Search Publications
Turbulence and Energetic Particles in Radiative Shock Waves in the Cygnus Loop. I. Shock Properties
Blair, William P.; Slavin, Jonathan D.; Raymond, John C. +3 more
We have obtained a contiguous set of long-slit spectra of a shock wave in the Cygnus Loop to investigate its structure, which is far from the morphology predicted by 1D models. Proper motions from Hubble Space Telescope images combined with the known distance to the Cygnus Loop provide an accurate shock speed. Earlier analyses of shock spectra est…
Recurring Homologous Solar Eruptions in NOAA AR 11429
Zhang, Jie; Vemareddy, Panditi; Karna, Nishu +1 more
We present the study of three homologous solar eruptions from NOAA active region (AR) 11429 over four days. This large and complex AR is divided into two relatively simple subregions: northeast (NE) and southwest (SW). Recurrent eruptions occurred from the SW subregion over different evolutionary phases, which provided a unique opportunity to isol…
Spectroscopic Constraints on the Buildup of Intracluster Light in the Coma Cluster
van Dokkum, Pieter; Bizyaev, Dmitry; Pan, Kaike +14 more
The stellar content of the intracluster light (ICL) provides unique insight into the hierarchical assembly process of galaxy clusters. We present optical spectra of three ICL regions (µg ≈ 25.3-26.2 mag arcsec-2) in the Coma cluster, located between 100 and 180 kpc from their nearest brightest cluster galaxies (BCGs): N…
Super-resolution of SDO/HMI Magnetograms Using Novel Deep Learning Methods
Moon, Yong-Jae; Lim, Daye; Rahman, Sumiaya +3 more
Image super-resolution is a technique of enhancing the resolution of an image where a high-resolution (HR) image is reconstructed from a low-resolution (LR) image. In this Letter, we apply two novel deep learning models (residual attention model and progressive GAN model) for enhancing Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Ima…
IRIS Mg II Observations and Non-LTE Modeling of Off-limb Spicules in a Solar Polar Coronal Hole
Heinzel, Petr; Shibata, Kazunari; Okamoto, Takenori J. +4 more
We investigated the off-limb spicules observed in the Mg II h and k lines by IRIS in a solar polar coronal hole. We analyzed the large data set of obtained spectra to extract quantitative information about the line intensities, shifts, and widths. The observed Mg II line profiles are broad and double peaked at lower altitudes, broad but flat toppe…
The Ionized- and Cool-gas Content of the BR1202-0725 System as Seen by MUSE and ALMA
Walter, F.; Riechers, D.; Decarli, R. +7 more
We present Multi Unit Spectroscopic Explorer (MUSE) observations of the gas-rich major merger BR1202-0725 at z ∼ 4.7, which constitutes one of the most overdense fields known in the early universe. We utilize these data in conjunction with existing Atacama Large Millimeter/submillimeter Array (ALMA) observations to compare and contrast the spatial…
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…
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 …
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…
REQUIEM-2D Methodology: Spatially Resolved Stellar Populations of Massive Lensed Quiescent Galaxies from Hubble Space Telescope 2D Grism Spectroscopy
Mahler, Guillaume; Bezanson, Rachel; Brammer, Gabriel +13 more
We present a novel Bayesian methodology to jointly model photometry and deep Hubble Space Telescope 2D grism spectroscopy of high-redshift galaxies. Our requiem2d code measures both unresolved and resolved stellar populations, ages, and star formation histories (SFHs) for the ongoing REsolving QUIEscent Magnified (REQUIEM) Galaxies Survey, which t…