Search Publications

The debris of the 'last major merger' is dynamically young
DOI: 10.1093/mnras/stae1264 Bibcode: 2024MNRAS.531.1422D

Horta, Danny; Sanderson, Robyn; Donlon, Thomas +4 more

The Milky Way's (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the 'last major merger.' Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor collided with the MW proto-disc 8-11 Gyr ago, and the Virgo Radial Merger (VRM), where the proge…

2024 Monthly Notices of the Royal Astronomical Society
Gaia 20
A SPectroscopic Survey of Biased Halos In the Reionization Era (ASPIRE): Broad-line AGN at z = 4‑5 Revealed by JWST/NIRCam WFSS
DOI: 10.3847/1538-4357/ad6565 Bibcode: 2024ApJ...974..147L

Hennawi, Joseph F.; Shen, Yue; Fan, Xiaohui +33 more

Low-luminosity active galactic nuclei (AGNs) with low-mass black holes (BHs) in the early universe are fundamental to understanding the BH growth and their coevolution with the host galaxies. Utilizing JWST NIRCam Wide Field Slitless Spectroscopy, we perform a systematic search for broad-line Hα emitters (BHAEs) at z ≈ 4–5 in 25 fields of the A SP…

2024 The Astrophysical Journal
Gaia JWST 19
Star Formation at the Epoch of Reionization with CANUCS: The Ages of Stellar Populations in MACS1149-JD1
DOI: 10.3847/2041-8213/ad0e73 Bibcode: 2024ApJ...961L..21B

Harshan, Anishya; Martis, Nicholas S.; Rihtaršič, Gregor +15 more

We present measurements of stellar populations properties of a z = 9.1 gravitationally lensed galaxy MACS1149-JD1 using deep James Webb Space Telescope NIRISS slitless spectroscopy as well as NIRISS and NIRCam imaging from the CAnadian NIRISS Unbiased Cluster Survey (CANUCS). The galaxy is split into four components. Three magnified (µ ~ 11)…

2024 The Astrophysical Journal
eHST JWST 19
GOALS-JWST: Gas Dynamics and Excitation in NGC 7469 Revealed by NIRSpec
DOI: 10.3847/1538-4357/ad2a50 Bibcode: 2024ApJ...965..103B

Inami, Hanae; Böker, Torsten; Law, David R. +36 more

We present new JWST NIRSpec integral field spectroscopy (IFS) data for the luminous infrared galaxy NGC 7469, a nearby (70.6 Mpc) active galaxy with a Seyfert 1.5 nucleus that drives a highly ionized gas outflow and a prominent nuclear star-forming ring. Using the superb sensitivity and high spatial resolution of the JWST instrument NIRSpec IFS, w…

2024 The Astrophysical Journal
JWST 19
Local primordial non-Gaussianity from the large-scale clustering of photometric DESI luminous red galaxies
DOI: 10.1093/mnras/stae886 Bibcode: 2024MNRAS.532.1902R

Miquel, Ramon; Sanchez, Eusebio; Font-Ribera, Andreu +46 more

We use angular clustering of luminous red galaxies from the Dark Energy Spectroscopic Instrument (DESI) imaging surveys to constrain the local primordial non-Gaussianity parameter fNL. Our sample comprises over 12 million targets, covering 14 000 deg2 of the sky, with redshifts in the range 0.2 < z < 1.35. We identify G…

2024 Monthly Notices of the Royal Astronomical Society
Gaia 19
The Sunburst Arc with JWST: I. Detection of Wolf-Rayet stars injecting nitrogen into a low-metallicity, z = 2.37 proto-globular cluster leaking ionizing photons
DOI: 10.1051/0004-6361/202450359 Bibcode: 2024A&A...690A.269R

Dahle, H.; Rigby, J. R.; Bayliss, M. B. +13 more

We report the detection of a population of Wolf-Rayet (WR) stars in the Sunburst Arc, a strongly gravitationally lensed galaxy at redshift z = 2.37. As the brightest known lensed galaxy, the Sunburst Arc has become an important cosmic laboratory for studying star and cluster formation, Lyman α (Lyα) radiative transfer, and Lyman continuum (LyC) es…

2024 Astronomy and Astrophysics
JWST 19
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. V. Do Self-consistent Atmospheric Models Represent JWST Spectra? A Showcase with VHS 1256–1257 b
DOI: 10.3847/2041-8213/ad3e7c Bibcode: 2024ApJ...966L..11P

Henning, Thomas; Fortney, Jonathan J.; Carter, Aarynn L. +119 more

The unprecedented medium-resolution (R λ ∼ 1500–3500) near- and mid-infrared (1–18 µm) spectrum provided by JWST for the young (140 ± 20 Myr) low-mass (12–20 M Jup) L–T transition (L7) companion VHS 1256 b gives access to a catalog of molecular absorptions. In this study, we present a comprehensive analysis of this da…

2024 The Astrophysical Journal
Gaia JWST 19
Mapping Obscured Star Formation in the Host Galaxy of FRB 20201124A
DOI: 10.3847/1538-4357/ad0cbd Bibcode: 2024ApJ...961...44D

Kilpatrick, Charles D.; Simha, Sunil; Prochaska, J. Xavier +23 more

We present high-resolution 1.5-6 GHz Karl G. Jansky Very Large Array and Hubble Space Telescope (HST) optical and infrared observations of the extremely active repeating fast radio burst (FRB) FRB 20201124A and its barred spiral host galaxy. We constrain the location and morphology of star formation in the host and search for a persistent radio so…

2024 The Astrophysical Journal
Gaia eHST 19
Standard siren measurement of the Hubble constant using GW170817 and the latest observations of the electromagnetic counterpart afterglow
DOI: 10.1103/PhysRevD.109.063508 Bibcode: 2024PhRvD.109f3508P

Palmese, A.; Margutti, R.; Hajela, A. +3 more

We present a new constraint on the Hubble constant H0 using the latest measurements of the electromagnetic counterpart to the gravitational wave (GW) event GW170817. We use the latest optical, x-ray and radio observations of the afterglow up to ∼3.5 years after the GW detection, and properly take into account the impact of the host gala…

2024 Physical Review D
eHST 19
A Large and Variable Leading Tail of Helium in a Hot Saturn Undergoing Runaway Inflation
DOI: 10.3847/1538-3881/ad1ee8 Bibcode: 2024AJ....167..142G

Vanderburg, Andrew; Cochran, William D.; Mahadevan, Suvrath +14 more

Atmospheric escape shapes the fate of exoplanets, with statistical evidence for transformative mass loss imprinted across the mass–radius–insolation distribution. Here, we present transit spectroscopy of the highly irradiated, low-gravity, inflated hot Saturn HAT-P-67 b. The Habitable Zone Planet Finder spectra show a detection of up to 10% absorp…

2024 The Astronomical Journal
Gaia 19