Search Publications
Lord of the Rings - Return of the King: Swift-XRT observations of dust scattering rings around V404 Cygni
Altamirano, D.; Motta, S. E.; Sivakoff, G. R. +5 more
On 2015 June 15, the black hole X-ray binary V404 Cygni went into outburst, exhibiting extreme X-ray variability which culminated in a final flare on June 26. Over the following days, the Swift-X-ray Telescope detected a series of bright rings, comprising five main components that expanded and faded with time, caused by X-rays scattered from the o…
Swift J174540.7-290015: a new accreting binary in the Galactic Centre
Haberl, F.; Ponti, G.; Rea, N. +8 more
We report on the identification of the new Galactic Centre (GC) transient Swift J174540.7-290015 as a likely low-mass X-ray binary located at only 16 arcsec from Sgr A⋆. This transient was detected on 2016 February 6, during the Swift GC monitoring, and it showed long-term spectral variations compatible with a hard- to soft-state transi…
Star formation and AGN activity in the most luminous LINERs in the local universe
Pérez, Enrique; Netzer, Hagai; Pović, Mirjana +4 more
This work presents the properties of 42 objects in the group of the most luminous, highest star formation rate (SFR) low-ionization nuclear emission-line regions (LINERs) at z = 0.04-0.11. We obtained long-slit spectroscopy of the nuclear regions for all sources, and FIR data (Herschel and IRAS) for 13 of them. We measured emission-line intensitie…
The ultraluminous X-ray source NGC 5643 ULX1: a large stellar mass black hole accreting at super-Eddington rates?
Pintore, Fabio; Middleton, Matthew J.; Sutton, Andrew D. +3 more
A sub-set of the brightest ultraluminous X-ray sources (ULXs), with X-ray luminosities well above 1040 erg s-1, typically have energy spectra which can be well described as hard power laws, and short-term variability in excess of ∼10 per cent. This combination of properties suggests that these ULXs may be some of the best can…
Using cm observations to constrain the abundance of very small dust grains in Galactic cold cores
Paladini, R.; Ysard, N.; Laureijs, R. J. +9 more
In this analysis, we illustrate how the relatively new emission mechanism, known as spinning dust, can be used to characterize dust grains in the interstellar medium. We demonstrate this by using spinning dust emission observations to constrain the abundance of very small dust grains (a ≲ 10 nm) in a sample of Galactic cold cores. Using the physic…
Spectral analysis of SMC X-2 during its 2015 outburst
Tiengo, A.; Mereghetti, S.; Sidoli, L. +3 more
We report on the results of XMM-Newton and Swift observations of SMC X-2 during its last outburst in 2015 October, the first one since 2000. The source reached a very high luminosity (L ∼ 1038 erg s-1), which allowed us to perform a detailed analysis of its timing and spectral properties. We obtained a pulse period Pspin…
Simultaneous radio and X-ray observations of PSR B0611+22
Rajwade, K.; Seymour, A.; Lorimer, D. R. +4 more
We report results from simultaneous radio and X-ray observations of PSR B0611+22 which is known to exhibit bursting in its single-pulse emission. The pulse phase of the bursts vary with radio frequency. The bursts are correlated in 327/150 MHz data sets while they are anti-correlated, with bursts at one frequency associated with normal emission at…
Evidence that widespread star formation may be underway in G0.253+0.016, `The Brick'
Marsh, K. A.; Whitworth, A. P.; Clark, P. C. +1 more
Image cubes of differential column density as a function of dust temperature are constructed for Galactic Centre molecular cloud G0.253+0.016 (`The Brick') using the recently described PPMAP procedure. The input data consist of continuum images from the HerschelSpace Telescope in the wavelength range 70-500 µm, supplemented by previously pub…
Probing star formation in the dense environments of z ∼ 1 lensing haloes aligned with dusty star-forming galaxies detected with the South Pole Telescope
Omont, A.; Dole, H.; Doré, O. +46 more
We probe star formation in the environments of massive (∼1013 M⊙) dark matter haloes at redshifts of z ∼ 1. This star formation is linked to a submillimetre clustering signal which we detect in maps of the Planck High Frequency Instrument that are stacked at the positions of a sample of high redshift (z > 2) strongly lense…
Complex central structures suggest complex evolutionary paths for barred S0 galaxies
Knapen, Johan H.; Dullo, Bililign T.; Martínez-Lombilla, Cristina
We investigate three barred lenticular galaxies (NGC 2681, NGC 3945 and NGC 4371), which were previously reported to have complex central structures but without a detailed structural analysis of these galaxies' high-resolution data. We have therefore performed four- to six-component (pseudo-)bulge/disc/bar/ring/point source) decompositions of the …