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Euclid preparation. IV. Impact of undetected galaxies on weak-lensing shear measurements
Lilje, P. B.; Scott, D.; Schrabback, T. +22 more
In modern weak-lensing surveys, the common approach to correct for residual systematic biases in the shear is to calibrate shape measurement algorithms using simulations. These simulations must fully capture the complexity of the observations to avoid introducing any additional bias. In this paper we study the importance of faint galaxies below th…
The Near-ultraviolet Continuum Radiation in the Impulsive Phase of HF/GF-type dMe Flares. I. Data
Kowalski, Adam F.; Hawley, Suzanne L.; Valenti, Jeff A. +8 more
We present near-UV (NUV) flare spectra from the Hubble Space Telescope (HST)/Cosmic Origins Spectrograph during two moderate-amplitude U-band flares on the dM4e star GJ 1243. These spectra are some of the first accurately flux-calibrated, NUV flare spectra obtained over the impulsive phase in M dwarf flares. We observed these flares with a fleet o…
Benchmarking CME Arrival Time and Impact: Progress on Metadata, Metrics, and Events
Jian, L. K.; Temmer, M.; Dumbović, M. +9 more
Accurate forecasting of the arrival time and subsequent geomagnetic impacts of coronal mass ejections (CMEs) at Earth is an important objective for space weather forecasting agencies. Recently, the CME Arrival and Impact working team has made significant progress toward defining community-agreed metrics and validation methods to assess the current…
LRG-BEASTS: Transmission Spectroscopy and Retrieval Analysis of the Highly Inflated Saturn-mass Planet WASP-39b
Kirk, James; López-Morales, Mercedes; Espinoza, Néstor +5 more
We present a ground-based transmission spectrum and comprehensive retrieval analysis of the highly inflated Saturn-mass planet WASP-39b. We obtained low-resolution spectra (R ≈ 400) of a transit of WASP-39b using the ACAM instrument on the 4.2 m William Herschel Telescope as part of the LRG-BEASTS survey. Our transmission spectrum is in good agree…
CME-HSS Interaction and Characteristics Tracked from Sun to Earth
Veronig, Astrid M.; Dumbović, Mateja; Temmer, Manuela +9 more
In a thorough study, we investigate the origin of a remarkable plasma and magnetic field configuration observed in situ on June 22, 2011, near L1, which appears to be a magnetic ejecta (ME) and a shock signature engulfed by a solar wind high-speed stream (HSS). We identify the signatures as an Earth-directed coronal mass ejection (CME), associated…
Confirmation of the radial velocity super-Earth K2-18c with HARPS and CARMENES
Bouchy, F.; Doyon, R.; Bonfils, X. +13 more
In an earlier campaign to characterize the mass of the transiting temperate super-Earth K2-18b with HARPS, a second, non-transiting planet was posited to exist in the system at 9 days. Further radial velocity follow-up with the CARMENES spectrograph visible channel revealed a much weaker signal at 9 days, which also appeared to vary chromatically …
Rotational modulation in TESS B stars
Handler, G.; Wade, G. A.; Cantiello, M. +6 more
Light curves and periodograms of 160 B stars observed by the Transiting Exoplanet Survey Satellite (TESS) space mission and 29 main-sequence B stars from Kepler and K2 were used to classify the variability type. There are 114 main-sequence B stars in the TESS sample, of which 45 are classified as possible rotational variables. This confirms previo…
Discovery of a Close-separation Binary Quasar at the Heart of a z ∼ 0.2 Merging Galaxy and Its Implications for Low-frequency Gravitational Waves
Strauss, Michael A.; Mingarelli, Chiara M. F.; Greene, Jenny E. +3 more
Supermassive black hole (SMBH) binaries with masses of ∼108-109 M ⊙ are expected to dominate the contribution to the as-yet undetected gravitational wave background (GWB) signal at the nanohertz frequencies accessible to pulsar timing arrays. We currently lack firm empirical constraints on the amplitude of the GWB …
HyDRA-H: Simultaneous Hybrid Retrieval of Exoplanetary Emission Spectra
Madhusudhan, Nikku; Gandhi, Siddharth; Hawker, George +1 more
High-resolution Doppler spectroscopy has been used to detect several chemical species in exoplanetary atmospheres. Such detections have traditionally relied on cross correlation of observed spectra against spectral model templates, an approach that is successful for detecting chemical species but not optimized for constraining abundances. Recent w…
The Onset and Growth of the 2018 Martian Global Dust Storm
Sánchez-Lavega, A.; Delcroix, M.; Hernández-Bernal, J. +1 more
We analyze the onset and initial expansion of the 2018 Martian Global Dust Storm (GDS 2018) using ground-based images in the visual range. This is the first case of a confirmed GDS initiating in the Northern Hemisphere. A dusty area extending about 1.4×105 km2 and centered at latitude +31.7°±1.8° and west longitude 18°±5°W in…