Results 81 to 90 of about 56,805 (216)

The Case for the Anthropocene Epoch Is Stronger Than the Case for the Holocene Epoch

Earth's Future, Volume 13, Issue 5, May 2025.
Abstract The recommendation that the Anthropocene be denoted as a geological epoch was recently rejected by the International Union of Geological Sciences. Here, we compare the scientific rationales presented for the Anthropocene, the Holocene and the six other epochs in the Cenozoic Era: the Pleistocene, the Pliocene, the Miocene, the Oligocene, the ...
Alasdair Skelton, Kevin J. Noone
wiley   +1 more source

Interpolating detailed simulations of kilonovae: Adaptive learning and parameter inference applications

Physical Review Research, 2022
Detailed radiative transfer simulations of kilonovae are difficult to apply directly to observations; they only sparsely cover simulation parameters, such as the mass, velocity, morphology, and composition of the ejecta.
M. Ristic, E. Champion, R. O'Shaughnessy, R. Wollaeger, O. Korobkin, E. A. Chase, C. L. Fryer, A. L. Hungerford, C. J. Fontes   +8 more
doaj   +1 more source

Conditions for jet break-out in NS mergers [PDF]

, 2019
We consider conditions for jet break-out through ejecta following mergers of neutron stars and provide simple relations for the break out conditions. We demonstrate that: (i) break-out requires that the isotropic-equivalent jet energy $E_j$ exceeds the ejecta energy $E_{ej}$ by $E_j \geq E_{ej}/ \beta_0$, where $ \beta_0 = V_{ej}/c$, $V_{ej}$ is the ...
arxiv   +1 more source

The ejecta of η Carinae [PDF]

Symposium - International Astronomical Union, 2003
Since New Year's Eve 1998, we have been studying η Carinae and the surrounding complex ejecta with the HST-stis instrument. Angular resolution of 0.1″ and spectral resolving power R = 5000-118000 have revealed a multitude of emission and absorption lines identified from many heavy elements.
Kris Davidson, η Carinae Hst-Stis Team, Theodore R. Gull, K. Ishibashi   +3 more
openaire   +2 more sources

The Link Between Subsurface Rheology and Ejecta Mobility: The Case of Small New Impacts on Mars

Journal of Geophysical Research: Planets, Volume 130, Issue 5, May 2025.
Abstract The dynamics of crater ejecta are sensitive to the material properties of the target, much like the crater size and morphology. We isolate and quantify the effect of target properties on the ejecta mobility (EM) ‐ the maximum radial extent of ejecta scaled by the crater radius.
A. J. Sokolowska, G. S. Collins, I. J. Daubar, M. Jutzi   +3 more
wiley   +1 more source

Chronology, Local Stratigraphy, and Foreign Ejecta Materials at the Chang'e‐6 Landing Site: Constraints on the Provenance of Samples Returned From the Moon's Farside

Geophysical Research Letters
China's Chang'e‐6 (CE‐6) mission has returned the first‐ever lunar farside samples from a mare plain on the southern Apollo basin floor. The crater statistics of the CE‐6 mare unit and the provenance of the samples are crucial in interpreting the CE‐6 ...
Luyuan Xu, Le Qiao, Minggang Xie, Yiran Wang, Meng‐Hua Zhu, Jianguo Yan   +5 more
doaj   +1 more source

JWST NIRSpec Observations of Supernova 1987A—From the Inner Ejecta to the Reverse Shock

The Astrophysical Journal Letters, 2023
We present initial results from JWST NIRSpec integral field unit observations of the nearby supernova SN 1987A. The observations provide the first spatially resolved spectroscopy of the ejecta and equatorial ring (ER) over the 1–5 μ m range. We construct
J. Larsson, C. Fransson, B. Sargent, O. C. Jones, M. J. Barlow, P. Bouchet, M. Meixner, J. A. D. L. Blommaert, A. Coulais, O. D. Fox, R. Gastaud, A. Glasse, N. Habel, A. S. Hirschauer, J. Hjorth, J. Jaspers, P. J. Kavanagh, O. Krause, R. M. Lau, L. Lenkić, O. Nayak, A. Rest, T. Temim, T. Tikkanen, R. Wesson, G. S. Wright   +25 more
doaj   +1 more source

The 3-D Structure of SN 1987A's inner Ejecta

, 2010
Twenty years after the explosion of SN 1987A, we are now able to observe the three-dimensional spatially resolved inner ejecta. Detailed mapping of newly synthesised material and its radioactive decay daughter products sheds light on the explosion ...
A. Jerkstrand, Ahmad, Arnett, B. Leibundgut, Blondin, Blondin, Buras, Burrows, C. Fransson, Chugai, Cohen, Cropper, Dessart, Fassia, Fitzpatrick, Fransson, Gröningsson, Gröningsson, Gröningsson, Hammer, J. Spyromilio, Jeffery, K. Kjær, Kifonidis, Kitaura, Kjær, Kozma, Kozma, Kozma, Krause, McCray, Meikle, Nisenson, Pun, Reed, Rousselot, Sonneborn, Staveley-Smith, Sugerman, Walborn, Wang, Wang, West, Wheeler, Wooden, Woosley, Woosley, Zanardo   +47 more
core   +1 more source

Reviewing: The outer ejecta of eta Carinae [PDF]

arXiv, 2004
The nebula around eta Carinae consists of two distinct parts: the Homunculus and the outer ejecta. The outer ejecta are mainly a collection of numerous filaments, shaped irregularly and distributed over an area of 1arcminx1arcmin. While the Homunculus is mainly a reflection nebula, the outer ejecta are an emission nebula.
arxiv  

Constraining the ejecta for the nonthermal emission from GW170817 [PDF]

, 2018
We consider a simple model for the nonthermal emission from GW170817, in which a quasi-spherical ejecta is released in the merger event, with the kinetic energy distributed over the momentum as $E(>\gamma\beta)\propto(\gamma\beta)^{-k}$. The ejecta drives a shock into the medium and gives rise to synchrotron radiation.
arxiv   +1 more source