• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-27
Yusuke Tampo; Kojiguchi Naoto; Keisuke Isogai; Taichi Kato; Mariko Kimura; Yasuyuki Wakamatsu; Daisaku Nogami; Tonny Vanmunster; Tamás Tordai; Hidehiko Akazawa; Felipe Mugas; Taku Nishiumi; Víctor J S Béjar; Kiyoe Kawauchi; Nicolas Crouzet; Noriharu Watanabe; Núria Casasayas-Barris; Yuka Terada; Akihiko Fukui; Norio Narita; Enric Palle; Motohide Tamura; Nobuhiko Kusakabe; Roi Alonso; Hiroshi Itoh;

We report on photometric and spectroscopic observations and analysis of the 2019 superoutburst of TCP J21040470+4631129. This object showed a 9 mag superoutburst with early superhumps and ordinary superhumps, which are the features of WZ Sge-type dwarf novae. Five rebrightenings were observed after the main superoutburst. The spectra during the post-superoutburst stage showed Balmer, He i, and possible

更新日期：2020-05-27
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-27
Takuya Akahori; Tetsu Kitayama; Shutaro Ueda; Takuma Izumi; Kianhong Lee; Ryohei Kawabe; Kotaro Kohno; Masamune Oguri; Motokazu Takizawa

We report the results of the Australia Telescope Compact Array (ATCA) 15 mm observation of the Phoenix galaxy cluster possessing an extreme star-burst brightest cluster galaxy (BCG) at the cluster center. We spatially resolved radio emission around the BCG, and found diffuse bipolar and bar-shape structures extending from the active galactic nucleus (AGN) of the BCG. They are likely radio jets/lobes

更新日期：2020-05-27
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-27
Riku Urago; Ryohei Yamaguchi; Toshihiro Omodaka; Takumi Nagayama; James O Chibueze; Masayuki Y Fujimoto; Takahiro Nagayama; Akiharu Nakagawa; Yuji Ueno; Miho Kawabata; Tatsuya Nakaoka; Kengo Takagi; Masayuki Yamanaka; Koji Kawabata

OZ Geminorum (OZ Gem) is a galactic Mira variable in the Milky Way (MW). We measured its annual parallax with VLBI Exploration of Radio Astrometry to be π = 0.806 ± 0.039 mas, corresponding to a distance of D = 1.24 ± 0.06 kpc. Based on multi-epoch infrared observations with the Kagoshima University 1 m telescope, we also derived the mean J-, H-, and K′-band magnitudes of OZ Gem to be 5.75 ± 0.47 mag

更新日期：2020-05-27
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-25
Yuji Shirasaki; Masayuki Akiyama; Yoshiki Toba; Wanqiu He; Tomotsugu Goto

We investigated the properties of active galactic nucleus (AGN) environments, particularly environments where the association of a luminous galaxy (LG) is found within 4 Mpc from an AGN with redshift 0.8–1.1. For comparison, three additional AGN environments, (namely, AGNs of all types, type 1 AGNs with X-ray and/or radio detection, and type 2 AGNs) and an environment of blue M*, the characteristic

更新日期：2020-05-25
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-25
Wanggi Lim; Fumitaka Nakamura; Benjamin Wu; Thomas G Bisbas; Jonathan C Tan; Edward Chambers; John Bally; Shuo Kong; Peregrine McGehee; Dariusz C Lis; Volker Ossenkopf-Okada; Álvaro Sánchez-Monge

We introduce new analysis methods for studying the star cluster formation processes in Orion A, especially examining the scenario of a cloud–cloud collision. We utilize the CARMA–NRO Orion survey 13CO (1–0) data to compare molecular gas to the properties of young stellar objects from the SDSS III IN-SYNC survey. We show that the increase of |$v_{\rm {}^{13}CO} - v_{\rm YSO}$| and Σ scatter of older

更新日期：2020-05-25
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-25
Mariko Saito; Shigeo Yamauchi; Kumiko K Nobukawa; Aya Bamba; Thomas G Pannuti

We present the results of a spectral analysis of the central region of the mixed-morphology supernova remnant HB 9. A prior Ginga observation of this source detected a hard X-ray component above 4 keV, and the origin of this particular X-ray component is still unknown. Our results demonstrate that the extracted X-ray spectra are best represented by a model consisting of a collisional ionization equilibrium

更新日期：2020-05-25
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-25
Takumi Nagayama; Hideyuki Kobayashi; Tomoya Hirota; Mareki Honma; Takaaki Jike; Mi Kyoung Kim; Akiharu Nakagawa; Toshihiro Omodaka; Tomoaki Oyama; Daisuke Sakai; Katsunori M Shibata; Yoshiaki Tamura

Very Long Baseline Interferometry (VLBI) astrometry using the phase-referencing technique remains an open issue for the quantitative characterization of the observing conditions to achieve a feasible parallax precision of 10 micro-arcseconds (μas). To address this issue, we evaluated the astrometric performance of the VLBI Exploration of Radio Astrometry (VERA) through the parallax measurements of

更新日期：2020-05-25
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-23
Hiroyuki Nakanishi; Shinji Fujita; Kengo Tachihara; Natsuko Izumi; Mitsuhiro Matsuo; Tomofumi Umemoto; Yumiko Oasa; Tsuyoshi Inoue

We analyze molecular-gas formation in neutral atomic hydrogen (H i) clouds using the latest CO data, obtained from the FOREST (four-beam receiver system on the 45 m telescope) unbiased Galactic plane imaging survey with the Nobeyama 45 m telescope, and using H i data taken from the Very Large Array Galactic plane survey. We applied a dendrogram algorithm to the H i data cube to identify H i clouds

更新日期：2020-05-23
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-22
Suchetha Cooray; Tsutomu T Takeuchi; Moe Yoda; Kazuo Sorai

Photometric surveys have provided incredible amounts of astronomical information in the form of images. However, astronomical images often contain artifacts that can critically hinder scientific analysis by misrepresenting intensities or contaminating catalogs as artificial objects. These affected pixels need to be masked and dealt with in any data reduction pipeline. We present a flexible, iterative

更新日期：2020-05-22
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-22
Mikio Kurita; Masaru Kino; Fumihide Iwamuro; Kouji Ohta; Daisaku Nogami; Hideyuki Izumiura; Michitoshi Yoshida; Kazuya Matsubayashi; Daisuke Kuroda; Yoshikazu Nakatani; Kodai Yamamoto; Hironori Tsutsui; Masatsugu Iribe; Ichiro Jikuya; Hiroshi Ohtani; Kazunari Shibata; Keisuke Takahashi; Hitoshi Tokoro; Toshinori Maihara; Tetsuya Nagata

An overview of the Seimei telescope, a 3.8 m optical infrared telescope located on Mt. Chikurinji in the Okayama prefecture of Japan, is presented. Seimei is a segmented-mirror telescope whose primary mirror consists of 18 petal-shaped segments. The telescope tube supporting the thin segmented mirrors is structurally incorporated within large arc-rails providing the elevation axis. The tube has a light-weight

更新日期：2020-05-22
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-22
Yong Zhang; Wayne Chau; Jun-ichi Nakashima; Sun Kwok

We report an unbiased radio line survey towards the circumstellar envelopes of evolved stars at the frequency range from 20 to 25 GHz, aiming to obtain a more complete unbiased picture of the chemical evolution in the final stages of stellar evolution. The observation sample includes the asymptotic giant branch (AGB) star IRC +10216, the proto-planetary nebulae (PPNs) CRL 2688 and CRL 618, and the

更新日期：2020-05-22
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-21
Yurika Yamada; Makoto Uemura; Ryosuke Itoh; Yasushi Fukazawa; Masanori Ohno; Fumiya Imazato

We report on the variations of the physical parameters of the jet observed in the blazar Mrk 421, and discuss the origin of X-ray flares in the jet, based on analysis of several spectral energy distributions (SEDs). The SEDs are modeled using the one-zone synchrotron self-Compton model, its parameters determined using a Markov chain Monte Carlo method. The lack of data at TeV energies means many of

更新日期：2020-05-21
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-21
Minori Shikauchi; Jun Kumamoto; Ataru Tanikawa; Michiko S Fujii

Black hole–main sequence star (BH–MS) binaries are one of the targets of future data releases of the astrometric satellite Gaia. They are supposed to be formed in two main sites: a galactic field and star clusters. However, previous work has never predicted the number of BH–MS binaries originating in the latter sites. In this paper we estimate the number of BH–MS binaries formed in open clusters and

更新日期：2020-05-21
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-20
Hai-Ming Zhang; Zhen-Jie Wang; Jin Zhang; Ting-Feng Yi; Liang Chen; Rui-Jing Lu; En-Wei Liang

Violent multi-wavelength variabilities are observed in γ-ray-selected blazars. We present an analysis of long-term light curves for eight bright blazars to explore the co-variation pattern in the γ-ray and radio bands. We extract their γ-ray light curves and spectra with data observed by the Fermi Large Area Telescope (LAT) since 2008. We find diverse co-variation patterns between the γ-ray and radio

更新日期：2020-05-20
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-18
Xinhua Gao

In this paper we present an investigation of tidal tails around the old open cluster M 67 using Gaia-DR2. We identify likely extra-tidal stars around M 67 using principal component analysis (PCA) and a Gaussian mixture model (GMM). We find 1618 stars closely related to M 67, 85 of which are likely extra-tidal stars. We find clear evidence for the existence of two well-defined tidal tails emerging from

更新日期：2020-05-18
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-16
Masako Matsuno; Akiharu Nakagawa; Atsushi Morita; Tomoharu Kurayama; Toshihiro Omodaka; Takumi Nagayama; Mareki Honma; Katsunori M Shibata; Yuji Ueno; Takaaki Jike; Yoshiaki Tamura

We report the results of astrometric VLBI observations toward the Mira variable star BX Cam using the VERA VLBI array. The observation was performed from 2012 February to 2014 November. The parallax obtained is 1.73 ± 0.03 mas corresponding to a distance of 0.58 ± 0.01 kpc. The parallax of this source was reported in Gaia DR2 as 4.13 ± 0.25 mas, and there is a 240% difference between these two measurements

更新日期：2020-05-16
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-12
Shuntaro Ide; Kiyoshi Hayashida; Hirofumi Noda; Hiroyuki Kurubi; Tomokage Yoneyama; Hironori Matsumoto

We report the serendipitous discovery of a transient X-ray source, Suzaku J1305−4930, ∼3 kpc southwest of the nucleus of the Seyfert 2 galaxy NGC 4945. Among the seven Suzaku observations of NGC 4945 from 2005 to 2011, Suzaku J1305−4930 was detected four times in July and August in 2010. The X-ray spectra are better approximated with a multi-color disk model than a power-law model. At the first detection

更新日期：2020-05-12
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-05-04
Fei Li; Junzhi Wang; Min Fang; Qing-Hua Tan; Zhi-Yu Zhang; Yu Gao; Shanghuo Li

We present observations of HCN 3–2 emissions towards 37 local galaxies using the 10 m Submillimeter Telescope. HCN 3–2 emission is detected in 23 galaxies. The correlation of infrared luminosity (LIR) and the luminosity of HCN 3–2 line emission measured in our sample is fitted with a slope of 1.11 and correlation coefficient of 0.91, which follows the linear correlation found in other dense gas tracers

更新日期：2020-05-04
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-04-30
Ataru Tanikawa; Tomoya Kinugawa; Jun Kumamoto; Michiko S Fujii

We estimate formation rates of LB-1-like systems through dynamical interactions in the framework of the theory of stellar evolution before the discovery of the LB-1 system. The LB-1 system contains a ∼70 |${M_{\odot}}$| black hole (BH), a so-called pair instability (PI) gap BH, and a B-type star with solar metallicity, and has nearly zero eccentricity. The most efficient formation mechanism is as follows

更新日期：2020-04-30
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-04-27
James O Chibueze; Takumi Nagayama; Toshihiro Omodaka; Masayuki Nagano; Koji Wada; Ken Hirano

W 48 A core H-2a is one of the young massive protostellar objects in the W 48 region. We conducted multi-epoch astrometric observations of the water (H2O) masers associated with the W 48 A core H-2a with VLBI Exploration of Radio Astrometry (VERA). The trigonometric annual parallax of W 48 A core H-2a was measured to be 0.433 ± 0.026 mas, corresponding to a distance of |$2.31^{+0.15}_{-0.13}$| kpc

更新日期：2020-04-27
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-04-24
Deqing Ren; Gang Wang

We have developed a portable solar adaptive optics (PSAO) for diffraction-limited imaging based on today’s multi-core personal computer. Our PSAO software is written in LabVIEW code, which features block-diagram function based programming and can dramatically speed up the software development. The PSAO can achieve a ~1000 Hz open-loop correction speed with a Shack–Hartmann Wave-front Sensor (SH-WFS)

更新日期：2020-04-24
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-04-24
Vojtěch Šimon

This analysis of the long-term optical activity of the propellers AE Aqr and AR Sco uses data from the Catalina Real-time Transient Survey, DASCH, and AAVSO. The site and character of the emissions from the phenomena caused by the magnetic field of the white dwarf (WD) vary from system to system. The histogram of intensities of the ensemble of flares of AE Aqr suggests that the long-term activity consists

更新日期：2020-04-24
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-04-24
Sho Kuwahara; Kazufumi Torii; Norikazu Mizuno; Shinji Fujita; Mikito Kohno; Yasuo Fukui

[DBS2003]179 is a super star cluster in the Galaxy discovered in deep near-infrared observations. We carried out CO |$J$| = 1–0 and |$J$| = 3–2 observations of the region of [DBS2003]179 with NANTEN2, ASTE, and the Mopra 22 m telescope. We identified and mapped two molecular clouds that are likely to be associated with the cluster. This association is supported by the spatial correlation with the corresponding

更新日期：2020-04-24
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-04-24
Tomoya Hirota; Takumi Nagayama; Mareki Honma; Yuuki Adachi; Ross A Burns; James O Chibueze; Yoon Kyung Choi; Kazuya Hachisuka; Kazuhiro Hada; Yoshiaki Hagiwara; Shota Hamada; Toshihiro Handa; Mao Hashimoto; Ken Hirano; Yushi Hirata; Takanori Ichikawa; Hiroshi Imai; Daichi Inenaga; Toshio Ishikawa; Takaaki Jike; Osamu Kameya; Daichi Kaseda; Jeong Sook Kim; Jungha Kim; Mi Kyoung Kim; Hideyuki Kobayashi;

We present the first astrometry catalog from the Japanese VLBI (very long baseline interferometer) project VERA (VLBI Exploration of Radio Astrometry). We have compiled all the astrometry results from VERA, providing accurate trigonometric-annual-parallax and proper-motion measurements. In total, 99 maser sources are listed in the VERA catalog. Among them, 21 maser sources are newly reported, while

更新日期：2020-04-24
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-04-24
Jae Woo Lee; Kyeongsoo Hong; Martti H Kristiansen

AI Hya has been known as an eclipsing binary with a monoperiodic |$\delta$| Sct pulsator. We present the results from its TESS (Transiting Exoplanet Survey Satellite) photometry observed during Sector 7. Including our five minimum epochs, the eclipse timing diagram displays the apsidal motion with a rate of |$\dot{\omega } = 0.075 \pm 0.031\:$|deg|$\:$|yr|$^{-1}$|⁠, which corresponds to an apsidal

更新日期：2020-04-24
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-04-20
Shoji Kato; Mami Machida

A possible origin of kilohertz quasi-periodic oscillations (QPOs) in low-mass X-ray binaries is proposed. Recent numerical magnetohydrodynamic simulations of accretion disks with turbulent magnetic fields of magneto-rotational instability definitely show the presence of two-armed spiral structure in the quasi-steady state of accretion disks. In such deformed disks, two-armed (⁠|$m=2$|⁠) c-mode (⁠|$n=1$|⁠)

更新日期：2020-04-20
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-26
Masato Tsuboi; Yoshimi Kitamura; Takahiro Tsutsumi; Ryosuke Miyawaki; Makoto Miyoshi; Atsushi Miyazaki

The Galactic Center IRS 13E cluster is a very intriguing infrared object located at |${\sim } 0.13$| pc from Sagittarius A|$^\ast$| (Sgr A|$^\ast$|⁠) in projection distance. There are arguments both for and against the hypothesis that a dark mass like an intermediate mass black hole (IMBH) exists in the cluster. We recently detected the rotating ionized gas ring around IRS 13E3, which belongs to the

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-18
Sanetaka Okada; Kiyoshi Ichimoto; Aki Machida; Satomi Tokuda; Yuwei Huang; Satoru UeNo

The aim of this paper is to determine the kinetic temperature of solar prominences from widths of emission lines with a careful evaluation of its validity, and to investigate the spatial distribution of the non-thermal velocity and the kinetic temperature in prominences. Spectroscopic observations of prominences were carried out using the Domeless Solar Telescope at the Hida observatory in four emission

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-02-06
Iwasawa M, Namekata D, Nitadori K, et al.

AbstractWe describe algorithms implemented in FDPS (Framework for Developing Particle Simulators) to make efficient use of accelerator hardware such as GPGPUs (general-purpose computing on graphics processing units). We have developed FDPS to make it possible for researchers to develop their own high-performance parallel particle-based simulation programs without spending large amounts of time on parallelization

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-02-05
Tomohisa Kawashima; Ken Ohsuga

We carry out axisymmetric two-dimensional radiation hydrodynamical simulations of super-critical accretion columns on to strongly magnetized neutron stars. The effect of the strong magnetic field is taken into account by inhibiting the fluid motion across the radial magnetic field of the neutron stars. It is found that the high-density matter falls on to the neutron star along the sidewall of the column

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-02-05
Taichi Kato

The post-outburst rebrightening phenomenon in dwarf novae and X-ray novae is still one of the most challenging subjects for theories of accretion disks. It has been widely recognized that post-outburst rebrightenings are a key feature of WZ Sge-type dwarf novae, which predominantly have short (≲0.06 d) orbital periods. The author found four post-outburst rebrightenings in ASASSN-14ho during its 2014

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-02-05
Takashi Hamana; Masato Shirasaki; Satoshi Miyazaki; Chiaki Hikage; Masamune Oguri; Surhud More; Robert Armstrong; Alexie Leauthaud; Rachel Mandelbaum; Hironao Miyatake; Atsushi J Nishizawa; Melanie Simet; Masahiro Takada; Hiroaki Aihara; James Bosch; Yutaka Komiyama; Robert Lupton; Hitoshi Murayama; Michael A Strauss; Masayuki Tanaka

We present measurements of cosmic shear two-point correlation functions (TPCFs) from Hyper Suprime-Cam Subaru Strategic Program (HSC) first-year data, and derive cosmological constraints based on a blind analysis. The HSC first-year shape catalog is divided into four tomographic redshift bins ranging from |$z=0.3$| to 1.5 with equal widths of |$\Delta z =0.3$|⁠. The unweighted galaxy number densities

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-02-05
Taichi Kato; Keisuke Isogai; Yasuyuki Wakamatsu; Franz-Josef Hambsch; Hiroshi Itoh; Tamás Tordai; Tonny Vanmunster; Pavol A Dubovsky; Igor Kudzej; Tomáš Medulka; Mariko Kimura; Ryuhei Ohnishi; Berto Monard; Elena P Pavlenko; Kirill A Antonyuk; Nikolaj V Pit; Oksana I Antonyuk; Julia V Babina; Aleksei V Baklanov; Aleksei A Sosnovskij; Roger D Pickard; Ian Miller; Yutaka Maeda; Enrique de Miguel; Stephen

Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 102 SU UMa-type dwarf novae observed mainly during the 2017 season, and characterized these objects. WZ Sge-type stars identified in this study are PT And, ASASSN-17ei, ASASSN-17el, ASASSN-17es, ASASSN-17fn, ASASSN-17fz, ASASSN-17hw, ASASSN-17kd, ASASSN-17la, PNV J20205397|$+$|2508145

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-12-23
Hajime Inoue

Structures of X-ray emitting magnetic polar regions on neutron stars in X-ray pulsars are studied in the accretion rate range 1017 g s−1–1018 g s−1. It is shown that a thin but tall, radiation-energy-dominated, X-ray emitting polar cone appears at each of the polar regions. The height of the polar cone is several times as large as the neutron star radius. The energy gain due to the gravity of the neutron

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-12-23
Okada N, Hashimoto I, Kimura K, et al.

AbstractWe have developed a system of simultaneous observations in the 22 and 43 GHz bands using the Nobeyama 45 m telescope, and are also working to add the 86 GHz band. Multi-frequency observations are realized by mounting perforated plates in the optics as dichroic frequency-selective devices. This paper presents the development of the perforated plate for the 22 and 43 GHz bands and the results

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-12-23
Gege Wang; Zhongxiang Wang; Liang Chen; Jianeng Zhou; Yi Xing

We search through |$\gamma$|-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope and find 24 blazars (or candidates) that have a single clear flare event in their 9.5 yr long-term light curves. We define these events as loner flares since each flare stands out significantly above the relatively stable, low-flux light curve. We analyze the LAT data in detail

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-12-23
Takuya Inoue; Eiichiro Komatsu; Wako Aoki; Takeshi Chiba; Toru Misawa; Tomonori Usuda

Redshifts of an astronomical body measured at multiple epochs (e.g., separated by 10 yr) are different due to the cosmic expansion. This so-called Sandage–Loeb test offers a direct measurement of the expansion rate of the Universe. However, acceleration in the motion of the Solar System with respect to the cosmic microwave background also changes redshifts measured at multiple epochs. If not accounted

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-12-06
Taichi Kato; Yasuyuki Wakamatsu; Naoto Kojiguchi; Mariko Kimura; Ryuhei Ohnishi; Keisuke Isogai; Keito Niijima; Tomohiro Yoshitake; Yuki Sugiura; Sho Sumiya; Daiki Ito; Kengo Nikai; Hanami Matsumoto; Katsura Matsumoto; Tonny Vanmunster; Franz-Josef Hambsch; Hiroshi Itoh; Julia V Babina; Oksana I Antonyuk; Alex V Baklanov; Elena P Pavlenko; Berto Monard; Shawn Dvorak

IW And stars are a recently recognized group of dwarf novae which are characterized by a repeated sequence of brightening from a standstill-like phase with damping oscillations followed by a deep dip. Kimura et al. (2019, PASJ, submitted) recently proposed a model based on thermal-viscous disk instability in a tilted disk to reproduce the IW And-type characteristics. IM Eri experienced the IW And-type

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-12-06
Michael W Richmond; Masaomi Tanaka; Tomoki Morokuma; Shigeyuki Sako; Ryou Ohsawa; Noriaki Arima; Nozomu Tominaga; Mamoru Doi; Tsutomu Aoki; Ko Arimatsu; Makoto Ichiki; Shiro Ikeda; Yoshifusa Ita; Toshihiro Kasuga; Koji S Kawabata; Hideyo Kawakita; Naoto Kobayashi; Mitsuru Kokubo; Masahiro Konishi; Hiroyuki Maehara; Hiroyuki Mito; Takashi Miyata; Yuki Mori; Mikio Morii; Kentaro Motohara; Yoshikazu Nakada;

Using a prototype of the Tomo-e Gozen wide-field CMOS mosaic camera, we acquire wide-field optical images at a cadence of |$2\:$|Hz and search them for transient sources of duration 1.5 to |$11.5\:$|s. Over the course of eight nights, our survey encompasses the equivalent of roughly two days on one square degree, to a fluence equivalent to a limiting magnitude of about |$V = 15.6$| in a 1-s exposure

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-12-06
Yoichi Takeda

It is known that stellar differential rotation can be detected by analyzing the Fourier transform of spectral line profiles, since the ratio of the first and second zero frequencies is a useful indicator. This approach essentially relies on the conventional formulation that the observed flux profile is expressible as a convolution of the rotational broadening function and the intrinsic profile, which

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-11-28
Ryo Kandori; Motohide Tamura; Masao Saito; Kohji Tomisaka; Tomoaki Matsumoto; Nobuhiko Kusakabe; Jungmi Kwon; Takahiro Nagayama; Tetsuya Nagata; Ryo Tazaki; Ken’ichi Tatematsu

The magnetic field structure, kinematical stability, and evolutionary status of the starless dense core Barnard 68 (B68) are revealed based on the near-infrared polarimetric observations of background stars, measuring the dichroically polarized light produced by aligned dust grains in the core. After subtracting unrelated ambient polarization components, the magnetic fields pervading B68 are mapped

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-11-28
Misaki Hanaoka; Hidehiro Kaneda; Toyoaki Suzuki; Takuma Kokusho; Shinki Oyabu; Daisuke Ishihara; Mikito Kohno; Takuya Furuta; Takuro Tsuchikawa; Futoshi Saito

Galactic infrared (IR) bubbles, which can be seen as shell-like structures at mid-IR wavelengths, are known to possess massive stars within their shell boundaries. In our previous study (Hanaoka, 2019, PASJ, 71, 6), we expanded the research area to the whole Galactic plane (⁠|$0^{\circ } \le l \le 360^{\circ }$|⁠, |$|b| \le 5^{\circ }$|⁠) and studied systematic differences in the shell morphology and

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-11-26
Masashi Nashimoto; Makoto Hattori; Ricardo Génova-Santos; Frédérick Poidevin

Complete studies of the radiative processes of thermal emission from the amorphous dust from microwave through far-infrared wavebands are presented by taking into account, self-consistently for the first time, the standard two-level systems (TLS) model of amorphous materials. The observed spectral energy distributions (SEDs) for the Perseus molecular cloud (MC) and W 43 from microwave through far-infrared

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-11-20
Akio Taniguchi; Yoichi Tamura; Kotaro Kohno; Shigeru Takahashi; Osamu Horigome; Jun Maekawa; Takeshi Sakai; Nario Kuno; Tetsuhiro Minamidani

We propose a new observing method for single-dish millimeter and submillimeter spectroscopy using a heterodyne receiver equipped with a frequency-modulating local oscillator (FMLO). Unlike conventional switching methods, which extract astronomical signals by subtracting the reference spectra of off-sources from those of on-sources, the FMLO method does not need to obtain any off-source spectra; rather

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-11-20
Mizuho Uchiyama; Takuya Yamashita; Koichiro Sugiyama; Tatsuya Nakaoka; Miho Kawabata; Ryosuke Itoh; Masayuki Yamanaka; Hiroshi Akitaya; Koji Kawabata; Yoshinori Yonekura; Yu Saito; Kazuhito Motogi; Kenta Fujisawa

We followed up the massive young stellar object S255-NIRS3 (= S255-IRS1b) during its recent accretion outburst event in the |$K_{\rm s}$| band with Kanata/HONIR for four years after its burst and obtained a long-term light curve. This is the most complete near-infrared light curve of the S255-NIRS3 burst event that has ever been presented. The light curve showed a steep increase reaching a peak flux

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2019-11-07
Naomi Ota; Ikuyuki Mitsuishi; Yasunori Babazaki; Hiroki Akamatsu; Yuto Ichinohe; Shutaro Ueda; Nobuhiro Okabe; Masamune Oguri; Ryuichi Fujimoto; Takashi Hamana; Keita Miyaoka; Satoshi Miyazaki; Hanae Otani; Keigo Tanaka; Ayumi Tsuji; Atsushi Yoshida

We present the first results of a pilot X-ray study of 37 rich galaxy clusters at 0.1 < z < 1.1 in the Hyper Suprime-Cam Subaru Strategic Program field. Diffuse X-ray emissions from these clusters were serendipitously detected in the XMM-Newton fields of view. We systematically analyze X-ray images of 37 clusters and emission spectra of a subsample of 17 clusters with high photon statistics by using

更新日期：2020-04-17
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-18
Fujita S, Tsutsumi D, Ohama A, et al.

Using the NANTEN2 Observatory, we carried out a molecular-line study of high-mass star forming regions with reflection nebulae, NGC 2068 and NGC 2071, in Orion in the $^{13}$CO($J = 2$–1) transition. The $^{13}$CO distribution shows that there are two velocity components at ${9.0}$ and ${10.5}\:$km$\:$s$^{-1}$. The blue-shifted component is in the northeast associated with NGC 2071, whereas the red-shifted

更新日期：2020-03-28
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-12
Yuh Tsunetoe; Shin Mineshige; Ken Ohsuga; Tomohisa Kawashima; Kazunori Akiyama

The spectacular images of the M 87 black hole taken by the Event Horizon Telescope (EHT) have opened a new era of black hole research. One of the next issues is to take polarization images around the central black hole (BH). Since radio emission is produced by synchrotron process, polarization properties should vividly reflect the magnetic field structures at the jet base and thus provide good information

更新日期：2020-03-12
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-12
Tetsu Kitayama; Shutaro Ueda; Takuya Akahori; Eiichiro Komatsu; Ryohei Kawabe; Kotaro Kohno; Shigehisa Takakuwa; Motokazu Takizawa; Takahiro Tsutsumi; Kohji Yoshikawa

We present measurements of the thermal Sunyaev–Zel’dovich effect (SZE) toward SPT-CL J2334-4243 (the Phoenix galaxy cluster) at |$z=0.597$| by the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 3. The SZE is imaged at |$5^{\prime \prime }$| resolution (corresponding to the physical scale of |$23\:h^{-1}\:$|kpc) within |$200\:h^{-1}\:$|kpc from the central galaxy, with the peak signal-to-noise

更新日期：2020-03-12
• Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-09
Masato Tsuboi; Yoshimi Kitamura; Takahiro Tsutsumi; Ryosuke Miyawaki; Makoto Miyoshi; Atsushi Miyazaki

IRS 7 is an M red supergiant star which is located at |${5{^{\prime \prime}_{.}}5}$| north of Sagittarius A|$^\ast$|⁠. We detected firstly the continuum emission at |$340\:$|GHz of IRS 7 using the Atacama Large Millimeter/submillimeter Array (ALMA). The total flux density of IRS 7 is |$S_{\, \nu} =448\pm 45\, \mu$|Jy. The flux density indicates that IRS 7 has a photosphere radius of |$R=1170\pm 60\ 更新日期：2020-03-09 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-09 Kumiko K Nobukawa; Masayoshi Nobukawa; Shigeo Yamauchi We report the discovery of an annular emission of |$\sim\!\! {3^{\prime }}\!-\!{9^{\prime }}$| radius around the center of a transient source, the X-ray burster MAXI J1421-613, in the Suzaku follow-up analysis. The spectrum of the annular emission shows no significant emission-line structure, and is well explained by an absorbed power-law model with a photon index of |$\sim\!\! 4.2$|⁠. These features 更新日期：2020-03-09 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-09 Yoshiaki Sofue Propagation of fast-mode magnetohydrodynamic (MHD) compression waves is traced in the Galactic Center with a poloidal magnetic cylinder. MHD waves ejected from the nucleus are reflected and guided along the magnetic field, exhibiting vertically stretched fronts. The radio threads and non-thermal filaments are explained as due to tangential views of the waves driven by sporadic activity in Sgr A|$^*|⁠ 更新日期：2020-03-09 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-09 Akihiro Inoue; Ken Ohsuga; Tomohisa Kawashima We calculate the pulsed fraction (PF) of the super-critical column accretion flows on to magnetized neutron stars (NSs), of which the magnetic axis is misaligned with the rotation axis, based on the simulation results by Kawashima et al. (2016, PASJ, 68, 83). Here, we solve the geodesic equation for light in the Schwarzschild spacetime in order to take into account the light-bending effect. The gravitational 更新日期：2020-03-09 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-02 Mariko Kimura; Yoji Osaki; Taichi Kato; Shin Mineshige IW And stars are a subgroup of dwarf novae characterized by repetition of the intermediate brightness state with oscillatory variations terminated by brightening. This group of dwarf novae is also known to exhibit a wide variety even within one system in long-term light curves, including the usual dwarf-nova outbursts, Z Cam-type standstills, and so on, besides the typical IW And-type variations mentioned 更新日期：2020-03-02 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-02 Tetsuya Zenko; Tetsuya Nagata; Mikio Kurita; Masaru Kino; Shogo Nishiyama; Noriyuki Matsunaga; Yasushi Nakajima A new method for measuring the global magnetic field structure of the Galactic plane is presented. We have determined the near-infrared polarization of field stars around 52 Cepheids found in recent surveys toward the Galactic plane. The Cepheids are located at the galactic longitudes |-10^{\circ} \le l \le +10.^{\!\!\!\circ }5$| and latitudes |$-0.^{\!\!\!\circ }22\le b \le +0.^{\!\!\!\circ }45$|⁠ 更新日期：2020-03-02 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-02 Gang Cao; Chuyuan Yang; Jianping Yang; Jiancheng Wang The potential association between the blazar TXS 0506+056 and the neutrino event IceCube-170922A provides a unique opportunity to study the possible physical connection between high-energy photons and neutrinos. We explore the correlated electromagnetic and neutrino emissions of blazar TXS 0506+056 by a self-consistent leptonic–hadronic model, taking into account particle stochastic acceleration and 更新日期：2020-03-02 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-02 Kazuyuki Ogura; Hideki Umehata; Yoshiaki Taniguchi; Yuichi Matsuda; Nobunari Kashikawa; Kartik Sheth; Katsuhiro Murata; Masaru Kajisawa; Masakazu A R Kobayashi; Takashi Murayama; Tohru Nagao We present our ALMA Band 8 observations of a damped Ly|$\alpha$| absorption (DLA) system at |$z = 3.150$| observed in the spectrum of the quasar Q2233+131 at |$z = 3.295$|⁠. The optical counterpart of this DLA has been identified and it shows a double-peaked Ly|$\alpha$| emission line. Since one possible origin of DLAs at high redshift is an outflowing gas from star-forming galaxies, DLA 2233+131 provides 更新日期：2020-03-02 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-02 Yoichi Takeda; Satoshi Honda; Hikaru Taguchi; Osamu Hashimoto An extensive spectroscopic study on ξ Boo A (a chromospherically active solar-type star) was conducted based on the spectra obtained from 2008 December through to 2010 May, with the aim of detecting any spectrum variability and understanding its physical origin. For each spectrum, the atmospheric parameters were spectroscopically determined based on Fe lines, and the equivalent widths (along with the 更新日期：2020-03-02 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-03-02 Zhong-Yi Lin The green comet C/2007 N3 (Lulin) is a new Oort cloud comet that has a retrograde orbit (inclination of |$178^{\circ }$|⁠). It reached its perihelion on 2009 January 10, and its closest distance to Earth was 0.411 astronomical units (au) on February 24. Soon after its discovery on 2007 July 11, the coma activity of Comet Lulin was monitored closely by an Super Light Telescope 41 cm telescope until 更新日期：2020-03-02 • Publ. Astron. Soc. Jpn. (IF 2.75) Pub Date : 2020-02-27 Yuki Chiba; Satoru Katsuda; Takashi Yoshida; Koh Takahashi; Hideyuki Umeda We report on robust measurements of elemental abundances of the Type IIn supernova SN 1978K, based on the high-resolution X-ray spectrum obtained with the Reflection Grating Spectrometer (RGS) onboard XMM-Newton. The RGS clearly resolves a number of emission lines, including N Ly|$\alpha$|⁠, O Ly|$\alpha$|⁠, O Ly|$\beta$|⁠, Fe xvii, Fe xviii, Ne He|$\alpha$|⁠, and Ne Ly|$\alpha\$| for the first time

更新日期：2020-02-27
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