Search Publications
Global-scale magnetosphere convection driven by dayside magnetic reconnection
Branduardi-Raymont, Graziella; Wang, Chi; Dai, Lei +8 more
Plasma convection on a global scale is a fundamental feature of planetary magnetosphere. The Dungey cycle explains that steady-state convection within the closed part of the magnetosphere relies on magnetic reconnection in the nightside magnetospheric tail. Nevertheless, time-dependent models of the Dungey cycle suggest an alternative scenario whe…
CHEOPS in-flight performance. A comprehensive look at the first 3.5 yr of operations
Guterman, P.; Alonso, R.; Deleuil, M. +128 more
Context. Since the discovery of the first exoplanet almost three decades ago, the number of known exoplanets has increased dramatically. By beginning of the 2000s it was clear that dedicated facilities to advance our studies in this field were needed. The CHaracterising ExOPlanet Satellite (CHEOPS) is a space telescope specifically designed to mon…
Dead or Alive? How Bursty Star Formation and Patchy Dust Can Cause Temporary Quiescence in High-redshift Galaxies
Morishita, Takahiro; Faisst, Andreas L.
The recent discovery of a galaxy at z = 7.3 with undetected optical emission lines and a blue UV-to-optical continuum ratio in JWST spectroscopy is surprising and needs to be explained physically. Here, we explore two possibilities that could cause such a seemingly quiescent ∼5 × 108 M ⊙ galaxy in the early Universe: (i) stoc…
JWST observations of the Ring Nebula (NGC 6720): I. Imaging of the rings, globules, and arcs
Matsuura, Mikako; Volk, Kevin; Cami, Jan +18 more
We present JWST images of the well-known planetary nebula NGC 6720 (the Ring Nebula), covering wavelengths from 1.6 to 25 $\, \mu$m. The bright shell is strongly fragmented with some 20 000 dense globules, bright in H2, with a characteristic diameter of 0.2 arcsec and density nH ~ 105-106 cm-3…
JWST Thermal Emission of the Terrestrial Exoplanet GJ 1132b
Eastman, Jason D.; Bean, Jacob L.; Zhang, Michael +9 more
We present thermal emission measurements of GJ 1132b spanning 5–12 µm obtained with the Mid-Infrared Instrument Low-Resolution Spectrometer on the James Webb Space Telescope. GJ 1132b is an M dwarf rocky planet with T eq = 584 K and an orbital period of 1.6 days. We measure a white-light secondary eclipse depth of 140 ± 17 ppm, wh…
Importance of Cosmic-Ray Propagation on Sub-GeV Dark Matter Constraints
De la Torre Luque, Pedro; Balaji, Shyam; Koechler, Jordan
We study sub-GeV dark matter (DM) particles that may annihilate or decay into Standard Model particles producing an exotic injection component in the Milky Way that leaves an imprint in both photon and cosmic-ray (CR) fluxes. Specifically, the DM particles may annihilate or decay into e + e ‑, µ + µ
Data reconstruction of the dynamical connection function in f(Q) cosmology
Ren, Xin; Wang, Bo; Cai, Yi-Fu +2 more
We employ Hubble data and Gaussian Processes in order to reconstruct the dynamical connection function in $f(Q)$ cosmology beyond the coincident gauge. In particular, there exist three branches of connections that satisfy the torsionless and curvatureless conditions, parametrized by a new dynamical function $\gamma$. We express the redshift depend…
Freeze-in production of sterile neutrino dark matter in a gauged U(1)‧ model with inverse seesaw
Poddar, Tanmay Kumar; Das, Arindam; Goswami, Srubabati +1 more
We consider a general, anomaly free U(1)‧ extension of the Standard Model (SM) where the neutrino mass is generated at the tree level via the inverse seesaw mechanism. The model contains three right handed neutrinos, three additional singlet fermions, one extra complex scalar and a neutral gauge boson (Z‧). Instead of resorting to a specific U(1) …
Proper Motions and Orbits of Distant Local Group Dwarf Galaxies from a Combination of Gaia and Hubble Data
van der Marel, Roeland P.; Watkins, Laura L.; Sacchi, Elena +12 more
We have determined the proper motions (PMs) of 12 dwarf galaxies in the Local Group (LG), ranging from the outer Milky Way (MW) halo to the edge of the LG. We used the Hubble Space Telescope (HST) as the first and Gaia as the second epoch using the GaiaHub software. For Leo A and Sag DIG, we also used multi-epoch HST measurements relative to backg…
A Rest-frame Near-IR Study of Clumps in Galaxies at 1 < z < 2 Using JWST/NIRCam: Connection to Galaxy Bulges
Ho, Luis C.; Daddi, Emanuele; Bottrell, Connor +4 more
A key question in galaxy evolution has been the importance of the apparent "clumpiness" of high-redshift galaxies. Until now, this property has been primarily investigated in rest-frame UV, limiting our understanding of their relevance. Are they short-lived or are they associated with more long-lived massive structures that are part of the underly…