Search Publications
Using principal component analysis to understand the variability of PDS 456
Fabian, A. C.; Buisson, D. J. K.; Reeves, J. N. +2 more
We present a spectral-variability analysis of the low-redshift quasar PDS 456 using principal component analysis. In the XMM-Newton data, we find a strong peak in the first principal component at the energy of the Fe absorption line from the highly blueshifted outflow. This indicates that the absorption feature is more variable than the continuum,…
A new powerful and highly variable disc wind in an AGN-star-forming galaxy, the case of MCG-03-58-007
Campana, S.; Turner, T. J.; Ballo, L. +7 more
We present the discovery of a new candidate for a fast disc wind, in the nearby Seyfert 2 galaxy MCG-03-58-007. This wind is discovered in a deep Suzaku observation that was performed in 2010. Overall the X-ray spectrum of MCG-03-58-007 is highly absorbed by a neutral column density of NH ∼1023 cm-2, in agreement w…
Flux rope breaking and formation of a rotating blowout jet
Joshi, Navin Chandra; Nishizuka, Naoto; Filippov, Boris +2 more
We analysed a small flux rope eruption converted into a helical blowout jet in a fan-spine configuration using multiwavelength observations taken by Solar Dynamics Observatory, which occurred near the limb on 2016 January 9. In our study, first, we estimated the fan-spine magnetic configuration with the potential-field calculation and found a sini…
Is there a UV/X-ray connection in IRAS 13224-3809?
Fabian, A. C.; Pinto, C.; Miniutti, G. +16 more
We present results from the optical, ultraviolet, and X-ray monitoring of the NLS1 galaxy IRAS 13224-3809 taken with Swift and XMM-Newton during 2016. IRAS 13224-3809 is the most variable bright AGN in the X-ray sky and shows strong X-ray reflection, implying that the X-rays strongly illuminate the inner disc. Therefore, it is a good candidate to …
CO excitation in the Seyfert galaxy NGC 34: stars, shock or AGN driven?
Cimatti, A.; Pozzi, F.; Massardi, M. +7 more
We present a detailed analysis of the X-ray and molecular gas emission in the nearby galaxy NGC 34, to constrain the properties of molecular gas, and assess whether, and to what extent, the radiation produced by the accretion on to the central black hole affects the CO line emission. We analyse the CO spectral line energy distribution (SLED) as re…
The Arcminute Microkelvin Imager catalogue of gamma-ray burst afterglows at 15.7 GHz
Wijers, R. A. M. J.; Fender, R. P.; van der Horst, A. J. +7 more
We present the Arcminute Microkelvin Imager (AMI) Large Array catalogue of 139 gamma-ray bursts (GRBs). AMI observes at a central frequency of 15.7 GHz and is equipped with a fully automated rapid-response mode, which enables the telescope to respond to high-energy transients detected by Swift. On receiving a transient alert, AMI can be on-target …
The Complete Local-volume Groups Sample - II. A study of the central radio galaxies in the high-richness sub-sample
Babul, Arif; Raychaudhury, Somak; Giacintucci, Simona +3 more
We present a study of the radio properties of the dominant early-type galaxies in 26 galaxy groups, the high-richness sub-sample of the Complete Local-volume Groups Sample (CLoGS). Combining new 610 and 235 MHz observations of 21 groups from the Giant Metrewave Radio Telescope (GMRT) with archival GMRT and Very Large Array (VLA) survey data, we fi…
Testing models of stellar structure and evolution - I. Comparison with detached eclipsing binaries
del Burgo, C.; Allende Prieto, C.
We present the results of an analysis aimed at testing the accuracy and precision of the PARSEC v1.2S library of stellar evolution models, combined with a Bayesian approach, to infer stellar parameters. We mainly employ the online DEBCat catalogue by Southworth, a compilation of detached eclipsing binary systems with published measurements of mass…
Star formation complexes in the `galaxy-sized' supergiant shell of the galaxy HolmbergI
Egorov, Oleg V.; Lozinskaya, Tatiana A.; Moiseev, Alexei V. +1 more
We present the results of observations of the galaxy Holmberg I carried out at the Russian 6-m telescope in the narrow-band imaging, long-slit spectroscopy, and scanning Fabry-Perot interferometer modes. A detailed analysis of gas kinematics, ionization conditions, and metallicity of star-forming regions in the galaxy is presented. The aim of the …
Cometary plasma response to interplanetary corotating interaction regions during 2016 June-September: a quantitative study by the Rosetta Plasma Consortium
Henri, Pierre; Simon Wedlund, Cyril; Nilsson, Hans +14 more
Four interplanetary corotating interaction regions (CIRs) were identified during 2016 June-September by the Rosetta Plasma Consortium (RPC) monitoring in situ the plasma environment of the comet 67P/Churyumov-Gerasimenko (67P) at heliocentric distances of ∼3-3.8 au. The CIRs, formed in the interface region between low- and high-speed solar wind st…