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On the basis of the near infrared observations of bulge red clump stars near the Galactic center, we have determined the galactocentric distance to be R 0 = 7.52 ± 0.10 (stat) ±0.35 (sys) kpc. We observed the red clump stars at | l | 1. • 0 and 0. • 7 | b | 1. • 0 with the IRSF 1.4 m telescope and the SIRIUS camera in the H and K S bands. After extinction(More)
We have determined the ratios of total to selective extinction in the near-infrared bands (J, H, K S) toward the Galactic center from the observations of the region | l | 2. • 0 and 0. • 5 | b | 1. • 0 with the IRSF telescope and the SIRIUS camera. Using the positions of red clump stars in color-magnitude diagrams as a tracer of the extinction and(More)
We determine and compare the color excess ratios E J ÀH /E HÀK S for the Ophiuchi and Chamaeleon dark clouds with the J-, Hand nd K s-band simultaneous camera, SIRIUS, on the IRSF 1.4 m telescope at SAAO. Determining accurate ratios is indispensable for discussions of the extinction law. However, previous surveys suffered from uncertainties in transforming(More)
Studies of the structure and evolution of protoplanetary disks are important for understanding star and planet formation. Here we present the direct image of an interacting binary protoplanetary system. Both circumprimary and circumsecondary disks are resolved in the near-infrared. There is a bridge of infrared emission connecting the two disks and a long(More)
– 2 – On the basis of near-infrared imaging observations, we derived visual extinction (A V) distribution toward ten Bok globules through measurements of both the color excess (E H−K) and the stellar density at J, H, and K s (star count). Radial column density profiles for each globule were analyzed with the Bonnor-Ebert sphere model. Using the data of our(More)
We have conducted J, H, and K S imaging observations for the Coalsack Globule 2 with the SIRIUS infrared camera on the IRSF 1.4 m telescope at SAAO, and determined the color excess ratio, E J−H /E H−K S. The ratio is determined in the same photometric system as our previous study for the ρ Oph and Cha clouds without any color transformation; this enables us(More)
We have developed a digital fast Fourier transform spectrometer made of an analog-to-digital converter (ADC) and a field-programmable gate array (FPGA). The base instrument has independent ADC and FPGA modules, which allow us to implement different spectrometers in a relatively easy manner. Two types of spectrometers have been instrumented: one with 4.096(More)
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