Search Publications
Evidence for a Redshifted Excess in the Intracluster Light Fractions of Merging Clusters at z 0.8
Jiménez-Teja, Yolanda; Dupke, Renato A.; Dimauro, Paola +1 more
The intracluster light (ICL) fraction is a well-known indicator of the dynamical activity in intermediate-redshift clusters. Merging clusters in the redshift interval 0.18 < z < 0.56 have a distinctive peak in the ICL fractions measured between ~3800 and 4800 Å . In this work, we analyze two higher-redshift, clearly merging clusters, ACT-CLJ…
A simple method to measure νmax for asteroseismology: application to 16 000 oscillating Kepler red giants
Li, Yaguang; Huber, Daniel; Bedding, Timothy R. +4 more
The importance of νmax (the frequency of maximum oscillation power) for asteroseismology has been demonstrated widely in the previous decade, especially for red giants. With the large amount of photometric data from CoRoT (Convection, Rotation, and planetary Transits), Kepler, and Transiting Exoplanet Survey Satellite, several automated…
Impact of far-side structures observed by Solar Orbiter on coronal and heliospheric wind simulations
Parenti, S.; Strugarek, A.; Brun, A. S. +4 more
Context. Solar Orbiter is a new space observatory that provides unique capabilities to understand the heliosphere. In particular, it has made several observations of the far-side of the Sun and therefore provides unique information that can greatly improve space weather monitoring.
Aims: In this study, we aim to quantify how the far-side data…
The Dynamical State of the Didymos System before and after the DART Impact
Hamilton, Douglas P.; Tanga, Paolo; Gramigna, Edoardo +50 more
NASA's Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, the natural satellite of (65803) Didymos, on 2022 September 26, as a first successful test of kinetic impactor technology for deflecting a potentially hazardous object in space. The experiment resulted in a small change to the dynamical state of the Didymos system consis…
Magnetic activity of red giants: Correlation between the amplitude of solar-like oscillations and chromospheric indicators
Godoy-Rivera, D.; Gaulme, P.; Gehan, C.
Previous studies have found that red giants (RGs) in close binary systems undergoing spin-orbit resonance exhibit an enhanced level of magnetic activity with respect to single RGs rotating at the same rate, from measurements of photometric variability, Sph', and the chromospheric emission S-index, SCa II. Here, we …
Paths to robust exoplanet science yield margin for the Habitable Worlds Observatory
Bryson, Steve; Tuchow, Noah W.; Stark, Christopher C. +11 more
The Habitable Worlds Observatory (HWO) will seek to detect and characterize potentially Earth-like planets around other stars. To ensure that the mission achieves the Astro2020 Decadal's recommended goal of 25 exoEarth candidates (EECs), we must take into account the probabilistic nature of exoplanet detections and provide a "science margin" to bu…
Galaxy Groups as the Ultimate Probe of AGN Feedback
Finoguenov, Alexis; Gastaldello, Fabio; O'Sullivan, Ewan +3 more
The co-evolution between supermassive black holes and their environment is most directly traced by the hot atmospheres of dark matter halos. The cooling of the hot atmosphere supplies the central regions with fresh gas, igniting active galactic nuclei (AGN) with long duty cycles. The outflows from the central engine tightly couple with the surroun…
Exoplanet transit spectroscopy with JWST NIRSpec: diagnostics and homogeneous case study of WASP-39 b
Madhusudhan, Nikku; Constantinou, Savvas; Sarkar, Subhajit +1 more
The JWST has ushered in a new era of exoplanet transit spectroscopy. Among the JWST instruments, the Near-Infrared Spectrograph (NIRSpec) has the most extensive set of configurations for exoplanet time-series observations. The NIRSpec Prism and G395H grating represent two extremes in NIRSpec instrument modes, with the Prism spanning a wider spectr…
A strontium-rich ultra-metal-poor star in the Atari disc component
Frebel, Anna; Mardini, Mohammad K.; Chiti, Anirudh
We report on the discovery of the first ultra-metal-poor (UMP) star 2MASS J20500194-6613298 (J2050-6613; [Fe/H] = -4.05) selected from the Gaia BP/RP spectral catalogue that belongs to the ancient Atari disc component. We obtained a high-resolution spectrum for the star with the MIKE spectrograph on the Magellan-Clay telescope. J2050-6613 displays…
Deconvolution of JWST/MIRI Images: Applications to an Active Galactic Nucleus Model and GATOS Observations of NGC 5728
Rouan, D.; Rigopoulou, D.; Stalevski, M. +32 more
The superb image quality, stability, and sensitivity of JWST permit deconvolution techniques to be pursued with a fidelity unavailable to ground-based observations. We present an assessment of several deconvolution approaches to improve image quality and mitigate the effects of the complex JWST point-spread function (PSF). The optimal deconvolutio…