Search Publications
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 …
A Massive AGB Donor in Scutum X-1: Identification of the First Mira Variable in an X-Ray Binary
Soria, Roberto; Conroy, Charlie; Chakrabarty, Deepto +9 more
The symbiotic X-ray binary Sct X-1 was suggested to be the first known neutron star accreting from a red supergiant companion. Although known for nearly 50 yr, detailed characterization of the donor remains lacking, particularly due to the extremely high reddening toward the source (A V ≳ 25 mag). Here, we present (i) improved localiz…
ALMA Observations of CO Emission from Luminous Lyman-break Galaxies at z = 6.0293-6.2037
Ono, Yoshiaki; Ouchi, Masami; Fujimoto, Seiji +14 more
We present our new Atacama Large Millimeter/submillimeter Array (ALMA) observations targeting CO(6-5) emission from three luminous Lyman-break galaxies (LBGs) at z spec = 6.0293-6.2037 found in the Subaru/Hyper Suprime-Cam survey, whose [O III] 88 µm and [C II] 158 µm emissions have been detected with ALMA. We find a margina…
Explanation of Heliospheric Energetic Neutral Atom Fluxes Observed by the Interstellar Boundary Explorer
McComas, D. J.; Rankin, J. S.; Dayeh, M. A. +3 more
Interstellar neutral atoms propagating into the heliosphere experience charge exchange with the supersonic solar wind (SW) plasma, generating ions that are picked up by the SW. These pickup ions (PUIs) constitute ~25% of the proton number density by the time they reach the heliospheric termination shock (HTS). Preferential acceleration of PUIs at …
Variations of the Internal Asymmetries of Sunspot Groups during Their Decay
Muraközy, Judit
The aim of the present study is to show the varying asymmetries during the decay of sunspot groups. The source of input data is the SOHO/MDI-Debrecen Database sunspot catalog that contains the magnetic polarity data for time interval 1996-2010. Several types of asymmetries were examined on the selected sample of 142 sunspot groups. The leading-fol…
No Evolution in the Half-mass Radius of Milky Way-type Galaxies over the Last 10 Gyr
Tacchella, Sandro; Park, Minjung; Naidu, Rohan P. +3 more
The Milky Way (MW) galaxy is in focus, thanks to new observational data. Here we shed new light on the MW's past by studying the structural evolution of MW progenitors, which we identify from extragalactic surveys. Specifically, we constrain the stellar-mass growth history (SMGH) of the MW with two methods: (i) direct measurement of the MW's star …
Ages of Main-sequence Turnoff Stars from the GALAH Survey
Wu, Yaqian; Chen, Yuqin; Bi, Shaolan +6 more
Main-sequence turnoff (MSTO) stars are good tracers of Galactic populations since their ages can be reliably estimated from atmospheric parameters. Based on the GALAH survey, we use the Yale rotation evolution code to determine the ages of 2926 MSTO stars with a mean age uncertainty of ~10% considering the variation of C and O abundances. The ages…