Search Publications
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…
A large range of haziness conditions in hot-Jupiter atmospheres
Lavvas, Panayotis; Arfaux, Anthony
We present a study of photochemical hazes of exoplanet atmospheres based on a self-consistent model including haze microphysics, disequilibrium chemistry, and radiative feedbacks. We derive the haze properties required to match Hubble Space Telescope observations of 10 hot-Jupiters. HAT-P-12b, HD-189733b, HD-209458b, and WASP-6b require haze mass …
Evidence in favour of density wave theory through age gradients observed in star formation history maps and spatially resolved stellar clusters
Davis, Benjamin L.; Eufrasio, Rafael; Monson, Erik B. +7 more
Quasi-stationary density wave theory predicts the existence of an age gradient across the spiral arms with a phase crossing at the corotation radius. We have examined evidence for such age gradients using star formation history (SFH) maps derived from LIGHTNING, a spectral energy distribution fitting procedure, and by using spatially resolved stel…
Combined spectroscopy and intensity interferometry to determine the distances of the blue supergiants P Cygni and Rigel
Domiciano de Souza, A.; Vakili, F.; Rivet, J. -P. +10 more
In this paper, we report on spatial intensity interferometry measurements within the Hα line on two stars: the Luminous Blue Variable supergiant P Cygni and the late-type B supergiant Rigel. The experimental setup was upgraded to allow simultaneous measurement of two polarization channels, instead of one in our previous setup, and the zero baselin…