Search Publications
Electron Acceleration in Middle-age Shell-type γ-Ray Supernova Remnants
Zhang, Xiao; Liu, Siming
Over the past decade, γ-ray observations of supernova remnants (SNRs) and accurate cosmic-ray (CR) spectral measurements have significantly advanced our understanding of particle acceleration in SNRs. In combination with multiwavelength observations of a large sample of SNRs, it has been proposed that the highest energy particles are mostly accele…
Asymmetric Mean Metallicity Distribution of the Milky Way’s Disk
An, Deokkeun
I present the mean metallicity distribution of stars in the Milky Way based on photometry from the Sloan Digital Sky Survey. I utilize an empirically calibrated set of stellar isochrones developed in previous work to estimate the metallicities of individual stars to a precision of 0.2 dex for reasonably bright stars across the survey area. I also …
Formation of Transition Alumina Dust around Asymptotic Giant Branch Stars: Condensation Experiments using Induction Thermal Plasma Systems
Tsuchiyama, Akira; Takigawa, Aki; Kim, Tae-Hee +5 more
Mid-infrared spectroscopic observations of oxygen-rich asymptotic giant branch (AGB) stars show the common presence of dust species that have a broad feature at ∼11-12 µm. Chemically synthesized amorphous alumina (Al2O3) is widely accepted as the source of this emission, although it is not obvious that amorphous alumina…
The Mass Dependence of Structure, Star Formation Rate, and Mass Assembly Mode at 0.5 < z < 2.5
Fang, Guanwen; Kong, Xu; Gu, Yizhou +5 more
To investigate the mass dependence of structural transformation and star formation quenching, we construct three galaxy samples using massive (M * > 1010 M ⊙) red, green, and blue galaxy populations at 0.5 < z < 2.5 in five 3D-HST/CANDELS fields. The structural parameters, including effective radius (r
Evolution of the Extended X-Ray Emission from the PSR B1259-63/LS 2883 Binary in the 2014-2017 Binary Cycle
Kargaltsev, Oleg; Hare, Jeremy; Pavlov, George +1 more
We have performed a series of Chandra X-ray Observatory observations of the gamma-ray binary LS 2883, which is composed of a young pulsar (PSR B1259-63) orbiting a massive Be star with a period of 1236.7 days. The system was observed in five epochs, spanning a range from 352 to 1175 days after the periastron passage on 2014 May 4. The observations…
Does High-density or Mass Help Star Clusters Produce X-Ray Binaries in Star-forming Galaxies?
Chandar, R.; Johns Mulia, P.; Rangelov, B.
It is now widely accepted that many X-ray binaries (XRBs) form in compact star clusters. Therefore, it follows that there may be a link between the properties of star clusters and the production of XRBs. We study the masses and densities of compact clusters with different ages found in the merging Antennae galaxies and in the dwarf starburst NGC 4…
Atmospheres and UV Environments of Earth-like Planets throughout Post-main-sequence Evolution
Kaltenegger, Lisa; Kozakis, Thea
During the post-main-sequence (post-MS) phase of stellar evolution, the orbital distance of the habitable zone (HZ), which allows for liquid surface water on terrestrial planets, moves out past the system’s original frost line, providing an opportunity for outer planetary system surface habitability. We use a 1D coupled climate/photochemistry code…
Multiwavelength Investigation of Pulsar Wind Nebula DA 495 with HAWC, VERITAS, and NuSTAR
Zhang, H.; Li, H.; Gotthelf, E. V. +10 more
Pulsar wind nebula DA 495 (G65.7+1.2) was detected in TeV gamma-rays by the High Altitude Water Cerenkov Observatory in 2017 (2HWC J1953+294). Follow-up observations by the Very Energetic Radiation Imaging Telescope Array System confirmed the association between 2HWC J1953+294 and DA 495 and found the TeV emission to be spatially coincident with t…
Nonthermal Emission from the Interaction of Magnetized Exoplanets with the Wind of Their Host Star
Loeb, Abraham; Wang, Xiawei
We study the nonthermal emission from the interaction between magnetized Jupiter-like exoplanets and the wind from their host star. The supersonic motion of planets through the wind forms a bow shock that accelerates electrons that produce nonthermal radiation across a broad wavelength range. We discuss three wind mass-loss rates: {\dot{M}}{{…
Cross-correlation of CMB Polarization Lensing with High-z Submillimeter Herschel-ATLAS Galaxies
Baccigalupi, C.; Borrill, J.; Stompor, R. +46 more
We report a 4.8σ measurement of the cross-correlation signal between the cosmic microwave background (CMB) lensing convergence reconstructed from measurements of the CMB polarization made by the POLARBEAR experiment and the infrared-selected galaxies of the Herschel-ATLAS survey. This is the first measurement of its kind. We infer a best-fit galax…