Search Publications
In situ observations of large-amplitude Alfvén waves heating and accelerating the solar wind
Stawarz, Julia E.; Kasper, Justin C.; Louarn, Philippe +16 more
After leaving the Sun’s corona, the solar wind continues to accelerate and cools, but more slowly than expected for a freely expanding adiabatic gas. Alfvén waves are perturbations of the interplanetary magnetic field that transport energy. We use in situ measurements from the Parker Solar Probe and Solar Orbiter spacecraft to investigate a stream…
Spatially resolved Hα and ionizing photon production efficiency in the lensed galaxy MACS1149-JD1 at a redshift of 9.11
Ilbert, O.; Östlin, G.; Colina, L. +32 more
We present MIRI/JWST medium-resolution spectroscopy (MRS) and imaging (MIRIM) of the lensed galaxy MACS1149-JD1 at a redshift of z = 9.1092 ± 0.0002, when the Universe was about 530 Myr old. We detect, for the first time, spatially resolved Hα emission in a galaxy at a redshift above nine. The structure of the Hα emitting gas consists of two clump…
The Chandra Source Catalog Release 2 Series
Azadi, Mojegan; Lauer, Jennifer; Fabbiano, Giuseppina +17 more
The Chandra Source Catalog (CSC) is a virtual X-ray astrophysics facility that enables both detailed individual source studies and statistical studies of large samples of X-ray sources detected in Advanced CCD Imaging Spectrometer and High Resolution Camera-I imaging observations obtained by the Chandra X-ray Observatory. The catalog provides care…
Multivariate Predictors of Lyman Continuum Escape. I. A Survival Analysis of the Low-redshift Lyman Continuum Survey
Ferguson, Henry C.; Giavalisco, Mauro; Pentericci, Laura +19 more
To understand how galaxies reionized the Universe, we must determine how the escape fraction of Lyman continuum (LyC) photons (f esc) depends on galaxy properties. Using the z ∼ 0.3 Low-redshift Lyman Continuum Survey (LzLCS), we develop and analyze new multivariate predictors of f esc. These predictions use the Cox proportio…
LHS 1140 b Is a Potentially Habitable Water World
Yang, Jeehyun; Hu, Renyu; Bello-Arufe, Aaron +1 more
LHS 1140 b is a small planet orbiting in the habitable zone of its M4.5V dwarf host. Recent mass and radius constraints have indicated that it has either a thick H2-rich atmosphere or substantial water by mass. Here we present a transmission spectrum of LHS 1140 b between 1.7 and 5.2 µm, obtained using the NIRSpec instrument on JW…
AspGap: Augmented Stellar Parameters and Abundances for 37 Million Red Giant Branch Stars from Gaia XP Low-resolution Spectra
Hogg, David W.; Li, Jiadong; Rix, Hans-Walter +2 more
We present AspGap, a new approach to inferring stellar labels from the low-resolution Gaia XP spectra, including precise [α/M] estimates—the first time these are obtained by such an approach. AspGap is a neural-network-based regression model trained on APOGEE spectra. In the training step, AspGap learns to use not only XP spectra to predict stella…
Multivariate Predictors of Lyman Continuum Escape. II. Predicting Lyman Continuum Escape Fractions for High-redshift Galaxies
Ferguson, Henry C.; Giavalisco, Mauro; Pentericci, Laura +19 more
JWST is uncovering the properties of ever-increasing numbers of galaxies at z > 6, during the epoch of reionization. Connecting these observed populations to the process of reionization requires understanding how efficiently they produce Lyman continuum (LyC) photons and what fraction (f esc) of these photons escape into the intergal…
A quasar-galaxy merger at z ∼ 6.2: Black hole mass and quasar properties from the NIRSpec spectrum
Strauss, Michael A.; Fan, Xiaohui; Trebitsch, Maxime +31 more
We present JWST/NIRSpec integral field data of the quasar PJ308-21 at z = 6.2342. As shown by previous ALMA and HST imaging, the quasar has two companion sources, interacting with the quasar host galaxy. The high-resolution G395H/290LP NIRSpec spectrum covers the 2.87 − 5.27 µm wavelength range and shows the rest-frame optical emission of th…
Gaia DR3 detectability of unresolved binary systems
Casey, Andrew R.; Rix, Hans-Walter; Brown, Anthony G. A. +10 more
Context.Gaia cannot individually resolve very close binary systems; however, the collected data can still be used to identify them. A powerful indicator of stellar multiplicity is the sources' reported re-normalised unit weight error (RUWE), which effectively captures the astrometric deviations from single-source solutions.
Aims: We aim to ch…
Can we really pick and choose? Benchmarking various selections of Gaia Enceladus/Sausage stars in observations with simulations
Grand, Robert J. J.; Fattahi, Azadeh; Carrillo, Andreia +2 more
Large spectroscopic surveys plus Gaia astrometry have shown us that the inner stellar halo of the Galaxy is dominated by the debris of Gaia Enceladus/Sausage (GES). With the richness of data at hand, there are a myriad of ways these accreted stars have been selected. We investigate these GES selections and their effects on the inferred progenitor …