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200 papers

Metal-rich asteroids and iron meteorites are considered core remnants of differentiated planetesimals and or products of oxygen-depleted accretion. Investigating the origins of iron-rich planetesimals could provide key insights into planet…

Earth and Planetary Astrophysics · Physics 2025-11-12 Terry-Ann Suer , Edgar S. Steenstra , Simone Marchi , John A. Tarduno , Ilaria Pascucci

CONTEXT: Dense cores are thought to be isolated from the surrounding cloud. However, observations of streamers and subsonic material outside core boundaries challenges this idea. AIMS: In this study, we aim to probe the extended subsonic…

Astrophysics of Galaxies · Physics 2025-04-30 Spandan Choudhury , Jongsoo Kim , Paola Caselli , Chang Won Lee , Jaime E. Pineda

The $l\!=\!+1.\!\!^\circ3$ region in the Galactic center is characterized by multiple shell-like structures and their extremely broad velocity widths. We revisit the molecular superbubble hypothesis for this region, based on high resolution…

Chondrites, the building blocks of the terrestrial planets, have mass and atomic proportions of oxygen, iron, magnesium, and silicon totaling $\geq$90\% and variable Mg/Si ($\sim$25\%), Fe/Si (factor of $\geq$2), and Fe/O (factor of…

Earth and Planetary Astrophysics · Physics 2020-09-10 William F. McDonough , Takashi Yoshizaki

On basis of the first principle calculation we show that a crystalline structure of silicon, as a novel allotrope with nanotubular holes along two perpendicular directions, is stable. The calculations on geometrical and electronic…

Materials Science · Physics 2011-06-16 Chi-Pui Tang , Jie Cao , Shi-Jie Xiong

The Central Molecular Zone (CMZ; the central ~ 500 pc of the Milky Way) hosts molecular clouds in an extreme environment of strong shear, high gas pressure and density, and complex chemistry. G0.253+0.016, also known as `the Brick', is the…

Here we critically examine the geophysical and geochemical properties of the Moon in order to identify the extent to which dynamical scenarios satisfy these observations. New joint inversions of existing lunar geophysical data (mean mass,…

Earth and Planetary Astrophysics · Physics 2025-12-22 Paolo A. Sossi , Miki Nakajima , Amir Khan

Characterization of medium-range order in amorphous materials and its relation to short-range order is discussed. A new topological approach is presented here to extract a hierarchical structure of amorphous materials, which is robust…

Soft Condensed Matter · Physics 2015-02-27 Takenobu Nakamura , Yasuaki Hiraoka , Akihiko Hirata , Emerson G. Escolar , Yasumasa Nishiura

Based on the \textit{Gaia} DR3 RR Lyrae catalog, we use two methods to fit the density profiles with an improved broken power law, and find that there are two break radii coinciding with the two apocenter pile-ups of high-eccentricity…

Astrophysics of Galaxies · Physics 2023-08-09 Dashuang Ye , Cuihua Du , Jianrong Shi , Jun Ma

Nitrogen, the most abundant element in Earth's atmosphere, exists as a diatomic gas under standard temperature and pressure. In the two-dimensional (2D) limit, atomically thin nitrogen, termed nitrogene, has been theoretically predicted to…

With the Submillimeter Array, the brightest (sub)millimeter continuum source in the OMC-2/3 region, MMS 6, has been observed in the 850 um continuum emission with approximately 10 times better angular resolution than previous studies…

Astrophysics of Galaxies · Physics 2015-06-04 Satoko Takahashi , Kazuya Saigo , Paul T. P. Ho , Kengo Tomida

Direct imagery and long-slit, spatially resolved echellograms of the high excitation planetary nebula NGC 1501 allowed us to study in detail the expansion velocity field, the physical conditions (electron temperature, electron density,…

Astrophysics · Physics 2007-05-23 Franco Sabbadin , Stefano Benetti , Enrico Cappellaro , Massimo Turatto

An ellipsoid, the simplest non-spherical shape, has been extensively used as models for elongated building blocks for a wide spectrum of molecular, colloidal and granular systems. Yet the densest packing of congruent hard ellipsoids, which…

Statistical Mechanics · Physics 2017-03-29 Weiwei Jin , Yang Jiao , Lufeng Liu , Ye Yuan , Shuixiang Li

Terrestrial planets in the solar system, such as the Earth, are oxygen-rich, with silicates and iron being the most common minerals in their interiors. However, the true chemical diversity of rocky planets orbiting other stars is yet…

Earth and Planetary Astrophysics · Physics 2015-06-11 Nikku Madhusudhan , Kanani K. M. Lee , Olivier Mousis

The physical structure of hot molecular cores, where forming massive stars have heated up dense dust and gas, but have not yet ionized the molecules, poses a prominent challenge in the research of high-mass star formation and…

Astrophysics of Galaxies · Physics 2018-07-04 Rainer Rolffs , Peter Schilke , Qizhou Zhang , Luis Zapata

The molecular structures of amorphous silica and crystalline quartz are used to predict their intrinsic strength and fracture toughness together with the theoretical strength of silicon dioxide. At the atomic scale, the amorphous silica is…

Materials Science · Physics 2024-10-15 Xiaozhi Hu

We have observed the massive star forming region associated with the early B protostar G192.16-3.84 in NH3(1,1), 22.2 GHz water masers, 1.3 cm continuum emission, and at 850 microns. The dense gas associated with G192.16 is clumpy,…

Astrophysics · Physics 2009-11-10 D. S. Shepherd , T. Borders , M. Claussen , Y. Shirley , S. E. Kurtz

Following a number of conflicting studies of M87's mass profile, we undertake a dynamical analysis of multiple tracer populations to constrain its mass over a large radius range. We combine stellar kinematics in the central regions with the…

Astrophysics of Galaxies · Physics 2016-01-27 L. J. Oldham , M. W. Auger

Structural studies on the icosahedral quasicrystals in Zn-Mg-Sc, Cu-Ga-Mg-Sc, and Zn-Mg-Ti alloys as well as their corresponding 1/1 cubic approximants, have revealed that these quasicrystals belong to a new structural group similar to…

Materials Science · Physics 2009-11-10 Tsutomu Ishimasa , Yasushi Kaneko , Hiroshi Kaneko

Massive planetary cores embedded in protoplanetary discs are believed to accrete extended atmospheres, providing a pathway to forming gas giants and gas-rich super-Earths. The properties of these atmospheres strongly depend on the nature of…

Earth and Planetary Astrophysics · Physics 2019-07-17 William Béthune , Roman R. Rafikov