Search Publications
The Low-mass Stellar Initial Mass Function in Nearby Ultrafaint Dwarf Galaxies
van der Marel, Roeland P.; Wyse, Rosemary F. G.; Sacchi, Elena +3 more
The stellar initial mass function (IMF) describes the distribution of stellar masses that form in a given star formation event. The long main-sequence lifetimes of low-mass stars mean that the IMF in this regime (below ∼ 1 M ⊙) can be investigated through star counts. Ultrafaint dwarf galaxies are low-luminosity systems with ancient, me…
DESI Emission-line Galaxies: Unveiling the Diversity of [O II] Profiles and Its Links to Star Formation and Morphology
Brooks, D.; Doel, P.; Gutierrez, G. +34 more
We study the [O II] profiles of emission-line galaxies (ELGs) from the Early Data Release of the Dark Energy Spectroscopic Instrument (DESI). To this end, we decompose and classify the shape of [O II] profiles with the first two eigenspectra derived from principal component analysis. Our results show that DESI ELGs have diverse line profiles, whic…
Infrared spectra of solid-state ethanolamine: Laboratory data in support of JWST observations
Henning, Th.; Perotti, G.; Jäger, C. +4 more
Context. Ethanolamine (NH2CH2CH2OH; EA) has been identified in the gas phase of the interstellar medium within molecular clouds. Although EA has not been directly observed in the molecular ice phase, a solid-state formation mechanism has been proposed. However, the current literature lacks an estimation of the infr…
Characterization of carbon dioxide on Ganymede and Europa supported by experiments: Effects of temperature, porosity, and mixing with water
Caselli, P.; Cazaux, S.; Muñoz Caro, G. M. +8 more
Context. The surfaces of icy moons are primarily composed of water ice that can be mixed with other compounds, such as carbon dioxide. The carbon dioxide (CO2) stretching fundamental band observed on Europa and Ganymede appears to be a combination of several bands that are shifting location from one moon to another.
Aims: We invest…
The Regulation of the Solar Wind Electron Heat Flux by Wave–Particle Interactions
Verscharen, Daniel; Chen, Christopher H. K.; Maksimovic, Milan +11 more
The solar wind electrons carry a significant heat flux into the heliosphere. The weakly collisional state of the solar wind implicates collisionless processes as the primary factor that constrains nonthermal features of the velocity distribution function (VDF), including the heat flux. Previous observational work suggests that the electron VDF som…
3D evolution of a solar flare thermal X-ray loop-top source
Müller, D.; Nicula, B.; Krucker, S. +6 more
Context. The recent launch of Solar Orbiter has placed a solar X-ray imager (Spectrometer/Telescope for Imaging X-rays; STIX) beyond Earth orbit for the first time. This introduces the possibility of deriving the 3D locations and volumes of solar X-ray sources by combining STIX observations with those of Earth-orbiting instruments such as the Hino…
Hot Stars in the GALEX Ultraviolet Sky Surveys (GUVcat_AISxSDSS_HS) and the Binary Fraction of Hot Evolved Stars
Bianchi, Luciana
We present a catalog of 71,364 pointlike UV sources with Sloan Digital Sky Survey (SDSS) photometry and GALEX far-UV (FUV)‑near-UV (NUV) ≤0.1 mag. The limit corresponds to stellar T eff ≳15,000‑20,000 K, slightly depending on gravity but nearly reddening independent for Milky Way‑type dust. Most sources are hot white dwarfs (WDs) and su…
Improving the light curves of gravitationally lensed quasars with Gaia proper motion data
Schmidt, R. W.; Wambsganss, J.; Sorgenfrei, C.
Aims: We show how to significantly improve difference image analysis (DIA) of gravitationally lensed quasars over long periods of time using Gαία proper motions.
Methods: DIA requires the subtraction of a reference image from the individual images of a monitoring campaign, using stars in the field to align the images. Since the proper mo…
A Testbed for Tidal Migration: The 3D Architecture of an Eccentric Hot Jupiter HD 118203 b Accompanied by a Possibly Aligned Outer Giant Planet
Huber, Daniel; Claytor, Zachary R.; Saunders, Nicholas +32 more
Characterizing outer companions to hot Jupiters plays a crucial role in deciphering their origins. We present the discovery of a long-period giant planet, HD 118203 c (
Discovery and characterization of a dense sub-Saturn TOI-6651b
Bieryla, Allyson; Latham, David W.; Eastman, Jason D. +13 more
We report the discovery and characterization of a transiting sub-Saturn exoplanet TOI-6651b using PARAS-2 spectroscopic observations. The host, TOI-6651 (mV ≈ 10.2), is a sub-giant, metal-rich G-type star with [Fe / H] = 0.225‑0.0450.044[Fe/H] = 0.225‑0.045+0.044, Teff = 5940 ± 110 …