Search Publications
The Origin of the 300 km s-1 Stream near Segue 1
Bovy, Jo; Beers, Timothy C.; Placco, Vinicius M. +13 more
We present a search for new members of the 300 km s-1 stream (300S) near the dwarf galaxy Segue 1 using wide-field survey data. We identify 11 previously unknown bright stream members in the APOGEE-2 and SEGUE-1 and 2 spectroscopic surveys. Based on the spatial distribution of the high-velocity stars, we confirm for the first time that …
A Study of Magnetic Field Characteristics of the Flaring Active Region Based on Nonlinear Force-free Field Extrapolation
Kusano, Kanya; Inoue, Satoshi; Bamba, Yumi +1 more
Coronal magnetic fields are responsible for the onset of solar flares and solar eruptions. However, the type of magnetic field parameters that can be used to measure the critical condition for a solar eruption is still unclear. As an effort to understand the possible condition for a solar flare, we have examined the nondimensional parameter κ intr…
Identification of the Infrared Counterpart of SGR 1935+2154 with the Hubble Space Telescope
Kouveliotou, Chryssa; Levan, Andrew; Fruchter, Andrew
We present deep Hubble Space Telescope observations of a new magnetar source, the soft gamma-repeater SGR 1935+2154, discovered by Swift. We obtained three epochs of observations: while the source was active in 2015 March, during a quiescent period in 2015 August, and during a further active phase in 2016 May. Close to the center of the X-ray erro…
The Orbit of the New Milky Way Globular Cluster FSR1716 = VVV-GC05
Hanke, Michael; Minniti, Dante; Gran, Felipe +10 more
We use deep, multi-epoch near-IR images of the VISTA Variables in the Vía Láctea (VVV) Survey to measure proper motions (PMs) of stars in the Milky Way globular cluster (GC) FSR1716 = VVV-GC05. The color-magnitude diagram of this object, made by using PM-selected members, shows an extended horizontal branch, nine confirmed RR Lyrae (RRL) members i…
Magnetic Loops above a Small Flux-emerging Region Observed by IRIS, Hinode, and SDO
Huang, Zhenghua
I report on observations of a set of magnetic loops above a region with late-phase flux emergence taken by IRIS, Hinode, and SDO. The loop system consists of many transition-region loop threads that are 5″-12″ in length and ∼0.″5 in width and coronal loops with similar length and ∼2″ width. Although the loop system consists of threads with differe…
An Empirical Correlation of T max-M WD of Dwarf Novae and the Average White Dwarf Mass in Cataclysmic Variables in the Galactic Bulge
Li, Xiang-Dong; Bao, Tong; Xu, Xiao-jie +4 more
The mean white dwarf (WD) mass in the Galactic bulge cataclysmic variables (CVs) was measured by applying the shock temperature-WD mass correlation of magnetic cataclysmic variables (mCVs) to the Galactic bulge X-ray emission (GBXE) spectra. However, the resulting mean WD mass is lower than that of the local CVs. This discrepancy could be explaine…
Dissecting the X-Ray Emission in the Young Planetary Nebula NGC 7027
Kastner, Joel H.; Montez, Rodolfo, Jr.
We present an analysis of a second observation of the young planetary nebula (PN) NGC 7027 by the Chandra X-ray Observatory. This latest 59.2 ks exposure with ACIS-S was acquired approximately 14 years after the initial 18.2 ks ACIS-S observation, and the improved photon statistics allow us to perform a detailed spatial and spectral analysis of th…
Confirmation of a New Metal-poor Globular Cluster in the Galactic Bulge
Smith, Leigh C.; Minniti, Dante; Garofalo, Alessia +14 more
We use deep near-IR photometry of the VISTA Variables in the Vía Láctea (VVV) Survey and deep DECam Plane Survey (DECaPS) optical photometry to confirm the physical reality of the candidate globular cluster (GC) Minni 22, which is located in the Galactic bulge. This object, which was detected as a high density region in our maps of bulge red giant…
Direction-finding Analysis of the 2012 July 6 Type II Solar Radio Burst at Low Frequencies
Gopalswamy, Nat; Akiyama, Sachiko; Mäkelä, Pertti
The 2012 July 6 X1.1 flare at S13W59 and a halo coronal mass ejection (CME) with a space speed of ∼1900 km s-1 were associated with type III and type II radio bursts. The metric-to-decametric type II radio burst extended down to ∼5 MHz. Simultaneously, a slowly drifting feature with a harmonic structure was observed by Wind and Solar Te…
The Lyα Reference Sample. VIII. Characterizing Lyα Scattering in Nearby Galaxies
Cannon, John M.; Hayes, Matthew; Östlin, Göran +13 more
We examine the dust geometry and Lyα scattering in the galaxies of the Lyman Alpha Reference Sample (LARS), a set of 14 nearby (0.02< z< 0.2) Lyα-emitting and starbursting systems with Hubble Space Telescope Lyα, Hα, and Hβ imaging. We find that the global dust properties determined by line ratios are consistent with other studies, with some…