Search Publications
Drift-Bounce Resonance Between Charged Particles and Ultralow Frequency Waves: Theory and Observations
Zong, Qiu-Gang; Liu, Ying; Zhang, Shuai +7 more
Ultralow frequency (ULF) waves have long been known to resonate with magnetospheric charged particles through their drift and bounce motions. Most research interest has focused on the resonance with drift motion, which can accelerate charged particles at very high energies. The role of the bounce motion, especially for particles with lower energie…
Plasma Diagnostics of the Supernova Remnant N132D using Deep XMM-Newton Observations with the Reflection Grating Spectrometer
Miller, Eric D.; Ishida, Manabu; Yamaguchi, Hiroya +4 more
We present XMM-Newton observations of N132D, the X-ray brightest supernova remnant in the Large Magellanic Cloud, using the Reflection Grating Spectrometer (RGS), which enables high-resolution spectroscopy in the soft X-ray band. A dozen emission lines from L-shell transitions of Si, S, Ar, Ca, and Fe at intermediate charge states are newly detect…
Chandra reveals a luminous Compton-thick QSO powering a Lyα blob in a z = 4 starbursting protocluster
Ivison, R. J.; Lehmer, B. D.; Bauer, F. E. +7 more
Context. Galaxy clusters in the local universe descend from high-redshift overdense regions known as protoclusters. The large gas reservoirs and high rate of galaxy interaction in protoclusters are expected to enhance star-formation activity and trigger luminous supermassive black-hole accretion in the nuclear regions of the host galaxies.
Ai…
Observations and Modeling of the Onset of Fast Reconnection in the Solar Transition Region
Peter, H.; De Pontieu, Bart; Huang, Y. -M. +2 more
Magnetic reconnection is a fundamental plasma process that plays a critical role not only in energy release in the solar atmosphere, but also in fusion, astrophysics, and other space plasma environments. One of the challenges in explaining solar observations in which reconnection is thought to play a critical role is to account for the transition …
Discarding the disc in a changing-state AGN: the UV/X-ray relation in NGC 4151
Done, Chris; Mahmoud, Ra'ad D.
Recent monitoring campaigns designed to map the accretion regime in active galactic nuclei (AGN) show major discrepancies with models where the optical/ultraviolet (UV) is produced by X-ray-illuminated, optically thick disc material within a few hundred gravitational radii. However, these campaigns only monitored X-rays below 10 keV, whereas the b…
Young stars as tracers of a barred-spiral Milky Way
Ragan, Sarah E.; Pettitt, Alex R.; Smith, Martin C.
Identifying the structure of our Galaxy has always been fraught with difficulties, and while modern surveys continue to make progress building a map of the Milky Way, there is still much to understand. The arm and bar features are important drivers in shaping the interstellar medium (ISM), but their exact nature and influence still require attenti…
HST Survey of the Orion Nebula Cluster in the H2O 1.4 µm Absorption Band. I. A Census of Substellar and Planetary-mass Objects
Da Rio, Nicola; Gennaro, Mario; Pacifici, Camilla +15 more
In order to obtain a complete census of the stellar and substellar population, down to a few ${M}_{\mathrm{Jup}}$ in the ∼1 Myr old Orion Nebula Cluster, we used the infrared channel of the Wide Field Camera 3 of the Hubble Space Telescope with the F139M and F130N filters. These bandpasses correspond to the 1.4 µm H2O absorption f…
Morphological Reconstruction of a Small Transient Observed by Parker Solar Probe on 2018 November 5
Stenborg, Guillermo; Howard, Russell A.; Hess, Phillip +2 more
On 2018 November 5, about 24 hr before the first close perihelion passage of Parker Solar Probe (PSP), a coronal mass ejection (CME) entered the field of view of the inner detector of the Wide-field Imager for Solar PRobe (WISPR) instrument on board PSP, with the northward component of its trajectory carrying the leading edge of the CME off the to…
The role of small-scale surface motions in the transfer of twist to a solar jet from a remote stable flux rope
Aulanier, Guillaume; Schmieder, Brigitte; Joshi, Reetika +2 more
Context. Jets often have a helical structure containing ejected plasma that is both hot and also cooler and denser than the corona. Various mechanisms have been proposed to explain how jets are triggered, primarily attributed to a magnetic reconnection between the emergence of magnetic flux and environment or that of twisted photospheric motions t…
ISA, a High Sensitivity Accelerometer in the Interplanetary Space
Lucente, Marco; Lefevre, Carlo; Fiorenza, Emiliano +6 more
ISA (Italian Spring Accelerometer) is a high sensitivity accelerometer flying, as scientific payload, on-board one of the two spacecraft (the Mercury Planetary Orbiter) of BepiColombo, the first ESA mission to Mercury. The first commissioning phase (performed in the period November 2018 - August 2019) allowed to verify the functionality of the ins…