Search Publications
Spatial power spectra of dust across the Local Group: No constraint on disc scale height
Sandstrom, Karin M.; Leroy, Adam K.; Koch, Eric W. +4 more
We analyse the 1D spatial power spectra of dust surface density and mid to far-infrared emission at 24-500 µm in the LMC, SMC, M31, and M33. By forward-modelling the point spread function (PSF) on the power spectrum, we find that nearly all power spectra have a single power-law and point source component. A broken power-law model is only fav…
Interstellar comet 2I/Borisov exhibits a structure similar to native Solar system comets
Bedin, L. R.; Ochner, P.; Manzini, F. +1 more
We processed images taken with the Hubble Space Telescope(HST) to investigate any morphological features in the inner coma suggestive of a peculiar activity on the nucleus of the interstellar comet 2I/Borisov. The coma shows an evident elongation, in the position angle (PA) ∼0-180○ direction, which appears related to the presence of a j…
The extreme colliding-wind system Apep: resolved imagery of the central binary and dust plume in the infrared
Callingham, J. R.; Crowther, P. A.; Marcote, B. +6 more
The recent discovery of a spectacular dust plume in the system 2XMM J160050.7-514245 (referred to as 'Apep') suggested a physical origin in a colliding-wind binary by way of the 'Pinwheel' mechanism. Observational data pointed to a hierarchical triple-star system, however, several extreme and unexpected physical properties seem to defy the establi…
Global analysis of the TRAPPIST Ultra-Cool Dwarf Transit Survey
Queloz, D.; Delrez, L.; Gillon, M. +10 more
We conducted a global analysis of the TRAPPIST Ultra-Cool Dwarf Transit Survey - a prototype of the SPECULOOS transit search conducted with the TRAPPIST-South robotic telescope in Chile from 2011 to 2017 - to estimate the occurrence rate of close-in planets such as TRAPPIST-1b orbiting ultra-cool dwarfs. For this purpose, the photometric data of 4…
New empirical constraints on the cosmological evolution of gas and stars in galaxies
Loeb, Abraham; Padmanabhan, Hamsa
We combine the latest observationally motivated constraints on stellar properties in dark matter haloes, along with data-driven predictions for the atomic (H I) and molecular (H2) gas evolution in galaxies, to derive empirical relationships between the build-up of galactic components and their evolution over cosmic time. At high redshif…
Embedding globular clusters in dark matter minihaloes solves the cusp-core and timing problems in the Fornax dwarf galaxy
Silk, Joseph; Boldrini, Pierre; Mohayaee, Roya
We use a fully GPU N-body code to demonstrate that dark matter (DM) minihaloes, as a new component of globular clusters (GCs), resolve both the timing and cusp-core problems in Fornax if the (five or six) GCs were recently accreted (≤3 Gyr ago) by Fornax. Under these assumptions, infall of these GCs does not occur and no star clusters form in the …
The Blanco DECam bulge survey. I. The survey description and early results
Clarkson, William I.; Robin, Annie C.; Martin, Nicolas +18 more
The Blanco Dark Energy Camera (DECam) Bulge survey is a Vera Rubin Observatory (LSST) pathfinder imaging survey, spanning ~200 deg2 of the Southern Galactic bulge, -2° < b < -13° and -11° < l < +11°. We have employed the CTIO-4 m telescope and the DECam to image a contiguous ~200 deg2 region of the relatively less…
H0LiCOW - XI. A weak lensing measurement of the external convergence in the field of the lensed quasar B1608+656 using HST and Subaru deep imaging
Treu, T.; Fassnacht, C. D.; Meylan, G. +11 more
We investigate the environment and line of sight (LoS) of the H0LiCOW (H0 Lenses in COSMOGRAIL's Wellspring) lens B1608+656 using Subaru Suprime-Cam and the Hubble Space Telescope (HST) to perform a weak lensing analysis. We compare three different methods to reconstruct the mass map of the field, i.e. the standard Kaiser-Squires invers…
Modelling the AGN broad-line region using single-epoch spectra - II. Nearby AGNs
Treu, T.; Vestergaard, M.; Peterson, B. M. +4 more
The structure of the broad-line region (BLR) is an essential ingredient in the determination of active galactic nucleus (AGN) virial black hole masses, which in turn are important to study the role of black holes in galaxy evolution. Constraints on the BLR geometry and dynamics can be obtained from velocity-resolved studies using reverberation map…
A kpc-scale-resolved study of unobscured and obscured star formation activity in normal galaxies at z = 1.5 and 2.2 from ALMA and HiZELS
Ivison, R. J.; Smail, Ian; Sobral, David +12 more
We present Atacama Large Millimeter/Submillimeter Array (ALMA) continuum observations of a sample of nine star-forming galaxies at redshifts 1.47 and 2.23 selected from the High-z Emission Line Survey (HiZELS). Four galaxies in our sample are detected at high significance by ALMA at a resolution of 0 ${_{.}^{\prime\prime}}$ 25 at rest-frame 355 &m…