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Optical and soft X-ray light-curve analysis during the 2022 eruption of U Scorpii: Structural changes in the accretion disk Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-03-07 Katsuki Muraoka, Naoto Kojiguchi, Junpei Ito, Daisaku Nogami, Taichi Kato, Yusuke Tampo, Kenta Taguchi, Keisuke Isogai, Teofilo Arranz, John Blackwell, David Blane, Stephen M Brincat, Graeme Coates, Walter Cooney, Shawn Dvorak, Charles Galdies, Daniel Glomski, Franz-Josef Hambsch, Barbara Harris, John Hodge, Jose L Hernández-Verdejo, Marco Iozzi, Hiroshi Itoh, Seiichiro Kiyota, Darrell Lee, Magnus
We present our optical photometric observations of the 2022 eruption of the recurrent nova U Scorpii (U Sco) using 49152 data points over 70 d following the optical peak. We have also analyzed its soft X-ray (0.3–1 keV) light curve by the Neil Gehrels Swift Observatory. During the 2022 eruption, the optical plateau stage started 13.8–15.0 d and ended 23.8–25.0 d after the optical peak. The soft X-ray
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Impulsive gas fueling to the galactic center in a barred galaxy due to falls of gas clouds Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-03-07 Hidenori Matsui, Toshiyasu Masakawa, Asao Habe, Takayuki R Saitoh
We have studied the evolution of the central hundred parsec region of barred galaxies by performing numerical simulations realizing the multi-phase nature of gas. Our simulations have shown that a stellar bar produces an oval gas ring, namely the x-2 ring, within 1 kpc as the bar grows. The ring is self-gravitationally unstable enough to trigger the formation of gas clouds. Although the gas clouds
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Peak energy–isotropic luminosity correlation and jet opening angle evolution in Swift-BAT short GRBs with soft-tail emission Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-03-06 Naoki Ogino, Daisuke Yonetoku, Makoto Arimoto, Tatsuya Sawano, Hamid Hamidani
Some short gamma-ray bursts (SGRBs) exhibit a short-duration and spectral hard emission (referred to as a “hard spike”) followed by a slightly longer soft emission (known as a “soft tail”). We identified nine SGRBs with the known redshift in the Swift/BAT gamma-ray burst catalog by specifically searching for the soft tail. We found that the spectra of these SGRBs can be described as a cutoff power-law
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Model of a “Warm Corona” as the origin of the soft X-ray excess of active galactic nuclei Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-02-27 Norita Kawanaka, Shin Mineshige
The soft X-ray excess in the spectra of active galactic nuclei is characterized by similar electron temperatures of 0.1–0.3 keV and similar photon indices around 2.2–3, if fitted with inverse Comptonization. It remains a puzzle why both values are not sensitive to the black hole mass nor the accretion rate. Supposing that the scattering-dominated surface layer of an accretion disk can act as a warm
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Discovery of diffuse radio source in Abell 1060 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-02-24 Kohei Kurahara, Takuya Akahori, Aika Oki, Yuki Omiya, Kazuhiro Nakazawa
Non-thermal components in the intra-cluster medium (ICM), such as turbulence, magnetic field, and cosmic rays, imprint the past and current energetic activities of jets from active galactic nuclei (AGN) of member galaxies as well as disturbance caused by galaxy cluster mergers. Meter- and centimeter-radio observations of synchrotron radiation allow us to diagnose the nonthermal component. Here we report
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Near-ultraviolet radiation toward molecular cloud N4 in W 50/SS 433: Evidence for direct interaction of the jet with molecular cloud Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-02-17 Hiroaki Yamamoto, Tatsumi Ishikawa, Tsutomu T Takeuchi
We compared the molecular clouds in the western part of SS 433 with near-ultraviolet radiation data obtained from GALEX. Near-ultraviolet radiation is prominently confirmed toward only N4, while no near-ultraviolet radiation is detected toward N1, N2, or N3. The radiative region of near-ultraviolet radiation is nearly the same as the CO-emitting region in N4, and does not extend beyond the jet seen
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Synthesized modeling and active disturbance rejection control for the Leighton Chajnantor Telescope Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-02-13 Weirui Chen, Yiwei Yao, Zheng Wang
The Caltech Submillimeter Observatory telescope was completely disassembled in 2023 October and will be shipped from Hawaii, USA to the new site at Chajnantor Plateau, Chile in 2024, where it is expected to be refurbished and renamed the Leighton Chajnantor Telescope (LCT). Since the much stronger wind load at the new site will provide a great challenge for LCT’s realization of a higher pointing and
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Hitomi HXT deconvolution imaging of the Crab Nebula dazzled by the Crab pulsar Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-02-09 Mikio Morii, Yoshitomo Maeda, Hisamitsu Awaki, Kouichi Hagino, Manabu Ishida, Koji Mori
We develop a new deconvolution method to recover the precise Crab Nebula image taken by the Hitomi HXT, suppressing the artifact due to the bright Crab pulsar. We extend the Richardson–Lucy method, introducing two components corresponding to the nebula and pulsar with regularization for smoothness and flux, respectively, and performing simultaneous deconvolution of multi-pulse-phase images. The structures
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Detection of the neutral iron line from the supernova remnant W 49 B with Suzaku Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-02-08 Nari Suzuki, Shigeo Yamauchi, Kumiko K Nobukawa, Masayoshi Nobukawa, Satoru Katsuda
Recent studies of supernova remnants (SNRs) have revealed that some SNRs exhibit a neutral iron line emission at 6.4 keV. This line has been proposed to originate from the interaction of high-energy particles formed in the SNR shell with the surrounding cold matter. We searched for the neutral iron line emission in the SNR W 49 B. Significant detection of the 6.4 keV line is found in the north-west
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Census for the rest-frame optical and UV morphologies of galaxies at z = 4–10: First phase of inside-out galaxy formation Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-02-07 Yoshiaki Ono, Yuichi Harikane, Masami Ouchi, Kimihiko Nakajima, Yuki Isobe, Takatoshi Shibuya, Minami Nakane, Hiroya Umeda, Yi Xu, Yechi Zhang
We present the rest-frame optical and UV surface brightness (SB) profiles for 149 galaxies with Mopt < −19.4 mag at z = 4–10 (29 of which are spectroscopically confirmed with JWST NIRSpec), securing high signal-to-noise ratios of 10–135 with deep JWST NIRCam 1–$5\, \mu$m images obtained by the CEERS survey. We derive morphologies of our high-z galaxies, carefully evaluating the systematics of SB profile
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The Milky Way tomography with Subaru Hyper Suprime-Cam. I. Halo substructures Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-31 Yoshihisa Suzuki, Masashi Chiba, Yutaka Komiyama, Kohei Hayashi, Masayuki Tanaka, Tetsuya Fukushima, Scott G Carlsten, Akira Tokiwa, Tian Qiu, Masahiro Takada
We analyze the photometric data in the Wide layer of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) over ∼1200 deg2 to uncover new halo substructures beyond the distance, D⊙ ∼ 30 kpc, from the Sun. For this purpose, we develop an isochrone filter for an old, metal-poor stellar system to extract the faint main-sequence stars at a range of distances. With this method, we detect not only the
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Multiwavelength observation of an active M-dwarf star EV Lacertae and its stellar flare accompanied by a delayed prominence eruption Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-29 Shun Inoue, Teruaki Enoto, Kosuke Namekata, Yuta Notsu, Satoshi Honda, Hiroyuki Maehara, Jiale Zhang, Hong-Peng Lu, Hiroyuki Uchida, Takeshi Go Tsuru, Daisaku Nogami, Kazunari Shibata
We conducted four-night multiwavelength observations of an active M-dwarf star EV Lacertae on 2022 October 24–27 with simultaneous coverage of soft X-rays (NICER; 0.2–12 keV, Swift XRT; 0.2–10 keV), near-ultraviolet (Swift UVOT/UVW2; 1600–3500 Å), optical photometry (TESS; 6000–10000 Å), and optical spectroscopy (Nayuta/MALLS; 6350–6800 Å). During the campaign, we detected a flare starting at 12:28
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GALAXY CRUISE: Spiral and ring classifications for bright galaxies at z = 0.01–0.3 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-29 Rhythm Shimakawa, Masayuki Tanaka, Kei Ito, Makoto Ando
This paper presents a morphology classification catalog of spiral and ring features of 59854 magnitude-limited galaxies (r < 17.8 mag, and additional 628005 subsamples down to r = 20 mag) at z = 0.01–0.3 based on the Third Public Data Release of the Hyper Suprime-Cam Subaru Strategic Program. We employ two deep-learning classifiers to determine the spiral and ring structures separately based on GALAXY
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Trigonometric parallax and proper motion of Sagittarius A* measured by VERA using the new broad-band back-end system OCTAVE-DAS Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-27 Tomoaki Oyama, Takumi Nagayama, Aya Yamauchi, Daisuke Sakai, Hiroshi Imai, Mareki Honma, Yu Asakura, Kazuhiro Hada, Yoshiaki Hagiwara, Tomoya Hirota, Takaaki Jike, Yusuke Kono, Syunsaku Suzuki, Hideyuki Kobayashi, Noriyuki Kawaguchi
We successfully measured the trigonometric parallax of Sagittarius A* (Sgr A*) to be 117 ± 17 micro-arcseconds ($\, \mu \mbox{as}$) using the VLBI Exploration of Radio Astrometry (VERA) with the newly developed broad-band signal-processing system named “OCTAVE-DAS.” The measured parallax corresponds to a Galactocentric distance at the Sun of $R_0 = 8.5^{+1.5}_{-1.1}\:$kpc. By combining the astrometric
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Absolute properties of the oscillating eclipsing Algol XZ Ursae Majoris Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-25 Jae Woo Lee, Kyeongsoo Hong, Hye-Young Kim, Marek Wolf, Jang-Ho Park, Pakakaew Rittipruk
It is known from archival TESS data that the semi-detached Algol system XZ Ursae Majoris (UMa) is one of the candidate binary stars exhibiting short-period oscillations. We secured new high-resolution spectroscopic observations for the program target to better understand its binary and pulsation properties. From the echelle spectra, the radial velocities (RVs) of the eclipsing pair were derived, and
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Survivability of amorphous ice in comets depends on the latent heat of crystallization of impure water ice Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-22 Sota Arakawa, Shigeru Wakita
Comets are believed to have amorphous rather than crystalline ice at the epoch of their accretion. Cometary ice contains some impurities that govern the latent heat of ice crystallization, Lcry. However, it is still controversial whether the crystallization process is exothermic or endothermic. In this study, we perform one-dimensional simulations of the thermal evolution of kilometer-sized comets
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Survey of public attitudes toward astronomy in Japan Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-20 Naohiro Takanashi, Masaaki Hiramatsu, Shio Kawagoe, Nobuhiko Kusakabe, Koki Sawada, Harufumi Tamazawa
We report on the results of a survey we conducted on the Japanese public’s attitudes toward astronomy. This survey was conducted via an online questionnaire, with 2000 responses received. Based on these data, we present what kind of interest the general public in Japan has in astronomy. We also conducted a questionnaire survey of those involved in communicating astronomy to the public, in order to
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The variability of the broad line profiles of SDSS J1430+2303 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-12 Atsushi Hoshi, Toru Yamada, Kouji Ohta
It has been argued that SDSS J1430+2303 possesses a supermassive black hole binary that has been predicted to merge within a few months or three years from 2022 January. We have conducted follow-up optical spectroscopic observations of SDSS J1430+2303 with the KOOLS-IFU on the Seimei Telescope in 2022 May, June, and July, and 2023 April. The observed spectrum around Hα shows a central broad component
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The history of the Milky Way: The evolution of star formation, cosmic rays, metallicity, and stellar dynamics over cosmic time Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-12 Jiro Shimoda, Shu-ichiro Inutsuka, Masahiro Nagashima
We study the long-term evolution of the Milky Way (MW) over cosmic time by modeling the star formation, cosmic rays, metallicity, stellar dynamics, outflows, and inflows of the galactic system to obtain various insights into the galactic evolution. The mass accretion is modeled by the results of cosmological N-body simulations for the cold dark matter. We find that the star formation rate is about
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X-ray iron absorption line in Swift J1858.6−0814 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2024-01-12 Kazumi Asai, Tatehiro Mihara, Kento Sakai, Aya Kubota
We present the spectral analysis of bright steady states in an outburst of the transient neutron star low-mass X-ray binary Swift J1858.6−0814 observed with the Neutron star Interior Composition Explorer (NICER). We detected an ionized iron K absorption line (H-like Fe) at 6.97 keV in the spectrum. We estimate the photoionization parameter using the ratio of the equivalent widths of the Fe xxvi (H-like)
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Tentative detection of cyanoformamide NCCONH2 in space Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-12-18 Juan Li, Donghui Quan, Junzhi Wang, Xia Zhang, Xing Lu, Qian Gou, Feng Gao, Yajun Wu, Edwin Bergin, Shanghuo Li, Zhiqiang Shen, Fujun Du, Meng Li, Siqi Zheng, Xingwu Zheng
The peptide-like molecule cyanoformamide (NCCONH2) is the cyano (CN) derivative of formamide (NH2CHO). It is known to play a role in the synthesis of nucleic acid precursors under prebiotic conditions. In this paper, we present a tentative detection of NCCONH2 in the interstellar medium with the Atacama Large Millimeter/submillimeter Array (ALMA) archive data. 10 unblended lines of NCCONH2 were seen
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KAgoshima Galactic Object survey with Nobeyama 45 m telescope by Mapping in Ammonia lines (KAGONMA): Discovery of parsec-scale CO depletion in the Canis Major star-forming region Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-12-07 Yushi Hirata, Takeru Murase, Junya Nishi, Yoshito Shimajiri, Toshihiro Omodaka, Makoto Nakano, Kazuyoshi Sunada, Takumi Ito, Toshihiro Handa
In observational studies of infrared dark clouds, the number of detections of CO freeze-out on to dust grains (CO depletion) at the pc scale is extremely limited, and the conditions for its occurrence are, therefore, still unknown. We report a new object where pc-scale CO depletion is expected. As part of the Kagoshima Galactic Object survey with Nobeyama 45 m telescope by Mapping in Ammonia lines
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Sulfur isotopes toward the extended envelope of Sagittarius B2 in the Galactic Center Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-12-04 Qingxu Li, Juan Li, Siqi Zheng, Junzhi Wang, Feng Gao, Yajun Wu
Isotopic ratios are good tools for probing stellar nucleosynthesis and chemical evolution. We perform high-sensitivity mapping observations of the J = 7–6 rotational transitions of OCS, OC34S, O13CS, and OC33S toward the Galactic Center giant molecular cloud Sagittarius B2 with the IRAM 30 m telescope. Positions with optically thin and uncontaminated lines are chosen to determine the sulfur isotope
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Magnetic activity variability of nearby bright Sun-like stars by 4 yr intensive Hα line monitoring Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-12-04 Sanghee Lee, Yuta Notsu, Bun’ei Sato
We report intensive monitoring of the activity variability in the Hα line for 10 Sun-like stars using the 1.88 m reflector at Okayama Branch Office, Subaru Telescope, during the last four years (2019–2022). Our aim was to investigate features of the stellar magnetic activity behavior. We correlated the Hα line variability of each star with the stellar activity levels derived from the Ca ii H&K line
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HINOTORI I: The nature of rejuvenation galaxies Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-11-28 Takumi S Tanaka, Kazuhiro Shimasaku, Sandro Tacchella, Makoto Ando, Kei Ito, Hassen M Yesuf, Suin Matsui
We present the HINOTORI (Star Formation History Investigation To Find Rejuvenation) project to reveal the nature of rejuvenation galaxies (RGs), which are galaxies that restarted their star formation after being quiescent. As the first step of HINOTORI, we construct the largest RG sample with 1071 sources. We select these RGs from 8857 MaNGA (Mapping Nearby Galaxies at APO) survey galaxies by reconstructing
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12CO and 13CO observation of the low-metallicity dwarf galaxy DDO 154 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-11-17 Shinya Komugi, Miku Inaba, Tetsuo Shindou
The conversion factor from carbon monoxide (CO) intensity to molecular gas mass is a source of large uncertainty in understanding gas and its relation to star formation in galaxies. In particular, the conversion factor in low-metallicity environments have remained elusive, as currently only two galaxies have been detected in any CO isotopes in environments with 12 + log (O$/$H) < 8.0. Here we report
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The soft X-ray background with Suzaku. II. Supervirial temperature bubbles? Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-11-14 Hayato Sugiyama, Masaki Ueda, Kotaro Fukushima, Shogo B Kobayashi, Noriko Y Yamasaki, Kosuke Sato, Kyoko Matsushita
Observations of the hot X-ray emitting interstellar medium in the Milky Way are important for studying the stellar feedback and for understanding the formation and evolution of galaxies. We present measurements of the soft X-ray background emission for 130 Suzaku observations at 75° < l < 285° and |b| > 15°. With the standard soft X-ray background model consisting of the local hot bubble and of the
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Seimei/KOOLS-IFU mapping of the gas and dust distributions in Galactic PNe: Unveiling the origin and evolution of the Galactic halo PN H4-1 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-10-27 Masaaki Otsuka, Toshiya Ueta, Akito Tajitsu
H4-1 is a planetary nebula (PN) located in the Galactic halo, and is notably carbon-rich and one of the most metal-deficient PNe in the Milky Way. To unveil its progenitor evolution through accurate measurement of the gas mass, we conducted a comprehensive investigation of H4-1, using the newly obtained Seimei/KOOLS-IFU spectra and multiwavelength spectro-photometry data. The emission-line images generated
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A comparative study of three modes of s-process nucleosynthesis in extremely metal-poor AGB stars Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-10-18 Shimako Yamada, Takuma Suda, Yutaka Komiya, Masayuki Aikawa, Masayuki Y Fujimoto
Carbon-enhanced metal-poor (CEMP) stars in the Galactic halo have a wide range of neutron-capture element abundance patterns. To identify their origin, we investigate three modes of s-process nucleosynthesis that have been proposed to operate in extremely metal-poor asymptotic giant branch (AGB) stars: convective 13C burning, which occurs when hydrogen is engulfed by helium-flash convection in low-mass
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Solar horizontal flow evaluation using neural network and numerical simulations with snapshot data Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-09-23 Hiroyuki Masaki, Hideyuki Hotta, Yukio Katsukawa, Ryohtaroh T Ishikawa
We suggest a method that evaluates the horizontal velocity in the solar photosphere with easily observable values using a combination of neural network and radiative magnetohydrodynamics simulations. All three-component velocities of thermal convection on the solar surface have important roles in generating waves in the upper atmosphere. However, the velocity perpendicular to the line of sight (LoS)
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Water maser distributions and their internal motions in the Sagittarius B2 complex Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-09-20 Daisuke Sakai, Tomoaki Oyama, Takumi Nagayama, Mareki Honma, Hideyuki Kobayashi
We conducted a multi-epoch very long baseline interferometry (VLBI) observation of 22 GHz H2O maser sources, which are associated with the Sagittarius B2 (Sgr B2) complex, one of the most active star-forming regions in the Galactic center. Using the VLBI exploration of radio astrometry (VERA) array, we detected 29, 90, and seven maser features in Sgr B2(North), (Main), and (South), respectively. We
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Discovery of a molecular cloud possibly associated with the youngest Galactic SNR G1.9+0.3 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-09-04 Rei Enokiya, Hidetoshi Sano, Miroslav D Filipović, Rami Z E Alsaberi, Tsuyoshi Inoue, Tomoharu Oka
The youngest known Galactic supernova remnant (SNR) G1.9+0.3 has high-velocity supernova shock beyond 10000 km s−1, and it is considered to be one of the major candidates of a PeVatron. Despite these outstanding properties, the surrounding interstellar matter of this object is poorly understood. We investigated the interstellar gas toward G1.9+0.3 using the 12CO(J = 3−2) data with the angular resolution
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Bright Type II supernova 2023ixf in M 101: A quick analysis of the early-stage spectra and near-infrared light curves Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-08-18 Masayuki Yamanaka, Mitsugu Fujii, Takahiro Nagayama
We present early-stage analyses of low-resolution (R = 1000) optical spectra and near-infrared light curves of the bright Type II supernova (SN II) 2023ixf in the notable nearby face-on spiral galaxy M 101, which were obtained from t = 1.7 to 8.0 d. Our first spectrum showed remarkable emission features of the Balmer series, He ii, N iii, C iv, and N iv with a strong blue continuum. Compared with the
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The additional pressure of white dwarf stars generated by net charges Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-08-09 Ting-Han Pei
The upper-mass limit of a white dwarf star is predicted to be 1.44 ${M}_{\odot} $ based on an ideally degenerate Fermi electron gas at a temperature of absolute zero. However, more conditions should be considered, such as temperature and charge. In this research, first, we use the grand partition function in statistical mechanics to build expressions for the electron gas pressure and the particle number
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The correlation between the 500 pc scale molecular gas masses and AGN powers for massive elliptical galaxies Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-08-03 Yutaka Fujita, Takuma Izumi, Nozomu Kawakatu, Hiroshi Nagai, Ryo Hirasawa, Yu Ikeda
Massive molecular clouds have been discovered in massive elliptical galaxies at the center of galaxy clusters. Some of this cold gas is expected to flow in the central supermassive black holes and activate galactic nucleus (AGN) feedback. In this study, we analyze archival Atacama Large Millimeter Array (ALMA) data of nine massive elliptical galaxies, focusing on CO line emissions, to explore the circumnuclear
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Plasma diagnostics and Alfvén wave heating of solar prominences by multiwavelength observations Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-07-27 Yuki Hashimoto, Kiyoshi Ichimoto, Yuwei Huang
Solar prominences are cool and dense plasma supported by the magnetic field in the solar corona. They are composed of fine-scale structures called threads. Prominences are heated by the incident radiation from the solar atmosphere, but previous studies have shown that additional heating is necessary to maintain the temperature of prominences of about 104 K. This study aims to investigate quantitatively
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Cosmic-ray-driven enhancement of the C0/CO abundance ratio in W 51 C Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-07-25 Mitsuyoshi Yamagishi, Kenji Furuya, Hidetoshi Sano, Natsuko Izumi, Tatsuya Takekoshi, Hidehiro Kaneda, Kouichiro Nakanishi, Takashi Shimonishi
We examine spatial variations of the C0$/$CO abundance ratio (XC/CO) in the vicinity of the γ-ray supernova remnant W 51 C, based on [C i] (3P1–3P0), 12CO(1–0), and 13CO(1–0) observations with the ASTE and Nobeyama 45 m telescopes. We find that XC/CO varies in a range of 0.02–0.16 (0.05 in median) inside the molecular clouds of AV > 100 mag, where photodissociation of CO by the interstellar UV is negligible
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Suzaku spectral analysis of an X-ray emitting plasma in the supernova remnant G352.7−0.1 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-07-25 Asahi Fujishige, Shigeo Yamauchi, Kumiko K Nobukawa, Masayoshi Nobukawa
The results of a Suzaku observation of the supernova remnant (SNR) G352.7−0.1 are presented in this paper. We conducted spectral analysis based on careful sky background estimation and found an emission line from Al at 1.6 keV, in addition to previously detected emission lines from Mg, Si, S, Ar, Ca, and Fe ions. The X-ray spectrum in the 0.7–10 keV band is represented by a two-component ionizing plasma
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A 3 mm molecular line survey toward the C-star envelope CIT 6 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-07-18 Kuilu Yang, Yong Zhang, Jianjie Qiu, Yina Ao, Xiaohu Li
We present an unbiased molecular line survey toward the carbon-rich circumstellar envelope CIT 6 carried out between 90 and 116 GHz with the Arizona Radio Observatory 12 m telescope. A total of 42 lines assigned to 10 molecular species and four isotopologues are detected. Despite the absence of any newly identified circumstellar molecules, several transitions are freshly reported for this object. This
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Data processing pipeline for multiple-exposure photo-plate digital archives Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-06-28 Peng Jia, Zhimin Yang, Zhengjun Shang, Yong Yu, Jianhai Zhao
Photo-plates are an invaluable historical legacy that have been used for over a hundred years to capture images of celestial objects. By digitizing these photo-plates and processing the images with digital image processing methods, scientists can study celestial objects that exhibit temporal variations. Multiple-exposure photo-plates are a unique type of observation data that can capture images of
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Nobeyama 45 m CO J = 1–0 observations of luminous type 1 AGNs at z ≈ 0.3 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-06-24 Tomonari Michiyama, Ming-Yang Zhuang, Jinyi Shangguan, Hassen M Yesuf, Hiroyuki Kaneko, Luis C Ho
We have performed CO J = 1–0 observations of 10 galaxies hosting luminous (Lbol > 1046 erg s−1) type 1 active galactic nuclei (AGNs) with the Nobeyama 45 m radio telescope. The targets are selected because they are expected to be rich in molecular gas based on their high nebular dust extinction (AV). However, no significant CO emission lines were detected in any of the targets. The upper limits of
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Magnetic configurations related to the coronal heating and solar wind generation. II. Quantitative characterization of active-region magnetic structure based on the geometric property of force-free α Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-06-13 Yeonwoo Jang, Sibaek Yi, Tetsuya Magara
We investigate the geometric property of a scalar position function, the so-called force-free α, to see how it quantitatively characterizes the magnetic structure of solar active regions, which is reminiscent of the electrostatic potential whose geometric property provides information on the structure of electrified objects. Scatter plots of (α, ∇2α) show characteristic shapes representing twisted
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CO multi-line imaging of nearby galaxies (COMING). XII. CO-to-H2 conversion factor and dust-to-gas ratio Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-06-10 Atsushi Yasuda, Nario Kuno, Kazuo Sorai, Kazuyuki Muraoka, Yusuke Miyamoto, Hiroyuki Kaneko, Yoshiyuki Yajima, Takahiro Tanaka, Kana Morokuma-Matsui, Tsutomu T Takeuchi, Masato I N Kobayashi
We simultaneously measured the spatially resolved CO-to-H2 conversion factor (αCO) and dust-to-gas ratio (DGR) in nearby galaxies on a kiloparsec scale. In this study, we used 12CO(J = 1–0) data obtained by the Nobeyama 45 m radio telescope with H i and dust mass surface densities. We obtained the values of global αCO and DGR in 22 nearby spiral galaxies, with averages of 2.66 ± 1.36 M⊙ pc−2 (K km
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Detection of six massive contact binaries with tertiary component candidates in the Small Magellanic Cloud Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-06-08 Chu-Qi Wu, Sheng-Bang Qian, Fu-Xing Li, Li-Ying Zhu, Er-Gang Zhao, Wen-Ping Liao
To study massive binaries in different evolution stages or environments, we use the Small Magellanic Cloud (SMC) as our target because the metallicity in the SMC is much lower than that in our Milky Way. The period change of early-type close binary systems in the SMC was studied based on OGLE collections. Six of these systems are found to have periodic period changes. Since all of them are of early
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Very long baseline interferometry imaging of H2O maser emission in the nearby radio galaxy NGC 4261 Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-05-25 Satoko Sawada-Satoh, Nozomu Kawakatu, Kotaro Niinuma, Seiji Kameno
We report dual-frequency very long baseline interferometry (VLBI) observations at 22 and 43 GHz toward the nucleus of a nearby radio galaxy NGC 4261. In particular, we present a VLBI image of the 22 GHz H2O maser line and its location in the circumnuclear region of NGC 4261. H2O maser emission is marginally detected above the three times the image rms level at channels within a velocity range of approximately
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The mass of TOI-519 b: A close-in giant planet transiting a metal-rich mid-M dwarf Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-05-19 Taiki Kagetani, Norio Narita, Tadahiro Kimura, Teruyuki Hirano, Masahiro Ikoma, Hiroyuki Tako Ishikawa, Steven Giacalone, Akihiko Fukui, Takanori Kodama, Rebecca Gore, Ashley Schroeder, Yasunori Hori, Kiyoe Kawauchi, Noriharu Watanabe, Mayuko Mori, Yujie Zou, Kai Ikuta, Vigneshwaran Krishnamurthy, Jon Zink, Kevin Hardegree-Ullman, Hiroki Harakawa, Tomoyuki Kudo, Takayuki Kotani, Takashi Kurokawa, Nobuhiko
We report on the determination of the mass of TOI-519 b, a transiting substellar object around a mid-M dwarf. We carried out radial velocity measurements using Subaru/InfraRed Doppler (IRD), revealing that TOI-519 b is a planet with a mass of $0.463^{+0.082}_{-0.088}\, M_{\rm Jup}$. We also found that the host star is metal rich ([Fe/H] = 0.27 ± 0.09 dex) and has the lowest effective temperature (Teff
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Photometric analysis on RZ Horologii: An evolved and active Algol with a δ Scuti component Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-05-16 Huiting Zhang, Shengbang Qian, Wenping Liao
RZ Hor (TIC 31653503) is a long-period (P = 6.68 d) EA-type eclipsing binary that exhibits both chromospheric activity and oscillation. The physical properties of RZ Hor are determined with binary modelling for the first time. It is found that it has a semi-detached configuration with a low mass ratio of q = 0.1606(13), where the secondary component is filled with its Roche lobe. By analyzing all available
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New results on the two low-mass-ratio overcontact binaries V1309 Herculis and AS Coronae Borealis Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-05-08 Azizbek Matekov, Fangbin Meng, Shengbang Qian, Ildar Asfandiyarov, Linjia Li, Shuhrat Ehgamberdiev, Liying Zhu
We present new multi-color light curves of V1309 Her and AS CrB, which were observed by the 60 cm telescope located at the Maidanak Astronomical Observatory. Combined with the Large-Sky-Area Multi-Object Fiber Spectroscopic Telescope atmospheric parameters, we analyzed our BVRCIC light curves for both systems by employing the Wilson–Devinney program. Our results show that both systems are low-mass-ratio
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Predicting the 25th and 26th solar cycles using the long short-term memory method Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-05-02 Xiaohuan Liu, Shuguang Zeng, Linhua Deng, Xiangyun Zeng, Sheng Zheng
Solar activities directly or indirectly affect space missions, geophysical environment, space climate, and human activities. We used the long short-term memory (LSTM) deep learning method to predict the amplitude and peak time of solar cycles (SCs) 25 and 26 by using the monthly relative sunspot number data taken from the National Astronomical Observatory of Japan (NAOJ). The dataset is divided into
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Magnetic field of solar dark filaments obtained from He i 10830 Å spectropolarimetric observation Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-30 Daiki Yamasaki, Yu Wei Huang, Yuki Hashimoto, Denis P Cabezas, Tomoko Kawate, Satoru UeNo, Kiyoshi Ichimoto
Solar filaments are dense, cool plasma clouds in the solar corona. They are supposed to be supported in a dip of the coronal magnetic field. However, the models still disagree between two types of field configuration; one is the normal polarity model proposed by Kippenhahn and Schlueter (1957, Z. Astrophys., 43, 36), and the other is the reverse polarity model proposed by Kuperus and Raadu (1974, A&A
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Transient jet ejections associated with limit-cycle behaviors in the very high state of black hole binaries Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-26 Hajime Inoue
The ejection mechanism of transient relativistic jets from black hole binaries is studied. Based on observations of the limit-cycle behaviors of the superluminal jet source GRS 1915+105, we infer that transient jet ejections could happen just after the slim disk emerging from the standard disk at some distance runs over the standard disk and reaches the vicinity of the central black hole. The standard
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Synthetic red supergiant explosion model grid for systematic characterization of Type II supernovae Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-25 Takashi J Moriya, Bhagya M Subrayan, Dan Milisavljevic, Sergei I Blinnikov
A new model grid containing 228016 synthetic red supergiant explosions (Type II supernovae) is introduced. Time evolution of spectral energy distributions from 1 to 50000 Å (100 frequency bins in a log scale) is computed at each time step up to 500 d after explosion in each model. We provide light curves for the filters of Vera C, Rubin Observatory’s Legacy Survey of Space and Time (LSST), the Zwicky
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Investigating physical states of molecular gas in the overlapping region of interacting galaxies NGC 4567/4568 using ALMA Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-21 Hiroyuki Kaneko, Shoya Tokita, Nario Kuno
We present ALMA observations of a diffuse gas tracer, CO(J = 1–0), and a warmer and denser gas tracer, CO(J = 3–2), in the overlapping region of interacting galaxies NGC 4567/4568, which are in the early stage of interaction. To understand the impact of galaxy interactions on molecular gas properties, we focus on interacting galaxies during the early stage and study their molecular gas properties.
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The asymmetric sunrise effect on Thales’ alleged measurement of the Sun angular size Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-20 Jorge Cuadra
Reports from the second and third centuries AD attribute the first measurement of the angular size of the Sun to Thales of Miletus, in the sixth century BC. Cleomedes, also in the second century AD, described a method to perform the measurement based on timing the duration of the sunrise. Several modern authors have suggested that Thales used Cleomedes’ method, but others are skeptical of the connection
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2021 superoutburst of the WZ Sge-type dwarf nova V627 Pegasi lacks an early superhump phase Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-18 Yusuke Tampo, Taichi Kato, Naoto Kojiguchi, Sergey Yu Shugarov, Hiroshi Itoh, Katsura Matsumoto, Momoka Nakagawa, Yukitaka Nishida, Michael Richmond, Masaaki Shibata, Junpei Ito, Gulchehra Kokhirova, Firuza Rakhmatullaeva, Tamás Tordai, Seiichiro Kiyota, Javier Ruiz, Pavol A Dubovsky, Tomáš Medulka, Elena P Pavlenko, Oksana I Antonyuk, Aleksei A Sosnovskij, Aleksei V Baklanov, Viktoriia Krushevska
Superoutbursts in WZ Sge-type dwarf novae (DNe) are characterized by both early superhumps and ordinary superhumps originating from the 2 : 1 and 3 : 1 resonances, respectively. However, some WZ Sge-type DNe show a superoutburst lacking early superhumps; it is not well established how these differ from superoutbursts with an early superhump phase. We report time-resolved photometric observations of
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Novel application to estimate the mass-loss and the dust-formation rates in O-type gamma-ray binaries using near-infrared photometry Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-14 Yuki Moritani, Akiko Kawachi, Atsuo T Okazaki, Sho Chimasu, Hiromi Yoshida
We have performed the near-infrared photometric monitoring observations of two TeV gamma-ray binaries with O-stars (LS 5039 and 1FGL J1018.6−5856), using IRSF/SIRIUS at SAAO, in order to study the stellar parameters and their perturbations caused by the binary interactions. The whole orbital phase was observed multiple times and no significant variabilities including orbital modulations were detected
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Detection of a new molecular cloud in the LHAASO J2108+5157 region supporting a hadronic PeVatron scenario Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-12 Eduardo de la Fuente, Ivan Toledano-Juarez, Kazumasa Kawata, Miguel A Trinidad, Daniel Tafoya, Hidetoshi Sano, Kazuki Tokuda, Atsushi Nishimura, Toshikazu Onishi, Takashi Sako, Binita Hona, Munehiro Ohnishi, Masato Takita
PeVatrons are the most powerful naturally occurring particle accelerators in the Universe. The identification of counterparts associated to astrophysical objects such as dying massive stars, molecular gas, star-forming regions, and star clusters is essential to clarify the underlying nature of the PeV emission, i.e., hadronic or leptonic. We present 12,13CO (J = 2→1) observations made with the 1.85
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Multicolor and multi-spot observations of Starlink’s Visorsat Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-08 Takashi Horiuchi, Hidekazu Hanayama, Masatoshi Ohishi, Tatsuya Nakaoka, Ryo Imazawa, Koji S Kawabata, Jun Takahashi, Hiroki Onozato, Tomoki Saito, Masayuki Yamanaka, Daisaku Nogami, Yusuke Tampo, Naoto Kojiguchi, Jumpei Ito, Masaaki Shibata, Malte Schramm, Yumiko Oasa, Takahiro Kanai, Kohei Oide, Katsuhiro L Murata, Ryohei Hosokawa, Yutaka Takamatsu, Yuri Imai, Naohiro Ito, Masafumi Niwano, Seiko Takagi
This study provides the results of simultaneous multicolor observations for the first Visorsat (STARLINK-1436) and the ordinary Starlink satellite (STARLINK-1113) in the U, B, V, g′, r, i, RC, IC, $z$, J, H, and Ks bands to quantitatively investigate the extent to which Visorsat reduces its reflected light. Our results are as follows: (1) in most cases, Visorsat is fainter than STARLINK-1113, and the
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Investigation of mid-infrared long-term variability of dusty AGB stars using multi-epoch scan data of AKARI and WISE Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-06 Kengo Tachibana, Takashi Miyata, Takafumi Kamizuka, Ryou Ohsawa, Satoshi Takita, Akiharu Nakagawa, Yoshifusa Ita, Mizuho Uchiyama
Asymptotic giant branch (AGB) stars are one of the main sources of dust in the Universe. They form and supply dust triggered by stellar pulsations, but the details of the mechanism are still unknown. Among all AGB stars, dusty AGB stars are the most important in terms of dust supply because they contain the star with a high mass-loss rate. To investigate the relationship between the pulsation and the
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Ka-band cryogenic low-noise receiver of the Misasa 54 m antenna for deep-space communications and radio astronomy Publ. Astron. Soc. Jpn. (IF 2.3) Pub Date : 2023-04-06 Masato Tsuboi, Yutaka Hasegawa, Go Tabuchi, Yasuhiro Murata, Koji Yuchi, Tomoaki Toda, Takashi Uchimura, Kimihiro Kimura, Takashi Kasuga
We built a Ka-band dual-circular-polarization low-noise receiver for the Misasa 54 m parabola antenna in Misasa, Japan. The antenna is designed to be combined with a transmitter and receiver system at the X band (around 8 GHz) and simultaneously with a receiver system at the Ka band. The Ka band is the frequency band around 30 GHz, which is important for deep-space communications and radio astronomy