five radio quasars at early cosmological epochs
S. Frey, Z. Paragi, L. I. Gurvits +2
Context: Until now, there have only been seven quasars at z>4.5 whose the high-resolution radio structure had been studied in detail with Very Long Baseline Interferometry (VLBI) i…
Disclosing the properties of low-redshift dual AGN through XMM-Newton and SDSS spectroscopy
A. De Rosa, C. Vignali, B. Husemann +10
We report on an optical (SDSS) and X-ray (XMM) study of an optically selected sample of four dual AGN systems at projected separations of 30--60~kpc. All sources are detected in th…
High-Resolution Radio Image of a Candidate Radio Galaxy at z=5.72
K. Ã. Gabányi, S. Frey, L. I. Gurvits +2
Recently, Saxena et al. (2018) reported the discovery of a possible radio galaxy, J15301049 at a redshift of z=5.72. We observed the source with the European Very Long Baseline…
A new perspective on the submillimetre galaxy MM 18423+5938 at redshift 3.9296 from radio continuum imaging
J. P. McKean, A. Berciano Alba, F. Volino +5
The bright submillimetre (sub-mm) galaxy MM 18423+5938 at redshift 3.9296 has been predicted from mid-infrared and millimetre photometry to have an exceptionally large total infrar…
FRB 121102: drastic changes in the burst polarization contrasts with the stability of the persistent emission
A. V. Plavin, Z. Paragi, B. Marcote +5
We study milliarcsecond-scale properties of the persistent radio counterpart to FRB 121102 and investigate the spectro-polarimetric properties of a bright burst. For the former, we…
On the Doppler boosting in the compact radio jet of the distant blazar J1026+2542 at z=5.3
S. Frey, J. O. Fogasy, Z. Paragi +1
Based on its broad-band spectral energy distribution, and the X-ray spectrum in particular, the radio-loud active galactic nucleus (AGN) SDSS J102623.61+254259.5 (J1026+2542) has r…
VLBI search for the radio counterpart of HESS J1943+213
K. E. Gabanyi, G. Dubner, E. Giacani +3
HESS J1943+213, a TeV point source close to the Galactic plane recently discovered by the H.E.S.S. collaboration, was proposed to be an extreme BL Lacertae object, though a pulsar…
The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1
D. Cseh, J. C. A. Miller-Jones, P. G. Jonker +7
We present quasi-simultaneous, multi-epoch radio and X-ray measurements of Holmberg II X-1 using the European VLBI Network (EVN), the Karl G. Jansky Very Large Array (VLA), and the…
Constraining the radio jet proper motion of the high-redshift quasar J2134-0419 at z=4.3
K. Perger, S. Frey, K. Ã. Gabányi +12
To date, PMN J2134-0419 (at a redshift z=4.33) is the second most distant quasar known with a milliarcsecond-scale morphology permitting direct estimates of the jet proper motion.…
Radio structure of the most distant radio-detected quasar at the ten milli- arcsecond scale
S. Frey, L. Mosoni, Z. Paragi +1
We present a high resolution radio image of SDSS 0836+0054 identified recently as the most distant radio-detected quasar at a redshift of z=5.82. The observation was carried out wi…
The Search for Binary Black holes in Seyferts with Double Peaked Emission Lines
P. Kharb, M. Das, S. Subramanian +1
We discuss results from very long baseline interferometry (VLBI) observations of two Seyfert galaxies with double peaked emission lines in their SDSS optical spectra. Such AGN are…
Panning for gold, but finding helium: discovery of the ultra-stripped supernova SN2019wxt from gravitational-wave follow-up observations
I. Agudo, L. Amati, T. An +96
We present the results from multi-wavelength observations of a transient discovered during the follow-up of S191213g, a gravitational wave (GW) event reported by the LIGO-Virgo Col…
Deep Extragalactic VLBI-Optical Survey (DEVOS) II. Efficient VLBI detection of SDSS quasars
S. Frey, L. I. Gurvits, Z. Paragi +3
Context: The Deep Extragalactic VLBI-Optical Survey (DEVOS) aims at constructing a large sample of compact radio sources up to two orders of magnitude fainter than those studied in…
High-resolution radio imaging of the most distant radio quasar SDSS J0836+0054
S. Frey, Z. Paragi, L. Mosoni +1
We observed SDSS J0836+0054, the most distant radio-loud quasar known at present (z=5.774) with the European Very Long Baseline Interferometry (VLBI) Network at the 5 GHz frequency…
The Future Of The Arecibo Observatory: The Next Generation Arecibo Telescope
D. Anish Roshi, N. Aponte, E. Araya +71
The Arecibo Observatory (AO) is a multidisciplinary research and education facility that is recognized worldwide as a leading facility in astronomy, planetary, and atmospheric and…
On the nature of FRB 150418: clues from European VLBI Network and e-MERLIN observations
M. Giroletti, B. Marcote, M. Garrett +5
We investigate the nature of the compact, and possibly variable nuclear radio source in the centre of WISE J0716-19, the proposed host galaxy of fast radio burst, FRB 150418. We ob…
e-MERLIN observations of the puzzling TeV source HESS J1943+213
K. E. Gabanyi, G. Dubner, E. Giacani +2
HESS J1943+213 is a TeV source close to the Galactic plane proposed to be a BL Lac object. Our high resolution EVN observation failed to recover two thirds of the source flux densi…
Hanny's Voorwerp: a nuclear starburst in IC2497
M. A. Garrett, H. Rampadarath, G. I. G. Jozsa +7
We present high and intermediate resolution radio observations of the central region in the spiral galaxy IC 2497, performed using the European VLBI Network (EVN) at 18 cm, and the…
VLBI observations of SN2011dh: imaging of the youngest radio supernova
I. Marti-Vidal, V. Tudose, Z. Paragi +11
We report on the VLBI detection of supernova SN2011dh at 22GHz using a subset of the EVN array. The observations took place 14 days after the discovery of the supernova, thus resul…
The rise and fall of a binary AGN candidate: the story of PSO J334.2028+1.4075
P. Benke, S. Frey, K. Ã. Gabányi +7
Apparently periodic optical variations of the luminous high-redshift (z=2.06) quasar PSO J334.2028+1.4075 led Liu et al. (2015) to interpret the variability as the orbital period o…
A single radio-emitting nucleus in the dual AGN candidate NGC 5515
K. Ã. Gabányi, S. Frey, T. Xiao +4
The Seyfert galaxy NGC 5515 has double-peaked narrow-line emission in its optical spectrum, and it has been suggested that this could indicate that it has two active nuclei. We obs…
The Equatorial Outflow of SS433
Z. Paragi, I. Fejes, R. C. Vermeulen +3
We present VLBI imaging results for SS433 from the period 1995-2000. An equatorial emission region is detected and confirmed in 7 experiments at 1.6 and 5 GHz. The structure of the…
Simultaneous X-ray, gamma-ray, and Radio Observations of the repeating Fast Radio Burst FRB 121102
P. Scholz, S. Bogdanov, J. W. T. Hessels +19
We undertook coordinated campaigns with the Green Bank, Effelsberg, and Arecibo radio telescopes during Chandra X-ray Observatory and XMM-Newton observations of the repeating fast…
An extreme magneto-ionic environment associated with the fast radio burst source FRB 121102
D. Michilli, A. Seymour, J. W. T. Hessels +31
Fast radio bursts (FRBs) are millisecond-duration, extragalactic radio flashes of unknown physical origin. FRB 121102, the only known repeating FRB source, has been localized to a…
The radio-loud active nucleus in the "dark lens" galaxy J1218+2953
S. Frey, Z. Paragi, R. M. Campbell +1
Context: There is a possibility that the optically unidentified radio source J1218+2953 may act as a gravitational lens, producing an optical arc ~4" away from the radio position.…
High-Redshift Quasars at the Highest Resolution: VSOP Results
S. Frey, L. I. Gurvits, A. P. Lobanov +2
We studied the radio structure of high-redshift (z>3) quasars with VSOP at 1.6 and 5 GHz. These sources are the most distant objects ever observed with Space VLBI, at rest-frame fr…
The Detection of a Compact Radio Feature in a Seyfert Galaxy After an Accretion Rate Change
K. Ã. Gabányi, K. Smith, S. Frey +3
X-ray binaries are known to show state transitions related to accretion rate changes which are often accompanied with dramatic changes in the jet emission. However, it is not clear…
The first estimate of radio jet proper motion at z>5
S. Frey, Z. Paragi, J. O. Fogasy +1
The extremely high redshift (z=5.3) radio source SDSS J102623.61+254259.5 (J1026+2542) is among the most distant and most luminous radio-loud active galactic nuclei (AGN) known to…
Future mmVLBI Research with ALMA: A European vision
R. P. J. Tilanus, T. P. Krichbaum, J. A. Zensus +165
Very long baseline interferometry at millimetre/submillimetre wavelengths (mmVLBI) offers the highest achievable spatial resolution at any wavelength in astronomy. The anticipated…
Three little radio galaxies in the early Universe
K. Ã. Gabányi, S. Frey, Z. Paragi +7
Volonteri et al. (2011) found that the number of radio-loud quasars above redshift 4 calculated from the luminosity function (based upon Swift/BAT observations) is much smaller tha…
VLBI observations of four radio quasars at : blazars or not?
H. -M. Cao, S. Frey, K. Ã. Gabányi +5
Blazars are active galactic nuclei (AGN) whose relativistic jets point nearly to the line of sight. Their compact radio structure can be imaged with very long baseline interferomet…
From binary to singular: the AGN PSO J334.2028+1.4075 under the high-resolution scope
P. Benke, K. Ã. Gabányi, S. Frey +6
PSO J334.2028+1.4075 (PSO J334) is a luminous quasar located at redshift z=2.06. The source gained attention when periodic flux density variations were discovered in its optical li…
The radio core and jet in the broad absorption line quasar PG 1700+518
J. Yang, F. Wu, Z. Paragi +1
The blue-shifted broad absorption lines (BAL) or troughs are observed in Active Galactic Nuclei (AGNs) when our line of sight is intercepted by a high speed outflow (wind), likely…
Global e-VLBI observations of the gamma-ray narrow line Seyfert 1 PMN J0948+0022
M. Giroletti, Z. Paragi, H. Bignall +16
There is growing evidence of relativistic jets in radio-loud narrow-line Seyfert 1 (RL-NLS1) galaxies. We constrain the observational properties of the radio emission in the first…
The direct localization of a fast radio burst and its host
S. Chatterjee, C. J. Law, R. S. Wharton +22
Fast radio bursts are astronomical radio flashes of unknown physical nature with durations of milliseconds. Their dispersive arrival times suggest an extragalactic origin and imply…
The VSOP 5 GHz AGN Survey: III. Imaging Results for the First 102 Sources
W. K. Scott, E. B. Fomalont, S. Horiuchi +17
The VSOP mission is a Japanese-led project to study radio sources with sub-milliarcsec resolution using an orbiting 8 m telescope, HALCA, along with global arrays of Earth-based te…
Multiwavelength monitoring of the enigmatic Narrow-Line Seyfert 1 PMN J0948+0022 in March-July 2009
LAT Collaboration, E. Angelakis, C. Bailyn +39
Following the recent discovery of gamma rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z=0.5846), we started a multiwavelength campaign from radio to gamma r…
The radio structure of 3C 316, a galaxy with double-peaked narrow optical emission lines
T. An, Z. Paragi, S. Frey +6
The galaxy 3C\,316 is the brightest in the radio band among the optically-selected candidates exhibiting double-peaked narrow optical emission lines. Observations with the Very Lar…
Redshift, Time, Spectrum - the most distant radio quasars with VLBI
S. Frey, L. I. Gurvits, Z. Paragi +1
The highest-redshift quasars are still rare and valuable objects for observational astrophysics and cosmology. They provide important constraints on the growth of the earliest supe…
Milliarcsecond localisation of the repeating FRB 20201124A
K. Nimmo, D. M. Hewitt, J. W. T. Hessels +28
Very long baseline interferometric (VLBI) localisations of repeating fast radio bursts (FRBs) have demonstrated a diversity of local environments: from nearby star-forming regions…
J2102+6015: an Intriguing Radio-loud Active Galactic Nucleus in the Early Universe
S. Frey, T. An, K. Gabányi +10
The powerful high-redshift quasar J2102+6015 (at z=4.575) may provide useful information for studying supermassive black hole growth, galaxy evolution and feedback in the early Uni…
Resolving the decades-long transient FIRST J141918.9+394036: an orphan long gamma-ray burst or a young magnetar nebula?
B. Marcote, K. Nimmo, O. S. Salafia +4
Ofek (2017) identified FIRST J141918.9+394036 (hereafter FIRST J1419+3940) as a radio source sharing similar properties and host galaxy type to the compact, persistent radio source…
Towards the origin of the radio emission in AR Sco, the first radio-pulsing white dwarf binary
B. Marcote, T. R. Marsh, E. R. Stanway +2
The binary system AR Sco contains an M star and the only known radio-pulsing white dwarf. The system shows emission from radio to X-rays, likely dominated by synchrotron radiation.…
A repeating fast radio burst source localised to a nearby spiral galaxy
B. Marcote, K. Nimmo, J. W. T. Hessels +51
Fast radio bursts (FRBs) are brief, bright, extragalactic radio flashes. Their physical origin remains unknown, but dozens of possible models have been postulated. Some FRB sources…
LLAGN and jet-scaling probed with the EVN
Z. Paragi, Z. Shen, F. de Gasperin +3
Accreting black holes on all mass scales (from stellar to supermassive) appear to follow a nonlinear relation between X-ray luminosity, radio luminosity and BH mass, indicating tha…
The radio structure of the peculiar narrow-line Seyfert 1 galaxy candidate J1100+4421
K. Ã. Gabányi, S. Frey, Z. Paragi +5
Narrow-line Seyfert 1 galaxies (NLS1) are an intriguing subclass of active galactic nuclei. Their observed properties indicate low central black hole mass and high accretion rate.…
Four hot DOGs in the microwave
S. Frey, Z. Paragi, K. Ã. Gabányi +1
Hot dust-obscured galaxies (hot DOGs) are a rare class of hyperluminous infrared galaxies identified with the Wide-field Infrared Survey Explorer (WISE) satellite. The majority of…
A Comprehensive Radio View of the Extremely Bright Gamma-Ray Burst 130427A
A. J. van der Horst, Z. Paragi, A. G. de Bruyn +11
GRB 130427A was extremely bright as a result of occurring at low redshift whilst the energetics were more typical of high-redshift gamma-ray bursts (GRBs). We collected well-sample…
SS433, microquasars, and other transients
Z. Paragi, R. C. Vermeulen, R. E. Spencer
X-ray binaries have been an important key in understanding the jet-disc symbiosis in accreting black holes on all mass scales, from stellar-mass to supermassive black holes. SS433…
VLBI observations of VIK J2318-3113, a quasar at z = 6.44
Y. Zhang, T. An, A. Wang +5
The nature of jets in active galactic nuclei (AGN) in the early Universe and their feedback to the host galaxy remain a highly topical question. Observations of the radio structure…
A weak compact jet in a soft state of Cygnus X-1
A. Rushton, J. C. A. Miller-Jones, R. Campana +8
We present evidence for the presence of a weak compact jet during a soft X-ray state of Cygnus X-1. Very-high-resolution radio observations were taken with the VLBA, EVN and MERLIN…
GRB 080319B: A Naked-Eye Stellar Blast from the Distant Universe
J. L. Racusin, S. V. Karpov, M. Sokolowski +81
Long duration gamma-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation…
Searching for a pair of accreting supermassive black holes in J1425+3231
K. Ã. Gabányi, S. Frey, Z. Paragi +2
In hierarchical structure formation scenarios, merging galaxies are expected to be seen in different phases of their coalescence. Simulations suggest that simultaneous activity of…