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Initial state of the recombining plasma in supernova remnant W 28
Nobukawa, Masayoshi; Nobukawa, Kumiko K.; Yamauchi, Shigeo +2 more
We have investigated supernova remnant (SNR) W 28 using Suzaku archival data, and we report here the results of our spatially resolved analyses. We carried out spectral analyses using a recombining-plasma (RP) model with element-dependent initial ionization temperatures, obtaining ~0.5 keV for Ne, ~0.7 keV for Mg, ~1.0 keV for Si, ~1.2 keV for S, …
First Detection of Radio Emission Associated with a Classical Cepheid
Rupen, M. P.; Evans, N. R.; Matthews, L. D.
We report the detection of 15 GHz radio continuum emission associated with the classical Cepheid variable star δ Cephei (δ Cep) based on observations with the Karl G. Jansky Very Large Array. Our results constitute the first probable detection of radio continuum emission from a classical Cepheid. We observed the star at pulsation phase ϕ ≈ 0.43 (c…
Ba-enhanced Dwarf and Subgiant Stars in the LAMOST Galactic Surveys
Xiang, Maosheng; Ting, Yuan-Sen; Zhang, Meng +3 more
Ba-enhanced stars are interesting probes of stellar astrophysics and Galactic formation history. In this work, we investigate the chemistry and kinematics of a large sample of Ba-enhanced ([Ba/Fe]>1.0) dwarf and subgiant stars with 5000 < T eff < 6700 K from LAMOST. We find that both stellar internal evolution processes and ext…
The Search for Thermonuclear Transients from the Tidal Disruption of a White Dwarf by an Intermediate-mass Black Hole
Gezari, Suvi; Gomez, Sebastian
The close encounter of a white dwarf (WD) with a black hole (BH) could result in the tidal disruption of the WD. During this encounter, the WD can undergo a thermonuclear explosion due to its tidal compression, resulting in an optical transient similar to a Type Ia supernova, hereafter a Ia-TDE. Nevertheless, this will only be physically observabl…
The dual nature of the tidal tails of NGC 5904 (M5)
Piatti, Andrés E.
The tangential velocity dispersion of stars belonging to the Milky Way globular cluster's tidal tails has recently been found from N-body simulations to be a parameter that distinguishes between cored and cuspy profiles of low-mass dwarf galaxy dark matter subhaloes where that globular cluster formed, and the in situ formation scenario. In this co…
The High Energy X-ray Probe (HEX-P): supernova remnants, pulsar wind nebulae, and nuclear astrophysics
Woo, Jooyun; An, Hongjun; Mori, Kaya +29 more
HEX-P is a probe-class mission concept that will combine high spatial resolution X-ray imaging (<10″ full width at half maximum) and broad spectral coverage (0.2–80 keV) with an effective area far superior to current facilities (including XMM-Newton and NuSTAR) to enable revolutionary new insights into a variety of important astrophysical probl…
DiskMINT: A Tool to Estimate Disk Masses with CO Isotopologues
Pascucci, Ilaria; Gorti, Uma; Ruaud, Maxime +1 more
CO is one of the most abundant molecules in protoplanetary disks, and optically thin emission from its isotopologues has been detected in many of them. However, several past works have argued that reproducing the relatively low emission of CO isotopologues requires a very low disk mass or significant CO depletion. Here, we present a Python code, D…
Magnetosphere-Ionosphere Drivers of Transient-Large-Amplitude Geomagnetic Disturbances: Statistical Analysis and Event Study
Nishimura, Yukitoshi; Moldwin, Mark B.; Weygand, James M. +2 more
We present a comprehensive statistical analysis of high-frequency transient-large-amplitude (TLA) magnetic perturbation events that occurred at 12 high-latitude ground magnetometer stations throughout Solar Cycle 24 from 2009 to 2019. TLA signatures are defined as one or more second-timescale dB/dt interval with magnitude ≥6 nT/s within an hour ev…
Fabry-Pérot etalons in solar astronomy. A review
del Toro Iniesta, J. C.; Orozco Suárez, D.; Bailén, F. J.
During the last decades, the use of Fabry-Pérot etalons as filtergraphs has become frequent in solar instruments. The main reason is that they stand out for offering quasi-monochromatic, two-dimensional fields of view much higher than those provided by conventional slit-based spectrographs in a given time interval. Unfortunately, they also present…
Dissecting Earth's Magnetosphere: 3D Energy Transport in a Simulation of a Real Storm Event
Toth, G.; Pulkkinen, T. I.; Brenner, A. +1 more
We present new analysis methods of 3D MHD output data from the Space Weather Modeling Framework during a simulated storm event. Earth's magnetosphere is identified in the simulation domain and divided based on magnetic topology and the bounding magnetopause definition. Volume energy contents and surface energy fluxes are analyzed for each subregio…