Search Publications
Is Extended Hard X-Ray Emission Ubiquitous in Compton-thick AGN?
Elvis, Martin; Risaliti, Guido; Fabbiano, G. +4 more
The recent Chandra discovery of extended ∼kiloparsec-scale hard (>3 keV) X-ray emission in nearby Compton-thick (CT) active galactic nuclei (AGN) opens a new window to improving AGN torus modeling and investigating how the central supermassive black hole interacts with and impacts the host galaxy. Since there are only a handful of detections so…
Inverse First Ionization Potential Effects in Giant Solar Flares Found from Earth X-Ray Albedo with Suzaku/XIS
Maeda, Yoshitomo; Katsuda, Satoru; Sato, Kosuke +21 more
We report X-ray spectroscopic results for four giant solar flares that occurred on 2005 September 7 (X17.0), 2005 September 8 (X5.4), 2005 September 9 (X6.2), and 2006 December 5 (X9.0), obtained from Earth albedo data with the X-ray Imaging Spectrometer (XIS) on board Suzaku. The good energy resolution of the XIS (FWHM ∼ 100 eV) enables us to sep…
Magnetosheath Jets and Plasmoids: Characteristics and Formation Mechanisms from Hybrid Simulations
Blanco-Cano, Xóchitl; Burgess, David; Trotta, Domenico +2 more
Magnetosheath jets and plasmoids are very common phenomena downstream of Earth's quasi-parallel bow shock. As the increase of the dynamic pressure is one of the principal characteristics of magnetosheath jets, the embedded paramagnetic plasmoids have been considered as an special case of the former. Although the properties of both types of structu…
SOFIA/FORCAST Galactic Center Legacy Survey: Overview
Morris, Mark R.; Longmore, Steven N.; García-Marín, Macarena +12 more
The Galactic Center contains some of the most extreme conditions for star formation in our Galaxy, as well as many other phenomena that are unique to this region. Given our relative proximity to the Galactic Center, we are able to study details of physical processes to a level that is simply not yet possible for more distant galaxies, yielding an …
Chemistry and Physics of a Low-metallicity Hot Core in the Large Magellanic Cloud
Onaka, Takashi; Aikawa, Yuri; Shimonishi, Takashi +5 more
We here present the results of 0.1 pc scale observations in 250 and 350 GHz toward a newly-discovered hot molecular core in a nearby low-metallicity galaxy, the Large Magellanic Cloud (LMC), with the Atacama Large Millimeter/submillimeter Array. A variety of C/N/O/Si/S-bearing molecules are detected toward the high-mass young stellar object, ST16.…
Possible Production of Solar Spicules by Microfilament Eruptions
Yurchyshyn, Vasyl; Moore, Ronald L.; Sterling, Alphonse C. +1 more
We examine Big Bear Solar Observatory (BBSO) Goode Solar Telescope (GST) high spatial resolution (0"06), high-cadence (3.45 s), Hα-0.8 Å images of central-disk solar spicules, using data of Samanta et al. We compare with coronal-jet chromospheric-component observations of Sterling et al. Morphologically, bursts of spicules, referred to as "enhance…
A Comparison of UV and Optical Metallicities in Star-forming Galaxies
Kewley, Lisa J.; Acharyya, Ayan; Rigby, Jane R. +4 more
Our ability to study the properties of the interstellar medium in the earliest galaxies will rely on emission-line diagnostics at rest-frame ultraviolet (UV) wavelengths. In this work, we identify metallicity-sensitive diagnostics using UV emission lines. We compare UV-derived metallicities with standard, well-established optical metallicities usi…
MCSED: A Flexible Spectral Energy Distribution Fitting Code and Its Application to z ∼ 2 Emission-line Galaxies
Schneider, Donald P.; Gronwall, Caryl; Ciardullo, Robin +7 more
We present MCSED, a new spectral energy distribution (SED) fitting code that mates flexible stellar evolution calculations with the Markov Chain Monte Carlo algorithms of the software package emcee. It takes broad-, intermediate-, and narrowband photometry, emission-line fluxes, and/or absorption-line spectral indices and returns probability distr…
Detailed Iron-peak Element Abundances in Three Very Metal-poor Stars
Roederer, Ian U.; Sneden, Christopher; Cowan, John J. +4 more
We have obtained new detailed abundances of the Fe-group elements Sc through Zn (Z = 21-30) in three very metal-poor ([Fe/H] ≈ -3) stars: BD+03o740, BD-13o3442, and CD-33o1173. High-resolution ultraviolet Hubble Space Telescope/Space Telescope Imaging Spectrograph spectra in the wavelength range 2300-3050 Å were ga…
Long-term Orbital Evolution of Galactic Satellites and the Effects on Their Star Formation Histories
Chiba, Masashi; Miyoshi, Takahiro
We investigate the orbital motions of dwarf spheroidal galaxies (dSphs) in the halo of the Milky Way (MW) to understand their possible effects on the diversity of the star formation histories seen in these MW satellites. In this work, we explicitly consider a time-varying gravitational potential due to the growth of the MW's dark halo mass to calc…