Publications of the Astronomical Society of Japan最新文献

{"title":"Revisiting planetary systems in the Okayama Planet Search Program: A new long-period planet, RV astrometry joint analysis, and a multiplicity-metallicity trend around evolved stars","authors":"Huan-Yu Teng, Bun’ei Sato, Masayuki Kuzuhara, Takuya Takarada, Masashi Omiya, Hiroki Harakawa, Hideyuki Izumiura, Eiji Kambe, Mesut Yilmaz, Ilfan Bikmaev, Selim O Selam, Timothy D Brandt, Guang-Yao Xiao, Michitoshi Yoshida, Yoichi Itoh, Hiroyasu Ando, Eiichiro Kokubo, Shigeru Ida","doi":"10.1093/pasj/psad056","DOIUrl":"https://doi.org/10.1093/pasj/psad056","url":null,"abstract":"Abstract In this study, we revisit 32 planetary systems around evolved stars observed within the framework of the Okayama Planet Search Program (OPSP) and its collaborative framework of the East Asian Planet Search Network to search for additional companions and investigate the properties of stars and giant planets in multiple-planet systems. With our latest radial velocities obtained from Okayama Astrophysical Observatory, we confirm an additional giant planet in the wide orbit of the 75 Cet system ($P_{rm {c}} = 2051.62_{-40.47}^{+45.98} rm {d}$, $M_{rm {c}}sin i=0.912_{-0.090}^{+0.088},,M_{rm {J}}$, and $a_{rm {c}}=3.929_{-0.058}^{+0.052} rm {au}$), along with five stars exhibiting long-term radial velocity accelerations, which indicates massive companions in the wide orbits. We also find that the radial velocity variations of several planet-harboring stars may indicate additional planet candidates, stellar activities, or other understudied sources. These stars include ϵ Tau, 11 Com, 24 Boo, 41 Lyn, 14 And, HD 32518, and ω Ser. We further constrain the orbital configuration of the HD 5608, HD 14067, HD 120084, and HD 175679 systems by combining radial velocities with astrometry, as their host central stars exhibit significant astrometric accelerations. For other systems, we simply refine their orbital parameters. Moreover, our study indicates that the OPSP planet-harboring stars are more metal poor compared to the currently known planet-harboring stars, and this is likely due to the B − V color upper limit at 1.0 for star selection in the beginning of the survey. Finally, by investigating the less massive giant planets (<5 MJ) around currently known planet-harboring evolved stars, we find that metallicity positively correlates with the multiplicity and total planet mass of the system, which can be evidence for the core-accretion planet formation model.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135690047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transition luminosities of Galactic black hole transients with Swift/XRT and NICER/XTI observations","authors":"Sili Wang, Nobuyuki Kawai, Megumi Shidatsu, Yoshiki Matsuoka","doi":"10.1093/pasj/psad057","DOIUrl":"https://doi.org/10.1093/pasj/psad057","url":null,"abstract":"Abstract The X-ray spectral state transitions of Galactic black hole transients (GBHTs) are often linked to the changes in the mass accretion rate. A narrow distribution of transition luminosity in terms of the Eddington ratio has been found in previous studies of GBHTs based on RXTE data (Maccarone, 2003, A&A, 409, 697; Vahdat Motlagh et al., 2019, MNRAS, 485, 2744) and this Eddington ratio at the transition is often used in recent studies with instruments such as Swift/XRT and NICER/XTI, covering soft energies below 1 to 10 keV. However, the X-ray states characterized by spectral parameters may have different definitions depending on the energy ranges adopted in the spectral analysis, leaving the question of whether the distribution of transition luminosity obtained with RXTE remains the same when we use the instruments covering softer energy bands. In this work, we investigated the X-ray state evolutions and the variations of luminosities of eight outbursts of seven GBHTs. We found that the bolometric luminosity of the power-law component was tightly constrained to $sim! 1.3%$ Eddington luminosity at index transition when the photon index starts to decrease towards the hard state, which is consistent with the previous RXTE results (Vahdat Motlagh et al. 2019, MNRAS, 485, 2744; Kalemci et al. 2013, ApJ, 779, 95). Moreover, the tightest clustering was found to be the power-law luminosity right after the start of disk recession, with a mean logarithmic Eddington ratio of −1.84 ± 0.28. In addition, our results suggest that the disk recession starts after the bolometric disk luminosity drops below 1% Eddington luminosity.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135982378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>N</i>-body simulation of planetary formation through pebble accretion in a radially structured protoplanetary disk","authors":"Tenri Jinno, Takayuki R Saitoh, Yota Ishigaki, Junichiro Makino","doi":"10.1093/pasj/psad053","DOIUrl":"https://doi.org/10.1093/pasj/psad053","url":null,"abstract":"Abstract In the conventional theory of planet formation, it is assumed that protoplanetary disks are axisymmetric and have a smooth radial profile. However, recent radio observations of protoplanetary disks have revealed that many of them have complex radial structures. In this study, we perform a series of N-body simulations to investigate how planets are formed in protoplanetary disks with radial structures. For this purpose, we consider the effect of continuous pebble accretion onto the discontinuity boundary within the terrestrial planet-forming region (∼0.6 au). We find that protoplanets grow efficiently at the discontinuity boundary, reaching the Earth mass within ∼104 yr. We confirm that giant collisions of protoplanets occur universally in our model. Moreover, we find that multiple planet-sized bodies form at regular intervals in the vicinity of the discontinuity boundary. These results indicate the possibility of the formation of solar system-like planetary systems in radially structured protoplanetary disks.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135048159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovery of a molecular cloud possibly associated with the youngest Galactic SNR G1.9+0.3","authors":"Rei Enokiya, Hidetoshi Sano, Miroslav D Filipović, Rami Z E Alsaberi, Tsuyoshi Inoue, Tomoharu Oka","doi":"10.1093/pasj/psad054","DOIUrl":"https://doi.org/10.1093/pasj/psad054","url":null,"abstract":"Abstract 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 of 15″ obtained by the CHIMPS2 survey by the James Clerk Maxwell Telescope, and discovered three individual clouds at −1, 7, and 45 km s−1. From its morphological and velocity structures, the −1 km s−1 cloud, having the largest velocity width &amp;gt;20 km s−1 and located at the distance of the Galactic Center, is possibly associated with the SNR. The associated cloud shows a cavity structure both in space and velocity and coincides well with the SNR. We found that the associated cloud has higher column densities toward three bright, radio synchrotron-emitted rims where the radial expansion velocity of the supernova shock is decelerated, and the cloud is faint in the other parts of the SNR. This is the first direct evidence indicating that the highly anisotropic expansion of G1.9+0.3 observed by previous studies results from the deceleration by the interaction between the supernova shock and surrounding dense interstellar medium.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135369645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bright Type II supernova 2023ixf in M 101: A quick analysis of the early-stage spectra and near-infrared light curves","authors":"M. Yamanaka, M. Fujii, T. Nagayama","doi":"10.1093/pasj/psad051","DOIUrl":"https://doi.org/10.1093/pasj/psad051","url":null,"abstract":"\u0000 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 SNe II which show flash-ionized features, we suggest that this SN could be categorized as a high-luminosity SN II with a nitrogen/helium-rich circumstellar material (CSM), e.g., SNe 2014G, 2017ahn, and 2020pni. The Hα emission line can be tentatively explained by a narrower component with a velocity of <300 km s−1 and a broader one with ∼2200 km s−1. The near-infrared light curves were well consistent with those of the another luminous SN 2017ahn, and its absolute magnitudes are located at the bright end of the luminosity distribution of SNe II. These observational facts support that SN 2023ixf is well consistent with high-luminosity SNe II showing evidence of a dense nitrogen/helium-rich CSM.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"30 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84105880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The additional pressure of white dwarf stars generated by net charges","authors":"Ting-Han Pei","doi":"10.1093/pasj/psad047","DOIUrl":"https://doi.org/10.1093/pasj/psad047","url":null,"abstract":"\u0000 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 depending on temperature. At 1.16 × 107 K, there is a total of about 1.50 × 10−4 electrons exceeding the Fermi energy, and about 1.50 × 10−7 at 1.16 × 104 K. Because some of these Fermi electrons are extremely relativistic, some of them can escape the gravity and some return to the star after leaving. These two mechanisms result in a positively charged star and the net positive charges produce a repulsive force and pressure against gravity. The increased pressure is comparable to that of the Fermi electron gas at T = 0 when the star is charged at 1020 C. The net charges will decrease the mass density of the star but increase the upper-mass limit.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82292092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasma diagnostics and Alfvén wave heating of solar prominences by multiwavelength observations","authors":"Yuki Hashimoto, K. Ichimoto, Yuwei Huang","doi":"10.1093/pasj/psad049","DOIUrl":"https://doi.org/10.1093/pasj/psad049","url":null,"abstract":"\u0000 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 the mechanical heating of the prominences from observations. We performed spectroscopic observations of prominences in Hα (6563 Å), Hβ (4861 Å), and Ca ii IR (8542 Å) with the Domeless Solar Telescope at Hida observatory. The plasma parameters of the prominences are estimated by fittings of line profiles using the single-slab model and by solving the statistical equilibrium equation. By assuming that the turbulent motion is the manifestation of propagating Alfvén waves, net radiative losses and Alfvén wave energy flux in the prominences are estimated from these parameters. As a result, it was found that the energy flux by Alfvén waves is sufficient to compensate for the net radiative losses in most regions of the central part of the prominences. On the other hand, Alfvén wave energy flux tends to be insufficient at the outer part of prominences. In such regions, another heating mechanism such as enthalpy flux of mixing with coronal plasma needs to be considered.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"11 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74053385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retraction of: Transient jet ejections associated with limit-cycle behaviors in the very high state of black hole binaries","authors":"","doi":"10.1093/pasj/psad045","DOIUrl":"https://doi.org/10.1093/pasj/psad045","url":null,"abstract":"","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"15 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87858517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suzaku spectral analysis of an X-ray emitting plasma in the supernova remnant G352.7−0.1","authors":"Asahi Fujishige, S. Yamauchi, K. Nobukawa, M. Nobukawa","doi":"10.1093/pasj/psad048","DOIUrl":"https://doi.org/10.1093/pasj/psad048","url":null,"abstract":"\u0000 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 model with different temperatures and ionization timescales. Based on the results, properties of the X-ray emitting plasma and the explosion type are discussed.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"4 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87377766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 3 mm molecular line survey toward the C-star envelope CIT 6","authors":"Kuilu Yang, Yong Zhang, J. Qiu, Yina Ao, Xiaohu Li","doi":"10.1093/pasj/psad043","DOIUrl":"https://doi.org/10.1093/pasj/psad043","url":null,"abstract":"\u0000 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 work is a complement to our previous line survey toward CIT 6 in the frequency ranges of 36–49 GHz and 131–268 GHz. Based on the measurements and in combination with previously published data, we perform a rotation-diagram analysis to determine the column densities, excitation temperatures, and fractional abundances of the molecules. The excitation temperature varies along the radius. The abundance pattern of CIT 6 is broadly consistent with that of the prototype C-star IRC +10216 at the specified detection sensitivity, indicating that the molecular richness in IRC +10216 cannot be attributed to an interpretation of unusual chemistry. Nevertheless, subtle distinctions between the two C-stars are found. The higher abundance of carbon-chain molecules and lower 12C$/$13C ratio in CIT 6 compared to IRC +10216 imply that the former is more massive or in a more evolved phase than the latter.","PeriodicalId":20733,"journal":{"name":"Publications of the Astronomical Society of Japan","volume":"58 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90903460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}