Monthly Notices of the Royal Astronomical Society最新文献_第8页

The origin of the Hα line profiles in simulated disc galaxies 模拟圆盘星系中 Hα 线剖面的起源

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-07 DOI: 10.1093/mnras/stae2099

Timmy Ejdetjärn, Oscar Agertz, Göran Östlin, Martin P Rey, Florent Renaud

{"title":"The origin of the Hα line profiles in simulated disc galaxies","authors":"Timmy Ejdetjärn, Oscar Agertz, Göran Östlin, Martin P Rey, Florent Renaud","doi":"10.1093/mnras/stae2099","DOIUrl":"https://doi.org/10.1093/mnras/stae2099","url":null,"abstract":"Observations of ionised Hα gas in high-redshift disc galaxies have ubiquitously found significant line broadening, σHα ∼ 10 − 100 km s−1. To understand whether this broadening reflects gas turbulence within the interstellar medium (ISM) of galactic discs, or arises from out-of-plane emission in mass-loaded outflows, we perform radiation hydrodynamic (RHD) simulations of isolated Milky Way-mass disc galaxies in a gas-poor (low-redshift) and gas rich (high-redshift) condition and create mock Hα emission line profiles. We find that the majority of the total (integrated) Hα emission is confined within the ISM, with extraplanar gas contributing $sim 45~{{%}}$ of the extended profile wings (vz ≥ 200${, rm {km, s^{-1}} }$) in the gas-rich galaxy. This substantiates using the Hα emission line as a tracer of mid-plane disc dynamics. We investigate the relative contribution of diffuse and dense Hα emitting gas, corresponding to diffuse ionised gas (DIG; ρ ≲ 0.1 cm−3, T ∼ 8 000 K) and HII regions (ρ ≳ 10 cm−3, T ∼ 10 000 K), respectively, and find that DIG contributes $f_{rm DIG}lesssim 10~{{%}}$ of the total LHα. However, the DIG can reach upwards of σHα ∼ 60 − 80 km s−1 while the HII regions are much less turbulent σHα ∼ 10 − 40 km s−1. This implies that the σHα observed using the full Hα emission line is dependent on the relative Hα contribution from DIG/HII regions and a larger fDIG would shift σHα to higher values. Finally, we show that σHα evolves, in both the DIG and HII regions, with the galaxy gas fraction. Our high-redshift equivalent galaxy is roughly twice as turbulent, except for in the DIG which has a more shallow evolution.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"4 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

A targeted search for strongly lensed supernovae with the Las Cumbres Observatory 利用拉斯坎布雷斯天文台有针对性地搜索强透镜超新星

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-07 DOI: 10.1093/mnras/stae2103

Peter Craig, Kyle O’Connor, Sukanya Chakrabarti, Steven A Rodney, Justin R Pierel, Curtis McCully, Ismael Perez-Fournon

{"title":"A targeted search for strongly lensed supernovae with the Las Cumbres Observatory","authors":"Peter Craig, Kyle O’Connor, Sukanya Chakrabarti, Steven A Rodney, Justin R Pierel, Curtis McCully, Ismael Perez-Fournon","doi":"10.1093/mnras/stae2103","DOIUrl":"https://doi.org/10.1093/mnras/stae2103","url":null,"abstract":"Gravitationally lensed supernovae (glSNe) are of interest for time delay cosmology and SN physics. However, glSNe detections are rare, owing to the intrinsic rarity of SN explosions, the necessity of alignment with a foreground lens, and the relatively short window of detectability. We present the Las Cumbres Observatory Lensed Supernova Search, LCOLSS, a targeted survey designed for detecting glSNe in known strong lensing systems. Using cadenced r′-band imaging, LCOLSS targeted 114 galaxy-galaxy lensing systems with high expected SN rates, based on estimated star formation rates. No plausible glSN was detected by LCOLSS during our two year observing program. We carry out an analysis here to measure a detection efficiency for these observations. We then perform Monte Carlo simulations using the predicted supernova rates to determine the expected number of glSN detections. The results of the simulation suggest an expected number of detections and $68%$ Poisson confidence intervals, NSN = 0.20, [0, 2.1], NIa = 0.08, [0, 2.0], NCC = 0.12, [0, 2.0], for all SNe, Type Ia SNe, and core-collapse (CC) SNe respectively. These results are broadly consistent with the absence of a detection in our survey. Analysis of the survey strategy can provide insights for future efforts to develop targeted glSN discovery programs, especially considering the large anticipated yields of upcoming surveys.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"2020 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

Mean-motion resonances with interfering density waves 具有干涉密度波的均动共振

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-07 DOI: 10.1093/mnras/stae2097

Huan Yang, Ya-Ping Li

{"title":"Mean-motion resonances with interfering density waves","authors":"Huan Yang, Ya-Ping Li","doi":"10.1093/mnras/stae2097","DOIUrl":"https://doi.org/10.1093/mnras/stae2097","url":null,"abstract":"In this work, we study the dynamics of two less massive objects moving around a central massive object, which are all embedded within a thin accretion disc. In addition to the gravitational interaction between these objects, the disc-object interaction is also crucial for describing the long-term dynamics of the multi-body system, especially in the regime of mean-motion resonances. We point out that near the resonance the density waves generated by the two moving objects generally coherently interfere with each other, giving rise to extra angular momentum fluxes. The resulting backreaction on the objects is derived within the thin-disc scenario, which explicitly depends on the resonant angle and sensitively depends on the smoothing scheme used in the two-dimensional theory. We have performed hydrodynamical simulations with planets embedded within a thin accretion disc and have found qualitatively agreement on the signatures of interfering density waves by measuring the torques on the embedded objects, for the cases of 2 : 1 and 3 : 2 resonance. By including in interference torque and the migration torques in the evolution of a pair of planets, we show that the chance of resonance trapping depends on the sign of the interference torque. For negative interference torques the pairs are more likely located at off-resonance regimes. The negative interference torques may also explain the $1~{{%}}-2~{{%}}$ offset (for the period ratios) from the exact resonance values as observed in Kepler multi-planet systems.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"32 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

The symbiotic recurrent nova V745 Sco at radio wavelengths 射电波长下的共生周期新星V745 Sco

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-07 DOI: 10.1093/mnras/stae2093

Isabella Molina, Laura Chomiuk, Justin D Linford, Elias Aydi, Amy J Mioduszewski, Koji Mukai, Kirill V Sokolovsky, Jay Strader, Peter Craig, Dillon Dong, Chelsea E Harris, Miriam M Nyamai, Michael P Rupen, Jennifer L Sokoloski, Frederick M Walter, Jennifer H S Weston, Montana N Williams

{"title":"The symbiotic recurrent nova V745 Sco at radio wavelengths","authors":"Isabella Molina, Laura Chomiuk, Justin D Linford, Elias Aydi, Amy J Mioduszewski, Koji Mukai, Kirill V Sokolovsky, Jay Strader, Peter Craig, Dillon Dong, Chelsea E Harris, Miriam M Nyamai, Michael P Rupen, Jennifer L Sokoloski, Frederick M Walter, Jennifer H S Weston, Montana N Williams","doi":"10.1093/mnras/stae2093","DOIUrl":"https://doi.org/10.1093/mnras/stae2093","url":null,"abstract":"V745 Sco is a Galactic symbiotic recurrent nova with nova eruptions in 1937, 1989 and 2014. We study the behaviour of V745 Sco at radio wavelengths (0.6–37 GHz), covering both its 1989 and 2014 eruptions and informed by optical, X-ray, and γ-ray data. The radio light curves are synchrotron-dominated. Surprisingly, compared to expectations for synchrotron emission from explosive transients such as radio supernovae, the light curves spanning 0.6–37 GHz all peak around the same time (∼18–26 days after eruption) and with similar flux densities (5–9 mJy). We model the synchrotron light curves as interaction of the nova ejecta with the red giant wind, but find that simple spherically symmetric models with wind-like circumstellar material (CSM) cannot explain the radio light curve. Instead, we conclude that the shock suddenly breaks out of a dense CSM absorbing screen around 20 days after eruption, and then expands into a relatively low density wind ($dot{M}_{out} approx 10^{-9}-10^{-8}$ M⊙ yr−1 for vw = 10 km s−1) out to ∼1 year post-eruption. The dense, close-in CSM may be an equatorial density enhancement or a more spherical red giant wind with $dot{M}_{in} approx [5-10] times 10^{-7}$ M⊙ yr−1, truncated beyond several × 1014 cm. The outer lower-density CSM would not be visible in typical radio observations of Type Ia supernovae: V745 Sco cannot be ruled out as a Type Ia progenitor based on CSM constraints alone. Complementary constraints from the free–free radio optical depth and the synchrotron luminosity imply the shock is efficient at accelerating relativistic electrons and amplifying magnetic fields, with εe and εB ≈ 0.01 − 0.1.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

Assembly of the Intracluster Light in the Horizon-AGN Simulation 地平线-AGN 模拟中的星团内光的组合

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-07 DOI: 10.1093/mnras/stae2084

Harley J Brown, Garreth Martin, Frazer R Pearce, Nina A Hatch, Yannick M Bahé, Yohan Dubois

{"title":"Assembly of the Intracluster Light in the Horizon-AGN Simulation","authors":"Harley J Brown, Garreth Martin, Frazer R Pearce, Nina A Hatch, Yannick M Bahé, Yohan Dubois","doi":"10.1093/mnras/stae2084","DOIUrl":"https://doi.org/10.1093/mnras/stae2084","url":null,"abstract":"The diffuse stellar component of galaxy clusters made up of intergalactic stars is termed the intracluster light (ICL). Though there is a developing understanding of the mechanisms by which the ICL is formed, no strong consensus has yet been reached on which objects the stars of the ICL are primarily sourced from. We investigate the assembly of the ICL starting approximately 10 Gyr before z = 0 in 11 galaxy clusters (halo masses between ∼1 × 1014 M⊙ and ∼7 × 1014 M⊙ at z ≈ 0) in the Horizon-AGN simulation. By tracking the stars of galaxies that fall into these clusters past cluster infall, we are able to link almost all of the z ≈ 0 ICL back to progenitor objects. Satellite stripping, mergers, and pre-processing are all found to make significant contributions to the ICL, but any contribution from in-situ star-formation directly into the ICL appears negligible. Even after compensating for resolution effects, we find that approximately 90percnt of the stacked ICL of the 11 clusters that is not pre-processed should come from galaxies infalling with stellar masses above 109 M⊙, with roughly half coming from infalling galaxies with stellar masses within half a dex of 1011 M⊙. The fact that the ICL appears largely sourced from such massive objects suggests that the ICL assembly of any individual cluster may be principally stochastic.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"53 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

An explanation for the slow-rise phase of solar eruptions 太阳爆发缓慢上升阶段的解释

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-07 DOI: 10.1093/mnras/stae2088

Yaoyu Xing, Aiying Duan, Chaowei Jiang

{"title":"An explanation for the slow-rise phase of solar eruptions","authors":"Yaoyu Xing, Aiying Duan, Chaowei Jiang","doi":"10.1093/mnras/stae2088","DOIUrl":"https://doi.org/10.1093/mnras/stae2088","url":null,"abstract":"Solar eruptions are sudden release of the magnetic free energy accumulated within a quasi-static evolutionary process of the corona. Interestingly, many solar eruptions are preceded by a short-term slow-rise phase, during which the pre-eruption structure rises at a speed significantly larger than that of the quasi-static evolution. Here we suggest an explanation for the slow-rise phase based on a recent high-accuracy magnetohydrodynamic simulation for initiation of solar eruption. The simulation shows that by continuously shearing a bipolar magnetic arcade, an internal current sheet forms gradually, and an eruption begins once magnetic reconnection is triggered at the current sheet. We find in the simulation that the overlying field presents a slow-rise phase before the reconnection sets in. In addition, the rising speed is significantly larger than that of the core field during this phase. This slow rise is a manifestation of the growing expansion of the arcade in the process of approaching a fully open field state, which is inherent to the formation of a current sheet before the eruption. We also show three flare events with slow-rise phases that are highly consistent with these key characteristics in the simulation: an expansion of the overlying coronal loops with speeds much larger than the quasi-static evolution speed, and for those events with filament eruption, the slow rise of filament is much smaller than that of the overlying loops. In this type of events, the eruption might be initiated through the mechanism as shown in the simulation, and the expansion of overlying coronal loops is a better indicator of the slow-rise phase.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"56 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

The active role of co-evolving haloes in stellar bar formation 共同演化的光环在恒星条形成过程中的积极作用

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-07 DOI: 10.1093/mnras/stae2086

Matthew Frosst, Danail Obreschkow, Aaron Ludlow

{"title":"The active role of co-evolving haloes in stellar bar formation","authors":"Matthew Frosst, Danail Obreschkow, Aaron Ludlow","doi":"10.1093/mnras/stae2086","DOIUrl":"https://doi.org/10.1093/mnras/stae2086","url":null,"abstract":"We use idealised N-body simulations of equilibrium discs in live and static haloes to study how dark matter co-evolution impacts the assembly of stellar particles into a bar and the halo response. Initial conditions correspond to a marginally unstable disc according to commonly used disc stability criteria, and are evolved for the equivalent of about 150 disc dynamical times (10Gyr). An extensive convergence study ensures accurate modelling of the bar formation process. Live haloes lead to the formation of a strong bar, but the same disc remains unbarred when evolved in a static halo. Neither seeded disc instabilities, nor longer (60Gyr) simulations result in the formation of a bar when the halo is static. When the live halo is replaced with a static analogue at later times the previously robust bar slowly dissipates, suggesting: (1) the co-evolution of the disc and halo is critical for the assembly and long-term survival of bars in marginally unstable discs; and (2) global disc stability criteria must be modified for discs in the presence of live haloes. In our live halo runs, a ‘dark bar’ grows synchronously with the stellar bar. Processes that inhibit the transfer of angular momentum between the halo and disc may stabilise a galaxy against bar formation, and can lead to the dissolution of the bar itself. This raises further questions about the puzzling stability of observed discs that are marginally unstable, but unbarred.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

Orbital architectures of planet-hosting binaries III. Testing mutual inclinations of stellar and planetary orbits in triple-star systems 行星寄宿双星的轨道结构 III.测试三重星系统中恒星和行星轨道的相互倾角

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-06 DOI: 10.1093/mnras/stae2095

Elise L Evans, Trent J Dupuy, Kendall Sullivan, Adam L Kraus, Daniel Huber, Michael J Ireland, Megan Ansdell, Rajika L Kuruwita, Raquel A Martinez, Mackenna L Wood

{"title":"Orbital architectures of planet-hosting binaries III. Testing mutual inclinations of stellar and planetary orbits in triple-star systems","authors":"Elise L Evans, Trent J Dupuy, Kendall Sullivan, Adam L Kraus, Daniel Huber, Michael J Ireland, Megan Ansdell, Rajika L Kuruwita, Raquel A Martinez, Mackenna L Wood","doi":"10.1093/mnras/stae2095","DOIUrl":"https://doi.org/10.1093/mnras/stae2095","url":null,"abstract":"Transiting planets in multiple-star systems, especially high-order multiples, make up a small fraction of the known planet population but provide unique opportunities to study the environments in which planets would have formed. Planet-hosting binaries have been shown to have an abundance of systems in which the stellar orbit aligns with the orbit of the transiting planet, which could give insights into the planet formation process in such systems. We investigate here if this trend of alignment extends to planet-hosting triple-star systems. We present long-term astrometric monitoring of a novel sample of triple-star systems that host Kepler transiting planets. We measured orbit arcs in 21 systems, including 12 newly identified triples, from a homogeneous analysis of our Keck adaptive optics data and, for some systems, Gaia astrometry. We examine the orbital alignment within the nine most compact systems (≲ 500 au), testing if either (or both) of the stellar orbits align with the edge-on orbits of their transiting planets. Our statistical sample of triple systems shows a tendency toward alignment, especially when assessing the alignment probability using stellar orbital inclinations computed from full orbital fits, but is formally consistent with isotropic orbits. Two-population tests where half of the stellar orbits are described by a planet-hosting-binary-like moderately aligned distribution give the best match when the other half (non-planet-hosting) has a Kozai-like misaligned distribution. Overall, our results suggest that our sample of triple-star planet-hosting systems are not fully coplanar systems and have at most one plane of alignment.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

Exploring the high-density reflection model for the soft excess in RBS 1124 探索 RBS 1124 中软过量的高密度反射模型

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-06 DOI: 10.1093/mnras/stae2104

A Madathil-Pottayil, D J Walton, Javier García, Jon Miller, Luigi C Gallo, C Ricci, Mark T Reynolds, D Stern, T Dauser, Jiachen Jiang, William Alston, A C Fabian, M J Hardcastle, Peter Kosec, Emanuele Nardini, Christopher S Reynolds

{"title":"Exploring the high-density reflection model for the soft excess in RBS 1124","authors":"A Madathil-Pottayil, D J Walton, Javier García, Jon Miller, Luigi C Gallo, C Ricci, Mark T Reynolds, D Stern, T Dauser, Jiachen Jiang, William Alston, A C Fabian, M J Hardcastle, Peter Kosec, Emanuele Nardini, Christopher S Reynolds","doi":"10.1093/mnras/stae2104","DOIUrl":"https://doi.org/10.1093/mnras/stae2104","url":null,"abstract":"‘Bare’ active galactic nuclei (AGN) are a subclass of Type 1 AGN that show little or no intrinsic absorption. They offer an unobscured view of the central regions of the AGN and therefore serve as ideal targets to study the relativistic reflection features originating from the innermost regions of the accretion disc. We present a detailed broadband spectral analysis (0.3 – 70 keV) of one of the most luminous bare AGN in the local universe, RBS 1124 (z = 0.208) using a new, co-ordinated high signal-to-noise observation obtained by XMM-Newton and NuSTAR. The source exhibits a power-law continuum with Γ ∼ 1.8 along with a soft excess below 2 keV, a weak neutral iron line and curvature at high energies (∼30 keV). The broadband spectrum, including the soft excess and the high-energy continuum, is well fit by the relativistic reflection model when the accretion disc is allowed to have densities of log(ne/cm−3) ≳ 19.2. Our analysis therefore suggests that when high-density effects are considered, relativistic reflection remains a viable explanation for the soft excess.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0

Impact of the High-Speed Solar Wind stream over the low latitude Ionospheric system - A Study combining Indian MOM and InSWIM observations 高速太阳风流对低纬度电离层系统的影响--结合印度 MOM 和 InSWIM 观测结果的研究

IF 4.8 3区物理与天体物理

Monthly Notices of the Royal Astronomical Society Pub Date : 2024-09-06 DOI: 10.1093/mnras/stae2091

Richa N Jain, R K Choudhary, K M Ambili, M V Roopa, Bijoy K Dai

{"title":"Impact of the High-Speed Solar Wind stream over the low latitude Ionospheric system - A Study combining Indian MOM and InSWIM observations","authors":"Richa N Jain, R K Choudhary, K M Ambili, M V Roopa, Bijoy K Dai","doi":"10.1093/mnras/stae2091","DOIUrl":"https://doi.org/10.1093/mnras/stae2091","url":null,"abstract":"In this study, we map the origin, acceleration, and propagation of the High-Speed Solar wind streams (HSS) and observe their impact on the low-latitude Earth’s ionosphere. Data from radio-sounding experiments conducted by the Indian Mars Orbiter Mission (MOM) from 9-19 May 2015 is analyzed to understand the solar wind speed’s evolution at various helio-centric distances. The slope of the turbulence spectrum from 25 to 35 Rs was in the range of 0.2 - 0.4, indicative of the underdeveloped turbulence corresponding to the High flow streams. It coincided with the appearance of the earth-facing coronal holes as observed in the coronal EUV images. The particle bulk velocity at L1 showed that the speeds began to rise from 400 km/s on 11th-12th May, reaching a peak of around 800 km/s on 13th-14th May, followed by a gradual decrease to the average slow speeds. Geomagnetic disturbances during the same period manifested as a dip in the DST index values. The GNSS (Global Navigation Satellite System) data from the InSWIM (Indian network for Space Weather Impact Monitoring) network show an appreciable increase in the VTEC (vertical total electron content) of the ionosphere on disturbed days in entire low-latitude ionospheric region in the Indian sector. All these observed parameters correlate well with the HSS arrival. This is a unique study that connects the propagation of the HSS and its impact on Near -Earth’s environment from the different vantage points in interplanetary space and proposes the application of Radio beacons to improve space weather forecasting.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"43 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

引用次数: 0