Search Publications
Photometric Redshift Estimation with Galaxy Morphology Using Self-organizing Maps
Cooray, Asantha; Häußler, Boris; Nayyeri, Hooshang +1 more
We use multiband optical and near-infrared photometric observations of galaxies in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey to predict photometric redshifts using artificial neural networks. The multiband observations span from 0.39 to 8.0 µm for a sample of ∼1000 galaxies in the GOODS-S field for which robust size …
Stellar X-Ray Activity Across the Hertzsprung-Russell Diagram. I. Catalogs
Liu, Jifeng; Bai, Yu; Wang, Song +1 more
Stellar magnetic activity provides substantial information on the magnetic dynamo and the coronal heating process. We present a catalog of X-ray activity for about 6000 stars, based on the Chandra and Gaia DR2 data. We also classified more than 3000 stars as young stellar objects, dwarf stars, or giant stars. By using the stars with valid stellar …
Milky Way Subsystems from Globular Cluster Kinematics Using Gaia DR2 and HST Data
Bobylev, V. V.; Bajkova, A. T.; Carraro, G. +2 more
We employ Gaia DR2 proper motions for 151 Milky Way globular clusters (GCs) from Vasiliev in tandem with distances and line-of-sight velocities to derive their kinematical properties. To assign clusters to the Milky Way thick disk, bulge, and halo, we follow the approach of Posti et al., who distinguished among different Galactic stellar component…
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…