Search Publications
Differential Rotation of the Halo Traced by K-giant Stars
Tian, Hao; Xu, Yan; Yang, Chengqun +4 more
We use K-giant stars selected from the LAMOST DR5 to study the variation of the rotational velocity of the Galactic halo at different space positions. Modeling the rotational velocity distribution with both the halo and disk components, we find that the rotational velocity of the halo population decreases almost linearly with increasing vertical d…
The GBT Diffuse Ionized Gas Survey: Tracing the Diffuse Ionized Gas around the Giant Hii Region W43
Liu, Bin; Anderson, L. D.; Bania, T. M. +4 more
The Green Bank Telescope Diffuse Ionized Gas Survey (GDIGS) is a fully sampled radio recombination line (RRL) survey of the inner Galaxy at C-band (4-8 GHz). We average together ∼15 Hnα RRLs within the receiver bandpass to improve the spectral signal-to-noise ratio. The average beam size for the RRL observations at these frequencies is ∼2'. We gri…
White-light Emission and Chromospheric Response by an X1.8-class Flare on 2012 October 23
Watanabe, Kyoko; Imada, Shinsuke
On 2012 October 23, a strong white-light emission, associated with an X1.8-class flare, was observed by the Solar Optical Telescope on board the Hinode satellite. White-light kernels were clearly observed along the Ca II H ribbons. RHESSI also observed hard X-ray emissions that were almost located on the white-light kernels. The total energy of th…
MOSEL Survey: Tracking the Growth of Massive Galaxies at 2 < z < 4 Using Kinematics and the IllustrisTNG Simulation
Papovich, Casey; Kewley, Lisa J.; Harshan, Anishya +13 more
We use K-band spectroscopic data from the Multi-Object Spectroscopic Emission Line survey to analyze the kinematic properties of galaxies at z > 3. Our sample consists of 34 galaxies at 3.0 < zspec < 3.8 between 9.0 < $\mathrm{log}({M}_{* }/{M}_{\odot })$ < 11.0. We find that galaxies with $\mathrm{log}({M}_{* }/{M}_{\odo…
Intercycle and Intracycle Variation of Halo CME Rate Obtained from SOHO/LASCO Observations
Gopalswamy, Nat; Akiyama, Sachiko; Yashiro, Seiji +3 more
We report on the properties of halo coronal mass ejections (HCMEs) in solar cycles 23 and 24. We compare the HCME properties between the corresponding phases (rise, maximum, and declining) in cycles 23 and 24 and compare those between the whole cycles. Despite the significant decline in the sunspot number (SSN) in cycle 24, which dropped by 46% wi…
Hα Distances to the Leading Arm of the Magellanic Stream
Antwi-Danso, Jacqueline; Barger, Kathleen A.; Haffner, L. Matthew
The Leading Arm (LA) is a tidal feature that is in front of the Magellanic Clouds (MCs) on their orbit through the Galaxy's halo. Many physical properties of the LA, such as its mass and size, are poorly constrained because it has few distance measurements. While Hα measurements have been used to estimate the distances to halo clouds, many studies…
A Catalog of Emission-line Galaxies from the Faint Infrared Grism Survey: Studying Environmental Influence on Star Formation
Finkelstein, Steven L.; Hathi, Nimish; Windhorst, Rogier +18 more
We present a catalog of 208 0.3 < z < 2.1 emission-line galaxies (ELGs) selected from 1D slitless spectroscopy obtained using Hubble’s WFC3 G102 grism, as part of the Faint Infrared Grism Survey. We identify ELG candidates by searching for significant peaks in all continuum-subtracted G102 spectra and, where possible, confirm candidates by i…
The Elusive Distance Gradient in the Ultrafaint Dwarf Galaxy Hercules: A Combined Hubble Space Telescope and Gaia View
Strader, Jay; Seth, Anil C.; Sand, David J. +6 more
The ultrafaint dwarf galaxy Hercules has an extremely elongated morphology with both photometric overdensities and kinematic members at large radii, suggesting that it may be tidally disrupting due to a previous close encounter with the Milky Way. To explain its observational peculiarities, we present a deep Hubble Space Telescope (HST) imaging st…
Gas Kinematics of the Massive Protocluster G286.21+0.17 Revealed by ALMA
Tan, Jonathan C.; Lim, Wanggi; Andersen, Morten +2 more
We study the gas kinematics and dynamics of the massive protocluster G286.21+0.17 with the Atacama Large Millimeter/submillimeter Array using spectral lines of C18O(2-1), ${{\rm{N}}}_{2}{{\rm{D}}}^{+}$ (3-2), ${\mathrm{DCO}}^{+}$ (3-2), and $\mathrm{DCN}$ (3-2). On the parsec clump scale, C18O emission appears highly filament…
Intrusion of Magnetic Peninsula toward the Neighboring Opposite-polarity Region That Triggers the Largest Solar Flare in Solar Cycle 24
Inoue, Satoshi; Bamba, Yumi; Imada, Shinsuke
The largest X9.3 solar flare in solar cycle 24 and the preceding X2.2 flare occurred on 2017 September 6, in the solar active region NOAA 12673. This study aims to understand the onset mechanism of these flares via analysis of multiple observational data sets from the Hinode and Solar Dynamics Observatory and results from a nonlinear force-free fi…