Yuzuru Yoshii

Astronomical Distance Determination in the Space Age: Secondary Distance Indicators

The formal division of the distance indicators into primary and secondary leads to difficulties in description of methods which can actually be used in two ways: with, and without the support of the other methods for scaling. Thus instead of concentrating on the scaling requirement we concentrate on all methods of distance determination to extragalactic sources which are designated, at least formally, to use for individual sources. Among those, the Supernovae Ia is clearly the leader due to its enormous success in determination of thexa0expansion rate of the Universe. However, new methods are rapidly developing, and there is also a progress in more traditional methods. We give a general overview of the methods but we mostly concentrate on the most recent developments in each field, and future expectations.

Development status of the simultaneous two-color near-infrared multi-object spectrograph SWIMS for the TAO 6.5m telescope

The Simultaneous-color Wide-field Infrared Multi-object Spectrograph, SWIMS, is a first-generation near-infrared instrument for the University of Tokyo Atacama Observatory (TAO) 6.5m Telescope now being constructed in northern Chile. To utilize the advantage of the site that almost continuous atmospheric window appears from 0.9 to 2.5 μm, the instrument is capable of simultaneous two-color imaging with a field-of-view of 9.′6 in diameter or λ/∆λ ∼ 1000 multi-object spectroscopy at 0.9–2.5 μm in a single exposure. The instrument has been transported in 2017 to the Subaru Telescope as a PI-type instrument for carrying out commissioning observations before starting science operation on the 6.5m telescope. In this paper, we report the latest updates on the instrument and present preliminary results from the on-sky performance verification observations.

Calibration of AGN Reverberation Distance Measurements

In Yoshii et al. (2014), we described a new method for measuring extragalactic distances based on dust reverberation in active galactic nuclei (AGNs), and we validated our new method with Cepheid variable stars. In this paper, we validate our new method with Type Ia supernovae (SNe Ia) which occurred in two of the AGN host galaxies during our AGN monitoring program: SN 2004bd in NGC 3786 and SN 2008ec in NGC 7469. Their multicolor light curves were observed and analyzed using two widely accepted methods for measuring SN distances, and the distance moduli derived are

Laboratory performance evaluation of the mid-infrared camera and spectrograph MIMIZUKU for the TAO 6.5-m telescope

mu=33.47pm 0.15

The 1.87- and 2.07-μm observations of three Galactic Centre clusters with miniTAO at Atacama: classification of stellar components in massive star clusters

for SN 2004bd and

Chemical Evolution of the Universe at 0.7 < z < 1.6 Derived from Abundance Diagnostics of Quasars

33.83pm 0.07

Thermal infrared observations of an asteroid 2005YU55 during the closet approach

for SN 2008ec. These results are used to obtain independently the distance measurement calibration factor,

Photometry of GRB 071025 (Perley+, 2010)

g

The spectral variability of UV-optical continuum emission of Active Galactic Nuclei

. The

The Lick AGN monitoring project (Walsh+, 2009)

g