Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202452081
Mike Y. M. Lau, Matteo Cantiello, Adam S. Jermyn, Morgan MacLeod, Ilya Mandel, Daniel J. Price
Hot Jupiters are gas giant planets with orbital periods of a few days and are found in 0.1–1% of Sun-like stars. They are expected to be engulfed during their host star’s radial expansion on the red giant branch, which may account for observed rapidly rotating and chemically enriched giant stars. We performed 3D hydrodynamical simulations of hot Jupiter engulfment by a 1 M⊙, 4 R⊙ early red giant. Our ‘global’ simulations simultaneously resolve the stellar envelope and planetary structure, modelling the hot Jupiter as a polytropic gas sphere. The hot Jupiter spirals in due to ram-pressure drag. A substantial fraction of its mass is continuously ablated in this process, although the mass-loss rate is resolution dependent. We estimate that this could enhance the surface lithium abundance by up to ≈0.1 dex. The hot Jupiter is disrupted by a combination of ram pressure and tidal forces near the base of the convective envelope, with the deepest material penetrating to the radiative zone. The star experiences modest spin-up (∼1 km s−1), and engulfing a more massive companion may be required to produce a rapidly rotating giant. Drag heating near the surface and hydrogen recombination in the small amount of unbound ejecta recorded in the simulation could power an optical transient, although this needs to be confirmed by a calculation that has adequate resolution at the stellar surface.
{"title":"Hot Jupiter engulfment by an early red giant in 3D hydrodynamics","authors":"Mike Y. M. Lau, Matteo Cantiello, Adam S. Jermyn, Morgan MacLeod, Ilya Mandel, Daniel J. Price","doi":"10.1051/0004-6361/202452081","DOIUrl":"https://doi.org/10.1051/0004-6361/202452081","url":null,"abstract":"Hot Jupiters are gas giant planets with orbital periods of a few days and are found in 0.1–1% of Sun-like stars. They are expected to be engulfed during their host star’s radial expansion on the red giant branch, which may account for observed rapidly rotating and chemically enriched giant stars. We performed 3D hydrodynamical simulations of hot Jupiter engulfment by a 1 M<sub>⊙<sub/>, 4 R<sub>⊙<sub/> early red giant. Our ‘global’ simulations simultaneously resolve the stellar envelope and planetary structure, modelling the hot Jupiter as a polytropic gas sphere. The hot Jupiter spirals in due to ram-pressure drag. A substantial fraction of its mass is continuously ablated in this process, although the mass-loss rate is resolution dependent. We estimate that this could enhance the surface lithium abundance by up to ≈0.1 dex. The hot Jupiter is disrupted by a combination of ram pressure and tidal forces near the base of the convective envelope, with the deepest material penetrating to the radiative zone. The star experiences modest spin-up (∼1 km s<sup>−1<sup/>), and engulfing a more massive companion may be required to produce a rapidly rotating giant. Drag heating near the surface and hydrogen recombination in the small amount of unbound ejecta recorded in the simulation could power an optical transient, although this needs to be confirmed by a calculation that has adequate resolution at the stellar surface.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"25 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202450977
M. Kärcher, J. Bel, S. de la Torre
Modified gravity (MG) theories have emerged as a promising alternative to explain the late-time acceleration of the Universe. However, the detection of MG in observations of the large-scale structure remains challenging due to the screening mechanisms that obscure any deviations from general relativity (GR) in high-density regions. The marked two-point correlation function, which is particularly sensitive to the surrounding environment, offers a promising approach to enhancing the discriminating power in clustering analyses and to potentially detecting MG signals. This work investigates novel marks based on large-scale environment estimates, which also that exploit the anti-correlation between objects in low- and high-density regions. This is the first time that the propagation of discreteness effects in marked correlation functions is investigated in depth. In contrast to standard correlation functions, the density-dependent marked correlation function estimated from catalogues is affected by shot noise in a non-trivial way. We assess the performance of various marks to distinguish GR from MG. This is achieved through the use of the ELEPHANT suite of simulations, which comprise five realisations of GR and two different MG theories: f(R) and nDGP. In addition, discreteness effects are thoroughly studied using the high-density Covmos catalogues. We have established a robust method to correct for shot-noise effects that can be used in practical analyses. This methods allows the recovery of the true signal, with an accuracy below 5% over the scales of 5 h−1 Mpc up to 150 h−1 Mpc. We find that such a correction is absolutely crucial to measure the amplitude of the marked correlation function in an unbiased manner. Furthermore, we demonstrate that marks that anti-correlate objects in low- and high-density regions are among the most effective in distinguishing between MG and GR; they also uniquely provide visible deviations on large scales, up to about 80 h−1 Mpc. We report differences in the marked correlation function between f(R) with |fR0| = 10−6 and GR simulations of the order of 3–5σ in real space. The redshift-space monopole of the marked correlation function in this MG scenario exhibits similar features and performance as the real-space marked correlation function. The combination of the proposed tanh-mark with shot-noise correction paves the way towards an optimal approach for the detection of MG in current and future spectroscopic galaxy surveys.
{"title":"Towards an optimal marked correlation function analysis for the detection of modified gravity","authors":"M. Kärcher, J. Bel, S. de la Torre","doi":"10.1051/0004-6361/202450977","DOIUrl":"https://doi.org/10.1051/0004-6361/202450977","url":null,"abstract":"Modified gravity (MG) theories have emerged as a promising alternative to explain the late-time acceleration of the Universe. However, the detection of MG in observations of the large-scale structure remains challenging due to the screening mechanisms that obscure any deviations from general relativity (GR) in high-density regions. The marked two-point correlation function, which is particularly sensitive to the surrounding environment, offers a promising approach to enhancing the discriminating power in clustering analyses and to potentially detecting MG signals. This work investigates novel marks based on large-scale environment estimates, which also that exploit the anti-correlation between objects in low- and high-density regions. This is the first time that the propagation of discreteness effects in marked correlation functions is investigated in depth. In contrast to standard correlation functions, the density-dependent marked correlation function estimated from catalogues is affected by shot noise in a non-trivial way. We assess the performance of various marks to distinguish GR from MG. This is achieved through the use of the ELEPHANT suite of simulations, which comprise five realisations of GR and two different MG theories: <i>f<i/>(<i>R<i/>) and nDGP. In addition, discreteness effects are thoroughly studied using the high-density Covmos catalogues. We have established a robust method to correct for shot-noise effects that can be used in practical analyses. This methods allows the recovery of the true signal, with an accuracy below 5% over the scales of 5 <i>h<i/><sup>−1<sup/> Mpc up to 150 <i>h<i/><sup>−1<sup/> Mpc. We find that such a correction is absolutely crucial to measure the amplitude of the marked correlation function in an unbiased manner. Furthermore, we demonstrate that marks that anti-correlate objects in low- and high-density regions are among the most effective in distinguishing between MG and GR; they also uniquely provide visible deviations on large scales, up to about 80 <i>h<i/><sup>−1<sup/> Mpc. We report differences in the marked correlation function between <i>f<i/>(<i>R<i/>) with |<i>f<i/><sub><i>R<i/>0<sub/>| = 10<sup>−6<sup/> and GR simulations of the order of 3–5<i>σ<i/> in real space. The redshift-space monopole of the marked correlation function in this MG scenario exhibits similar features and performance as the real-space marked correlation function. The combination of the proposed tanh-mark with shot-noise correction paves the way towards an optimal approach for the detection of MG in current and future spectroscopic galaxy surveys.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"81 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202452241
G. González-Torà, A. A. C. Sander, J. O. Sundqvist, D. Debnath, L. Delbroek, J. Josiek, R. R. Lefever, N. Moens, C. Van der Sijpt, O. Verhamme
<i>Context<i/>. The outer layers and the spectral appearance of massive stars are inherently affected by radiation pressure. Recent multidimensional, radiation-hydrodynamical (RHD) simulations of massive stellar atmospheres have shed new light on the complexity involved in the surface layers and the onset of radiation-driven winds. These findings include the presence of sub-surface, radiatively driven turbulent motion. For some regimes, the velocities associated with this turbulence and their localisation significantly exceed earlier estimates drawn from stellar structure models. This prompts the question of whether spectral diagnostics obtained with the typical assumptions in 1D spherically symmetric and stationary atmospheres are still sufficient.<i>Aims<i/>. For the foreseeable future, the inherent computation costs and necessary approximations will pose challenges to the common usage of multi-dimensional, time-dependent atmosphere models in the quantitative spectral analysis of populations of stars. Therefore, suitable approximations of multi-dimensional simulation results need to be implemented into 1D atmosphere models.<i>Methods<i/>. We compared current 1D and multi-dimensional atmosphere modelling approaches to understand their strengths and shortcomings. We calculated the averaged stratifications from selected multi-dimensional calculations for O stars – corresponding to spectral types O8, O4, and O2, with log 𝑔 ∼ 3.7 – to approximate them with 1D stellar atmosphere models using the PoWR model atmosphere code and assuming a fixed <i>β<i/>–law for the wind regime. We then studied the effects of our approximations and assumptions on current spectral diagnostics. In particular, we focus on the impact of an additional turbulent pressure in the subsonic layers of the 1D models.<i>Results<i/>. To match the 2D averages, the 1D stellar atmosphere models need to account for turbulent pressure in the hydrostatic equation. Moreover, an adjustment of the connection point between the (quasi)hydrostatic regime and the wind regime is required. The improvement between the density stratification of the 1D model and 2D average can be further increased if the mass-loss rate of the 1D model is not identical to that of the 2D simulation; rather, it is typically ∼0.2 dex higher. Especially in the case of an early-type star, this would imply a significantly more extended envelope with a lower effective temperature.<i>Conclusions<i/>. Already, the inclusion of a constant turbulence term in the solution of the hydrostatic equation is shown to sufficiently reproduce the 2D-averaged model density stratifications. The addition of a significant turbulent motion also smoothens the slope of the radiative acceleration term in the (quasi)hydrostatic domain, with several potential implications on the total mass-loss rate inferred from 1D modelling. Concerning the spectral synthesis, the addition of a turbulence term in the hydrostatic equation mimics the effect of a low
{"title":"Improving 1D stellar atmosphere models with insights from multi-dimensional simulations","authors":"G. González-Torà, A. A. C. Sander, J. O. Sundqvist, D. Debnath, L. Delbroek, J. Josiek, R. R. Lefever, N. Moens, C. Van der Sijpt, O. Verhamme","doi":"10.1051/0004-6361/202452241","DOIUrl":"https://doi.org/10.1051/0004-6361/202452241","url":null,"abstract":"<i>Context<i/>. The outer layers and the spectral appearance of massive stars are inherently affected by radiation pressure. Recent multidimensional, radiation-hydrodynamical (RHD) simulations of massive stellar atmospheres have shed new light on the complexity involved in the surface layers and the onset of radiation-driven winds. These findings include the presence of sub-surface, radiatively driven turbulent motion. For some regimes, the velocities associated with this turbulence and their localisation significantly exceed earlier estimates drawn from stellar structure models. This prompts the question of whether spectral diagnostics obtained with the typical assumptions in 1D spherically symmetric and stationary atmospheres are still sufficient.<i>Aims<i/>. For the foreseeable future, the inherent computation costs and necessary approximations will pose challenges to the common usage of multi-dimensional, time-dependent atmosphere models in the quantitative spectral analysis of populations of stars. Therefore, suitable approximations of multi-dimensional simulation results need to be implemented into 1D atmosphere models.<i>Methods<i/>. We compared current 1D and multi-dimensional atmosphere modelling approaches to understand their strengths and shortcomings. We calculated the averaged stratifications from selected multi-dimensional calculations for O stars – corresponding to spectral types O8, O4, and O2, with log 𝑔 ∼ 3.7 – to approximate them with 1D stellar atmosphere models using the PoWR model atmosphere code and assuming a fixed <i>β<i/>–law for the wind regime. We then studied the effects of our approximations and assumptions on current spectral diagnostics. In particular, we focus on the impact of an additional turbulent pressure in the subsonic layers of the 1D models.<i>Results<i/>. To match the 2D averages, the 1D stellar atmosphere models need to account for turbulent pressure in the hydrostatic equation. Moreover, an adjustment of the connection point between the (quasi)hydrostatic regime and the wind regime is required. The improvement between the density stratification of the 1D model and 2D average can be further increased if the mass-loss rate of the 1D model is not identical to that of the 2D simulation; rather, it is typically ∼0.2 dex higher. Especially in the case of an early-type star, this would imply a significantly more extended envelope with a lower effective temperature.<i>Conclusions<i/>. Already, the inclusion of a constant turbulence term in the solution of the hydrostatic equation is shown to sufficiently reproduce the 2D-averaged model density stratifications. The addition of a significant turbulent motion also smoothens the slope of the radiative acceleration term in the (quasi)hydrostatic domain, with several potential implications on the total mass-loss rate inferred from 1D modelling. Concerning the spectral synthesis, the addition of a turbulence term in the hydrostatic equation mimics the effect of a low","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"17 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202452507
R. Dastidar, K. Misra, S. Valenti, D. J. Sand, A. Pastorello, A. Reguitti, G. Pignata, S. Benetti, S. Bose, A. Gangopadhyay, M. Singh, L. Tomasella, J. E. Andrews, I. Arcavi, C. Ashall, C. Bilinski, K. A. Bostroem, D. A. H. Buckley, G. Cannizzaro, L. Chomiuk, E. Congiu, S. Dong, Y. Dong, N. Elias-Rosa, M. Fraser, C. Gall, M. Gromadzki, D. Hiramatsu, G. Hosseinzadeh, D. A. Howell, E. Y. Hsiao, C. McCully, N. Smith, J. Strader
We present a comprehensive photometric and spectroscopic study of the Type IIP supernova (SN) 2018is. The V band luminosity and the expansion velocity at 50 days post-explosion are −15.1 ± 0.2 mag (corrected for AV = 1.34 mag) and 1400 km s−1, classifying it as a low-luminosity SN II. The recombination phase in the V band is shorter, lasting around 110 days, and exhibits a steeper decline (1.0 mag per 100 days) compared to most other low-luminosity SNe II. Additionally, the optical and near-infrared spectra display hydrogen emission lines that are strikingly narrow, even for this class. The Fe II and Sc II line velocities are at the lower end of the typical range for low-luminosity SNe II. Semi-analytical modelling of the bolometric light curve suggests an ejecta mass of ∼8 M⊙, corresponding to a pre-supernova mass of ∼9.5 M⊙, and an explosion energy of ∼0.40 × 1051 erg. Hydrodynamical modelling further indicates that the progenitor had a zero-age main sequence mass of 9 M⊙, coupled with a low explosion energy of 0.19 × 1051 erg. The nebular spectrum reveals weak [O I] λλ6300,6364 lines, consistent with a moderate-mass progenitor, while features typical of Fe core-collapse events, such as He I, [C I], and Fe I, are indiscernible. However, the redder colours and low ratio of Ni to Fe abundance do not support an electron-capture scenario either. As a low-luminosity SN II with an atypically steep decline during the photospheric phase and remarkably narrow emission lines, SN 2018is contributes to the diversity observed within this population.
我们对 IIP 型超新星（SN）2018is 进行了全面的光度和光谱研究。爆炸后50天的V波段光度和膨胀速度分别为-15.1 ± 0.2 mag（AV校正后=1.34 mag）和1400 km s-1，将其归类为低光度SN II。与其他大多数低亮度 SNe II 相比，它在 V 波段的重组阶段持续时间较短，约为 110 天，而且衰减幅度较大（每 100 天 1.0 个品位）。此外，其光学和近红外光谱显示的氢发射线非常窄，即使对于该类星云来说也是如此。Fe II和Sc II线速度处于低亮度SNE II典型范围的下限。对测光曲线的半分析建模表明，喷射物质量为∼8 M⊙，相当于超新星前的质量∼9.5 M⊙，爆炸能量为∼0.40 × 1051 erg。流体力学模型进一步表明，原生星的零年龄主序质量为 9 M⊙，爆炸能量低至 0.19 × 1051 erg。星云光谱显示出微弱的[O I] λλ6300,6364 线，这与中等质量的祖星一致，而铁核塌缩事件的典型特征，如 He I、[C I] 和 Fe I，则无法辨别。然而，较红的颜色和较低的镍铁丰度比也不支持电子捕获的设想。作为一个低亮度的SN II，SN 2018is在光球阶段具有非典型的陡峭衰退和非常窄的发射线，它为这一族群中观测到的多样性做出了贡献。
{"title":"SN 2018is: A low-luminosity Type IIP supernova with narrow hydrogen emission lines at early phases","authors":"R. Dastidar, K. Misra, S. Valenti, D. J. Sand, A. Pastorello, A. Reguitti, G. Pignata, S. Benetti, S. Bose, A. Gangopadhyay, M. Singh, L. Tomasella, J. E. Andrews, I. Arcavi, C. Ashall, C. Bilinski, K. A. Bostroem, D. A. H. Buckley, G. Cannizzaro, L. Chomiuk, E. Congiu, S. Dong, Y. Dong, N. Elias-Rosa, M. Fraser, C. Gall, M. Gromadzki, D. Hiramatsu, G. Hosseinzadeh, D. A. Howell, E. Y. Hsiao, C. McCully, N. Smith, J. Strader","doi":"10.1051/0004-6361/202452507","DOIUrl":"https://doi.org/10.1051/0004-6361/202452507","url":null,"abstract":"We present a comprehensive photometric and spectroscopic study of the Type IIP supernova (SN) 2018is. The <i>V<i/> band luminosity and the expansion velocity at 50 days post-explosion are −15.1 ± 0.2 mag (corrected for A<sub><i>V<i/><sub/> = 1.34 mag) and 1400 km s<sup>−1<sup/>, classifying it as a low-luminosity SN II. The recombination phase in the <i>V<i/> band is shorter, lasting around 110 days, and exhibits a steeper decline (1.0 mag per 100 days) compared to most other low-luminosity SNe II. Additionally, the optical and near-infrared spectra display hydrogen emission lines that are strikingly narrow, even for this class. The Fe II and Sc II line velocities are at the lower end of the typical range for low-luminosity SNe II. Semi-analytical modelling of the bolometric light curve suggests an ejecta mass of ∼8 M<sub>⊙<sub/>, corresponding to a pre-supernova mass of ∼9.5 M<sub>⊙<sub/>, and an explosion energy of ∼0.40 × 10<sup>51<sup/> erg. Hydrodynamical modelling further indicates that the progenitor had a zero-age main sequence mass of 9 M<sub>⊙<sub/>, coupled with a low explosion energy of 0.19 × 10<sup>51<sup/> erg. The nebular spectrum reveals weak [O I] <i>λλ<i/>6300,6364 lines, consistent with a moderate-mass progenitor, while features typical of Fe core-collapse events, such as He I, [C I], and Fe I, are indiscernible. However, the redder colours and low ratio of Ni to Fe abundance do not support an electron-capture scenario either. As a low-luminosity SN II with an atypically steep decline during the photospheric phase and remarkably narrow emission lines, SN 2018is contributes to the diversity observed within this population.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"15 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202452182
Susmita Das, László Molnár, Gábor B. Kovács, Radoslaw Smolec, Meridith Joyce, Shashi M. Kanbur, Tamás Szklenár, Anupam Bhardwaj, Harinder P. Singh, Marcella Marconi, Vincenzo Ripepi
Context. In the era of precision stellar astrophysics, classical pulsating stars play a crucial role in determinations of the cosmological distance scale thanks to their period-luminosity (PL) relations. Therefore, it is important to constrain their stellar evolution and pulsation models not only through a comparison of empirical and theoretical PL relations and properties at mean light, but also using their light curve structure over the complete pulsation cycle.Aims. We carried out an extensive light curve comparison of BL Her stars using observations from Gaia DR3 and stellar pulsation models computed using MESA-RSP with the goal of obtaining the best-matched observed-model pairs for BL Her stars in the Large Magellanic Cloud (LMC).Methods. We used the Fourier decomposition technique to analyze the light curves in the G band obtained from Gaia DR3 and from MESA-RSP and used a robust light-curve-fitting approach to score the observed-model pairs with respect to their pulsation periods and over their Fourier parameter space.Results. We obtain the best-fit models for 48 BL Her stars in the LMC and thereby provide the stellar parameter estimates of these stars, 30 of which we classify as our “gold sample” due to their superior light curve fits. We find a relatively flat distribution of stellar masses between 0.5 and 0.65 M⊙ for the gold sample of observed-model pairs. An interesting result is that the majority of the best-matched models in the gold sample were computed using the convection parameter sets without radiative cooling. The period-Wesenheit (PW) relation for the best-matched gold sample of 30 BL Her models has a slope of −2.805 ± 0.164 and the corresponding period-radius relation a slope of 0.565 ± 0.035, both in good agreement with the empirical PW and period-radius slopes from BL Her stars in the LMC, respectively. We also used the Wesenheit magnitudes of the 30 best-matched observed-model pairs to estimate a distance modulus of μLMC = 18.582 ± 0.067 to the LMC, which lies within the bounds of previous literature values. We also discuss the degeneracy in the stellar parameters of the BL Her models that result in similar pulsation periods and light curve structure, and highlight that caution must be exercised while using the stellar parameter estimates.
{"title":"A theoretical framework for BL Her stars","authors":"Susmita Das, László Molnár, Gábor B. Kovács, Radoslaw Smolec, Meridith Joyce, Shashi M. Kanbur, Tamás Szklenár, Anupam Bhardwaj, Harinder P. Singh, Marcella Marconi, Vincenzo Ripepi","doi":"10.1051/0004-6361/202452182","DOIUrl":"https://doi.org/10.1051/0004-6361/202452182","url":null,"abstract":"<i>Context.<i/> In the era of precision stellar astrophysics, classical pulsating stars play a crucial role in determinations of the cosmological distance scale thanks to their period-luminosity (PL) relations. Therefore, it is important to constrain their stellar evolution and pulsation models not only through a comparison of empirical and theoretical PL relations and properties at mean light, but also using their light curve structure over the complete pulsation cycle.<i>Aims.<i/> We carried out an extensive light curve comparison of BL Her stars using observations from <i>Gaia<i/> DR3 and stellar pulsation models computed using MESA-RSP with the goal of obtaining the best-matched observed-model pairs for BL Her stars in the Large Magellanic Cloud (LMC).<i>Methods.<i/> We used the Fourier decomposition technique to analyze the light curves in the <i>G<i/> band obtained from <i>Gaia<i/> DR3 and from MESA-RSP and used a robust light-curve-fitting approach to score the observed-model pairs with respect to their pulsation periods and over their Fourier parameter space.<i>Results.<i/> We obtain the best-fit models for 48 BL Her stars in the LMC and thereby provide the stellar parameter estimates of these stars, 30 of which we classify as our “gold sample” due to their superior light curve fits. We find a relatively flat distribution of stellar masses between 0.5 and 0.65 <i>M<i/><sub>⊙<sub/> for the gold sample of observed-model pairs. An interesting result is that the majority of the best-matched models in the gold sample were computed using the convection parameter sets without radiative cooling. The period-Wesenheit (PW) relation for the best-matched gold sample of 30 BL Her models has a slope of −2.805 ± 0.164 and the corresponding period-radius relation a slope of 0.565 ± 0.035, both in good agreement with the empirical PW and period-radius slopes from BL Her stars in the LMC, respectively. We also used the Wesenheit magnitudes of the 30 best-matched observed-model pairs to estimate a distance modulus of <i>μ<i/><sub>LMC<sub/> = 18.582 ± 0.067 to the LMC, which lies within the bounds of previous literature values. We also discuss the degeneracy in the stellar parameters of the BL Her models that result in similar pulsation periods and light curve structure, and highlight that caution must be exercised while using the stellar parameter estimates.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"2 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202453189
A. ud-Doula, J. Krtička, B. Kubátová
Context. Classical chemically peculiar stars exhibit atmospheres that are often structured by the effects of atomic diffusion. As a result of these elemental diffusion and horizontal abundance variations, the photospheric temperature varies at a given height in the atmosphere. This may lead to horizontal flows in the photosphere. In addition, the suppression of such flows by a magnetic field can alter the elemental transport processes.Aims. Using a simplified model of such a structured atmosphere and 2D magnetohydrodynamic simulations of a typical He-rich star, we examined atmospheric flows in these chemically peculiar stars, which often are strongly magnetic.Methods. We used Zeus-MP, which is a publicly available Fortran 90-based parallel finite element modular code.Results. We find that for non-magnetic stars of spectral type BA, the atmospheric flow related to the horizontal temperature gradient can reach 1.0 km s−1, yielding mixing timescales of the order of tens of days. For the magnetic counterparts, the flow speeds are an order of magnitude lower, allowing for the stratification of chemical elements.Conclusions. Magnetic fields can significantly influence the dynamics in atmospheres. A strong horizontal magnetic field inhibits flow in the vertical direction, while a strong vertical magnetic field can suppress horizontal atmospheric flow and prevent elemental mixing.
{"title":"Horizontal flows in the atmospheres of chemically peculiar stars","authors":"A. ud-Doula, J. Krtička, B. Kubátová","doi":"10.1051/0004-6361/202453189","DOIUrl":"https://doi.org/10.1051/0004-6361/202453189","url":null,"abstract":"<i>Context<i/>. Classical chemically peculiar stars exhibit atmospheres that are often structured by the effects of atomic diffusion. As a result of these elemental diffusion and horizontal abundance variations, the photospheric temperature varies at a given height in the atmosphere. This may lead to horizontal flows in the photosphere. In addition, the suppression of such flows by a magnetic field can alter the elemental transport processes.<i>Aims<i/>. Using a simplified model of such a structured atmosphere and 2D magnetohydrodynamic simulations of a typical He-rich star, we examined atmospheric flows in these chemically peculiar stars, which often are strongly magnetic.<i>Methods<i/>. We used Zeus-MP, which is a publicly available Fortran 90-based parallel finite element modular code.<i>Results<i/>. We find that for non-magnetic stars of spectral type BA, the atmospheric flow related to the horizontal temperature gradient can reach 1.0 km s<sup>−1<sup/>, yielding mixing timescales of the order of tens of days. For the magnetic counterparts, the flow speeds are an order of magnitude lower, allowing for the stratification of chemical elements.<i>Conclusions<i/>. Magnetic fields can significantly influence the dynamics in atmospheres. A strong horizontal magnetic field inhibits flow in the vertical direction, while a strong vertical magnetic field can suppress horizontal atmospheric flow and prevent elemental mixing.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202452288
M. Rossi, S. Guastavino, M. Piana, A. M. Massone
Coronal mass ejections (CMEs) are one of the primary drivers of space weather disturbances, affecting both space-based and terrestrial technologies. The accurate prediction of CME trajectories and their arrival times at Earth is crucial for mitigating potential impacts. In this work, we introduce an extended drag-based model (EDBM) that incorporates an additional acceleration term to better capture the complex dynamics of CMEs as they propagate through the heliosphere. Preliminary results suggest that the EDBM can improve upon the classical drag-based model by providing more reliable estimates of CME travel times, particularly in cases where the CME experiences residual acceleration. However, further validation is required to fully assess the operational potential of the model for space weather forecasting. This study lays the groundwork for future investigations and applications, with the aim of enhancing the accuracy of CME prediction models.
{"title":"Extended drag-based model for better predicting the evolution of coronal mass ejections","authors":"M. Rossi, S. Guastavino, M. Piana, A. M. Massone","doi":"10.1051/0004-6361/202452288","DOIUrl":"https://doi.org/10.1051/0004-6361/202452288","url":null,"abstract":"Coronal mass ejections (CMEs) are one of the primary drivers of space weather disturbances, affecting both space-based and terrestrial technologies. The accurate prediction of CME trajectories and their arrival times at Earth is crucial for mitigating potential impacts. In this work, we introduce an extended drag-based model (EDBM) that incorporates an additional acceleration term to better capture the complex dynamics of CMEs as they propagate through the heliosphere. Preliminary results suggest that the EDBM can improve upon the classical drag-based model by providing more reliable estimates of CME travel times, particularly in cases where the CME experiences residual acceleration. However, further validation is required to fully assess the operational potential of the model for space weather forecasting. This study lays the groundwork for future investigations and applications, with the aim of enhancing the accuracy of CME prediction models.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"7 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202450731
S. M. Hejazi, T. Van Doorsselaere, M. Sadeghi, D. Y. Kolotkov, J. Hermans
Aims. It is well demonstrated that thermal misbalance, arising from the discrepancy between optically thin radiative energy loss and heating energy gain, disrupts the adiabatic nature of solar corona plasmas, directly affecting the propagation of slow magnetoacoustic waves. However, the extent to which this thermal misbalance, acting as a dispersion factor of an arbitrary intensity, influences the use of slow modes as seismological tools and affects sausage and kink harmonic modes within a magnetic plasma flux tube, remains unresolved.Methods. This study investigates the dispersion of magnetohydrodynamic waves influenced by thermal misbalance in a cylindrical configuration with a finite axial magnetic field within solar coronal plasmas. Specifically, it examines how thermal misbalance, characterized by two distinct timescales directly linked to the cooling and heating functions, influences the dispersion relation. This investigation is a key approach for understanding non-adiabatic effects on the behaviour of these waves.Results. The analysis explores the impact of non-adiabatic effects due to classical thermal misbalance, where the heating and cooling timescales vary across a range of values corresponding to each magnetohydrodynamic mode. The dispersion relation for magnetohydrodynamic waves propagating through a magnetic plasma tube, aligned with a finite magnetic field, is calculated under coronal conditions in the linear regime.Conclusions. Our findings reveal that the effect of thermal misbalance on fast sausage and kink modes, consistent with previous studies on slabs, is small but slightly more pronounced than previously thought. The impact is smaller at long-wavelength limits but increases at shorter wavelengths, leading to higher damping rates. This minor effect on fast modes occurs despite the complex interaction of thermal misbalance terms within the dispersion relation, even at low-frequency limits defined by the characteristic timescales. Additionally, a very small amplification is observed, indicating a suppressed damping state for the long-wavelength fundamental fast kink mode. In contrast, slow magnetoacoustic modes are significantly affected by thermal misbalance, with the cusp frequency shifting slightly to lower values, which is significant for smaller longitudinal wavenumbers. This thermal misbalance likely accounts for the substantial attenuation observed in the propagation of slow magnetoacoustic waves within the solar atmosphere. The long-wavelength limit leads to an analytical expression that accurately describes the frequency shifts in slow modes due to misbalance, closely aligning with both numerical and observational results.
{"title":"The effect of thermal misbalance on magnetohydrodynamic modes in coronal magnetic cylinders","authors":"S. M. Hejazi, T. Van Doorsselaere, M. Sadeghi, D. Y. Kolotkov, J. Hermans","doi":"10.1051/0004-6361/202450731","DOIUrl":"https://doi.org/10.1051/0004-6361/202450731","url":null,"abstract":"<i>Aims.<i/> It is well demonstrated that thermal misbalance, arising from the discrepancy between optically thin radiative energy loss and heating energy gain, disrupts the adiabatic nature of solar corona plasmas, directly affecting the propagation of slow magnetoacoustic waves. However, the extent to which this thermal misbalance, acting as a dispersion factor of an arbitrary intensity, influences the use of slow modes as seismological tools and affects sausage and kink harmonic modes within a magnetic plasma flux tube, remains unresolved.<i>Methods.<i/> This study investigates the dispersion of magnetohydrodynamic waves influenced by thermal misbalance in a cylindrical configuration with a finite axial magnetic field within solar coronal plasmas. Specifically, it examines how thermal misbalance, characterized by two distinct timescales directly linked to the cooling and heating functions, influences the dispersion relation. This investigation is a key approach for understanding non-adiabatic effects on the behaviour of these waves.<i>Results.<i/> The analysis explores the impact of non-adiabatic effects due to classical thermal misbalance, where the heating and cooling timescales vary across a range of values corresponding to each magnetohydrodynamic mode. The dispersion relation for magnetohydrodynamic waves propagating through a magnetic plasma tube, aligned with a finite magnetic field, is calculated under coronal conditions in the linear regime.<i>Conclusions.<i/> Our findings reveal that the effect of thermal misbalance on fast sausage and kink modes, consistent with previous studies on slabs, is small but slightly more pronounced than previously thought. The impact is smaller at long-wavelength limits but increases at shorter wavelengths, leading to higher damping rates. This minor effect on fast modes occurs despite the complex interaction of thermal misbalance terms within the dispersion relation, even at low-frequency limits defined by the characteristic timescales. Additionally, a very small amplification is observed, indicating a suppressed damping state for the long-wavelength fundamental fast kink mode. In contrast, slow magnetoacoustic modes are significantly affected by thermal misbalance, with the cusp frequency shifting slightly to lower values, which is significant for smaller longitudinal wavenumbers. This thermal misbalance likely accounts for the substantial attenuation observed in the propagation of slow magnetoacoustic waves within the solar atmosphere. The long-wavelength limit leads to an analytical expression that accurately describes the frequency shifts in slow modes due to misbalance, closely aligning with both numerical and observational results.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"2 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202453466
M. Molero, L. Magrini, M. Palla, G. Cescutti, C. Viscasillas Vázquez, G. Casali, E. Spitoni, F. Matteucci, S. Randich
Context. Chemical clocks based on [s-process element/α element] ratios are widely used to estimate the ages of Galactic stellar populations. However, the [s/α] versus age relations are not universal, varying with metallicity, location in the Galactic disc, and specific s-process elements. Moreover, current Galactic chemical evolution models struggle to reproduce the observed [s/α] increase at young ages, particularly for Ba.Aims. Our aim is to provide chemical evolution models for different regions of the Milky Way (MW) disc in order to identify the conditions required to reproduce the observed [s/H], [s/Fe], and [s/α] versus age relations.Methods. We adopted a detailed multi-zone chemical evolution model for the MW including state-of-the-art nucleosynthesis prescriptions for neutron-capture elements. The s-process elements were synthesised in asymptotic giant branch (AGB) stars and rotating massive stars, while r-process elements originate from neutron star mergers and magneto-rotational supernovae. Starting from a baseline model that successfully reproduces a wide range of neutron-capture element abundance patterns, we explored variations in gas infall/star formation history scenarios, AGB yield dependencies on progenitor stars, and rotational velocity distributions for massive stars. We compared the results of our model with the open clusters dataset from the sixth data release of the Gaia-ESO survey.Results. A three-infall scenario for disc formation aligns better with the observed trends. The models capture the rise of [s/α] with age in the outer regions but fail towards the inner regions, with larger discrepancies for second s-process peak elements. Specifically, Ba production in the last 3 Gyr of chemical evolution would need to increase by slightly more than half to match the observations. The s-process contribution from low-mass (∼1.1 M⊙) AGB stars helps reconcile predictions with data but it requires a too-strong increase that is not predicted by current nucleosynthesis calculations, even with a potential i-process contribution. Variations in the metallicity dependence of AGB yields either worsen the agreement or show inconsistent effects across elements, while distributions of massive star rotational velocities with lower velocity at high metallicities fail to improve results due to balanced effects on different elements.Conclusions. The predictions of our model confirm, as expected, that there is no single relationship [s/α] versus age and that it varies along the MW disc. However, the current prescriptions for neutron-capture element yields are not able to fully capture the complexity of evolution, particularly in the inner disc.
{"title":"Modelling chemical clocks","authors":"M. Molero, L. Magrini, M. Palla, G. Cescutti, C. Viscasillas Vázquez, G. Casali, E. Spitoni, F. Matteucci, S. Randich","doi":"10.1051/0004-6361/202453466","DOIUrl":"https://doi.org/10.1051/0004-6361/202453466","url":null,"abstract":"<i>Context<i/>. Chemical clocks based on [s-process element/<i>α<i/> element] ratios are widely used to estimate the ages of Galactic stellar populations. However, the [s/<i>α<i/>] versus age relations are not universal, varying with metallicity, location in the Galactic disc, and specific s-process elements. Moreover, current Galactic chemical evolution models struggle to reproduce the observed [s/<i>α<i/>] increase at young ages, particularly for Ba.<i>Aims<i/>. Our aim is to provide chemical evolution models for different regions of the Milky Way (MW) disc in order to identify the conditions required to reproduce the observed [s/H], [s/Fe], and [s/<i>α<i/>] versus age relations.<i>Methods<i/>. We adopted a detailed multi-zone chemical evolution model for the MW including state-of-the-art nucleosynthesis prescriptions for neutron-capture elements. The s-process elements were synthesised in asymptotic giant branch (AGB) stars and rotating massive stars, while r-process elements originate from neutron star mergers and magneto-rotational supernovae. Starting from a baseline model that successfully reproduces a wide range of neutron-capture element abundance patterns, we explored variations in gas infall/star formation history scenarios, AGB yield dependencies on progenitor stars, and rotational velocity distributions for massive stars. We compared the results of our model with the open clusters dataset from the sixth data release of the <i>Gaia<i/>-ESO survey.<i>Results<i/>. A three-infall scenario for disc formation aligns better with the observed trends. The models capture the rise of [s/<i>α<i/>] with age in the outer regions but fail towards the inner regions, with larger discrepancies for second s-process peak elements. Specifically, Ba production in the last 3 Gyr of chemical evolution would need to increase by slightly more than half to match the observations. The s-process contribution from low-mass (∼1.1 M<sub>⊙<sub/>) AGB stars helps reconcile predictions with data but it requires a too-strong increase that is not predicted by current nucleosynthesis calculations, even with a potential i-process contribution. Variations in the metallicity dependence of AGB yields either worsen the agreement or show inconsistent effects across elements, while distributions of massive star rotational velocities with lower velocity at high metallicities fail to improve results due to balanced effects on different elements.<i>Conclusions<i/>. The predictions of our model confirm, as expected, that there is no single relationship [s/<i>α<i/>] versus age and that it varies along the MW disc. However, the current prescriptions for neutron-capture element yields are not able to fully capture the complexity of evolution, particularly in the inner disc.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"13 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Pub Date : 2025-02-19DOI: 10.1051/0004-6361/202451612
Gabriele Demasi, Giulia Capurri, Angelo Ricciardone, Barbara Patricelli, Massimo Lenti, Walter Del Pozzo
Context. The scientific impact of GW170817 strongly supports the suggestion that we need an efficient electromagnetic follow-up campaign for gravitational-wave event candidates. The success of these campaigns critically depends on a fast and accurate localization of the source.Aims. We present SKYFAST, an algorithm for the rapid identification of gravitational-wave hosts to optimize electromagnetic follow-up searches. The goal is to produce a list of the galaxies within the localization volume, ranked by their probability of being the host, along with an estimate of the inclination angle conditioned on the position of each galaxy.Methods.SKYFAST runs alongside a full parameter estimation (PE) algorithm, from which posterior samples are taken. These samples are then used to reconstruct an analytical posterior of the sky position, luminosity distance, and inclination angle using a Dirichlet process Gaussian mixture model, which is a nonparametric Bayesian method.Results. We show that SKYFAST can reconstruct an accurate localization using only a fraction (∼10%) of the total posterior samples produced by the PE. Moreover, SKYFAST generates a ranked list of the most probable hosts from a galaxy catalog of choice in a few minutes. This list includes information on the inclination angle posterior conditioned on the position of each candidate host. This breaks the degeneracy between inclination angle and luminosity distance.Conclusions. The reconstruction of the posterior using fewer samples than the full PE can lead to significant time savings, depending on the PE algorithm employed. This is crucial for identifying the electromagnetic counterpart. The inclusion of the inclination angle information conditioned on the position of each galaxy can lead to an optimized electromagnetic follow-up.
背景。GW170817 的科学影响有力地支持了我们需要对引力波候选事件进行高效电磁跟踪的建议。这些活动的成功在很大程度上取决于对源头快速准确的定位。我们提出了 SKYFAST，一种用于快速识别引力波宿主以优化电磁跟踪搜索的算法。其目标是生成一份定位范围内的星系列表，按照星系成为宿主的概率进行排序，并根据每个星系的位置估算倾角。方法：SKYFAST与全参数估计（PE）算法同时运行，从中提取后验样本。然后利用这些样本，使用一种非参数贝叶斯方法--Dirichlet过程高斯混合模型，重建天空位置、光度距离和倾角的分析后验。我们的研究表明，SKYFAST 只需使用 PE 所产生的全部后验样本的一小部分（∼10%）就能重建精确定位。此外，SKYFAST还能在几分钟内从所选星系目录中生成一份最有可能的宿主排序列表。该列表包括以每个候选宿主位置为条件的倾角后验信息。这就打破了倾角与光度距离之间的退行性。根据所使用的 PE 算法，使用比完整 PE 更少的样本进行后验重建可以大大节省时间。这对于识别电磁对应体至关重要。根据每个星系的位置加入倾角信息，可以优化电磁跟踪。
{"title":"Enhancing the localization of gravitational-wave hosts with SKYFAST: Rapid volume and inclination angle reconstruction","authors":"Gabriele Demasi, Giulia Capurri, Angelo Ricciardone, Barbara Patricelli, Massimo Lenti, Walter Del Pozzo","doi":"10.1051/0004-6361/202451612","DOIUrl":"https://doi.org/10.1051/0004-6361/202451612","url":null,"abstract":"<i>Context.<i/> The scientific impact of GW170817 strongly supports the suggestion that we need an efficient electromagnetic follow-up campaign for gravitational-wave event candidates. The success of these campaigns critically depends on a fast and accurate localization of the source.<i>Aims.<i/> We present SKYFAST, an algorithm for the rapid identification of gravitational-wave hosts to optimize electromagnetic follow-up searches. The goal is to produce a list of the galaxies within the localization volume, ranked by their probability of being the host, along with an estimate of the inclination angle conditioned on the position of each galaxy.<i>Methods.<i/>SKYFAST runs alongside a full parameter estimation (PE) algorithm, from which posterior samples are taken. These samples are then used to reconstruct an analytical posterior of the sky position, luminosity distance, and inclination angle using a Dirichlet process Gaussian mixture model, which is a nonparametric Bayesian method.<i>Results.<i/> We show that SKYFAST can reconstruct an accurate localization using only a fraction (∼10%) of the total posterior samples produced by the PE. Moreover, SKYFAST generates a ranked list of the most probable hosts from a galaxy catalog of choice in a few minutes. This list includes information on the inclination angle posterior conditioned on the position of each candidate host. This breaks the degeneracy between inclination angle and luminosity distance.<i>Conclusions.<i/> The reconstruction of the posterior using fewer samples than the full PE can lead to significant time savings, depending on the PE algorithm employed. This is crucial for identifying the electromagnetic counterpart. The inclusion of the inclination angle information conditioned on the position of each galaxy can lead to an optimized electromagnetic follow-up.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"50 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
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