Search Publications
JWST's PEARLS: Mothra, a new kaiju star at z = 2.091 extremely magnified by MACS0416, and implications for dark matter models
Grogin, Norman A.; Koekemoer, Anton M.; Pirzkal, Nor +28 more
We report the discovery of Mothra, an extremely magnified monster star, likely a binary system of two supergiant stars, in one of the strongly lensed galaxies behind the galaxy cluster MACS J0416.1−2403. Mothra is in a galaxy with spectroscopic redshift z = 2.091 in a portion of the galaxy that is parsecs away from the cluster caustic. The binary …
Stepped partially acoustic dark matter, large scale structure, and the Hubble tension
Marques-Tavares, Gustavo; Buen-Abad, Manuel A.; Chacko, Zackaria +2 more
We propose a new interacting dark sector model, Stepped Partially Acoustic Dark Matter (SPartAcous), that can simultaneously address the two most important tensions in current cosmological data, the H0 and S8 problems. As in the Partially Acoustic Dark Matter (PAcDM) scenario, this model features a subcomponent of dark matter…
The Physical Drivers and Observational Tracers of CO-to-H2 Conversion Factor Variations in Nearby Barred Galaxy Centers
Sandstrom, Karin M.; Bolatto, Alberto D.; Leroy, Adam K. +24 more
The CO-to-H2 conversion factor (α CO) is central to measuring the amount and properties of molecular gas. It is known to vary with environmental conditions, and previous studies have revealed lower α CO in the centers of some barred galaxies on kiloparsec scales. To unveil the physical drivers of such variations, w…
Localizing Sources of Variability in Crowded TESS Photometry
Bell, Keaton J.; Higgins, Michael E.
The Transiting Exoplanet Survey Satellite (TESS) has an exceptionally large plate scale of 21″ px-1, causing most TESS light curves to record the blended light of multiple stars. This creates a danger of misattributing variability observed by TESS to the wrong source, which would invalidate any analysis. We developed a method that can l…
JWST/NIRSpec Measurements of the Relationships between Nebular Emission-line Ratios and Stellar Mass at z 3-6
Shapley, Alice E.; Reddy, Naveen A.; Sanders, Ryan L. +2 more
We analyze the rest-optical emission-line ratios of star-forming galaxies at 2.7 ≤ z < 6.5 drawn from the Cosmic Evolution Early Release Science (CEERS) Survey and their relationships with stellar mass (M *). Our analysis includes both line ratios based on the [N II] λ6583 feature ([N II] λ6583/Hα, ([O III] λ5007/Hβ)/([N II] λ6583/Hα…
The distribution of CO2 on Europa indicates an internal source of carbon
Brown, Michael E.; Trumbo, Samantha K.
Jupiter’s moon Europa has a subsurface ocean, the chemistry of which is largely unknown. Carbon dioxide (CO2) has previously been detected on the surface of Europa, but it was not possible to determine whether it originated from subsurface ocean chemistry, was delivered by impacts, or was produced on the surface by radiation processing …
Significance mode analysis (SigMA) for hierarchical structures. An application to the Sco-Cen OB association
Meingast, Stefan; Alves, João; Großschedl, Josefa E. +3 more
We present a new clustering method, significance mode analysis (SigMA), for extracting co-spatial and co-moving stellar populations from large-scale surveys such as ESA Gaia. The method studies the topological properties of the density field in the multidimensional phase space. We validated SigMA on simulated clusters and find that it outperforms …
High-frequency Decayless Waves with Significant Energy in Solar Orbiter/EUI Observations
Van Doorsselaere, Tom; Berghmans, David; Petrova, Elena +1 more
High-frequency wave phenomena present a great deal of interest as one of the possible candidates to contribute to the energy input required to heat the corona as a part of the alternating current heating theory. However, the resolution of imaging instruments up until the Solar Orbiter has made it impossible to resolve the necessary time and spatia…
A catalogue of cataclysmic variables from 20 yr of the Sloan Digital Sky Survey with new classifications, periods, trends, and oddities
Thorstensen, John R.; Breedt, Elmé; Gänsicke, Boris T. +7 more
We present a catalogue of 507 cataclysmic variables (CVs) observed in SDSS I to IV including 70 new classifications collated from multiple archival data sets. This represents the largest sample of CVs with high-quality and homogeneous optical spectroscopy. We have used this sample to derive unbiased space densities and period distributions for the…
Astrometric Accelerations as Dynamical Beacons: Discovery and Characterization of HIP 21152 B, the First T-dwarf Companion in the Hyades
Magnier, Eugene A.; Jensen-Clem, Rebecca; Crepp, Justin R. +28 more
Benchmark brown dwarf companions with well-determined ages and model-independent masses are powerful tools to test substellar evolutionary models and probe the formation of giant planets and brown dwarfs. Here, we report the independent discovery of HIP 21152 B, the first imaged brown dwarf companion in the Hyades, and conduct a comprehensive orbi…