Search Publications
A New Generation of Cool White Dwarf Atmosphere Models. III. WD J2356-209: Accretion of a Planetesimal with an Unusual Composition
Rich, R. M.; Koopmans, L. V. E.; Dufour, P. +3 more
WD J2356-209 is a cool metal-polluted white dwarf whose visible spectrum is dominated by a strong and broad sodium feature. Although it was discovered nearly two decades ago, no detailed and realistic analysis of this star had yet been realized. In the absence of atmosphere models taking into account the nonideal high-density effects arising at th…
Surviving companions of Type Ia supernovae: theory and observations
Ruiz-Lapuente, Pilar
We review the theoretical background and the observational searches made for surviving companions of Type Ia supernovae (SNe Ia). Theory comprises the characteristics of the stellar binary companions of the exploding white dwarfs at the time of the supernova outburst and the expected effects on them of the explosion, as well as their subsequent ev…
WASP-166b: a bloated super-Neptune transiting a V = 9 star
Bouchy, F.; Queloz, D.; Hellier, Coel +21 more
We report the discovery of WASP-166b, a super-Neptune planet with a mass of 0.1 MJup (1.9 MNep) and a bloated radius of 0.63 RJup. It transits a V = 9.36, F9V star in a 5.44-d orbit that is aligned with the stellar rotation axis (sky-projected obliquity angle λ = 3 ± 5 deg). Variations in the radial-velocity measur…
A Dramatic Decrease in Carbon Star Formation in M31
Chen, Y.; Dalcanton, J. J.; Girardi, L. +8 more
We analyze resolved stellar near-infrared photometry of 21 Hubble Space Telescope (HST) fields in M31 to constrain the impact of metallicity on the formation of carbon stars. Observations of nearby galaxies show that carbon stars are increasingly rare at higher metallicity. Models indicate that carbon star formation efficiency drops due to the dec…
Unbiased Differential Size Evolution and the Inside-out Growth of Galaxies in the Deep CANDELS GOODS Fields at 1 ≤ z ≤ 7
Conselice, C. J.; Duncan, K.; Bhatawdekar, R. +1 more
We present a size analysis of a sample of ∼49,000 galaxies from the Cosmic Assembly Near-infrared Deep Extragalactic Survey GOODS North and South fields, using redshift-independent relative surface-brightness metrics to determine an unbiased measure of the differential size evolution of galaxies at 1 ≤ z ≤ 7. We introduce a novel method of removin…
Electron Vorticity Indicative of the Electron Diffusion Region of Magnetic Reconnection
Russell, C. T.; Khotyaintsev, Y.; Hasegawa, H. +17 more
While vorticity defined as the curl of the velocity has been broadly used in fluid and plasma physics, this quantity has been underutilized in space physics due to low time resolution observations. We report Magnetospheric Multiscale (MMS) observations of enhanced electron vorticity in the vicinity of the electron diffusion region of magnetic reco…
NuSTAR Detection of X-Rays Concurrent with Gamma-Rays in the Nova V5855 Sgr
Sokoloski, J. L.; Chomiuk, Laura; Mukai, Koji +7 more
We report the first detection of hard (>10 keV) X-ray emission simultaneous with gamma-rays in a nova eruption. Observations of the nova V5855 Sgr carried out with the NuSTAR satellite on Day 12 of the eruption revealed faint, highly absorbed thermal X-rays. The extreme equivalent hydrogen column density toward the X-ray emitting region (∼3 × 1…
Smoking gun of the dynamical processing of solar-type field binary stars
Liu, Chao
I investigate the binarity properties of field stars using more than 50 000 main-sequence stars with stellar mass from 0.4 to 0.85 M⊙ observed by LAMOST and Gaia in the solar neighbourhood. By adopting a power-law shape for the mass-ratio distribution with a power index of γ, I conduct a hierarchical Bayesian model to derive the binary …
Exploring Plasma Heating in the Current Sheet Region in a Three-dimensional Coronal Mass Ejection Simulation
Reeves, Katharine K.; Mikić, Zoran; Török, Tibor +2 more
We simulate a coronal mass ejection using a three-dimensional magnetohydrodynamic code that includes coronal heating, thermal conduction, and radiative cooling in the energy equation. The magnetic flux distribution at 1 R s is produced by a localized subsurface dipole superimposed on a global dipole field, mimicking the presence of an…
HIDES spectroscopy of bright detached eclipsing binaries from the Kepler field - III. Spectral analysis, updated parameters and new systems
Kambe, E.; Pigulski, A.; Maehara, H. +5 more
We present the latest results of our spectroscopic observations and refined modelling of a sample of detached eclipsing binaries, selected from the Kepler Eclipsing Binary Catalog, that are also double-lined spectroscopic binaries (SB2s). New high-resolution spectra obtained with the HIgh-Dispersion Echelle Spectrograph (HIDES), attached to the 1.…