Search Publications
Neutron-capture elements record the ordered chemical evolution of the disc over time
Buder, Sven; Ness, Melissa K.; Horta, Danny +2 more
An ensemble of chemical abundances probing different nucleosynthetic channels can be leveraged to build a comprehensive understanding of the chemical and structural evolution of the Galaxy. Using GALAH DR3 data, we seek to trace the enrichment by the supernovae Ia, supernovae II, asymptotic giant branch stars, and neutron-star mergers and/or colla…
Serendipitous discovery of radio flaring behaviour from a nearby M dwarf with MeerKAT
Buckley, David A. H.; Osten, Rachel A.; Lintott, Chris J. +12 more
We report on the detection of MKT J174641.0-321404, a new radio transient found in untargeted searches of wide-field MeerKAT radio images centred on the black hole X-ray binary H1743-322. MKT J174641.0-321404 is highly variable at 1.3 GHz and was detected three times during 11 observations of the field in late 2018, reaching a maximum flux density…
Thermal and non-thermal X-ray emission from the rotation-powered radio/γ-ray pulsar PSR J1740+1000
Mereghetti, Sandro; Turolla, Roberto; Zane, Silvia +4 more
We report the results of new XMM-Newton observations of the middle-aged (τc = 1.1 × 105 yr) radio pulsar PSR J1740+1000 carried out in 2017-2018. These long pointings (~530 ks) show that the non-thermal emission, well described by a power-law spectrum with photon index Γ = 1.80 ± 0.17, is pulsed with a ~30 per cent pulsed fra…
WISDOM Project - XIII. Feeding molecular gas to the supermassive black hole in the starburst AGN-host galaxy Fairall 49
Williams, Thomas G.; Cappellari, Michele; Davis, Timothy A. +5 more
The mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) is probing supermassive black holes (SMBHs) in galaxies across the Hubble sequence via molecular gas dynamics. We present the first WISDOM study of a luminous infrared galaxy with an active galactic nuclei (AGNs): Fairall 49. We use new ALMA observations of the CO(2 - 1) line with a…
Mass transfer and tidally tilted pulsation in the Algol-type system TZ Dra
Handler, G.; Leone, F.; De Cat, P. +6 more
Oscillating eclipsing Algols (oEAs) are remarkable systems that allow us to determine accurate fundamental stellar parameters (mass, radius) and probe the stellar interiors through pulsations. TZ Dra is an oEA system containing a δ Scuti component. To examine particular characteristics of such close systems including pulsations and mass transfer, …
Still at odds with conventional galaxy evolution: the star formation history of ultradiffuse galaxy Dragonfly 44
van Dokkum, Pieter; Forbes, Duncan A.; Romanowsky, Aaron J. +7 more
We study the star formation history (SFH) of the ultradiffuse galaxy (UDG) Dragonfly 44 (DF44) based on the simultaneous fit to near-ultraviolet to near-infrared photometry and high signal-to-noise optical spectroscopy. In fitting the observations, we adopt an advanced physical model with a flexible SFH and discuss the results in the context of th…
Planetary nebulae with Wolf-Rayet-type central stars - III. A detailed view of NGC 6905 and its central star
Guerrero, M. A.; Toalá, J. A.; Todt, H. +6 more
We present a multiwavelength characterization of the planetary nebula (PN) NGC 6905 and its [Wolf-Rayet]-type ([WR]) central star (CSPN) HD 193949. Our Nordic Optical Telescope Alhambra Faint Object Spectrograph and Camera (ALFOSC) spectra and images unveil in unprecedented detail the high-ionization structure of NGC 6905. The high-quality spectra…
Spectral analysis of cool white dwarfs accreting from planetary systems: from the ultraviolet to the optical
Gänsicke, B. T.; Tremblay, P. -E.; Hollands, M. A. +1 more
The accretion of planetary debris into the atmospheres of white dwarfs leads to the presence of metal lines in their spectra. Cool metal-rich white dwarfs, which left the main sequence many Gyr ago, allow the study of the remnants of the oldest planetary systems. Despite their low effective temperatures (Teff), a non-negligible amount o…
Filling the gap between synchronized and non-synchronized sdBs in short-period sdBV+dM binaries with TESS: TIC 137608661, a new system with a well-defined rotational splitting
Németh, Péter; Silvotti, Roberto; Telting, John H. +5 more
TIC 137608661/TYC 4544-2658-1/FBS 0938+788 is a new sdBV+dM reflection-effect binary discovered by the TESS space mission with an orbital period of 7.21 h. In addition to the orbital frequency and its harmonics, the Fourier transform of TIC 137608661 shows many g-mode pulsation frequencies from the subdwarf B (sdB) star. The amplitude spectrum is …
The nova KT Eri Is a recurrent nova with a recurrence time-scale of 40-50 yr
Walter, Frederick M.; Schaefer, Bradley E.; Hounsell, Rebekah +1 more
KT Eridani was a very fast nova in 2009 peaking at V = 5.42 mag. We marshal large data sets of photometry to finally work out the nature of KT Eri. From the TESS light curve, as confirmed with our radial velocity curve, we find an orbital period of 2.61595 d. With our 272 spectral energy distributions from simultaneous BVRIJHK measures, the compan…