Shinobu Ozaki

Early Spectral Evolution of the Rapidly Expanding Type Ia Supernova 2006X

We present optical spectroscopic and photometric observations of Type Ia supernova (SN Ia) 2006X from 10 d before the B-band maximum to 91 d after. This object exhibits one of the highest expansion velocities ever published for SNe Ia. At its premaximum phases, the spectra show strong and broad features of intermediate-mass elements, such as Si, S, Ca, and Mg, while the O I � 7773 line is weak. The extremely high velocities of the Si II and S II lines and the weak feature of the O I line suggest that an intense nucleosynthesis might take place in the outer layers, favoring a delayed detonation model. Interestingly, the Si II � 5972 feature is quite shallow, resulting in an unusually low depth ratio of Si II � 5972 to Si II � 6355, R(Si II). The low R(Si II) is usually interpreted as being a high photospheric temperature. However, the weak Si III � 4560 line suggests a low temperature, in contradiction with an interpretation on the low R(Si II). This could imply that the Si II � 5972 line might be contaminated by underlying emission. We propose that R(Si II) may not be a good temperature indicator for a rapidly expanding SN Ia in the premaximum phases.

ISLE: Near-Infrared Imager/Spectrograph for the 1.88m Telescope at Okayama Astrophysical Observatory

ISLE is a near-infrared imager and spectrograph for the Cassegrain focus (f/18) of the 1.88 m telescope at Okayama Astrophysical Observatory. It is upgraded instrument with a new detector, HAWAII-1 HgCdTe array and new optics. ISLE provides imaging capabilities which covers 4.2 × 4.2 arcmin2 field-of-view at 0.25 arc-sec/ pixel and long-slit (4 arcmin) spectroscopic capabilities at λ/Δλ = 1000 - 4000 using reflection gratings. The noise performance of the detector is excellent. The read noise of 2.5 electrons with 25 Fowler pairs has been achieved, that is one of the worlds lowest level among the instruments which use HAWAII-1 array as the detector. We discuss the technical performance of ISLE and examine the upgrade effectiveness.

Kyoto tridimensional spectrograph II: progress

We are building the Kyoto tridimensional spectrograph II and are planning to mount it on Subaru telescope. The spectrograph has four observational modes: Fabry-Perot imager, integral field spectrograph (IFS) with a microlens array, long-slit spectrograph, and filter-imaging modes. The optics is designed to be used in wide wavelength range from 360 nm to 900 nm. The design well matches with high spatial resolution of Subaru: 0 inch .06 pixel-1 in Fabry- Perot mode, for which we actually will use binning before adaptive optics at optical wavelengths becomes available, and 0 inch .1 lens-1 in microlens array mode. These well sample image sizes obtained by Subaru, which are about 0 inch .4 in relatively good conditions. We have evaluated a point spread function of our cylindrical microlens array and found that it consists of a diffraction pattern and more extended component which probably comes from border regions between microlenses. With a suitable mask at the micro pupil position, the crosstalk between spectra will be limited down to a few percent. With a suitable mask at the micro pupil position, the crosstalk between spectra will be limited down to a few percent. We have succeeded in synchronizing frequency switching of Fabry-Perot etalons with the movement of charge on the CCD. This technique enables to average out all temporal variations between each passband.

SUBARCSECOND STRUCTURE AND VELOCITY FIELD OF OPTICAL LINE-EMITTING GAS IN NGC 1052

We have obtained integral field spectra of the low-ionization emission-line region in the galaxy NGC 1052 by using the Kyoto Tridimensional Spectrograph II mounted on the Subaru Telescope. Our high signal-to-noise ratio data with precise template subtraction have revealed weaker features at the nucleus, including the [Fe III] and He II emission lines, as well as a broad component of the Hβ emission. The broad Hβ component suggests the existence of a broad-line region. The spatial structure and velocity field derived from the data cube suggest the existence of three main components: a high-velocity bipolar outflow, low-velocity disk rotation, and a spatially unresolved nuclear component. The outflow axis does not coincide with the disk rotation axis. The opening angle of the outflow decreases with velocity shift from the systemic velocity both in bluer and redder velocity channels. This is explained only if the outflow has intrinsically higher velocity components inside, i.e., in regions closer to the outflow axis. At both sides of the bipolar outflow, we find that the highest velocity components are detached from the nucleus. This gap can be explained by an acceleration of at least a part of the flow or the surrounding matter, or by bow shocks that may be produced by even higher velocity outflow components that are not yet detected. Along the edges of the outflow and extending east-northeast and west-southwest, there exist strong [O III] emission ridges. These are closely related to the radio jet-counterjet structure. The abrupt change in the velocity field of the ionized gas and a large [O ]/Hβ line flux ratio in this region suggest a strong interaction of the jets, and possibly also of some ridge components of the line-emitting gas, with the interstellar matter.

Hα Intensity Map of the Repeating Fast Radio Burst FRB 121102 Host Galaxy from Subaru/Kyoto 3DII AO-assisted Optical Integral-field Spectroscopy

We present the H

Suzaku X-Ray and Optical Spectroscopic Observations of SS 433 in the 2006 April Multiwavelength Campaign

\alpha

Rapid large-scale metal enrichment in the starbursts of an interacting Galaxy system

intensity map of the host galaxy of the repeating fast radio burst FRB 121102 at a redshift of z=0.193 obtained with the AO-assisted Kyoto 3DII optical integral-field unit mounted on the 8.2-m Subaru Telescope. We detected a compact H

TMT-AGE: wide field of regard multi-object adaptive optics for TMT

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Development of an integral field unit for a near-infrared multi-object imaging spectrograph SWIMS

-emitting (i.e., star-forming) region in the galaxy, which has a much smaller angular size [

Kinematic and Excitation Structure of the NGC 1068 Narrow-Line Region

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