DESHIMA on ASTE: On-sky Responsivity Calibration of the Integrated Superconducting Spectrometer

25 Jul 2019, 17:45
1h 15m
Piazza Città di Lombardia (Milano)

Piazza Città di Lombardia

Milano

Piazza Città di Lombardia, 1, 20124 Milano MI
Poster Detector readout, signal processing, and related technologies Poster session

Speaker

Dr Tatsuya Takekoshi (The University of Tokyo)

Description

We are developing an ultra-wideband spectroscopic instrument, DESHIMA (Deep Spectroscopic HIgh-redshift Mapper), based on the technologies of an on-chip filterbank and Microwave Kinetic Inductance Detector (MKID) in order to investigate dusty starburst galaxies in the distant universe at millimeter and submillimeter wavelength. On-site experiment of prototype DESHIMA was performed using the ASTE 10-m telescope (Ezawa et al. 2008) in Oct. and Nov. 2017. In this session, we used 49 frequency channels in 332-377 GHz band (frequency step of $\sim$1 GHz), and successfully detected astronomical molecular lines such as the redshifted CO (J=3-2) line of VV114, a luminous infrared galaxy at z=0.020. We present a reliable responsivity model that converts frequency responses of the MKIDs to line-of-sight brightness temperature. Using a skydip dataset under various precipitable water vapors (PWV, 0.4-3.0 mm, obtained by the ALMA radiometers, Nikolic et al. 2013), we estimated the responsivity model parameters and PWVs iteratively. First, we estimated line-of-sight brightness temperature from the ALMA PWVs and elevation angles of the telescope using an atmospheric transmission model (ATM, Pardo et al. 2001) and obtained two fitting parameters of the responsivity model for each MKID. Then, we estimated PWVs (DESHIMA PWVs) using frequency response of MKIDs. Finally, we fit the parameters again assuming the DESHIMA PWVs. As a result of analysis, we obtained temperature calibration uncertainty of $1\sigma \sim$4% typically, which was smaller than those of other photometric errors (e.g., chopper wheel method, planet flux model, 5-20%).

Student (Ph.D., M.Sc. or B.Sc.) N
Less than 5 years of experience since completion of Ph.D N

Primary authors

Dr Tatsuya Takekoshi (The University of Tokyo) Dr Junya Suzuki (Kyoto University) Dr Kenichi Karatsu (TU Delft) Dr Akira Endo (Delft University of Technology) Dr Yoichi Tamura (Nagoya University) Dr Tai Oshima (National Astronomical Observatory of Japan) Dr Akio Taniguchi (Nagoya University) Dr Shin'ichiro Asayama (National Astronomical Observatory of Japan) Dr Tom Bakx (Nagoya University) Mr Sjoerd Bosma (Delft University of Technology) Juan Bueno (SRON) Mr Kah Wuy Chin (National Astronomical Observatory of Japan) Dr Yasunori Fujii (National Astronomical Observatory of Japan) Mr Kazuyuki Fujita (Hokkaido University) Mr Robert Huiting (SRON) Dr Soh Ikarashi (TU Delft) Mr Tsuyoshi Ishida (The University of Tokyo) Dr Shun Ishii (National Astronomical Observatory of Japan) Prof. Ryohei Kawabe (National Astronomical Observatory of Japan) Prof. Teun Klapwijk (Delft University of Technology) Prof. Kotaro Kohno (The University of Tokyo) Prof. Akira Kouchi (Hokkaido University) Prof. Nuria Llombart (Delft University of Technology) Dr Jun Maekawa (National Astronomical Observatory of Japan) Mr Vignesh Murugesan (SRON, Netherlands Institute for Space Research) Mr Shunichi Nakatsubo (JAXA) Dr Masato Naruse (saitama university) Dr Kazushige Ohtawara (National Astronomical Observatory of Japan) Alejandro Pascual Laguna (SRON) Mr Koyo Suzuki (Nagoya University) David Thoen (Delft University of Technology) Dr Takashi Tsukagoshi (National Astronomical Observatory of Japan, Mitaka) Mr Tetsutaro Ueda (Nagoya University) Dr Pieter de Visser (SRON) Prof. Paul van der Werf (Leiden University) Stephen Yates (SRON) Mr Yuki Yoshimura (The University of Tokyo) Dr Ozan Yurduseven (Delft University of Technology) Prof. Jochem Baselmans (SRON)

Presentation Materials