Search Publications
Chemo-kinematics of the Gaia RR Lyrae: the halo and the disc
Belokurov, Vasily; Iorio, Giuliano
We present the results of a multicomponent kinematic model of a large sample of RR Lyrae detected by Gaia. By imposing a fourfold symmetry and employing Gaia proper motions, we are able to infer the behaviour of the velocity ellipsoid between ≈3 and ≈30 kpc from the centre of the Galaxy. We detect the presence of two distinct components: a dominan…
The GALAH survey: effective temperature calibration from the InfraRed Flux Method in the Gaia system
Lewis, Geraint F.; Ting, Yuan-Sen; Casey, Andrew R. +23 more
In order to accurately determine stellar properties, knowledge of the effective temperature of stars is vital. We implement Gaia and 2MASS photometry in the InfraRed Flux Method and apply it to over 360 000 stars across different evolutionary stages in the GALAH DR3 survey. We derive colour-effective temperature relations that take into account th…
HELP: the Herschel Extragalactic Legacy Project
Aussel, H.; Shirley, R.; Buat, V. +29 more
We present the Herschel Extragalactic Legacy Project (HELP). This project collates, curates, homogenizes, and creates derived data products for most of the premium multiwavelength extragalactic data sets. The sky boundaries for the first data release cover 1270 deg2 defined by the Herschel SPIRE extragalactic survey fields; notably the …
Probing cosmic dawn: Ages and star formation histories of candidate z ≥ 9 galaxies
Chisholm, J.; Laporte, N.; Ellis, R. S. +3 more
We discuss the spectral energy distributions and physical properties of six galaxies whose photometric redshifts suggest they lie beyond a redshift z ≃ 9. Each was selected on account of a prominent excess seen in the Spitzer/IRAC 4.5 $\mu$m band which, for a redshift above z = 9.0, likely indicates the presence of a rest-frame Balmer break and a …
The Global Meteor Network - Methodology and first results
Vida, Denis; Brown, Peter G.; Mazur, Michael J. +10 more
The Global Meteor Network (GMN) utilizes highly sensitive low-cost CMOS video cameras which run open-source meteor detection software on Raspberry Pi computers. Currently, over 450 GMN cameras in 30 countries are deployed. The main goal of the network is to provide long-term characterization of the radiants, flux, and size distribution of annual m…
On the duration of the embedded phase of star formation
Kruijssen, J. M. Diederik; Leroy, Adam K.; Chevance, Mélanie +23 more
Feedback from massive stars plays a key role in molecular cloud evolution. After the onset of star formation, the young stellar population is exposed by photoionization, winds, supernovae, and radiation pressure from massive stars. Recent observations of nearby galaxies have provided the evolutionary timeline between molecular clouds and exposed y…
Selecting accreted populations: metallicity, elemental abundances, and ages of the Gaia-Sausage-Enceladus and Sequoia populations
Feuillet, Diane K.; Casagrande, Luca; Feltzing, Sofia +1 more
Identifying stars found in the Milky Way as having formed in situ or accreted can be a complex and uncertain undertaking. We use Gaia kinematics and APOGEE elemental abundances to select stars belonging to the Gaia-Sausage-Enceladus (GSE) and Sequoia accretion events. These samples are used to characterize the GSE and Sequoia population metallicit…
Dark Energy Survey year 3 results: point spread function modelling
Bechtol, K.; Smith, M.; Abbott, T. M. C. +79 more
We introduce a new software package for modelling the point spread function (PSF) of astronomical images, called PIFF (PSFs In the Full FOV), which we apply to the first three years (known as Y3) of the Dark Energy Survey (DES) data. We describe the relevant details about the algorithms used by PIFF to model the PSF, including how the PSF model va…
A cool and inflated progenitor candidate for the Type Ib supernova 2019yvr at 2.6 yr before explosion
Kilpatrick, Charles D.; Drout, Maria R.; Foley, Ryan J. +13 more
We present Hubble Space Telescope imaging of a pre-explosion counterpart to SN 2019yvr obtained 2.6 yr before its explosion as a type Ib supernova (SN Ib). Aligning to a post-explosion Gemini-S/GSAOI image, we demonstrate that there is a single source consistent with being the SN 2019yvr progenitor system, the second SN Ib progenitor candidate aft…
Investigating the young AU Mic system with SPIRou: large-scale stellar magnetic field and close-in planet mass
Gaidos, Eric; Doyon, René; Donati, Jean-François +12 more
We present a velocimetric and spectropolarimetric analysis of 27 observations of the 22-Myr M1 star AU Microscopii (AU Mic) collected with the high-resolution YJHK (0.98-2.35 µm) spectropolarimeter SPIRou from 2019 September 18 to November 14. Our radial velocity (RV) time-series exhibits activity-induced fluctuations of 45 m s-1 …