The Astrophysical Journal最新文献_第7页

The Milky Way Bar Potential Constrained by the Kinematics of SiO Maser Stars in BAaDE Survey 由 BAaDE 勘测中 SiO Maser 恒星的运动轨迹制约的银河条形势

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad834f

Tian-Ye Xia, Juntai Shen, Zhi Li, Huai-jin Feng, Loránt O. Sjouwerman, Ylva M. Pihlström, Megan O. Lewis and Michael C. Stroh

{"title":"The Milky Way Bar Potential Constrained by the Kinematics of SiO Maser Stars in BAaDE Survey","authors":"Tian-Ye Xia, Juntai Shen, Zhi Li, Huai-jin Feng, Loránt O. Sjouwerman, Ylva M. Pihlström, Megan O. Lewis and Michael C. Stroh","doi":"10.3847/1538-4357/ad834f","DOIUrl":"https://doi.org/10.3847/1538-4357/ad834f","url":null,"abstract":"We introduce a novel method that utilizes the longitude–velocity (l − v) envelope to constrain the Milky Way (MW) bar potential. Previous work used the l − v diagram to explain the distribution of the observed high-velocity stars. We successfully reproduce their results but find that their method is limited to only one type of periodic orbits. In contrast, we propose that the l − v envelope provides much more comprehensive constraints. We compare the properties of test particles in the M. Portail et al. MW potential model (P17) with the observed SiO maser stars from the Bulge Asymmetries and Dynamical Evolution (BAaDE) survey. We find that the l − v envelope generated by the bar potential demonstrates reasonable agreement with the observational data, albeit with slight discrepancies near the Galactic center. The inconsistencies suggest that the P17 potential yields a lower central rotation curve, a slightly larger quadrupole strength, or a possibly underestimated pattern speed. We also adopt an updated version of the P17 potential with a modified central mass component proposed by G. H. Hunter et al. (H24). The fitting of the l − v envelope suggests that the H24 potential does not completely address the existing challenges and may hint at a possible underestimation of the central bar mass. Our study demonstrates that the l − v envelope can be used as a valuable tool for constraining the Galactic potential and provides insights into the MW bar potential.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Two Intermittent Eruptions of a Minifilament Triggered by a Two-step Magnetic Reconnection Within a Fan-spine Configuration 扇形棘配置内两步磁重联触发的微丝两次间歇喷发

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad84f9

Liping Yang, Zhike Xue, Jincheng Wang, Liheng Yang, Qiaoling Li, Yian Zhou, Yang Peng and Xinsheng Zhang

{"title":"Two Intermittent Eruptions of a Minifilament Triggered by a Two-step Magnetic Reconnection Within a Fan-spine Configuration","authors":"Liping Yang, Zhike Xue, Jincheng Wang, Liheng Yang, Qiaoling Li, Yian Zhou, Yang Peng and Xinsheng Zhang","doi":"10.3847/1538-4357/ad84f9","DOIUrl":"https://doi.org/10.3847/1538-4357/ad84f9","url":null,"abstract":"Although numerous works have concentrated on minifilament eruption in complex configurations, the detailed triggering mechanism is still an open question. Using the observational data from the New Vacuum Solar Telescope and Solar Dynamics Observatory, we studied a two-step magnetic reconnection process that triggered a minifilament that erupted intermittently within a fan-spine structure in the active region NOAA 13272. The first-step reconnection occurred between a set of low-lying small-scale magnetic loops and their nearby inner spine, resulting in the appearance of a brightening at the reconnection site and the reconfiguration of the inner spine. As the reconfigured inner spine approached the outer spine, reconnection occurred between them at the null point and led to the minifilament erupting partially. Subsequently, this two-step reconnection scenario occurred again and triggered the minifilament to erupt completely. The null point reconnection was supported by the changes in the topological structure of the inner spine and the outer spine, circular ribbon flares, remote brightenings, and the brightening of the outer spine. The null point reconnection related to the second eruption was also confirmed by some plasmoids expelled from the reconnection site. Further, the results of the magnetic field extrapolation reveal the existence of a fan-spine structure involving a three-dimensional null point. We suggest that the two-step reconnection triggers the two eruptions, in which the null point reconnection plays a direct role, but the dynamical evolution of the inner spine and the outer spine driven by the first-step reconnection might be a precursor of the subsequent null point reconnection.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the Properties of X-Ray Corona in Seyfert 1 Galaxies 关于赛弗1星系中X射线日冕的特性

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad8088

Indrani Pal, Anju A., H. Sreehari, Gitika Rameshan, C. S. Stalin, Claudio Ricci and S. Marchesi

{"title":"On the Properties of X-Ray Corona in Seyfert 1 Galaxies","authors":"Indrani Pal, Anju A., H. Sreehari, Gitika Rameshan, C. S. Stalin, Claudio Ricci and S. Marchesi","doi":"10.3847/1538-4357/ad8088","DOIUrl":"https://doi.org/10.3847/1538-4357/ad8088","url":null,"abstract":"We carried out a uniform and systematic analysis of a sample of 112 nearby bright Seyfert 1 type active galactic nuclei, the observations of which were carried out by the Nuclear Spectroscopic Telescope Array between 2013 August and 2022 May. The main goal of this analysis is to investigate the nature of the X-ray corona in Seyfert 1 galaxies. By fitting a physical model to the NuSTAR spectra, we could constrain the high-energy cutoff (Ecut) for 73 sources in our sample. To estimate the temperature of the corona (kTe) in our sample of 112 sources, we used the Comptonization model to fit their spectra. We could constrain kTe in 42 sources. We found a strong positive correlation between Ecut and kTe, with most of the sources lying above the empirical approximation of Ecut = 2−3 kTe. We investigated for possible correlations between various properties of the corona obtained from physical model fits to the observed spectra and between various coronal parameters and physical properties of the sources such as Eddington ratio and black hole mass. We found (a) a strong correlation between Ecut and the photon index and (b) a significant negative correlation between kTe and the optical depth. From detailed statistical analysis of the correlation of coronal parameters with the Eddington ratio and black hole mass, we found no significant correlation. The correlations observed in this study indicate that an optically thin corona is needed to sustain a hotter corona with a steeper spectrum.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"250 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Particles in Relativistic Magnetohydrodynamic Jets. II. Bridging Jet Dynamics with Multi–wave band Nonthermal Emission Signatures 相对论磁流体喷流中的粒子。II.将喷流动力学与多波段非热发射特征联系起来

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad8135

Ravi Pratap Dubey, Christian Fendt and Bhargav Vaidya

{"title":"Particles in Relativistic Magnetohydrodynamic Jets. II. Bridging Jet Dynamics with Multi–wave band Nonthermal Emission Signatures","authors":"Ravi Pratap Dubey, Christian Fendt and Bhargav Vaidya","doi":"10.3847/1538-4357/ad8135","DOIUrl":"https://doi.org/10.3847/1538-4357/ad8135","url":null,"abstract":"Relativistic magnetized jets, originating near black holes, are observed to exhibit substructured flows. In this study, we present synthetic synchrotron-emission signatures for different lines of sight and frequencies, derived from three-dimensional relativistic magnetohydrodynamic simulations of pc-scale Active Galactic Nuclei jets. These simulations apply different injection nozzles, injecting steady, variable, and precessing jets. Extending our previous study, here, we have developed a bridge to connect jet dynamics and particle acceleration within relativistic shocks with nonthermal radiation dominant in jets. The emission is derived from Lagrangian particles—injected into the jet and following the fluid—accelerated through diffusive shock acceleration and subsequently cooled by emitting energy via synchrotron and inverse-Compton processes. Overall, the different shock structures lead to the formation of numerous localized emission patterns—interpreted as jet knots. These knot patterns can fade or flare, also as a consequence of merging or Doppler boosting, leading to jet variability. We find knots with high-enough pattern speed supposed to be visible as superluminal motion ≲5c. Synchrotron spectra of all jets reveal double-humped structures, reflecting multiple electron populations characterized by the nature of underlying shock and their age. The precessing jet is the most powerful emitter, featuring a spectrum flatter than the steady and the variable jet. The emission, although essentially governed by the acceleration through shocks, depends on the cooling history of the particle as well. Overall, the continuous reacceleration of electrons through shocks along the jet we found is an essential prerequisite for observing extended jet emission over large timescales and length scales.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multidimensional Radiation Hydrodynamics Simulations of SN 1987A Shock Breakout SN 1987A 冲击突破的多维辐射流体力学模拟

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad7de3

Wun-Yi Chen, Ke-Jung Chen and Masaomi Ono

{"title":"Multidimensional Radiation Hydrodynamics Simulations of SN 1987A Shock Breakout","authors":"Wun-Yi Chen, Ke-Jung Chen and Masaomi Ono","doi":"10.3847/1538-4357/ad7de3","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7de3","url":null,"abstract":"Shock breakout is the first electromagnetic signal from supernovae (SNe), which contains important information on the explosion energy and the size and chemical composition of the progenitor star. This paper presents the first two-dimensional (2D) multiwavelength radiation hydrodynamics simulations of SN 1987A shock breakout by using the CASTRO code with the OPAL opacity table considering eight photon groups from infrared to X-ray. To investigate the impact of the pre-SN environment of SN 1987A, we consider three possible circumstellar medium environments: a steady wind, an eruptive mass loss, and the existence of a companion star. In sum, the resulting breakout light curve has an hour-long duration and a peak luminosity of ∼4 × 1046 erg s−1, with a decay rate of ∼3.5 mag hr−1 in X-ray. The dominant band transits to UV around 3 hr after the initial breakout, and its luminosity has a decay rate of ∼1.5 mag hr−1 that agrees well with the observed shock breakout tail. The detailed features of breakout emission are sensitive to the pre-explosion environment. Furthermore, our 2D simulations demonstrate the importance of multidimensional mixing and its impacts on shock dynamics and radiation emission. The mixing emerging from the shock breakout may lead to a global asymmetry of SN ejecta and affect its later SN remnant formation.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Why Do Semianalytic Models Predict Higher Scatter in the Stellar Mass–Halo Mass Relation Than Cosmological Hydrodynamic Simulations? 为什么半解析模型比宇宙学流体力学模拟预测的恒星质量-光质量关系散度更高？

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad7b0f

Antonio J. Porras-Valverde, John C. Forbes, Rachel S. Somerville, Adam R. H. Stevens, Kelly Holley-Bockelmann, Andreas A. Berlind and Shy Genel

{"title":"Why Do Semianalytic Models Predict Higher Scatter in the Stellar Mass–Halo Mass Relation Than Cosmological Hydrodynamic Simulations?","authors":"Antonio J. Porras-Valverde, John C. Forbes, Rachel S. Somerville, Adam R. H. Stevens, Kelly Holley-Bockelmann, Andreas A. Berlind and Shy Genel","doi":"10.3847/1538-4357/ad7b0f","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7b0f","url":null,"abstract":"Semianalytic models (SAMs) systematically predict higher-stellar mass scatter at a given halo mass than hydrodynamical simulations and most empirical models. Our goal is to investigate the physical origin of this scatter by exploring modifications to the physics in the SAM Dark Sage. We design two black hole formation models that approximate results from the IllustrisTNG 300-1 hydrodynamical simulation. In the first model, we assign a fixed black hole mass of 106M⊙ to every halo that reaches 1010.5M⊙. In the second model, we disregard any black hole growth as implemented in the standard Dark Sage model. Instead, we force all black hole masses to follow the median z = 0 black hole mass–halo mass relation in IllustrisTNG 300-1 with an imposed fixed scatter. We find that each model on its own does not significantly reduce the scatter in stellar mass. To explore the effects of active galactic nucleus (AGN) feedback in addition to black hole seeding, we replace the native Dark Sage AGN feedback model with a simple model where we turn off cooling for galaxies with black hole masses above 108M⊙. With the additional modification in AGN feedback, we find that the supermassive black hole seeding and fixed conditional distribution models create a significant reduction in the scatter in stellar mass at halo masses between 1011–14M⊙. These results suggest that AGN feedback in SAMs acts in a qualitatively different way than feedback implemented in cosmological simulations. Either or both may require substantial modification to match the empirically inferred scatter in the stellar mass–halo mass relation.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Cosmic Ultraviolet Baryon Survey (CUBS). IX. The Enriched Circumgalactic and Intergalactic Medium Around Star-forming Field Dwarf Galaxies Traced by O vi Absorption 宇宙紫外线重子巡天（CUBS）。IX.通过 O vi 吸收追踪恒星形成场矮星系周围富集的银河系外和银河系间介质

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad7b0a

Nishant Mishra, Sean D. Johnson, Gwen C. Rudie, Hsiao-Wen Chen, Joop Schaye, Zhijie Qu, Fakhri S. Zahedy, Erin T. Boettcher, Sebastiano Cantalupo, Mandy C. Chen, Claude-André Faucher-Giguére, Jenny E. Greene, Jennifer I-Hsiu Li, Zhuoqi (Will) Liu, Sebastian Lopez and Patrick Petitjean

{"title":"The Cosmic Ultraviolet Baryon Survey (CUBS). IX. The Enriched Circumgalactic and Intergalactic Medium Around Star-forming Field Dwarf Galaxies Traced by O vi Absorption","authors":"Nishant Mishra, Sean D. Johnson, Gwen C. Rudie, Hsiao-Wen Chen, Joop Schaye, Zhijie Qu, Fakhri S. Zahedy, Erin T. Boettcher, Sebastiano Cantalupo, Mandy C. Chen, Claude-André Faucher-Giguére, Jenny E. Greene, Jennifer I-Hsiu Li, Zhuoqi (Will) Liu, Sebastian Lopez and Patrick Petitjean","doi":"10.3847/1538-4357/ad7b0a","DOIUrl":"https://doi.org/10.3847/1538-4357/ad7b0a","url":null,"abstract":"The shallow potential wells of star-forming dwarf galaxies make their surrounding circumgalactic and intergalactic medium (CGM/IGM) sensitive laboratories for studying the inflows and outflows thought to regulate galaxy evolution. We present new absorption-line measurements in quasar sight lines, probing within projected distances of <300 kpc from 91 star-forming field dwarf galaxies with a median stellar mass of at 0.077 < z < 0.73, from the Cosmic Ultraviolet Baryon Survey (CUBS). In this redshift range, the CUBS quasar spectra cover a suite of transitions including H i, low, and intermediate metal ions (e.g., C ii, Si ii, C iii, and Si iii), and highly ionized O vi. This CUBS-Dwarfs survey enables constraints with samples nine times larger than past dwarf CGM/IGM studies with similar ionic coverage. We find that low and intermediate ionization metal absorption is rare around dwarf galaxies, consistent with previous surveys of local dwarfs. In contrast, highly ionized O vi is commonly observed in sight lines that pass within the virial radius of a dwarf, and O vi detection rates are nonnegligible at projected distances of 1−2× the virial radius. Based on these measurements, we estimate that the O vi-bearing phase of the CGM/IGM accounts for a dominant share of the metal budget of dwarf galaxies. The absorption kinematics suggest that a relatively modest fraction of the O vi-bearing gas is formally unbound. Together, these results imply that low-mass systems at z ≲ 1 effectively retain a substantial fraction of their metals within the nearby CGM and IGM.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Probing the Extended Atmospheres of AGB Stars. I. Synthetic Imaging of 1D Hydrodynamical Models at Radio and (Sub-)millimeter Wavelengths 探测 AGB 恒星的扩展大气层。I. 无线电和（亚）毫米波长一维流体力学模型的合成成像

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad83b8

Behzad Bojnordi Arbab, Wouter Vlemmings, Theo Khouri and Susanne Höfner

{"title":"Probing the Extended Atmospheres of AGB Stars. I. Synthetic Imaging of 1D Hydrodynamical Models at Radio and (Sub-)millimeter Wavelengths","authors":"Behzad Bojnordi Arbab, Wouter Vlemmings, Theo Khouri and Susanne Höfner","doi":"10.3847/1538-4357/ad83b8","DOIUrl":"https://doi.org/10.3847/1538-4357/ad83b8","url":null,"abstract":"We investigate the observable characteristics of the extended atmospheres of asymptotic giant branch (AGB) stars across a wide range of radio and (sub-)millimeter wavelengths using state-of-the-art 1D dynamical atmosphere and wind models over one pulsation period. We also study the relationships between the observable features and model properties. We further study practical distance ranges for observable sources assuming the capabilities of current and upcoming observatories. We present time-variable, frequency-dependent profiles of pulsating AGB stars’ atmospheres, illustrating observable features in resolved and unresolved observations, including disk brightness temperature, photosphere radius, and resolved and unresolved spectral indices. Notably, temporal variations in disk brightness temperature closely mirror the temperature variability of the stellar atmosphere. We find that while the photospheric radius decreases due to gas dilution in the layers between consecutive shocks, the increase in the observed stellar radius reflects shock propagation through the atmosphere during the expansion phase, providing a direct measurement method for the shock velocity. Furthermore, our models indicate that enhanced gas temperatures after the passage of a strong shock might be observable in the high-frequency Atacama Large Millimeter/submillimeter Array (ALMA) bands as a decrease in the brightness temperature with increasing frequency. We demonstrate that synthetic observations based on state-of-the-art dynamical atmosphere and wind models are necessary for proper interpretations of current (ALMA and Very Large Array (VLA)) and future (Square Kilometre Array and next-generation VLA) observations and that multiwavelength observations of AGB stars are crucial for empirical studies of their extended atmospheres.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sharp Periodic Flares and Long-term Variability in the High-mass X-Ray Binary XTE J1829−098 from RXTE PCA, Swift BAT, and MAXI Observations 通过RXTE PCA、Swift BAT和MAXI观测发现的高质X射线双星XTE J1829-098的尖锐周期性耀斑和长期变异性

The Astrophysical Journal Pub Date : 2024-11-19 DOI: 10.3847/1538-4357/ad83b9

Robin H. D. Corbet, Ralf Ballhausen, Peter A. Becker, Joel B. Coley, Felix Fuerst, Keith C. Gendreau, Sebastien Guillot, Nazma Islam, Gaurava Kumar Jaisawal, Peter Jenke, Peter Kretschmar, Alexander Lange, Christian Malacaria, Mason Ng, Katja Pottschmidt, Pragati Pradhan, Paul S. Ray, Richard E. Rothschild, Philipp Thalhammer, Lee J. Townsend, Joern Wilms, Colleen A. Wilson-Hodge and Michael T. Wolff

{"title":"Sharp Periodic Flares and Long-term Variability in the High-mass X-Ray Binary XTE J1829−098 from RXTE PCA, Swift BAT, and MAXI Observations","authors":"Robin H. D. Corbet, Ralf Ballhausen, Peter A. Becker, Joel B. Coley, Felix Fuerst, Keith C. Gendreau, Sebastien Guillot, Nazma Islam, Gaurava Kumar Jaisawal, Peter Jenke, Peter Kretschmar, Alexander Lange, Christian Malacaria, Mason Ng, Katja Pottschmidt, Pragati Pradhan, Paul S. Ray, Richard E. Rothschild, Philipp Thalhammer, Lee J. Townsend, Joern Wilms, Colleen A. Wilson-Hodge and Michael T. Wolff","doi":"10.3847/1538-4357/ad83b9","DOIUrl":"https://doi.org/10.3847/1538-4357/ad83b9","url":null,"abstract":"XTE J1829−098 is a transient X-ray pulsar with a period of ∼7.8 s. It is a candidate Be star system, although the evidence for this is not yet definitive. We investigated the twenty-year-long X-ray light curve using the Rossi X-ray Timing Explorer Proportional Counter Array (PCA), Neil Gehrels Swift Observatory Burst Alert Telescope, and the Monitor of All-sky X-ray Image. We find that all three light curves are clearly modulated on the ∼244 days orbital period previously reported from PCA monitoring observations, with outbursts confined to a narrow phase range. The light curves also show that XTE J1829−098 was in an inactive state between approximately 2008 December and 2018 April, and no strong outbursts occurred. Such behavior is typical of Be X-ray binary systems, with the absence of outbursts likely related to the dissipation of the Be star's decretion disk. The mean outburst shapes can be approximated with a triangular profile and, from a joint fit of this to all three light curves, we refine the orbital period to 243.95 ± 0.04 days. The mean outburst profile does not show any asymmetry and has a total phase duration of 0.140 ± 0.007. However, the PCA light curve shows that there is considerable cycle-to-cycle variability of the individual outbursts. We compare the properties of XTE J1829−098 with other sources that show short phase-duration outbursts, in particular GS 1843−02 (2S 1845−024), which has a very similar orbital period, but longer pulse period, and whose orbit is known to be highly eccentric.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The SAGA Survey. IV. The Star Formation Properties of 101 Satellite Systems around Milky Way–mass Galaxies SAGA 调查。IV.银河系质量星系周围 101 个卫星系统的恒星形成特性

The Astrophysical Journal Pub Date : 2024-11-18 DOI: 10.3847/1538-4357/ad61e7

Marla Geha, Yao-Yuan Mao, Risa H. Wechsler, Yasmeen Asali, Erin Kado-Fong, Nitya Kallivayalil, Ethan O. Nadler, Erik J. Tollerud, Benjamin Weiner, Mithi A. C. de los Reyes, Yunchong Wang and John F. Wu

{"title":"The SAGA Survey. IV. The Star Formation Properties of 101 Satellite Systems around Milky Way–mass Galaxies","authors":"Marla Geha, Yao-Yuan Mao, Risa H. Wechsler, Yasmeen Asali, Erin Kado-Fong, Nitya Kallivayalil, Ethan O. Nadler, Erik J. Tollerud, Benjamin Weiner, Mithi A. C. de los Reyes, Yunchong Wang and John F. Wu","doi":"10.3847/1538-4357/ad61e7","DOIUrl":"https://doi.org/10.3847/1538-4357/ad61e7","url":null,"abstract":"We present the star-forming properties of 378 satellite galaxies around 101 Milky Way analogs in the Satellites Around Galactic Analogs (SAGA) Survey, focusing on the environmental processes that suppress or quench star formation. In the SAGA stellar mass range of 106−10M⊙, we present quenched fractions, star-forming rates, gas-phase metallicities, and gas content. The fraction of SAGA satellites that are quenched increases with decreasing stellar mass and shows significant system-to-system scatter. SAGA satellite quenched fractions are highest in the central 100 kpc of their hosts and decline out to the virial radius. Splitting by specific star formation rate (sSFR), the least star-forming satellite quartile follows the radial trend of the quenched population. The median sSFR of star-forming satellites increases with decreasing stellar mass and is roughly constant with projected radius. Star-forming SAGA satellites are consistent with the star formation rate–stellar mass relationship determined in the Local Volume, while the median gas-phase metallicity is higher and median H i gas mass is lower at all stellar masses. We investigate the dependence of the satellite quenched fraction on host properties. Quenched fractions are higher in systems with larger host halo mass, but this trend is only seen in the inner 100 kpc; we do not see significant trends with host color or star formation rate. Our results suggest that lower-mass satellites and satellites inside 100 kpc are more efficiently quenched in a Milky Way–like environment, with these processes acting sufficiently slowly to preserve a population of star-forming satellites at all stellar masses and projected radii.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0