Soojong Pak

The chemical structure of neutral clouds in low metallicity environments is examined with particular emphasis on the H to H_2 and C+ to CO transitions. We observed near-IR H_2 lines and the CO J=1-0 line from 30 Doradus and N159/N160 in the Large Magellanic Cloud and from DEM S 16, DEM S 37, and LI-SMC 36 in the Small Magellanic Cloud. We find that the H_2 emission is UV-excited and that (weak) CO emission always exists (in our surveyed regions) toward positions where H_2 and [CII] emission have

Abstract. Global three-dimensional data are a key to understanding gravity waves in the mesosphere and lower thermosphere. MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is a new Swedish satellite mission that addresses this need. It applies space-borne limb imaging in combination with tomographic and spectroscopic analysis to obtain gravity wave data on relevant spatial scales. Primary measurement targets are O2 atmospheric band dayglow and nightglow in the near infrared, and su

Freeform mirrors can be readily fabricated by a single point diamond turning (SPDT) machine. However, this machining process often leaves mid-frequency errors (MFEs) that generate undesirable diffraction effects and stray light. In this work, we propose a novel thin electroless nickel plating procedure to remove MFE on freeform surfaces. The proposed procedure has a distinct advantage over a typical thick plating method in that the machining process can be endlessly repeated until the designed m

The HH 1-2 region in the L1641 molecular cloud was observed in the near-IR J, H, and Ks bands, and imaging polarimetry was performed. Seventy six point-like sources were detected in all three bands. The near-IR polarizations of these sources seem to be caused mostly by the dichroic extinction. Using a color-color diagram, reddened sources with little infrared excess were selected to trace the magnetic field structure of the molecular cloud. The mean polarization position angle of these sources i

The purpose of this research was to explore the relationship between degenerative joint disease (DJD) in the apophyseal joints and intervertebral joints in the vertebral column and assess which vertebral DJD is the more reliable indicator of general activity-related stress. We hypothesized that the more reflecting vertebral DJD for general activity-related stress would appear to show a higher correlation with Schmorl's nodes (SNs). To test this hypothesis, we examined 125 individuals from Eunpye

We have detected the v= 1 → 0 S(1) (λ= 2.1218 μm) and v= 2 → 1 S(1) (λ= 2.2477 μm) lines of H2 in the Galactic Centre, in a 90 × 27 arcsec2 region between the north-eastern boundary of the non-thermal source Sgr A East, and the giant molecular cloud (GMC) M−0.02 − 0.07. The detected H2v= 1 → 0 S(1) emission has an intensity of 1.6–21 × 10−18 W m−2 arcsec−2 and is present over most of the region. Along with the high intensity, the large linewidths (FWHM = 40–70 km s−1) and the H2v= 2 → 1 S(1) to

The central regions of many interacting and early-type spiral galaxies are actively forming stars. This process affects the physical and chemical properties of the local interstellar medium, as well as the evolution of the galaxies. We observed near-infrared H emission lines: v = 1-0 S(1), 3-2 S(3), 1-0 S(0), and 2-1 S(1) from the central ∼1 kpc regions of the archetypical starburst galaxies M82 and NGC 253 and the less dramatic but still vigorously star-forming galaxies NGC 6946 and IC 342. Lik

Abstract We describe the observing simulation software FISVI (FIS Virtual Instrument), which was developed for the Far-Infrared Surveyor (FIS) that will be on the Japanese infrared astronomy mission ASTRO-F. The FISVI has two purposes: one is to check the specifications and performances of the ASTRO-F/FIS as a whole; the other is to prepare input data sets for the data analysis softwares prior to launch. In the FISVI, special care was taken by introducing the “Compiled PSF (Point Spread Function

We have observed Hubble V, the brightest H ii region complex in the dwarf irregular galaxy NGC 6822, at near-infrared (near-IR; 1.8–2.4 μm) wavelengths. The line emission maps of Hubble V show the typical structure of a photodissociation region (PDR) where an ionized core, traced by compact He i emission (2.0587 μm) and Brγ emission (2.1661 μm), is surrounded by an outer layer traced by molecular hydrogen (H2) emission. The measured line ratios of H2 2–1 S(1) (2.2477 μm)/1-0 S(1) (2.1218 μm) fro

Local Volume Mapper Spectrograph Control Package (LVMSCP) is the software that controls three spectrographs to acquire science spectral data cubes automatically. The software architecture design based on Python 3.9 follows a hierarchical structure of Actors, the unit that controls each piece of hardware. We used the software framework Codified Likeness Utility to implement each Actor. The Actors communicate with each other through RabbitMQ, which implements the Advanced Message Queuing Protocol.