Search Publications
Improved Constraints on the Initial-to-final Mass Relation of White Dwarfs Using Wide Binaries
Chanamé, Julio; Barrientos, Manuel
We present observational constraints for the initial-to-final mass relation (IFMR) derived from 11 white dwarfs (WDs) in wide binaries (WBs) that contain a turnoff/subgiant primary. Because the components of WBs are coeval to a good approximation, the age of the WD progenitor can be determined from the study of its wide companion. However, previou…
Nonequilibrium Flux Rope Formation by Confined Flares Preceding a Solar Coronal Mass Ejection
Masuda, Satoshi; Liu, Chang; Liu, Rui +3 more
We present evidence that a magnetic flux rope was formed before a coronal mass ejection (CME) and its associated long-duration flare during a pair of preceding confined eruptions and associated impulsive flares in a compound event in NOAA Active Region 12371. Extreme-ultraviolet images and the extrapolated nonlinear force-free field show that the …
Exploring the Solar Wind from Its Source on the Corona into the Inner Heliosphere during the First Solar Orbiter-Parker Solar Probe Quadrature
Telloni, Daniele; Zank, Gary P.; Susino, Roberto +68 more
This Letter addresses the first Solar Orbiter (SO)-Parker Solar Probe (PSP) quadrature, occurring on 2021 January 18 to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in the corona at altitudes between 3.5 and 6.3 solar radii above …
The Metal-poor Metallicity Distribution of the Ancient Milky Way
Frebel, Anna; Mardini, Mohammad K.; Chiti, Anirudh +1 more
We present a low-metallicity map of the Milky Way consisting of ∼110,000 metal-poor giants with -3.5 < [Fe/H] < -0.75, based on public photometry from the second data release of the SkyMapper survey. These stars extend out to ∼7 kpc from the solar neighborhood and cover the main Galactic stellar populations, including the thick disk and the …
Icarus: A Flat and Fast Prograde Stellar Stream in the Milky Way Disk
Cignoni, Michele; Lattanzi, Mario G.; Re Fiorentin, Paola +1 more
We explore the local volume of the Milky Way via chemical and kinematical measurements from high-quality astrometric and spectroscopic data recently released by the Gaia, APOGEE, and GALAH programs. We chemically select 1137 stars up to 2.5 kpc of the Sun and [Fe/H] ≤ -1.0 dex, and find evidence of statistically significant substructures. Clusteri…
Measurements of Coronal Magnetic Field Strengths in Solar Active Region Loops
Landi, Enrico; Warren, Harry P.; Brooks, David H.
The characteristic electron densities, temperatures, and thermal distributions of 1 MK active region loops are now fairly well established, but their coronal magnetic field strengths remain undetermined. Here we present measurements from a sample of coronal loops observed by the Extreme-ultraviolet Imaging Spectrometer on Hinode. We use a recently…
The Influence of Age on the Relative Frequency of Super-Earths and Sub-Neptunes
David, Trevor J.; Contardo, Gabriella; Sandoval, Angeli
There is growing evidence that the population of close-in planets discovered by the Kepler mission was sculpted by atmospheric loss, though the typical timescale for this evolution is not well-constrained. Among a highly complete sample of planet hosts of varying ages the age-dependence of the relative fraction of super-Earth and sub-Neptune detec…
TIC 454140642: A Compact, Coplanar, Quadruple-lined Quadruple Star System Consisting of Two Eclipsing Binaries
Kostov, Veselin B.; Powell, Brian P.; Rappaport, Saul A. +30 more
We report the discovery of a compact, coplanar, quadruple-lined, eclipsing quadruple star system from Transiting Exoplanet Survey Satellite data, TIC 454140642, also known as TYC 0074-01254-1. The target was first detected in Sector 5 with a 30-minute cadence in full-frame images and then observed in Sector 32 with a 2-minute cadence. The light cu…
Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. VII. The Stellar Disk Structure Revealed by the Mono-abundance Populations
Shi, Jianrong; Xiang, Maosheng; Huang, Yang +7 more
Using a sample of 96,201 primary red clump stars selected from the LAMOST and Gaia surveys, we investigate the stellar structure of the Galactic disk. The sample stars show two separated sequences of high-[α/Fe] and low-[α/Fe] in the [α/Fe]-[Fe/H] plane. We divide the sample stars into five mono-abundance populations (MAPs) with different ranges o…
First HETDEX Spectroscopic Determinations of Lyα and UV Luminosity Functions at z = 2-3: Bridging a Gap between Faint AGNs and Bright Galaxies
Ono, Yoshiaki; Ouchi, Masami; Finkelstein, Steven L. +21 more
We present Lyα and ultraviolet (UV)-continuum luminosity functions (LFs) of galaxies and active galactic nuclei (AGNs) at z = 2.0-3.5 determined by the untargeted optical spectroscopic survey of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). We combine deep Subaru imaging with HETDEX spectra resulting in 11.4 deg2 of fiber …