Search Publications
JWST catches the assembly of a z 5 ultra-low-mass galaxy
Ravindranath, Swara; Willott, Chris J.; Harshan, Anishya +14 more
Using CANUCS imaging we found an apparent major merger of two $z$ ~ 5 ultra-low-mass galaxies (M⋆~107M⊙ each) that are doubly imaged and magnified ~12-15× by the lensing cluster MACS 0417. Both galaxies are experiencing young (~100 Myr), synchronised bursts of star formation with log (sSFR/Gyr-1) ~1.3-1.…
On the masses, age, and architecture of the VHS J1256-1257AB b system
Dupuy, Trent J.; Bardalez Gagliuffi, Daniella C.; Liu, Michael C. +5 more
VHS J1256-1257 AB is an ultracool dwarf binary that hosts a wide-separation planetary-mass companion that is a key target of the JWST Exoplanet Early Release Science programme. Using Keck adaptive optics imaging and aperture masking interferometry, we have determined the host binary's orbit (a = 1.96 ± 0.03 au, P = 7.31 ± 0.02 yr, e = 0.883 ± 0.00…
Formation of star clusters and enrichment by massive stars in simulations of low-metallicity galaxies with a fully sampled initial stellar mass function
Kauffmann, Guinevere; Naab, Thorsten; Lahén, Natalia +6 more
We present new GRIFFIN project hydrodynamical simulations that model the formation of galactic star cluster populations in low-metallicity (Z = 0.00021) dwarf galaxies, including radiation, supernova, and stellar wind feedback of individual massive stars. In the simulations, stars are sampled from the stellar initial mass function (IMF) down to th…
Carbon-enhanced metal-poor star candidates from BP/RP spectra in Gaia DR3
Ting, Yuan-Sen; Yoon, Jinmi; Beers, Timothy C. +6 more
Carbon-enhanced metal-poor (CEMP) stars comprise almost a third of stars with [Fe/H] < -2, although their origins are still poorly understood. It is highly likely that one sub-class (CEMP-s stars) is tied to mass-transfer events in binary stars, while another sub-class (CEMP-no stars) are enriched by the nucleosynthetic yields of the first gene…
High-redshift metallicity calibrations for JWST spectra: insights from line emission in cosmological simulations
Somerville, Rachel S.; Charlot, Stephane; Hirschmann, Michaela
Optical emission-line ratios are traditionally used to estimate gas metallicities from observed galaxy spectra. While such estimators have been calibrated primarily at low redshift, they are commonly used to interpret observations of high-redshift galaxies, where their applicability may be questioned. We use comprehensive emission-line catalogues …
Another shipment of six short-period giant planets from TESS
Henning, Thomas; Vanderburg, Andrew; Hellier, Coel +130 more
We present the discovery and characterization of six short-period, transiting giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS) -- TOI-1811 (TIC 376524552), TOI-2025 (TIC 394050135), TOI-2145 (TIC 88992642), TOI-2152 (TIC 395393265), TOI-2154 (TIC 428787891), and TOI-2497 (TIC 97568467). All six planets orbit bright host stars…
A UV census of the environments of stripped-envelope supernovae
Sun, Ning-Chen; Crowther, Paul A.; Maund, Justyn R.
This paper reports an environmental analysis of 41 uniformly selected stripped-envelope supernovae (SESNe) based on deep ultraviolet-optical images acquired by the Hubble Space Telescope. Young stellar populations are detected in most SN environments and their ages are derived with a hierarchical Bayesian approach. The age distributions are indist…
Multiple stellar populations in globular clusters with JWST: an NIRCam view of 47 Tucanae
Milone, A. P.; Cordoni, G.; Marino, A. F. +11 more
We use images collected with the near-infrared camera (NIRCam) onboard the JWST and with the Hubble Space Telescope (HST) to investigate multiple populations at the bottom of the main sequence (MS) of 47 Tucanae. The mF115W versus mF115W - mF322W2 colour-magnitude diagram (CMD) from NIRCam shows that, below the kne…
Multimass modelling of Milky Way globular clusters - I. Implications on their stellar initial mass function above 1 M⊙
Hénault-Brunet, V.; Gieles, M.; Baumgardt, H. +2 more
The distribution of stars and stellar remnants (white dwarfs, neutron stars, and black holes) within globular clusters holds clues about their formation and long-term evolution, with important implications for their initial mass function (IMF) and the formation of black hole mergers. In this work, we present best-fitting multimass models for 37 Mi…
Molecular gas cloud properties at z ≃ 1 revealed by the superb angular resolution achieved with ALMA and gravitational lensing
Richard, Johan; Schaerer, Daniel; Egami, Eiichi +6 more
Current observations favour that the massive ultraviolet-bright clumps with a median stellar mass of $\sim 10^7\, {\rm M}_{\odot }$, ubiquitously observed in z ~ 1-3 galaxies, are star-forming regions formed in situ in galaxies. It has been proposed that they result from gas fragmentation due to gravitational instability of gas-rich, turbulent, an…