7 citations · 16 across the 15 of their papers we have counts for
17 papers
A Multiwavelength View of Oph II: Disentangling the Variability of the Multi-Star Component C
Sean J. Gunderson, Walter W. Golay, Jackson Codd +8
We present a multiwavelength analysis of the star Oph C, covering X-ray, optical, near-infrared, and radio observations to test for the presence of interferometrically-detected…
X-ray grating spectroscopy as a mission enhancement
Hans Moritz Guenther, Ehud Behar, Joel N. Bregman +27
We propose to add instruments to any potential future X-ray mission with focussing optics that is considered in NASA's ASTRA framework. Such an instrument is a necessity to study A…
A new NASA Pioneer: the Globe Orbiting Soft X-ray Polarimeter (GOSoX)
Herman L Marshall, Sarah N T Heine, Alan Garner +16
The Globe Orbiting Soft X-ray Polarimeter (GOSoX) is a spectropolarimeter for the soft X-ray band. GOSoX is based on the Rocket Experiment Demonstration of a Soft X-ray Polarimeter…
Star formation, stellar evolution, and planets in high-resolution X-ray imaging
Hans Moritz Günther, Scott J. Wolk, Sean J. Gunderson +3
Stars set the conditions for planet formation, planet evolution, and habitability -- all major topics in astronomy today. Stars are also important in their own right as the most vi…
Science of High Resolution X-ray Imaging
H. L. Marshall, K. Weaver, M. Schattenburg +34
This report summarizes potential studies of the Hi-ReX Science Analysis Group for an Ultra-High Angular Resolution X-ray Observatory. Many potential science cases are presented, sp…
Orbital motion detected in gamma Cas Fe K emission lines
Yael Naze, Masahiro Tsujimoto, Gregor Rauw +1
A subset of Be stars, typified by the naked-eye star gamma Cas, exhibits unusually bright and hard X-ray emission, the origin of which has remained debated for five decades. We per…
The Advanced X-ray Imaging Satellite (AXIS) Community Science Book
Michael Koss, Nafisa Aftab, Steven W. Allen +395
The AXIS Community Science Book represents the collective effort of 592 scientists worldwide to define the transformative science enabled by the Advanced X-ray Imaging Satellite (A…
Chandra/HETG and NuSTAR Observations of V750 Ara, a Cas-type Star
David P. Huenemoerder, Sean J. Gunderson, Richard Ignace +6
We present 197 ks HETG and 95 ks NuSTAR spectra of the Cas-type object V750 Ara. The high-resolution X-ray spectra show that the target is similar to other objects of this cla…
X-ray Polarimetry of Accreting White Dwarfs: A Case Study of EX Hydrae
Sean J. Gunderson, Swati Ravi, Herman L. Marshall +5
We present the first first X-ray polarization measurements of a white dwarf, the intermediate polar EX Hya. We measured significant polarization only in the 2 -- 3 keV energy band…
A Multiwavelength View of Oph I: Resolving the X-ray Source Between A and B
Sean J. Gunderson, Jackson Codd, Walter W. Golay +12
We present a multiwavelength analysis of the central stellar pair of Oph, components A and B. Using recent high-resolution \textit{Chandra X-ray Observatory} observations, we d…
Methods to Test the Source of the Extreme Gas Motions in WS 35
Sean J. Gunderson, Richard Ignace, Walter W. Golay
We present theoretical arguments toward the plausibility of a stellar wind to explain the 16000 km s line broadening in the optical spectra of WS 35, the central star in the…
A Time-Dependent Spectral Analysis of Cassiopeiae
Sean J. Gunderson, David P. Huenemoerder, José M. Torrejón +7
We investigated the temporal and spectral features of Cassiopeiae's X-ray emission within the context of the white dwarf accretion hypothesis. We find that the variabilities pr…
Unfolding X-ray Spectral Data: Conditions and Applications
Sean J. Gunderson, David P. Huenemoerder
We present conditions for which X-ray spectra can be ``unfolded'' to present accurate representation of the true source spectra. The method we use to unfold the data is implemented…
Chandra HETG X-ray Spectra and Variability of Aqr, a Cas-type Be star
David P. Huenemoerder, Pragati Pradhan, Claude R. Canizares +7
High-resolution X-ray spectra of Aqr, a Cas-type star, obtained with the Chandra/HETG grating spectrometer, revealed emission lines of H-like ions of Mg, Si, S, and Fe, a…
Deriving X-ray Line Profiles for Massive-Star Winds from Momentum-Conserving Dynamical Working Surface Solutions
Sean J. Gunderson, Kenneth G. Gayley
We present a general procedure for deriving a line profile model for massive star X-ray spectra that captures the dynamics of the wind more directly. The basis of the model is the…
Observed epochal variations in X-ray lines from the O Supergiant Puppis do not require substantial changes in the wind mass flux
Sean J. Gunderson, Kenneth G. Gayley, David P. Huenemoerder +2
We fit the high resolution \textit{Chandra} X-ray spectra of the O supergiant Puppis using the variable boundary condition (VBC) line model to test the stability of its mass-lo…
Testing the Reliability of X-rays as a Tool for Constraining Mass-loss Rates of Hot Stars
Sean J. Gunderson, Kenneth G. Gayley, Pragati Pradhan +2
We fit a new line shape model to \textit{Chandra} X-ray spectra of the O supergiant Puppis to test the robustness of mass-loss rates derived from X-ray wind line profiles again…