Search Publications
The acoustic size of the Sun
Gough, D. O.; Takata, M.
Analysis of f-mode frequencies has provided a measure of the radius of the Sun which is lower, by a few hundredths per cent, than the photospheric radius determined by direct optical measurement. Part of this difference can be understood by recognizing that it is primarily the variation of density well beneath the photosphere of the star that dete…
Weak gravitational lensing measurements of Abell 2744 using JWST and shear measurement algorithm pyRRG-JWST
Massey, Richard; Harvey, David R.
We update the publicly available weak lensing shear measurement algorithm pyRRG for the JWST, and apply it to UNCOVER DR1 imaging of galaxy cluster Abell 2744. At short wavelengths (${\lt}2.5\, \mu$m), shear measurements are consistent between independent observations through different JWST bandpasses, and calibrated within 1.5 per cent of those f…
Cool and data-driven: an exploration of optical cool dwarf chemistry with both data-driven and physical models
Casey, Andrew R.; Monty, Stephanie; Nordlander, Thomas +6 more
Detailed chemical studies of F/G/K - or solar-type - stars have long been routine in stellar astrophysics, enabling studies in both Galactic chemodynamics and exoplanet demographics. However, similar understanding of the chemistry of M and late-K dwarfs - the most common stars in the Galaxy - has been greatly hampered both observationally and theo…
JWST/NIRISS and HST: Exploring the improved ability to characterize exoplanet atmospheres in the JWST era
Parmentier, Vivien; Taylor, Jake; Radica, Michael +6 more
The Hubble Space Telescope has been a pioneering instrument for studying the atmospheres of exoplanets, specifically its WFC3 and STIS instruments. With the launch of JWST, we are able to observe larger spectral ranges at higher precision. NIRISS/SOSS covers the range 0.6-2.8 microns, and thus, it can serve as a direct comparison to WFC3 (0.8-1.7 …
A population of Optically Quiescent Quasars from WISE and SDSS
Gandhi, Poshak; Stern, Daniel; Toba, Yoshiki +4 more
The growth of active galactic nuclei (AGNs) occurs under some form of obscuration in a large fraction of the population. The difficulty in constraining this population leads to high uncertainties in cosmic X-ray background and galaxy evolution models. Using an SDSS-WISE cross-match, we target infrared luminous AGN (W1 - W2 > 0.8, and monochroma…
TOI-837 b is a young Saturn-sized exoplanet with a massive 70 M⊕ core
Aigrain, Suzanne; Gillen, Edward; Mortier, Annelies +10 more
We present an exhaustive photometric and spectroscopic analysis of TOI-837, a F9/G0 35 Myr young star, hosting a transiting exoplanet, TOI-837 b, with an orbital period of ~8.32 d. Utilizing data from the Transiting Exoplanet Survey Satellite and ground-based observations, we determine a planetary radius of $0.818_{-0.024}^{+0.034}$ RJ …
Identifying 850 δ Scuti pulsators in a narrow Gaia colour range with TESS 10-min full-frame images
Li, Yaguang; Bedding, Timothy R.; Murphy, Simon J. +7 more
We use TESS 10-min full-frame images (Sectors 27-55) to study a sample of 1708 stars within 500 pc of the Sun that lie in a narrow colour range in the centre of the δ Scuti instability strip (0.29 < GBP - GRP < 0.31). Based on the Fourier amplitude spectra, we identify 848 δ Scuti stars, as well as 47 eclipsing or conta…
Signatures of gas flows - II. Connecting the kinematics of the multiphase circumgalactic medium to galaxy rotation
Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +4 more
The multiphase circumgalactic medium (CGM) hosts critical processes that affect galaxy evolution such as accretion and outflows. We searched for evidence of these phenomena by using the EW co-rotation fraction (
Compositions of the Hercules-Aquila Cloud and Virgo Overdensity
Shi, Jianrong; Huang, Yang; Ma, Jun +4 more
Based on a sample of K giant from Large sky Area Multi-Object fibre Spectroscopic Telescope Data Release 8 and a sample of RR Lyrae (RRL) from Gaia Data Release 3, we investigate the compositions of the Hercules-Aquila Cloud (HAC) and Virgo Overdensity (VOD) and their collective contribution to the tilt and triaxiality of the stellar halo ($r\, \l…
The Magellanic Puzzle: origin of the periphery
Nidever, David L.; Massana, Pol; Olsen, Knut
In this paper, we analyse the metallicity structure of the Magellanic Clouds using parameters derived from the Gaia Data Release 3 (DR3) low-resolution XP (for Blue/Red Photometer) spectra, astrometry, and photometry. We find that the qualitative behaviour of the radial metallicity gradients in the Large Magellanic Cloud (LMC) and Small Magellanic…