Search Publications
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…
Doppler shift oscillations of a sunspot detected by CYRA and IRIS
Li, D.; Su, J. T.; Cao, W. +4 more
Context. The carbon monoxide (CO) molecular line at around 46655 Å in solar infrared spectra is often used to investigate the dynamic behavior of the cold heart of the solar atmosphere, i.e., sunspot oscillation, especially at the sunspot umbra.
Aims: We investigated sunspot oscillation at Doppler velocities of the CO 7-6 R67 and 3-2 R14 line…
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…
Reconstruction of Extreme Geomagnetic Storms: Breaking the Data Paucity Curse
Merkin, V. G.; Sitnov, M. I.; Roelof, E. C. +5 more
Reconstruction of the magnetic field, electric current, and plasma pressure is provided using a new data mining (DM) method with weighted nearest neighbors (NN) for strong storms with the storm activity index Sym-H < -300 nT, the Bastille Day event (July 2000), and the 20 November 2003 superstorm. It is shown that the new method significantly r…
Physical conditions of five O VI absorption systems towards PG 1522+101
Savage, Blair D.; Wakker, Bart P.; Charlton, Jane +4 more
We present the analysis of five O VI absorbers identified across a redshift path of z ~ (0.6-1.3) towards the background quasar PG 1522+101 with information on five consecutive ionization stages of oxygen from O II to O VI. The combined HST and Keck spectra cover UV, redshifted extreme-UV, and optical transitions from a multitude of ions spanning …
NuSTAR observation of the supergiant fast X-ray transient IGR J11215-5952 during its 2017 outburst
Tiengo, A.; Sidoli, L.; Esposito, P. +4 more
We report on the results of a NuSTAR observation of the supergiant fast X-ray transient pulsar IGR J11215-5952 during the peak of its outburst in June 2017. IGR J11215-5952 is the only SFXT undergoing strictly periodic outbursts (every 165 days). NuSTAR caught several X-ray flares, spanning a dynamic range of 100, and detected X-ray pulsations at …
X-ray study of the merging galaxy cluster Abell 3411-3412 with XMM-Newton and Suzaku
Simionescu, A.; Kaastra, J. S.; Zhang, X. +3 more
Context. Previous Chandra observations of the
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…
Strengthening the bounds on the r-mode amplitude with X-ray observations of millisecond pulsars
Göğüş, Ersin; Güver, Tolga; Schwenzer, Kai +1 more
R-mode oscillations have been shown to have a significant potential to constrain the composition of fast spinning neutron stars. Due to their high rotation rates, millisecond pulsars (MSPs) provide a unique platform to constrain the properties of such oscillations, if their surface temperatures can be inferred. We present the results of our invest…