Search Publications
TOI-4600 b and c: Two Long-period Giant Planets Orbiting an Early K Dwarf
Vanderburg, Andrew; Bieryla, Allyson; Latham, David W. +31 more
We report the discovery and validation of two long-period giant exoplanets orbiting the early K dwarf TOI-4600 (V = 12.6, T = 11.9), first detected using observations from the Transiting Exoplanet Survey Satellite (TESS) by the TESS Single Transit Planet Candidate Working Group. The inner planet, TOI-4600 b, has a radius of 6.80 ± 0.31 R ⊕
Metallicities of Classical Cepheids in the Inner Galactic Disk
Matsunaga, Noriyuki; D'Orazi, Valentina; McWilliam, Andrew +14 more
Metallicity gradients refer to the sloped radial profiles of the metallicities of gas and stars and are commonly seen in disk galaxies. A well-defined metallicity gradient of the Galactic disk is observed particularly well with classical Cepheids, which are good stellar tracers thanks to their period-luminosity relation, allowing precise distance …
A High-precision Survey of the D/H Ratio in the Nearby Interstellar Medium
Tripp, Todd M.; Jenkins, Edward B.; Chayer, Pierre +4 more
We present high signal-to-noise ratio measurements of the H I Lyα absorption line toward 16 Galactic targets that are at distances between approximately 190 and 2200 pc, all beyond the wall of the Local Bubble. We describe the models used to remove stellar emission and absorption features and the methods used to account for all known sources of er…
A Tale of Three Dwarfs: No Extreme Cluster Formation in Extreme Star-forming Galaxies
Whitmore, Bradley C.; Chandar, Rupali; Ubeda, Leonardo +8 more
Nearly all current simulations predict that outcomes of the star formation process, such as the fraction of stars that form in bound clusters (Γ), depend on the intensity of star formation activity (ΣSFR) in the host galaxy. The exact shape and strength of the predicted correlations, however, vary from simulation to simulation. Observat…
Dimming of Continuum Captured in Mrk 841: New Clues on the Nature of the Soft X-Ray Excess
Kriss, Gerard A.; Mehdipour, Missagh; Mao, Junjie +2 more
We report on a remarkable change in the spectral energy distribution (SED) of Mrk 841, providing new insights on how the soft X-ray excess emission in active galactic nuclei (AGNs) is produced. By Swift monitoring of a sample of Seyfert-1 galaxies, we found an X-ray spectral hardening event in Mrk 841. We thereby triggered our XMM-Newton, NuSTAR, …
The Most Obscured AGNs in the XMM-SERVS Fields
Brandt, W. N.; Zou, Fan; Bauer, Franz E. +9 more
We perform X-ray spectral analyses to derive the characteristics (e.g., column density, X-ray luminosity) of ≈10,200 active galactic nuclei (AGNs) in the XMM-Spitzer Extragalactic Representative Volume Survey, which was designed to investigate the growth of supermassive black holes across a wide dynamic range of cosmic environments. Using physical…
The Closest View of a Fast Coronal Mass Ejection: How Faulty Assumptions Near Perihelion Lead to Unrealistic Interpretations of PSP/WISPR Observations
Reeves, Katharine K.; Hess, Phillip; West, Matthew J. +3 more
We report on the closest view of a coronal mass ejection (CME) observed by the Parker Solar Probe (PSP)/ Wide-field Imager for Parker Solar PRobe (WISPR) instrument on 2022 September 5, when PSP was traversing from a distance of 15.3 to 13.5 R ⊙ from the Sun. The CME leading edge and an arc-shaped concave-up structure near the core were…
PEARLS: Low Stellar Density Galaxies in the El Gordo Cluster Observed with JWST
Grogin, Norman A.; Koekemoer, Anton M.; Pirzkal, Nor +23 more
A full understanding of how unusually large ultradiffuse galaxies (UDGs) fit into our conventional theory of galaxy formation remains elusive, despite the large number of objects identified locally. A natural extension of UDG research is the study of similar galaxies at higher redshift to establish how their properties may evolve over time. Howeve…
A 2:1 Mean-motion Resonance Super-Jovian Pair Revealed by TESS, FEROS, and HARPS
Trifonov, Trifon; Henning, Thomas; Latham, David W. +24 more
We report the discovery of a super-Jovian 2:1 mean-motion resonance (MMR) pair around the G-type star TIC 279401253, whose dynamical architecture is a prospective benchmark for planet formation and orbital evolution analysis. The system was discovered thanks to a single-transit event recorded by the Transiting Exoplanet Survey Satellite mission, w…
Examining the Rotation Period Distribution of the 40 Myr Tucana-Horologium Association with TESS
Kiman, Rocio; Faherty, Jacqueline K.; Gagné, Jonathan +6 more
The Tucana-Horologium association (Tuc-Hor) is a 40 Myr old moving group in the southern sky. In this work, we measure the rotation periods of 313 Tuc-Hor objects with TESS light curves derived from TESS full-frame images and membership lists driven by Gaia EDR3 kinematics and known youth indicators. We recover a period for 81.4% of the sample and…