Search Publications
Mapping Solar X-Ray Images from SDO/AIA EUV Images by Deep Learning
Yang, Bo; Yang, Jiayan; Bi, Yi +6 more
The full-Sun corona is now imaged every 12 s in extreme ultraviolet (EUV) passbands by Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), whereas it is only observed several times a day at X-ray wavelengths by Hinode/X-Ray Telescope (XRT). In this paper, we apply a deep-learning method, i.e., the convolution neural network (CNN), to es…
Identifying Circumgalactic Medium Absorption in QSO Spectra: A Bayesian Approach
Scott, Jennifer E.; Shoemaker, Emileigh S.; Hamill, Colin D.
We present a study of candidate galaxy-absorber pairs for 43 low-redshift QSO sightlines (0.06 < z < 0.85) observed with the Hubble Space Telescope/Cosmic Origins Spectrograph that lie within the footprint of the Sloan Digital Sky Survey with a statistical approach to match absorbers with galaxies near the QSO lines of sight using only the S…
Characterizing Magnetic Connectivity of Solar Flare Electron Sources to STEREO Spacecraft Using ADAPT-WSA Modeling
Arge, C. N.; Henney, C. J.; Kahler, S. W. +1 more
Onsets and intensity profiles of six energetic (E > 30 keV) electron events common to STEREO A and B (STA and STB) spacecraft were analyzed by Klassen et al. with the STEREO Solar Electron and Proton Telescopes when the spacecraft were separated by <70° in solar longitude. All six events were characterized by earlier onsets and higher peak i…
Long-term Evolution of the Short-term X-Ray Variability of the Jetted TDE Swift J1644+57
Jin, Chichuan
The short-term X-ray variability of tidal disruption events (TDEs) and its similarities with that of active galactic nuclei are poorly understood. In this work, we show the diversity of TDEs' short-term X-ray variability, and take Swift J1644+57 as an example to study the evolution of various properties related to the short-term X-ray variability,…
Deciphering the 3D Orion Nebula-IV: The HH 269 Flow Emerges from the Orion-S Embedded Molecular Cloud
Abel, N. P.; O'Dell, C. R.; Ferland, G. J.
We have extended the membership and determined the 3D structure of the large (0.19 pc) HH 269 sequence of shocks in the Orion Nebula. All of the components lie along a track that is highly tilted to the plane of the sky and emerge from within the Orion-S embedded molecular cloud. Their source is probably either the highly obscured mm 9 source asso…
Modeling the Hα Emission Surrounding Spica Using the Lyman Continuum from a Gravity-darkened Central Star
Aufdenberg, Jason P.; Hammill, Joseph M.
The large, faint Hα emission surrounding the early B-star binary Spica has been used to constrain the total hydrogen recombination rate of the nebula and indirectly probe the Lyman continuum luminosity of the primary star. Early analysis suggested that a stellar atmosphere model, consistent with Spica A's spectral type, has a Lyman continuum lumin…
The Energy Conversion Rate of an Active Region Transient Brightening Estimated by Hinode Spectroscopic Observations
Imada, Shinsuke; Kawai, Toshiki
We statistically estimate the conversion rate of the energy released during an active region transient brightening to Doppler motion and thermal and nonthermal energies. We used two types of data sets for the energy estimation and detection of transient brightenings. One includes spectroscopic images of Fe XIV, Fe XV, and Fe XVI lines observed by …
Photometric Variability of the Pre-main-sequence Stars toward the Sh 2-190 Region
Matsunaga, N.; Sharma, Saurabh; Panwar, Neelam +7 more
We present the results from our time-series imaging data taken with the 1.3 m Devasthal fast optical telescope and 0.81 m Tenagara telescope in V, Rc, and Ic bands covering an area of ~18'4 × 18'4 toward the star-forming region Sh 2-190. This photometric data helped us to explore the nature of the variability of pre-main-sequ…
Exploration of the Origin of Galactic and Extragalactic Star Clusters through Simulated H-R Diagrams
Chattopadhyay, Tanuka; Mondal, Sreerup; Paul, Suman +2 more
The present work explores the origin of the formation of star clusters in our Galaxy and in the Small Magellanic Cloud (SMC) through simulated H-R diagrams and compare those with observed star clusters. The simulation study produces synthetic H-R diagrams through the Markov Chain Monte Carlo (MCMC) technique using the star formation history (SFH),…
Probing Polarization and the Role of Magnetic Fields in Cloud Destruction in the Keyhole Nebula
Dowell, C. Darren; Majumdar, Liton; Goldsmith, Paul F. +2 more
We present polarimetric observations of the Keyhole Nebula in the Carina Nebula Complex carried out using the Stratospheric Observatory for Infrared Astronomy. The Keyhole Nebula, located to the west of η Carinae, is believed to be disturbed by the stellar winds from the massive star. We observed the Keyhole Nebula at 89 µm wavelength with t…