A class of graphs ℱ ${\rm{ {\mathcal F} }}$ admits the Erdős–Pósa property if for any graph G $G$ , either has k $k$ vertex-disjoint “copies” in or there is a set S ⊆ V ( ) $S\subseteq V(G)$ f $f(k)$ vertices that intersects all copies . For ${\mathscr{G}}$ it natural to ask whether family obstructions property. In this paper, we prove interval graphs—namely, chordless cycles and asteroidal wit...

We have performed a comprehensive noble gas study, including the isotopes of krypton and xenon, on set micrometeorites (MMs) collected from surface snow at Dome C (DC) Antarctic plateau. He Ne are generally dominated by solar component, with lower 4He concentrations 4He/20Ne ratios in crystalline (Xtal) compared to fine-grained carbonaceous (FgC) MMs. Concentrations (surface-correlated) wind (S...

-The long-lived 1475m-143Nd chronometer has been used in conjunction with the short-lived 146Sm-142Nd and 53Mn-53Cr chronometers to constrain the time of formation for the eucrite Caldera. The combination of these three chronometers has produced results that are consistent with one another and converge on a precise, high resolution age of 4537 +__ 12 Ma (within 95% confidence limits). So far th...

We report Spitzer Space Telescope photometry between 3.6 µm and 24 µm and spectroscopy between 5 µm and 15 µm of GD 362, a white dwarf with an effective temperature near 10,000 K that displays a remarkably high concentration of metals in its photosphere and a thermal infrared excess. We approximately reproduce both the infrared continuum and the very strong 10 µm silicate emission feature with ...