Search Publications
CHANG-ES. XXIV. First Detection of a Radio Nuclear Ring and Potential LLAGN in NGC 5792
Wang, Q. Daniel; Li, Zhiyuan; Sun, Wei +8 more
We report the discoveries of a nuclear ring of diameter 10″ (~1.5 kpc) and a potential low-luminosity active galactic nucleus (LLAGN) in the radio continuum emission map of the edge-on barred spiral galaxy NGC 5792. These discoveries are based on the Continuum Halos in Nearby Galaxies-an Expanded Very Large Array (VLA) Survey, as well as subsequen…
A Selection of Hα Emitters at z = 2.1-2.5 Using the K s -band Photometry of ZFOURGE
Spitler, Lee R.; Motohara, Kentaro; Chen, Nuo +1 more
Large and less-biased samples of star-forming galaxies are essential to investigate galaxy evolution. Hα emission line is one of the most reliable tracers of star-forming galaxies because its strength is directly related to recent star formation. However, it is observationally expensive to construct large samples of Hα emitters by spectroscopic or…
Very Large Telescope MUSE Observations of the Bubble Nebula around NGC 1313 X-2 and Evidence for Additional Photoionization
Feng, Hua; Bian, Fuyan; Zhou, Changxing +1 more
The bubble nebula surrounding NGC 1313 X-2 is believed to be powered by high velocity winds from the central ultraluminous X-ray source (ULX) as a result of supercritical accretion. With the Multi-Unit Spectroscopic Explorer (MUSE) observation of the nebula, we find enhanced [O III] emission at locations spatially coincident with clusters of stars…
Variations of the Plasma Environment Revealed by the Evolution of the Supra-arcade Fan in the 2017 September 10 Flare
Cai, Qiangwei; Ye, Jing; Feng, Hengqiang +1 more
Based on observations from the Interface Region Imaging Spectrograph and Hinode, we analyze the thermodynamic evolution of the supra-arcade fan (SAF) in the 2017 September 10 flare. The SAF presents discontinuous characters during the rising process, indicating a nonuniform process of magnetic reconnection in the solar eruption. The intensity peak…
Accurate Modeling of Lyα Profiles and Their Impact on Photolysis of Terrestrial Planet Atmospheres
Loyd, R. O. Parke; Peacock, Sarah; Schwieterman, Edward W. +4 more
Accurately measuring and modeling the Lyα (Lyα; λ1215.67 Å) emission line from low-mass stars is vital for our ability to build predictive high energy stellar spectra, yet interstellar medium (ISM) absorption of this line typically prevents model-measurement comparisons. Lyα also controls the photodissociation of important molecules, like water an…
A Near-infrared Look at AGN Feedback in Bulgeless Galaxies
Bohn, Thomas; Canalizo, Gabriela; Satyapal, Shobita +1 more
While it is generally believed that supermassive black holes (SMBHs) lie in most galaxies with bulges, few SMBHs have been confirmed in bulgeless galaxies. Identifying such a population could provide important insights to the BH seed population and secular BH growth. To this end, we obtained near-infrared (NIR) spectroscopic observations of a samp…
Changes in the Na D1 Absorption Components of η Carinae Provide Clues on the Location of the Dissipating Central Occulter
Moffat, Anthony F. J.; Hillier, D. John; Gull, Theodore R. +9 more
The Na D absorption doublet in the spectrum of η Carinae is complex, with multiple absorption features associated with the Great Eruption (1840s), the Lesser Eruption (1890s), and the interstellar clouds. The velocity profile is further complicated by the P Cygni profile originating in the system's stellar winds and blending with the He I λ5876 pr…
Identifying the 3FHL Catalog. VI. Swift Observations of 3FHL Unassociated Objects with Source Classification via Machine Learning
Ajello, M.; Marchesi, S.; Torres-Albà, N. +5 more
The Third Catalog of Hard Fermi Large Area Telescope Sources (3FHL) reports the detection of 1556 objects at E > 10 GeV. However, 177 sources remain unassociated and 23 are associated with a ROSAT X-ray detection of unknown origin. Pointed X-ray observations were conducted on 30 of these unassociated and unknown sources with Swift-XRT. A bright…
The Global Structure of the Milky Way's Stellar Halo Based on the Orbits of Local Metal-poor Stars
Chiba, Masashi; Sato, Genta
We analyze the global structure of the Milky Way (MW)'s stellar halo, including its dominant subcomponent, Gaia-Sausage-Enceladus (GSE). The method for reconstructing the global distribution of this old stellar component is to employ the superposition of the orbits covering the large MW's space, where each of the orbit-weighting factors is assigne…
The Physical Properties of Massive Green Valley Galaxies as a Function of Environments at 0.5 < z < 2.5 in 3D-HST/Candels Fields
Fang, Guanwen; Lin, Zesen; Kong, Xu +3 more
To investigate the effects of environment in the quenching phase, we study the empirical relations for green valley (GV) galaxies between overdensity and other physical properties (i.e., effective radius r e , Sérsic indices n, and specific star formation rate (sSFR)). Based on five 3D-HST/CANDELS fields, we construct a large sample of …