Search Publications
Electron Densities in the Solar Corona Measured Simultaneously in the Extreme Ultraviolet and Infrared
Del Zanna, Giulio; Dudík, Jaroslav; Dzifčáková, Elena +5 more
Accurate measurements of electron density are critical for determination of the plasma properties in the solar corona. We compare the electron densities diagnosed from Fe XIII lines observed by the Extreme-Ultraviolet Imaging Spectrometer (EIS) onboard the Hinode mission with the near-infrared (NIR) measurements provided by the ground-based Corona…
The Center of Expansion and Age of the Oxygen-rich Supernova Remnant 1E 0102.2-7219
Drout, Maria R.; Blair, William P.; Margutti, Raffaella +8 more
We present new proper-motion measurements of optically emitting oxygen-rich knots of supernova remnant 1E 0102.2-7219 (E0102), which are used to estimate the remnant's center of expansion and age. Four epochs of high-resolution Hubble Space Telescope images spanning 19 yr were retrieved and analyzed. We found a robust center of expansion of α = 1<…
Analysis of the Unconcentrated Background of the EPIC pn Camera on Board XMM-Newton
Esposito, Paolo; Tiengo, Andrea; De Luca, Andrea +8 more
Our understanding of the background of the EPIC/pn camera on board XMM-Newton is incomplete. This affects the study of extended sources and can influence the predictions of the expected background of future X-ray missions, such as the Advanced Telescope for High Energy Astrophysics (ATHENA). Here we provide new results based on the analysis of the…
Acceleration of Ring Current Protons Driven by Magnetosonic Waves: Comparisons of Test Particle Simulations with Quasilinear Calculations
Fu, Song; Ge, Yasong
Wave-particle interactions play important roles in local acceleration and pitch angle scattering loss of charged particle dynamics in astrophysics and space physics, and energy transfer between plasma waves and particles is a key problem in plasma physics. Using full relativistic test particle simulations, we quantitatively evaluate the magnetoson…
Star Formation Histories from Spectral Energy Distributions and Color-magnitude Diagrams Agree: Evidence for Synchronized Star Formation in Local Volume Dwarf Galaxies over the Past 3 Gyr
McQuinn, Kristen B. W.; Johnson, Benjamin D.; Gawiser, Eric +6 more
Star formation histories (SFHs) reveal physical processes that influence how galaxies form their stellar mass. We compare the SFHs of a sample of 36 nearby (D ⪅ 4 Mpc) dwarf galaxies from the ACS Nearby Galaxy Survey Treasury (ANGST), inferred from the color-magnitude diagrams (CMDs) of individually resolved stars in these galaxies, with those rec…
Blow-away in the Extreme Low-mass Starburst Galaxy Pox 186
Scarlata, Claudia; Jaskot, Anne; Skillman, Evan +1 more
Pox 186 is an exceptionally small dwarf starburst galaxy hosting a stellar mass of ∼105 M⊙. Undetected in H I (M < 106 M⊙) from deep 21 cm observations and with an [O III]/[O II] (5007/3727) ratio of 18.3 ± 0.11, Pox 186 is a promising candidate Lyman continuum emitter. It may be a possible analog of …
The Discovery of Two LISA Sources within 0.5 kpc
Kilic, Mukremin; Bédard, A.; Kosakowski, Alekzander +1 more
We report the discovery of the brightest detached binary white dwarfs with periods less than an hour, which provide two new gravitational-wave verification binaries for the Laser Interferometer Space Antenna (LISA). The first one, SMSS J033816.16-813929.9 (hereafter J0338), is a 30.6 minute orbital period, g = 17.2 mag detached double white dwarf …
The MAVERIC Survey: Variable Jet-accretion Coupling in Luminous Accreting Neutron Stars in Galactic Globular Clusters
Strader, Jay; Bahramian, Arash; Maccarone, Thomas J. +9 more
Accreting neutron stars in low-mass X-ray binaries show outflows-and sometimes jets-in the general manner of accreting black holes. However, the quantitative link between the accretion flow (traced by X-rays) and outflows and/or jets (traced by radio emission) is much less well understood for neutron stars than for black holes, other than the gene…
The 2175 Å Dust Feature in Star-forming Galaxies at 1.3 ≤ z ≤ 1.8: The Dependence on Stellar Mass and Specific Star Formation Rate
Kartaltepe, Jeyhan S.; Daddi, Emanuele; Kashino, Daichi +10 more
We present direct spectroscopic measurements of the broad 2175 Å absorption feature in 505 star-forming main-sequence galaxies at 1.3 ≤ z ≤ 1.8 using individual and stacked spectra from the zCOSMOS-deep survey. Significant 2175 Å excess absorption features of moderate strength are measured, especially in the composite spectra. The excess absorptio…
ALMA Super-resolution Imaging of T Tau: r = 12 au Gap in the Compact Dust Disk around T Tau N
Tamura, Motohide; Yamaguchi, Masayuki; Nomura, Hideko +5 more
Based on Atacama Large Millimeter/submillimeter Array (ALMA) observations, compact protoplanetary disks with dust radii of r ≲ 20-40 au were found to be dominant in nearby low-mass star formation regions. However, their substructures have not been investigated because of the limited spatial resolution achieved so far. We apply a newly developed su…