Search Publications
Identifying resonances of the Galactic bar in Gaia DR2: I. Clues from action space
Fragkoudi, Francesca; White, Simon D. M.; Mackereth, J. Ted +2 more
Action space synthesizes the orbital information of stars and is well suited to analyse the rich kinematic substructure of the disc in the second Gaia data release's radial velocity sample. We revisit the strong perturbation induced in the Milky Way disc by an m = 2 bar, using test particle simulations and the actions (JR, Lz…
The Hubble constant from eight time-delay galaxy lenses
Saha, Prasenjit; Williams, Liliya L. R.; Denzel, Philipp +1 more
We present a determination of the Hubble constant from the joint, free-form analysis of eight strongly, quadruply lensing systems. In the concordance cosmology, we find $H_0{} = 71.8^{+3.9}_{-3.3}\, \mathrm{km}\, \mathrm{s}^{-1}\, \mathrm{Mpc}^{-1}{}{}$ with a precision of $4.97{{\ \rm per\ cent}}$. This is in agreement with the latest measurement…
The search for failed supernovae with the Large Binocular Telescope: a new candidate and the failed SN fraction with 11 yr of data
Kochanek, C. S.; Stanek, K. Z.; Adams, S. M. +5 more
We present updated results of the Large Binocular Telescope Search for Failed Supernovae. This search monitors luminous stars in 27 nearby galaxies with a current baseline of 11 yr of data. We re-discover the failed supernova (SN) candidate N6946-BH1 as well as a new candidate, M101-OC1. M101-OC1 is a blue supergiant that rapidly disappears in opt…
An unexpected high concentration for the dark substructure in the gravitational lens SDSSJ0946+1006
Gad-Nasr, Sophia; Minor, Quinn; Kaplinghat, Manoj +1 more
The presence of an invisible substructure has previously been detected in the gravitational lens galaxy SDSSJ0946+1006 through its perturbation of the lensed images. Using flexible models for the main halo and the subhalo perturbation, we demonstrate that the subhalo has an extraordinarily high central density and steep density slope. We robustly …
Unveiling the distinct formation pathways of the inner and outer discs of the Milky Way with Bayesian Machine Learning
Davies, Guy R.; Grand, Robert J. J.; Ciucă, Ioana +2 more
We develop a Bayesian Machine Learning framework called BINGO (Bayesian INference for Galactic archaeOlogy) centred around a Bayesian neural network. After being trained on the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and Kepler asteroseismic age data, BINGO is used to obtain precise relative stellar age estimates with uncer…
The Alma catalogue of OB stars - II. A cross-match with Gaia DR2 and an updated map of the solar neighbourhood
Maíz Apellániz, J.; Barbá, R. H.; Pantaleoni González, M. +1 more
We cross-match the Alma catalogue of OB stars with Gaia DR2 astrometry and photometry as a first step towards producing a clean sample of massive stars in the solar neighbourhood with a high degree of completeness. We analyse the resulting colour-absolute magnitude diagram to divide our sample into categories and compare extinction estimates from …
Convolutional neural network identification of galaxy post-mergers in UNIONS using IllustrisTNG
Ellison, Sara L.; Gwyn, Stephen; Hudson, Michael J. +6 more
The Canada-France Imaging Survey (CFIS) will consist of deep, high-resolution r-band imaging over ~5000 deg2 of the sky, representing a first-rate opportunity to identify recently merged galaxies. Because of the large number of galaxies in CFIS, we investigate the use of a convolutional neural network (CNN) for automated merger classifi…
3D simulations of photochemical hazes in the atmosphere of hot Jupiter HD 189733b
Showman, Adam P.; Zhang, Xi; Tan, Xianyu +3 more
Photochemical hazes have been suggested as candidate for the high-altitude aerosols observed in the transmission spectra of many hot Jupiters. We present 3D simulations of the hot Jupiter HD 189733b to study how photochemical hazes are transported by atmospheric circulation. The model includes spherical, constant-size haze particles that gravitati…
Multiwavelength continuum sizes of protoplanetary discs: scaling relations and implications for grain growth and radial drift
Testi, L.; Tazzari, M.; Natta, A. +5 more
We analyse spatially resolved ALMA observations at 0.9, 1.3, and 3.1 mm for the 26 brightest protoplanetary discs in the Lupus star-forming region. We characterize the discs multiwavelength brightness profiles by fitting the interferometric visibilities in a homogeneous way, obtaining effective disc sizes at the three wavelengths, spectral index p…
A hard X-ray view of luminous and ultra-luminous infrared galaxies in GOALS - I. AGN obscuration along the merger sequence
Sanders, D. B.; Stern, D.; Inami, H. +25 more
The merger of two or more galaxies can enhance the inflow of material from galactic scales into the close environments of active galactic nuclei (AGNs), obscuring and feeding the supermassive black hole (SMBH). Both recent simulations and observations of AGN in mergers have confirmed that mergers are related to strong nuclear obscuration. However,…