Over the past decades, observational evidence of circumstellar disks around massive protostars has been steadily accumulating. However, there have also cases non-detections in high-mass star-forming regions, leaving role and prevalence still uncertain. The aim this work is to investigate substructures previously identified 2000-au-scale rotating structures search for embedded Keplerian disk inside. We used high-resolution (∼0.2 NOrthern Extended Millimeter Array (NOEMA) observations study...

Abstract Dense cores in massive, parsec-scale molecular clumps are sites that harbor protocluster formation. We present results from observations toward a hub–filament structure of massive infrared (IR) dark cloud G14.225-0.506 using the Atacama Large Millimeter/submillimeter Array. The dense revealed by 1.3 mm dust continuum emission at an angular resolution ∼1 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>.</mml:mi>...

Abstract We report the first arcsecond-resolution observations of magnetic field in ministarburst complex Sgr B2. SMA polarization revealed morphology three dense cores B2 N(orth), M(ain), and S(outh). The total plane-of-sky strengths these are estimated to be 4.3–10.0 mG, 6.2–14.7 1.9–4.5 mG derived from angular dispersion function method after applying correction factors 0.21 0.5. Combining with analyses parsec-scale data Stratospheric Observatory for Infrared Astronomy, we found that a...

Context . The physical properties, evolution, and fragmentation of massive dense cores (MDCs, ~0.1 pc) are fundamental pieces in our understanding high-mass star formation. Aims We aim to characterize the temperature, velocity dispersion, MDCs Cygnus X giant molecular cloud investigate stability dynamics these cores. Methods present Karl G. Jansky Very Large Array (VLA) observations NH 3 ( J , K ) = (1,1) (2,2) inversion lines towards 35 X, from which we calculated temperature dispersion....

Abstract The nature of the magnetic field structure throughout Galactic Center (GC) has long been interest. recent Far-InfraREd Polarimetric Large-Area Central Molecular Zone (CMZ) Exploration (FIREPLACE) Survey reveals preliminary connections between seemingly distinct vertical and horizontal distributions previously observed in GC. We use statistical techniques Histogram Relative Orientation Projected Rayleigh Statistic to assess whether CMZ preferentially aligns with molecular clouds or...

WTe2 and its sister alloys have attracted tremendous attention in recent years due to the large non-saturating magnetoresistance topological non-trivial properties. Herein, we briefly review electrical property studies on this new quantum material.

Context . The SiO emissions are usually used to trace high-velocity outflow shocks in star-forming regions. However, several studies have found low-velocity and widespread not associated with outflows molecular clouds. Aims We aim detect characterize the massive dense cores (MDCs), explore properties of central sources emission. Methods present high-angular-resolution (~1.5″) observations (5−4) line made Submillimeter Array towards a sample 48 MDCs Cygnus-X complex. studied emission...

Context. Theories and models have suggested that circumstellar disks could channel material to the central protostar, resist star formation feedback. Our current knowledge of picture role around massive protostars is unclear because observational evidence these limited. Aims. To investigate whether disk-mediated accretion primary mechanism in high-mass formation, we established a survey large sample dense cores within giant molecular cloud. Methods. We used high angular resolution (~1.8″)...

Silicon photonics based lidar sensors can enable chip scale for high volume 3D sensing applications. These require narrow linewidth and optical power semiconductor devices to long range lidars. Experimental results from 1550nm SOAs lasers are presented.

The physical properties, evolution, and fragmentation of massive dense cores (MDCs, $\sim$ 0.1 pc) are fundamental pieces in our understanding high-mass star formation. We aim to characterize the temperature, velocity dispersion, MDCs Cygnus X giant molecular cloud investigate stability dynamics these cores. present Karl G. Jansky Very Large Array (VLA) observations NH$_3$ (J,K) = (1,1) (2,2) inversion lines towards 35 X, from which we calculated temperature dispersion. extracted 202...

We report the first arcsecond-resolution observations of magnetic field in mini starburst complex Sgr B2. SMA polarization revealed morphology three dense cores B2 N(orth), M(ain), and S(outh). The total plane-of-sky strengths these are estimated to be 4.3-10.0 mG, 6.2-14.7 1.9-4.5 mG derived from angular dispersion function method after applying correction factors 0.21 0.5. Combining with analyses parsec-scale data SOFIA, we found that a magnetically supercritical condition is present...

The nature of the magnetic field structure throughout Galactic Center (GC) has long been interest. recent Far-InfraREd Polarimetric Large-Area CMZ Exploration (FIREPLACE) Survey reveals preliminary connections between seemingly distinct vertical and horizontal distributions previously observed in GC. We use statistical techniques Histogram Relative Orientation (HRO) Projected Rayleigh Statistic (PRS) to assess whether preferentially aligns with column density gradient derived from molecular...

The limitations imposed by stimulated Raman scattering on 1550 nm high-energy pulse transmission in single-mode optical fiber are investigated. generation of a Stokes from an input with peak power up to 60 W and duration the order 10 ns is experimentally studied numerically simulated. This first demonstration pump pulses within telecommunications window. Experiment theory show that there optimum for given distance maximizes energy transmitted over long fibers.< <ETX...

The SiO emissions are usually used to trace high-velocity outflow shocks in star-forming regions. However, several studies have found low-velocity and widespread not associated with outflows molecular clouds. We aim detect characterize the massive dense cores (MDCs), explore properties of central sources emission. present high-angular-resolution ($\sim$1.5$^{\prime\prime}$) observations (5$-$4) line made Submillimeter Array towards a sample 48 MDCs Cygnus-X complex. studied emission...

To investigate whether disk-mediated accretion is the primary mechanism in high-mass star formation, we have established a survey of large sample massive dense cores within giant molecular cloud. We used high angular resolution ($\sim 1.8''$) observations with SMA to study dust emission and line about 50 Cygnus-X. At typical distance 1.4 kpc for Cygnus-X, these are resolved into $\sim 2000$ au condensations. combined CO outflow gas kinematics traced by several high-density tracers search...

Rare-earth-doped fiber lasers and their applications are reviewed. Erbium-doped operating around 1.55 /spl mu/m thulium-doped 1.9 described. Mode-locking, Q-switching, wavelength tuning, narrow broad linewidth operation discussed. Presented of include lidar, remote sensing, coherent detection, gyroscope sources.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

In an effort to meet core, regional, and metro network requirements, 40G DWDM suppliers have employed numerous modulation formats. Each format brought its own unique set of optical, electrical, optoelectronic component which challenged prioritize research development efforts. addition a highly segmented market, lack investment in standardization has resulted fragmented market for technology. We explore how the 100G may differ.

Computer simulation of propagation and switching both temporal spatial solitons is presented. The based on the solutions a general wave equation by newly developed beam method.