Search Publications
ALMA-resolved salt emission traces the chemical footprint and inner wind morphology of VY Canis Majoris
Smith, N.; Decin, L.; Richards, A. M. S. +6 more
Context. At the end of their lives, most stars lose a significant amount of mass through a stellar wind. The specific physical and chemical circumstances that lead to the onset of the stellar wind for cool luminous stars are not yet understood. Complex geometrical morphologies in the circumstellar envelopes prove that various dynamical and chemica…
Formation and X-ray emission from hot bubbles in planetary nebulae - II. Hot bubble X-ray emission
Toalá, J. A.; Arthur, S. J.
We present a study of the X-ray emission from numerical simulations of hot bubbles in planetary nebulae (PNe). High-resolution, two-dimensional, radiation-hydrodynamical simulations of the formation and evolution of hot bubbles in PNe, with and without thermal conduction, are used to calculate the X-ray emission and study its time-dependence and r…
The Milky Way's Hot Gas Kinematics: Signatures in Current and Future OVII Absorption Line Observations
Bregman, Joel N.; Miller, Matthew J.; Hodges-Kluck, Edmund J.
Detections of z ≈ 0 oxygen absorption and emission lines indicate the Milky Way hosts a hot (∼ {10}6 K), low-density plasma extending ≳ 50 {{kpc}} into the Mily Way’s halo. Current X-ray telescopes cannot resolve the line profiles, but the variation of their strengths on the sky constrains the radial gas distribution. Interpreting the O…
Deep HST/STIS Visible-light Imaging of Debris Systems around Solar Analog Hosts
Henning, Thomas; Stark, Christopher C.; Debes, John H. +11 more
We present new Hubble Space Telescope observations of three a priori known starlight-scattering circumstellar debris systems (CDSs) viewed at intermediate inclinations around nearby close-solar analog stars: HD 207129, HD 202628, and HD 202917. Each of these CDSs possesses ring-like components that are more massive analogs of our solar system's Ed…
Oxygen, neon, and iron X-ray absorption in the local interstellar medium
García, Javier A.; Kallman, Timothy R.; Gatuzz, Efraín +1 more
Aims: We present a detailed study of X-ray absorption in the local interstellar medium by analyzing the X-ray spectra of 24 galactic sources obtained with the Chandra High Energy Transmission Grating Spectrometer and the XMM-Newton Reflection Grating Spectrometer.
Methods: By modeling the continuum with a simple broken power-law and by i…
CLASH-VLT: Strangulation of cluster galaxies in MACS J0416.1-2403 as seen from their chemical enrichment
Grillo, C.; Balestra, I.; Rosati, P. +9 more
Aims: Environmental effects gain importance as large scale structures in the Universe develop with time and have become the dominant mechanism for quenching galaxies of intermediate and low stellar masses at lower redshifts. Therefore, clusters of galaxies at z< 0.5 are the sites where environmental effects are expected to be more pronounc…
Tracing the Lowest Propeller Line in Magellanic High-mass X-Ray Binaries
Laycock, Silas G. T.; Christodoulou, Dimitris M.; Yang, Jun +1 more
We have combined the published observations of high-mass X-ray binary (HMXB) pulsars in the Magellanic Clouds with a new processing of the complete archival data sets from the XMM-Newton and Chandra observatories in an attempt to trace the lowest propeller line below which accretion to polar caps is inhibited by the centrifugal force and the pulsa…
Transition Region and Chromospheric Signatures of Impulsive Heating Events. II. Modeling
Warren, Harry P.; Crump, Nicholas A.; Reep, Jeffrey W. +1 more
Results from the Solar Maximum Mission showed a close connection between the hard X-ray (HXR) and transition region (TR) emission in solar flares. Analogously, the modern combination of RHESSI and IRIS data can inform the details of heating processes in ways that were never before possible. We study a small event that was observed with RHESSI, IRI…
A Cold Flare with Delayed Heating
Fleishman, Gregory D.; Lysenko, Alexandra L.; Pal'shin, Valentin D. +3 more
Recently, a number of peculiar flares have been reported that demonstrate significant nonthermal particle signatures with low, if any, thermal emission, which implies a close association of the observed emission with the primary energy release/electron acceleration region. This paper presents a flare that appears “cold” at the impulsive phase, whi…
Water in star-forming regions with Herschel (WISH). VI. Constraints on UV and X-ray irradiation from a survey of hydrides in low- to high-mass young stellar objects
Liseau, R.; van Dishoeck, E. F.; Lis, D. C. +18 more
Context. Hydrides are simple compounds containing one or a few hydrogen atoms bonded to a heavier atom. They are fundamental precursor molecules in cosmic chemistry and many hydride ions have become observable in high quality for the first time thanks to the Herschel Space Observatory. Ionized hydrides such as CH+ and OH+ (an…