A classical paradox in high-mass star formation is that powerful radiation pressure can halt accretion, preventing further growth of a central star. Disk accretion has been proposed to solve this problem, but the disks and process are poorly understood. We executed high-resolution ($R$=35,000-70,000) iSHELL spectroscopy $K$-band for eleven protostars. Br-$\gamma$ emission was observed toward ei...

Let $G$ be a compact connected Lie group and $n\geqslant 1$ an integer. Consider the space of ordered commuting $n$-tuples in $G$, $Hom(\mathbb{Z}^n,G)$, its quotient under adjoint action, $Rep(\mathbb{Z}^n,G):=Hom(\mathbb{Z}^n,G)/G$. In this article we study many cases compute homotopy groups $\pi_2(Hom(\mathbb{Z}^n,G))$. For simply--connected simple show that $\pi_2(Hom(\mathbb{Z}^2,G))\cong ...

Following up on our discovery of terahertz water masers, reported in 2017, we report two further detections maser emission at frequencies above 1 THz. Using the GREAT instrument SOFIA, have detected 1.296411 THz $8_{27}-7_{34}$ transition toward additional oxygen-rich evolved stars, omicron Ceti (Mira) and R Crateris, obtained an upper limit 1.296 line from U Orionis. Toward these three sources...

Abstract Detachment, an important mechanism for reducing target heat deposition, is achieved through reductions in power, particle and momentum; which are induced plasma–atom plasma–molecule interactions. Experimental research how those reactions precisely contribute to detachment limited. Both as well interactions can result excited hydrogen atoms emit atomic line emission. In this work, we in...

The role of HI content in galaxy interactions is still under debate. To study the pairs at different merging stages, we compile a sample 66 major-merger and 433 control galaxies from SDSS-IV MaNGA IFU survey. In this study, adopt kinematic asymmetry as new effective indicator to describe stage pairs. With archival data HI-MaNGA survey observations Five-hundred-meter Aperture Spherical Radio Tel...

The collisional pumping of CH3OH and OH masers in non-dissociative C-type shock waves is studied. chemical processes responsible for the evolution molecule abundances wave are considered detail. large velocity gradient approximation used to model radiative transfer molecular lines. We present calculations optical depth maser transitions a grid models that vary cosmic ray ionization rate, gas de...

Recent Herschel observations of nearby clouds have shown that filamentary structures are ubiquitous and most prestellar cores form in filaments. Probing the density ($n$) velocity ($V$) structure filaments is crucial for understanding star formation process. To characterize both $n$ $V$ field a fragmenting filament, we mapped NGC2024. 13CO, C18O, H13CO+ trace filament seen $N_{H_2}$ data. The r...

ABSTRACT We use the Gemini NIFS instrument to map H$_2\, 2.1218\, \mu$m and Br? flux distributions in inner 0.04–2 kpc of a sample 36 nearby active galaxies (0.001 ? z 0.056) at spatial resolutions from 4 250 pc. find extended emission 34 galaxies. In ?55 per cent them, both lines is most along galaxy major axis, while other 45 extent follows distinct orientation. The H2 less concentrated than ...