Search Publications
NuSTAR Hard X-Ray Observation of the Gamma-Ray Binary Candidate HESS J1832-093
Hailey, Charles J.; Mori, Kaya; Gotthelf, E. V. +13 more
We present a hard X-ray observation of the TeV gamma-ray binary candidate HESS J1832-093, which is coincident with the supernova remnant G22.7-0.2, using the Nuclear Spectroscopic Telescope Array. Non-thermal X-ray emission from XMMU J183245-0921539, the X-ray source associated with HESS J1832-093, is detected up to ∼30 keV and is well-described b…
Turbulent Density Fluctuations and Proton Heating Rate in the Solar Wind from 9-20 R ⊙
Vourlidas, Angelos; Ramesh, R.; Subramanian, Prasad +2 more
We obtain scatter-broadened images of the Crab Nebula at 80 MHz as it transits through the inner solar wind in 2017 and 2016 June. These images are anisotropic, with the major axis oriented perpendicular to the radially outward coronal magnetic field. Using these data, we deduce that the density modulation index (δ {N}e/{N}e)…
A Radio Relic and a Search for the Central Black Hole in the Abell 2261 Brightest Cluster Galaxy
Lauer, Tod R.; Postman, Marc; Lazio, T. Joseph W. +4 more
We present VLA images and HST/STIS spectra of sources within the center of the brightest cluster galaxy (BCG) in Abell 2261. These observations were obtained to test the hypothesis that its extremely large, flat core reflects the ejection of its supermassive black hole. Spectra of three of the four most luminous “knots” embedded in the core were t…
Outflow and Metallicity in the Broad-Line Region of Low-Redshift Active Galactic Nuclei
Nagao, Tohru; Woo, Jong-Hak; Shin, Jaejin
Outflows in active galactic nuclei (AGNs) are crucial to understand in investigating the co-evolution of supermassive black holes (SMBHs) and their host galaxies since outflows may play an important role as an AGN feedback mechanism. Based on archival UV spectra obtained with the Hubble Space Telescope and IUE, we investigate outflows in the broad…
Reddening and He I ∗ λ10830 Absorption Lines in Three Narrow-line Seyfert 1 Galaxies
Zhou, Hongyan; Ji, Tuo; Shi, Xiheng +6 more
We report the detection of heavy reddening and the He I* λ10830 absorption lines at the active galactic nucleus (AGN) redshift in three narrow-line Seyfert 1 galaxies: SDSS J091848.61+211717.0, SDSS J111354.66+124439.0, and SDSS J122749.13+321458.9. They exhibit very red optical to near-infrared colors, narrow Balmer/Paschen broad emission lines a…
Two-dimensional Molecular Gas and Ongoing Star Formation around H II Region Sh2-104
Wang, Jun-Jie; Xu, Jin-Long; Xu, Ye +6 more
We performed a multi-wavelength study toward H II region Sh2-104. New maps of 12CO J = 1 - 0 and 13CO J = 1 - 0 were obtained from the Purple Mountain Observatory 13.7 m radio telescope. Sh2-104 displays a double-ring structure. The outer ring with a radius of 4.4 pc is dominated by 12, 500 µm, 12CO J = 1 - 0…
Unusual Black Hole Binary LMC X-3: A Transient High-mass X-Ray Binary That Is Almost Always On?
Boyd, Patricia T.; Smale, Alan P.; Valencic, Lynne A. +1 more
We have analyzed a rich, multimission, multiwavelength data set from the black hole X-ray binary (BHXB) LMC X-3, covering a new anomalous low state (ALS), during which the source flux falls to an unprecedentedly low and barely detectable level, and a more normal low state. Simultaneous X-ray and UV/optical monitoring data from Swift are combined w…
The FluxCompensator: Making Radiative Transfer Models of Hydrodynamical Simulations Directly Comparable to Real Observations
Robitaille, Thomas P.; Koepferl, Christine M.
When modeling astronomical objects throughout the universe, it is important to correctly treat the limitations of the data, for instance finite resolution and sensitivity. In order to simulate these effects, and to make radiative transfer models directly comparable to real observations, we have developed an open-source Python package called the Fl…
High Radiation Pressure on Interstellar Dust Computed by Light-scattering Simulation on Fluffy Agglomerates of Magnesium-silicate Grains with Metallic-iron Inclusions
Kimura, Hiroshi
Recent space missions have provided information on the physical and chemical properties of interstellar grains such as the ratio β of radiation pressure to gravity acting on the grains in addition to the composition, structure, and size distribution of the grains. Numerical simulation on the trajectories of interstellar grains captured by Stardust…
Pseudo-automatic Determination of Coronal Mass Ejections’ Kinematics in 3D
Stenborg, Guillermo; Dal Lago, Alisson; Echer, Ezequiel +2 more
Coronal mass ejection (CME) events are among the main drivers of geomagnetic disturbances, and hence play a central role in the Sun-Earth system. Their monitoring and, in particular, the determination of their speed and direction of propagation are key issues for the forecasting of space weather near to Earth. We have implemented a method to track…