The Astrophysical Journal Supplement Series最新文献_第4页

Se-ResNet+SVM Model: An Effective Method of Searching for Hot Subdwarfs from LAMOST Se-ResNet+SVM模型：从 LAMOST 搜寻热亚矮星的有效方法

The Astrophysical Journal Supplement Series Pub Date : 2024-08-11 DOI: 10.3847/1538-4365/ad5b61

Zhongding Cheng, Xiaoming Kong, Tianmin Wu, Aina Zhang, Bowen Liu, Yude Bu, Zhenxin Lei, Yatao Zhang, Zhenping Yi and Meng Liu

{"title":"Se-ResNet+SVM Model: An Effective Method of Searching for Hot Subdwarfs from LAMOST","authors":"Zhongding Cheng, Xiaoming Kong, Tianmin Wu, Aina Zhang, Bowen Liu, Yude Bu, Zhenxin Lei, Yatao Zhang, Zhenping Yi and Meng Liu","doi":"10.3847/1538-4365/ad5b61","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5b61","url":null,"abstract":"This paper presents a robust neural network approach for identifying hot subdwarfs. Our method leveraged the Squeeze-and-Excitation Residual Network to extract abstract features, which were combined with experience features to create hybrid features. These hybrid features were then classified using a support vector machine. To enhance accuracy, we employed a two-stage procedure. In the first stage, a binary classification model was constructed to distinguish hot subdwarfs, achieving a precision of 98.55% on the test set. In the second stage, a four-class classification model was employed to further refine the candidates, achieving a precision of 91.75% on the test set. Using the binary classification model, we classified 333,534 spectra from LAMOST DR8, resulting in a catalog of 3086 hot subdwarf candidates. Subsequently, the four-class classification model was applied to filter these candidates further. When applying thresholds of 0.5 and 0.9, we identified 2132 and 1247 candidates, respectively. Among these candidates, we visually inspected their spectra and identified 58 and 30 new hot subdwarfs, respectively, resulting in a precision of 82.04% and 88.21% for these discoveries. Furthermore, we evaluated the 3086 candidates obtained in the first stage and identified 168 new hot subdwarfs, achieving an overall precision of 62.54%. Lastly, we trained a Squeeze-and-Excitation regression model with mean absolute error values of 3009 K for Teff, 0.20 dex for log g, and 0.42 dex for log(nHe/nH). Using this model, we predicted the atmospheric parameters of these 168 newly discovered hot subdwarfs.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937408","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

p adé: A Code for Protoplanetary Disk Turbulence Based on Padé Differencing p adé：基于帕代差分法的原行星盘湍流代码

The Astrophysical Journal Supplement Series Pub Date : 2024-08-07 DOI: 10.3847/1538-4365/ad5af3

Karim Shariff

引用次数: 0

Light-curve Recovery with Rubin-LSST. II. Unveiling the Darkness of the Galactic Bulge (VESTALE) with RR Lyrae 利用 Rubin-LSST 恢复光曲线。II.利用天琴座RR揭开银河凸起的黑暗面纱（VESTALE）

The Astrophysical Journal Supplement Series Pub Date : 2024-08-06 DOI: 10.3847/1538-4365/ad582d

M. Di Criscienzo, S. Leccia, V. Braga, I. Musella, G. Bono, M. Dall’Ora, G. Fiorentino, M. Marconi, R. Molinaro, V. Ripepi, L. Girardi, A. Mazzi, G. Pastorelli, M. Trabucchi, N. Matsunaga, M. Monelli, A. Saha, K. A. Vivas and R. Zanmar Sanchez

{"title":"Light-curve Recovery with Rubin-LSST. II. Unveiling the Darkness of the Galactic Bulge (VESTALE) with RR Lyrae","authors":"M. Di Criscienzo, S. Leccia, V. Braga, I. Musella, G. Bono, M. Dall’Ora, G. Fiorentino, M. Marconi, R. Molinaro, V. Ripepi, L. Girardi, A. Mazzi, G. Pastorelli, M. Trabucchi, N. Matsunaga, M. Monelli, A. Saha, K. A. Vivas and R. Zanmar Sanchez","doi":"10.3847/1538-4365/ad582d","DOIUrl":"https://doi.org/10.3847/1538-4365/ad582d","url":null,"abstract":"This work is part of VESTALE, a project initiated within the Legacy Survey of Space and Time (LSST) Cadence Strategy Optimization Process. Its goal is to explore the potential of Rubin-LSST observations aimed at the Galactic bulge (henceforth just “Bulge”) for studying RR Lyrae (RRL) stars. Observation and analysis of RRL stars in the Bulge are crucial for tracing the old population of the central part of our Galaxy and reconstructing its formation. Based on observations conducted with CTIO/DECam by Saha et al. toward Baade’s window, our simulations demonstrate that early Rubin-LSST observations will enable the recovery of RRL light curves (LCs) at Galactic center distances with sufficient precision. This will allow us to utilize theoretical relations from Marconi et al. to determine their distances and/or metallicity, following the REDIME algorithm introduced in Bono et al. We show how reddening and crowding affect our simulations and highlight the importance of considering these effects when deriving pulsation parameters (luminosity amplitudes, mean magnitudes) based on the LCs, especially if the goal is to explore the opposite side of the Bulge through the observation of its RRL. The simulations discussed in this investigation were conducted to support the Survey Cadence Optimization Committee’s decision to observe this important sky region since it has only recently been decided to include part of the Bulge as a target within the LSST main survey.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"91 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937411","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

Modeling the Magnetic Vectors of Interplanetary Coronal Mass Ejections at Different Heliocentric Distances with INFROS 利用 INFROS 模拟不同日心距离行星际日冕物质抛射的磁矢量

The Astrophysical Journal Supplement Series Pub Date : 2024-08-06 DOI: 10.3847/1538-4365/ad5835

Ranadeep Sarkar, Nandita Srivastava, Nat Gopalswamy and Emilia Kilpua

{"title":"Modeling the Magnetic Vectors of Interplanetary Coronal Mass Ejections at Different Heliocentric Distances with INFROS","authors":"Ranadeep Sarkar, Nandita Srivastava, Nat Gopalswamy and Emilia Kilpua","doi":"10.3847/1538-4365/ad5835","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5835","url":null,"abstract":"The INterplanetary Flux ROpe Simulator (INFROS) is an observationally constrained analytical model dedicated to forecasting the strength of the southward component (Bz) of the magnetic field embedded in interplanetary coronal mass ejections (ICMEs). In this work, we validate the model for six ICMEs sequentially observed by two radially aligned spacecraft positioned at different heliocentric distances. The six selected ICMEs in this study comprise cases associated with isolated coronal mass ejection (CME) evolution as well as those interacting with high-speed streams (HSSs) and high-density streams (HDSs). For the isolated CMEs, our results show that the model outputs at both spacecraft are in good agreement with in situ observations. However, for most of the interacting events, the model correctly captures the CME evolution only at the inner spacecraft. Due to the interaction with HSSs and HDSs, which in most cases occurred at heliocentric distances beyond the inner spacecraft, the ICME evolution no longer remains self-similar. Consequently, the model underestimates the field strength at the outer spacecraft. Our findings indicate that constraining the INFROS model with inner-spacecraft observations significantly enhances the prediction accuracy at the outer spacecraft for the three events undergoing self-similar expansion, achieving a 90% correlation between observed and predicted Bz profiles. This work also presents a quantitative estimation of the ICME magnetic field enhancement due to interaction which may lead to severe space weather. We conclude that the assumption of self-similar expansion provides a lower limit to the magnetic field strength estimated at any heliocentric distance, based on the remote-sensing observations.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141937490","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

A Robust Young Stellar Object Identification Method Based on Deep Learning 基于深度学习的稳健年轻恒星天体识别方法

The Astrophysical Journal Supplement Series Pub Date : 2024-08-01 DOI: 10.3847/1538-4365/ad5a08

Lei Tan, 磊谈, Zhicun Liu, 志存柳, Xiaolong Wang, 小龙王, Ying Mei, 盈梅, Feng Wang, 锋王, Hui Deng, 辉邓, Chao Liu and 超刘

{"title":"A Robust Young Stellar Object Identification Method Based on Deep Learning","authors":"Lei Tan, 磊谈, Zhicun Liu, 志存柳, Xiaolong Wang, 小龙王, Ying Mei, 盈梅, Feng Wang, 锋王, Hui Deng, 辉邓, Chao Liu and 超刘","doi":"10.3847/1538-4365/ad5a08","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5a08","url":null,"abstract":"Young stellar objects (YSOs) represent the earliest stage in the process of star formation, offering insights that contribute to the development of models elucidating star formation and evolution. Recent advancements in deep-learning techniques have enabled significant strides in identifying special objects within vast data sets. In this paper, we present a YSO identification method based on deep-learning principles and spectra from the LAMOST. We designed a structure based on a long short-term memory network and a convolutional neural network and trained different models in two steps to identify YSO candidates. Initially, we trained a model to detect stellar spectra featuring the Hα emission line, achieving an accuracy of 98.67%. Leveraging this model, we classified 10,495,781 stellar spectra from LAMOST, yielding 76,867 candidates displaying a Hα emission line. Subsequently, we developed a YSO identification model, which achieved a recall rate of 95.81% for YSOs. Utilizing this model, we further identified 35,021 YSO candidates from the Hα emission-line candidates. Following cross validation, 3204 samples were identified as previously reported YSO candidates. We eliminated samples with low signal-to-noise ratios and M dwarfs by using the equivalent widths of the N ii and He i emission lines and visual inspection, resulting in a catalog of 20,530 YSO candidates. To facilitate future research endeavors, we provide the obtained catalogs of Hα emission-line star candidates and YSO candidates along with the code used for training the model.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882119","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

Enhancing Morphological Measurements of the Cosmic Web with Delaunay Tessellation Field Estimation 利用德劳内细分场估计增强宇宙网的形态测量

The Astrophysical Journal Supplement Series Pub Date : 2024-08-01 DOI: 10.3847/1538-4365/ad5559

Yu Liu, Yu Yu, Pengjie Zhang, Hao-Ran Yu

{"title":"Enhancing Morphological Measurements of the Cosmic Web with Delaunay Tessellation Field Estimation","authors":"Yu Liu, Yu Yu, Pengjie Zhang, Hao-Ran Yu","doi":"10.3847/1538-4365/ad5559","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5559","url":null,"abstract":"The density fields constructed by traditional mass assignment methods are susceptible to irritating discreteness, which hinders morphological measurements of cosmic large-scale structure (LSS) through Minkowski functionals (MFs). To alleviate this issue, fixed-kernel smoothing methods are commonly used in the literature, at the expense of losing substantial structural information. In this work, we propose to measure MFs with the Delaunay tessellation field estimation (DTFE) technique, with the goal of maximizing the extraction of morphological information from sparse tracers. We perform our analyses starting from matter fields and progressively extending to halo fields. At the matter-field level, we elucidate how discreteness affects morphological measurements of LSS. Then, by comparing with the traditional Gaussian smoothing scheme, we preliminarily showcase the advantages of DTFE for enhancing measurements of MFs from sparse tracers. At the halo-field level, we first numerically investigate various systematic effects on MFs of DTFE fields, which are induced by finite voxel sizes, halo number densities, halo weightings, and redshift space distortions (RSDs), respectively. Then, we explore the statistical power of MFs measured with DTFE for extracting the cosmological information encoded in RSDs. We find that MFs measured with DTFE exhibit improvements by ∼2 orders of magnitude in discriminative power for RSD effects and by a factor of ∼3–5 in constraining power on the structure growth rate over the MFs measured with Gaussian smoothing. These findings demonstrate the remarkable enhancements in statistical power of MFs achieved by DTFE, showing enormous application potentials for our method in extracting various key cosmological information from galaxy surveys.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865407","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 Interpretation of Mid-infrared Absorption Lines of Gas-phase H2O as Observed by JWST/MIRI 关于 JWST/MIRI 观测到的气相 H2O 中红外吸收线的解释

The Astrophysical Journal Supplement Series Pub Date : 2024-07-31 DOI: 10.3847/1538-4365/ad571a

Jialu Li, Adwin Boogert, Alexander G. G. M. Tielens

{"title":"On the Interpretation of Mid-infrared Absorption Lines of Gas-phase H2O as Observed by JWST/MIRI","authors":"Jialu Li, Adwin Boogert, Alexander G. G. M. Tielens","doi":"10.3847/1538-4365/ad571a","DOIUrl":"https://doi.org/10.3847/1538-4365/ad571a","url":null,"abstract":"Rovibrational absorption lines of H2O in the 5–8 <italic toggle=\"yes\">μ</italic>m wavelength range selectively probe gas against the mid-infrared continuum-emitting background of the inner regions of young stellar objects and active galactic nuclei and deliver important information about these warm, dust-obscured environments. JWST/Mid-Infrared Instrument (MIRI) detects these lines in many lines of sight at a moderate spectral resolving power of <italic toggle=\"yes\">R</italic> ∼ 3500 (full width at half-maximum of 85 km s−1). Based on our analysis of high-resolution SOFIA/EXES observations, we find that the interpretation of JWST/MIRI absorption spectra can be severely hampered by the blending of individual transitions and the lost information on the intrinsic line width or the partial coverage of the background continuum source. In this paper, we point out problems such as degeneracy that arise in deriving physical properties from an insufficiently resolved spectrum. This can lead to differences in the column density by 2 orders of magnitude. We emphasize the importance of weighting optically thin and weak lines in spectral analyses and provide recipes for breaking down the coupled parameters. We also provide an online tool to generate the H2O absorption line spectra that can be compared to observations.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865497","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

A Method of Rapidly Deriving Late-type Contact Binary Parameters and Its Application in the Catalina Sky Survey 快速推导晚期接触双星参数的方法及其在卡特琳娜巡天中的应用

The Astrophysical Journal Supplement Series Pub Date : 2024-07-31 DOI: 10.3847/1538-4365/ad5953

JinLiang Wang, Xu Ding, JiaJia Li, JianPing Xiong, QiYuan Cheng, KaiFan Ji

{"title":"A Method of Rapidly Deriving Late-type Contact Binary Parameters and Its Application in the Catalina Sky Survey","authors":"JinLiang Wang, Xu Ding, JiaJia Li, JianPing Xiong, QiYuan Cheng, KaiFan Ji","doi":"10.3847/1538-4365/ad5953","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5953","url":null,"abstract":"With the continuous development of large optical surveys, a large number of light curves of late-type contact binary systems (CBs) have been released. Deriving parameters for CBs using the the Wilson–Devinney program and the PHOEBE program poses a challenge. Therefore, this study developed a method for rapidly deriving light curves based on the Neural Networks model combined with the Hamiltonian Monte Carlo (HMC) algorithm (NNHMC). The neural network was employed to establish the mapping relationship between the parameters and the pregenerated light curves by the PHOEBE program, and the HMC algorithm was used to obtain the posterior distribution of the parameters. The NNHMC method was applied to a large contact binary sample from the Catalina Sky Survey, and a total of 19,104 late-type contact binary parameters were derived. Among them, 5172 have an inclination greater than 70° and a temperature difference less than 400 K. The obtained results were compared with the previous studies for 30 CBs, and there was an essentially consistent goodness-of-fit (<italic toggle=\"yes\">R</italic>\u00002) distribution between them. The NNHMC method possesses the capability to simultaneously derive parameters for a vast number of targets. Furthermore, it can provide an extremely efficient tool for the rapid derivation of parameters in future sky surveys involving large samples of CBs.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865499","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

Discovery of Giant Radio Sources from TGSS Alternative Data Release 1: Radio, Optical, and Infrared Properties 从 TGSS 第 1 版备选数据中发现巨射电源：射电、光学和红外特性

The Astrophysical Journal Supplement Series Pub Date : 2024-07-30 DOI: 10.3847/1538-4365/ad5184

Netai Bhukta, Souvik Manik, Sabyasachi Pal, Sushanta K. Mondal

{"title":"Discovery of Giant Radio Sources from TGSS Alternative Data Release 1: Radio, Optical, and Infrared Properties","authors":"Netai Bhukta, Souvik Manik, Sabyasachi Pal, Sushanta K. Mondal","doi":"10.3847/1538-4365/ad5184","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5184","url":null,"abstract":"Giant radio sources (GRSs) are the single largest astrophysical objects known in the Universe that have grown to megaparsec scales (≥0.7 Mpc). GRSs are much rarer compared with normal-sized radio galaxies. Still, the reason for the formation of their gigantic sizes is under debate. We systematically search for GRSs from the TIFR Giant Metrewave Radio Telescope Sky Survey Alternative Data Release 1 at 150 MHz. We have newly identified 34 GRSs from this study. We have also studied the multiwavelength properties (radio, optical, and infrared) of these GRSs. We have used the likelihood ratio method to identify highly reliable multiwavelength counterparts of GRSs from Pan-STARRS (optical) and Wide-field Infrared Survey Explorer (mid-IR) data. We have classified GRSs based on their accretion mode of the central black holes using optical and mid-IR data. For all sources, we also discuss the principal characteristic parameters (redshift distribution, angular and projected linear size, total integrated radio flux density, spectral index, and radio power). We show the radio evolution track and the location of the GRSs in the <italic toggle=\"yes\">P</italic>–<italic toggle=\"yes\">D</italic> diagram. Using a radio–optical luminosity diagram, we identify GRSs in the Fanaroff–Riley classification. Only two GRGs in our sample reside close to the centers of galaxy clusters.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865411","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

Experimental Scattering Matrices of Martian Dust Aerosols with Narrow Particle-size Distributions 具有窄粒径分布的火星尘埃气溶胶的实验散射矩阵

The Astrophysical Journal Supplement Series Pub Date : 2024-07-29 DOI: 10.3847/1538-4365/ad5720

Julia Martikainen, Olga Muñoz, Juan Carlos Gómez Martín, Teresa Jardiel, Marco Peiteado, Amador C. Caballero, Santiago Pérez-Hoyos, Agustin Sánchez Lavega, Tim Becker, Gerhard Wurm, Yannick Willame, Ann Carine Vandaele

{"title":"Experimental Scattering Matrices of Martian Dust Aerosols with Narrow Particle-size Distributions","authors":"Julia Martikainen, Olga Muñoz, Juan Carlos Gómez Martín, Teresa Jardiel, Marco Peiteado, Amador C. Caballero, Santiago Pérez-Hoyos, Agustin Sánchez Lavega, Tim Becker, Gerhard Wurm, Yannick Willame, Ann Carine Vandaele","doi":"10.3847/1538-4365/ad5720","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5720","url":null,"abstract":"We present experimental scattering matrices of the JSC Mars-1, MMS-2, and MGS-1 simulants at 488 and 640 nm. The analogs were processed so that narrow size distributions representative of Martian dust aerosols during different dust cycles were obtained. We find that the forward peak of the phase function depends on particle size as it becomes narrower with increasing size, whereas the side- and backscattering directions depend on both composition and size so that increasing size and decreasing absorption produce a flatter curve. The position and maximum of the degree of linear polarization varies based on particle size and composition, and the negative polarization branch is more prominent for wavelength-scale particles diminishing with increasing size. The linear depolarization is strongly affected by size and composition. Finally, we compare sky-brightness curves measured by the Navcam and Hazcam engineering cameras on board the Mars Science Laboratory rover to the measured phase functions. The observations show a narrower peak at the forward direction and a flatter curve toward the side- and backscattering directions with an increasing dust load in the atmosphere, similar to what can be seen for the measured phase functions of the analogs with increasing particle size. In the case of the analogs, the flattening of the curve can be caused by an increase in multiple scattering within a particle by wavelength-scale surface roughness and/or internal inclusions. For the observed sky brightnesses, particle aggregation and multiple scattering among particles in denser dust conditions play a major role.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865501","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