Search Publications
Informing the Cataclysmic Variable Sequence from Gaia Data: The Orbital-period-Color-Absolute-magnitude Relationship
Rix, Hans-Walter; Szkody, Paula; Bloom, Joshua S. +2 more
The orbital-period (P orb) gap in the population of cataclysmic variables (CVs) informs the theoretical narrative of CV evolution, yet a complete understanding of the driving angular momentum loss mechanisms above and below this gap remains elusive. Here we identify, for standard CVs, a new, apparently monotonic relationship between qui…
The Origin of the Vanishing Soft X-Ray Excess in the Changing-look Active Galactic Nucleus Mrk 590
Dewangan, Gulab C.; Laha, Sibasish; Bhalerao, Varun +3 more
We have studied the nature and origin of the soft X-ray excess detected in the interesting changing-look active galactic nucleus (CLAGN) Mrk 590 using two decades of multiwavelength observations from XMM-Newton, Suzaku, Swift, and NuSTAR. In light of vanishing soft excess in this CLAGN, we test two models, "the warm Comptonization" and "the ionize…
Dependence of Energetic Storm Particle Heavy Ion Peak Intensities and Spectra on Source CME Longitude and Speed
Jian, L. K.; Desai, M. I.; Dayeh, M. A. +4 more
We examine variations in energetic storm particle (ESP) heavy ion peak intensities and energy spectra at CME-driven interplanetary shocks. We focus on their dependence with heliolongitude relative to the source region of their associated CMEs, and with CME speed, for events observed in Solar Cycle 24 at the STEREO-A, STEREO-B, and/or ACE spacecraf…
Supersonic Expansion of the Bipolar H II Region Sh2-106: A 3500 Year Old Explosion?
Ginsburg, Adam; Bally, John; Chia, Zen +4 more
Multi-epoch narrowband Hubble Space Telescope images of the bipolar H II region Sh2-106 reveal highly supersonic nebular proper motions that increase with projected distance from the massive young stellar object S106 IR, reaching over ~30 mas yr-1 (~150 km s-1 at D = 1.09 kpc) at a projected separation of ~1.'4 (0.44 pc) from…
Evolution of C IV Absorbers. II. Where Does C IV Live?
Kacprzak, Glenn G.; Churchill, Christopher W.; Nielsen, Nikole M. +4 more
We use the observed cumulative statistics of C IV absorbers and dark matter halos to infer the distribution of C IV-absorbing gas relative to galaxies at redshifts 0 ≤ z ≤ 5. We compare the cosmic incidence dN/dX of C IV absorber populations and galaxy halos, finding that massive L ≥ L ⋆ halos alone cannot account for all the observed W…
Herschel Optimized Tau and Temperature (HOTT) Maps: Uncertainty Analysis and Robust Parameter Extraction
Singh, Ayushi; Martin, Peter G.
We introduce the HOTT dust optical depth and temperature maps parameterizing thermal dust emission. Such maps have revolutionized studies of the distribution of matter in molecular clouds and processes relevant to star formation, including virial stability. HOTT maps for a suite of fields, including the Herschel Gould Belt Survey, are available on…
The North/South Asymmetry of the Galaxy: Possible Connection to the Vertical Phase-space Snail
Mao, Shude; Liu, Chao; Shen, Juntai +2 more
The galaxy is found to be in disequilibrium based on recent findings of the north/south (N/S) asymmetry and the phase mixing signatures, such as a phase spiral (snail) structure in the vertical phase space (z - V z ). We show that the N/S asymmetry in a tracer population of dwarfs may be quantitatively modeled with a simple phase snail…
The Solar Cycle Temporal Variation of the Solar Wind Charge Exchange X-Ray Lines
Kaaret, Philip; Bregman, Joel N.; Qu, Zhijie +2 more
Solar wind charge exchange (SWCX) is the primary contamination of soft X-ray emission lines from the Milky Way (MW) hot gas. We report a solar cycle (≈10 yr) temporal variation of observed O VII and O VIII emission line measurements in the XMM-Newton archive, which is tightly correlated with the solar cycle traced by the sunspot number (SSN). This…
Stumbling over Planetary Building Blocks: AU Microscopii as an Example of the Challenge of Retrieving Debris-disk Dust Properties
Weinberger, Alycia J.; Arnold, Jessica A.; Videen, Gorden +1 more
We explore whether assumptions about dust grain shape affect the resulting estimates of the composition and grain size distribution of the AU Microscopii (AU Mic) debris disk from scattered-light data collected by Lomax et al. The near edge-on orientation of the AU Mic debris disk makes it ideal for studying the effect of the scattering phase func…
The Baltimore Oriole's Nest: Cool Winds from the Inner and Outer Parts of a Star-forming Galaxy at z = 1.3
Barro, Guillermo; Weiner, Benjamin J.; Pacifici, Camilla +12 more
Strong galactic winds are ubiquitous at z ≳ 1. However, it is not well-known where inside galaxies these winds are launched from. We study the cool winds (~104 K) in two spatial regions of a massive galaxy at z = 1.3, which we nickname the "Baltimore Oriole's Nest." The galaxy has a stellar mass of 1010.3±0.3 M ⊙, …