Search Publications

Rimmed and rippled accretion disc models to explain AGN continuum lags
DOI: 10.1093/mnras/stac3579 Bibcode: 2023MNRAS.519.2754S

Starkey, D. A.; Huang, Jiamu; Horne, Keith +1 more

We propose a solution to the problem of accretion disc sizes in active galactic nuclei being larger when measured by reverberation mapping than predicted by theory. Considering the disc's exposed-surface thickness profile H(r), our solution invokes a steep rim or rippled structures irradiated by the central lamp-post. We model the continuum lags a…

2023 Monthly Notices of the Royal Astronomical Society
eHST 23
REQUIEM-2D: A Diversity of Formation Pathways in a Sample of Spatially Resolved Massive Quiescent Galaxies at z 2
DOI: 10.3847/1538-4357/aca677 Bibcode: 2023ApJ...943..179A

Mahler, Guillaume; Richard, Johan; Bezanson, Rachel +16 more

REQUIEM-2D (Resolving Quiescent Magnified Galaxies with 2D Grism Spectroscopy) comprises a sample of eight massive ( ${\rm{log}}({M}_{\ast }/{M}_{\odot })\gt 10.6$ ) strongly lensed quiescent galaxies at z ~ 2. REQUIEM-2D combines the natural magnification from strong gravitational lensing with the high-spatial-resolution grism spectroscopy of the…

2023 The Astrophysical Journal
Gaia eHST 23
JWST catches the assembly of a z 5 ultra-low-mass galaxy
DOI: 10.1093/mnrasl/slad054 Bibcode: 2023MNRAS.523L..40A

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.…

2023 Monthly Notices of the Royal Astronomical Society
eHST JWST 23
Element abundance patterns in stars indicate fission of nuclei heavier than uranium
DOI: 10.1126/science.adf1341 Bibcode: 2023Sci...382.1177R

Beers, Timothy C.; Placco, Vinicius M.; Holmbeck, Erika M. +9 more

The heaviest chemical elements are naturally produced by the rapid neutron-capture process (r-process) during neutron star mergers or supernovae. The r-process production of elements heavier than uranium (transuranic nuclei) is poorly understood and inaccessible to experiments so must be extrapolated by using nucleosynthesis models. We examined el…

2023 Science
Gaia 23
On the masses, age, and architecture of the VHS J1256-1257AB b system
DOI: 10.1093/mnras/stac3557 Bibcode: 2023MNRAS.519.1688D

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…

2023 Monthly Notices of the Royal Astronomical Society
Gaia 23
Formation of star clusters and enrichment by massive stars in simulations of low-metallicity galaxies with a fully sampled initial stellar mass function
DOI: 10.1093/mnras/stad1147 Bibcode: 2023MNRAS.522.3092L

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…

2023 Monthly Notices of the Royal Astronomical Society
Herschel 23
XUE: Molecular Inventory in the Inner Region of an Extremely Irradiated Protoplanetary Disk
DOI: 10.3847/2041-8213/ad03f8 Bibcode: 2023ApJ...958L..30R

Henning, Thomas; Bik, Arjan; Tabone, Benoît +24 more

We present the first results of the eXtreme UV Environments (XUE) James Webb Space Telescope (JWST) program, which focuses on the characterization of planet-forming disks in massive star-forming regions. These regions are likely representative of the environment in which most planetary systems formed. Understanding the impact of environment on pla…

2023 The Astrophysical Journal
Gaia JWST 23
CLASSY. VI. The Density, Structure, and Size of Absorption-line Outflows in Starburst Galaxies
DOI: 10.3847/1538-4357/acbf46 Bibcode: 2023ApJ...948...28X

Martin, Crystal L.; Scarlata, Claudia; Henry, Alaina +12 more

Galaxy formation and evolution are regulated by the feedback from galactic winds. Absorption lines provide the most widely available probe of winds. However, since most data only provide information integrated along the line of sight, they do not directly constrain the radial structure of the outflows. In this paper, we present a method to directl…

2023 The Astrophysical Journal
eHST 23
Carbon-enhanced metal-poor star candidates from BP/RP spectra in Gaia DR3
DOI: 10.1093/mnras/stad1675 Bibcode: 2023MNRAS.523.4049L

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…

2023 Monthly Notices of the Royal Astronomical Society
Gaia 23
Detection of the Low-stellar-mass Host Galaxy of a z 6.25 Quasar with JWST
DOI: 10.3847/1538-4357/acebe0 Bibcode: 2023ApJ...953..180S

Lyu, Jianwei; Rieke, George H.; Alberts, Stacey +1 more

We characterize the stellar mass of J2239+0207, a z ~ 6.25 sub-Eddington quasar (M 1450 = -24.6), using dedicated JWST/NIRCam medium-band observations of a nearby point-spread function star to remove the central point source and reveal the underlying galaxy emission. We detect the host galaxy in two bands longward of the Balmer break, o…

2023 The Astrophysical Journal
JWST 22