The top 500 results for "pillars of creation" are:

The Pillars of Creation, one of the most recognized objects in the sky, are believed to be associated with the formation of young stars. However, so far, the formation and maintenance mechanism of the pillars are still not fully understood due to the complexity of the nonlinear radiation magnetohydrodynamics (RMHD). Here, assuming laboratory laser-driven conditions, we studied the self-consistent dynamics of pillar structures in magnetic fields by means of two-dimensional and three-dimensional (3D) RMHD simulations, and the results support our proposed experimental scheme. We find that only when the magnetic pressure and ablation pressure are comparable, the magnetic field can significantly alter the plasma hydrodynamics. For medium-magnetized cases (β_initial ≈ 3.5), the initial magnetic fields undergo compression and amplification. This amplification results in the magnetic pressure inside the pillar becoming large enough to support the sides of the pillar against radial collapse due to pressure from the surrounding hot plasma. This effect is particularly pronounced for the parallel component (B_y), which is consistent with observational results. In contrast, a strong perpendicular (B_x, B_z) magnetic field (β_initial < 1) almost retains its initial distribution and significantly suppresses the expansion of blown-off gas plasma, leading to the inability to form pillar-like structures. The 3D simulations suggest that the bending at the head of "Column I" in the Pillars of Creation may be due to nonparallel magnetic fields. After similarity scaling transformation, our results can be applied to explain the formation and maintenance mechanism of the pillars, and can also provide useful information for future experimental designs.

We present the first high-resolution, submillimeter-wavelength polarimetric observations of—and thus direct observations of the magnetic field morphology within—the dense gas of the Pillars of Creation in M16. These 850 μm observations, taken as part of the B-Fields in Star-forming Region Observations Survey (BISTRO) using the POL-2 polarimeter on the Submillimeter Common-User Bolometer Array 2 (SCUBA-2) camera on the James Clerk Maxwell Telescope (JCMT), show that the magnetic field runs along the length of the Pillars, perpendicular to and decoupled from the field in the surrounding photoionized cloud. Using the Chandrasekhar–Fermi method we estimate a plane-of-sky magnetic field strength of 170–320 μG in the Pillars, consistent with their having been formed through the compression of gas with initially weak magnetization. The observed magnetic field strength and morphology suggests that the magnetic field may be slowing the Pillars' evolution into cometary globules. We thus hypothesize that the evolution and lifetime of the Pillars may be strongly influenced by the strength of the coupling of their magnetic field to that of their parent photoionized cloud—i.e., that the Pillars' longevity results from magnetic support.

We investigate the physical structure and conditions of photodissociation regions (PDRs) and molecular gas within the Pillars of Creation in the Eagle Nebula using SOFIA FEEDBACK observations of the [C ii] 158 μm line. These observations are velocity resolved to 0.5 km s⁻¹ and are analyzed alongside a collection of complimentary data with similar spatial and spectral resolution: the [O i] 63 μm line, also observed with SOFIA, and rotational lines of CO, HCN, HCO⁺, CS, and N₂H⁺. Using the superb spectral resolution of SOFIA, APEX, CARMA, and BIMA, we reveal the relationships between the warm PDR and cool molecular gas layers in context of the Pillars' kinematic structure. We assemble a geometric picture of the Pillars and their surroundings informed by illumination patterns and kinematic relationships and derive physical conditions in the PDRs associated with the Pillars. We estimate an average molecular gas density ${n}_{{{\rm{H}}}_{2}}\sim 1.3\,\times \,{10}^{5}$ cm⁻³ and an average atomic gas density n_H ∼ 1.8 × 10⁴ cm⁻³ and infer that the ionized, atomic, and molecular phases are in pressure equilibrium if the atomic gas is magnetically supported. We find pillar masses of 103, 78, 103, and 18 M_⊙ for P1a, P1b, P2, and P3, respectively, and evaporation times of ∼1–2 Myr. The dense clumps at the tops of the pillars are currently supported by the magnetic field. Our analysis suggests that ambipolar diffusion is rapid and these clumps are likely to collapse within their photoevaporation timescales.

We developed a pillar-shaped microelectrode array (MEA) with varying heights for enhancing the spherical conformity of fully implantable epiretinal prosthesis comprising a 3D stacked retinal chip. The fabricated MEA is composed of 100 pillar electrodes with heights ranging from 60 to 80 µm. The Pt-coated Cu pillar electrode with a surface diameter of 70 µm and a height of 75 µm and the Pt planar electrode with a surface diameter of 70 µm have 24.6 and 125 kΩ impedances, respectively, at 1 kHz in vitro experiment. The pillar electrode shows lower impedance than the planar electrode because of a larger surface area. However, to avoid cross-talking between pillar electrodes, we developed a sidewall passivation process of the pillar electrode by using the surface tension of polyimide. The impedance of the isolated pillar electrode 116 kΩ at 1 kHz is similar to the impedance of the planar electrode, because they have similar electrode surface areas. The pillar-shaped MEA shows a better spherical conformity.

We present and analyze the first high-resolution X-ray images ever obtained of the Eagle Nebula star-forming region. On 2001 July 30 the Chandra X-Ray Observatory obtained a 78 ks image of the Eagle Nebula (M16) that includes the core of the young galactic cluster NGC 6611 and the dark columns of dust and cold molecular gas in M16 known as the "Pillars of Creation." We find a total of 1101 X-ray sources in the 17' × 17' ACIS-I field of view. Most of the X-ray sources are low-mass pre-main-sequence or high-mass main-sequence stars in this young cluster. A handful of hard X-ray sources in the pillars are spatially coincident with deeply embedded young stellar objects seen in high-resolution near-infrared images recently obtained with the VLT (McCaughrean & Andersen). In this paper, we focus on the 40 X-ray sources in and around pillars 1-4 at the heart of the Eagle Nebula. None of the X-ray sources are associated with the evaporating gaseous globules (EGGs) first observed by Hester and coworkers) in HST WFPC2 images of M16, implying either that the EGGs do not contain protostars or that the protostars have not yet become X-ray active. Eight X-ray counts are coincident with the Herbig-Haro object HH 216, implying log L_X ≈ 30.0.

We study the structural evolution of turbulent molecular clouds under the influence of ionizing radiation emitted from a nearby massive star by performing a high-resolution parameter study with the iVINE code. The temperature is taken to be 10 K or 100 K, the mean number density is either 100 cm⁻³ or 300 cm⁻³. Furthermore, the turbulence is varied between Mach 1.5 and Mach 12.5, the main driving scale of the turbulence is varied between 1 pc and 8 pc. We vary the ionizing flux by an order of magnitude, corresponding to allowing between 0.5% and 5% of the mass in the domain to be ionized immediately. In our simulations, the ionizing radiation enhances the initial turbulent density distribution and thus leads to the formation of pillar-like structures observed adjacent to H ii regions in a natural way. Gravitational collapse occurs regularly at the tips of the structures. We find a clear correlation between the initial state of the turbulent cold cloud and the final morphology and physical properties of the structures formed. The most favorable regime for the formation of pillars is Mach 4–10. Structures and therefore stars only form if the initial density contrast between the high-density unionized gas and the gas that is going to be ionized is lower than the temperature contrast between the hot and the cold gas. The density of the resulting pillars is determined by a pressure equilibrium between the hot and the cold gas. A thorough analysis of the simulations shows that the complex kinematical and geometrical structure of the formed elongated filaments reflects that of observed pillars to an impressive level of detail. In addition, we find that the observed line-of-sight velocities allow for a distinct determination of different formation mechanisms. Comparing the current simulations to previous results and recent observations, we conclude that, e.g., the pillars of creation in M16 formed by the mechanism proposed here and not by the radiation driven implosion of pre-existing clumps.

We present ALMA observations of CO isotopes and 1.3 mm continuum emission toward the N159E-Papillon Nebula in the Large Magellanic Cloud (LMC). The spatial resolution is 025–028 (0.06–0.07 pc), which is a factor of 3 higher than previous ALMA observations in this region. The high resolution allowed us to resolve highly filamentary CO distributions with typical widths of ∼0.1 pc (full width half maximum) and line masses of a few 100 M_⊙ pc⁻¹. The filaments (more than ten in number) show an outstanding hub-filament structure emanating from the nebular center toward the north. We identified for the first time two massive protostellar outflows of ∼10⁴ yr dynamical age along one of the most massive filaments. The observations also revealed several pillar-like CO features around the Nebula. The H ii region and the pillars have a complementary spatial distribution and the column density of the pillars is an order of magnitude higher than that of the pillars in the Eagle nebula (M16) in the Galaxy, suggesting an early stage of pillar formation with an age younger than ∼10⁵ yr. We suggest that a cloud–cloud collision triggered the formation of the filaments and protostar within the last ∼2 Myr. It is possible that the collision is more recent, as part of the kpc-scale H i flows come from the tidal interaction resulting from the close encounter between the LMC and SMC ∼200 Myr ago as suggested for R136 by Fukui et al.

This paper reports a multiple-scale hierarchically structured superhydrophobic surface that is composed of inclined-wall regular micro-pillar arrays covered entirely with an alumina nanowire forest (ANF) to improve the surface wettability. The multiple-scaled structures were fabricated stably using a simple batch process based on an anisotropic chemical silicon etching process and a subsequent time-controlled anodic aluminum oxide technique. The surface wetting properties of the mono-roughened surfaces with inclined-wall micro-pillar arrays, which are normally in the Wenzel wetting regime, could be transitioned perfectly to the slippery Cassie mode and enhanced greatly in the Wenzel regime in cases of a high- and low-density of the micro-pillars, respectively, by easily amplifying the intrinsic contact angle through the entire coverage of the ANF on the micro-roughened surfaces. The wettability of the proposed multiple-scaled surfaces could also be predicted using analytic surface models and the experimental results agreed greatly with the wetting trends estimated theoretically due to the geometrical regularity of the base micro-structures.

A vertical ferromagnetic (FM) nanopillar can be used as magnetic memory owing to characteristics such as its high storage capacity and high thermal stability. The perpendicular shape anisotropy (PSA) of the pillar enables its magnetization direction to be stabilized. A pillar with a high aspect ratio exhibits both strong PSA and magnetization with high thermal stability. Reversing the magnetization direction of such a pillar using the current flowing through it is a significant challenge in spintronics. However, spin injection from another FM layer alone cannot reverse the magnetization of pillars of which the length exceeds 100 nm. This motivated us to propose a magnetic junction (MJ) consisting of a high-aspect-ratio FM nanopillar with two thin FM layers. Using micromagnetic simulation, we demonstrate the magnetization reversal of a 150 nm-long pillar with a diameter of 15 nm. The simulation revealed that the magnetization of the pillar reverses because of the spin transfer torque induced by the spin injection from the two thin FM layers and the spin-polarized current (SPC) flowing in the pillar in the longitudinal direction. During the magnetization reversal process, a domain wall (DW) first forms at one end of the pillar due to the spin injection. Then, driven by the SPC, the DW moves to the other end of the pillar, and the magnetization is reversed. The magnetization direction of the pillar, controlled by changing the direction of the current flowing through the pillar, can be evaluated from the respective magnetoresistance values of the two MJs. Alternatively, by pinning the DW in the pillar, a three-value magnetic memory can be developed. In addition, multi-bit and analog memories can be developed by controlling the pinning position of the DW. The high-aspect-ratio pillar-writing scheme is foreseen to pave the way for the practical development of next-generation spintronic devices.

A copper-to-copper bonding process was developed for an all-copper, chip-to-substrate interconnect technology. High aspect ratio polymer molds for electroplating were formed using a photodefinable polymer on both the chip and the substrate surfaces. Copper pillars were fabricated by electroplating metal in the polymer molds. The chip-to-substrate all-copper connections were formed by joining the two pillars with electroless copper plating followed by an anneal process. The copper-to-copper bonding of the high aspect ratio pillars does not require the use of solder or other noncopper metals. Mechanical shear force measurements were used to characterize the bonding process as a function of annealing conditions. Excellent bond strength of the electrolessly joined pillars was achieved with a anneal, with the bond strength of the copper pillar interconnects exceeding . High aspect ratio pillars can provide mechanical compliance, and the electroless fabrication method compensates for pillar misalignment and nonplanarity of the bonded surfaces.