Fahad Nasir, Prakash Gaikwad, Frederick B Davies, James S Bolton, Ewald Puchwein, Sarah E I Bosman
Unveiling the thermal history of the intergalactic medium (IGM) at 4 ≤ z ≤ 5 holds the potential to reveal early onset He ii reionization or lingering thermal fluctuations from H i reionization. We set out to reconstruct the IGM gas properties along simulated Lyman-alpha forest data on pixel-by-pixel basis, employing deep neural networks. Our approach leverages the Sherwood-Relics simulation suite, consisting of diverse thermal histories, to generate mock spectra. Our convolutional and residual networks with likelihood metric predicts the Lyα optical depth-weighted density or temperature for each pixel in the Lyα forest skewer. We find that our network can successfully reproduce IGM conditions with high fidelity across range of instrumental signal-to-noise. These predictions are subsequently translated into the temperature-density plane, facilitating the derivation of reliable constraints on thermal parameters. This allows us to estimate temperature at mean cosmic density, T0 , with one sigma confidence, $delta {rm T_{rm 0}},$≲ 1000K, using only one 20h−1cMpc sightline (Δz ≃ 0.04) with a typical reionization history. Existing studies utilize redshift pathlength comparable to Δz ≃ 4 for similar constraints. We can also provide more stringent constraints on the slope (1σ confidence interval, δγ ≲ 0.1) of the IGM temperature-density relation as compared to other traditional approaches. We test the reconstruction on a single high signal-to-noise observed spectrum (20h−1cMpc segment), and recover thermal parameters consistent with current measurements. This machine learning approach has the potential to provide accurate yet robust measurements of IGM thermal history at the redshifts in question.
揭示 4 ≤ z ≤ 5 星系间介质（IGM）的热历史，有可能揭示早期开始的 He ii 再电离或 H i 再电离的残余热波动。我们开始利用深度神经网络，沿着模拟的莱曼-阿尔法森林数据，逐像素地重建IGM气体特性。我们的方法利用由不同热历史组成的 Sherwood-Relics 模拟套件来生成模拟光谱。我们的卷积和残差网络利用似然度量预测了 Lyα 森林串联图中每个像素的 Lyα 光学深度加权密度或温度。我们发现，在仪器信噪比范围内，我们的网络能够成功地高保真地再现 IGM 条件。这些预测随后被转化为温度-密度平面，从而有助于推导出可靠的热参数约束。这使得我们能够仅利用一条具有典型再电离历史的20h-1cMpc视线（Δz ≃0.04），以一个西格玛的置信度（$delta {rm T_{rm 0}}）来估计平均宇宙密度T0的温度。现有的研究利用与Δz ≃ 4相当的红移路径长度来获得类似的约束条件。与其他传统方法相比，我们还能对IGM温度-密度关系的斜率（1σ置信区间，δγ ≲0.1）提供更严格的约束。我们在单个高信噪比观测光谱（20h-1cMpc 段）上测试了重构，恢复的热参数与当前的测量结果一致。这种机器学习方法有可能为相关红移下的IGM热历史提供准确而稳健的测量结果。
{"title":"Deep learning the intergalactic medium using lyman-alpha forest at 4 ≤ z ≤ 5","authors":"Fahad Nasir, Prakash Gaikwad, Frederick B Davies, James S Bolton, Ewald Puchwein, Sarah E I Bosman","doi":"10.1093/mnras/stae2153","DOIUrl":"https://doi.org/10.1093/mnras/stae2153","url":null,"abstract":"Unveiling the thermal history of the intergalactic medium (IGM) at 4 ≤ z ≤ 5 holds the potential to reveal early onset He ii reionization or lingering thermal fluctuations from H i reionization. We set out to reconstruct the IGM gas properties along simulated Lyman-alpha forest data on pixel-by-pixel basis, employing deep neural networks. Our approach leverages the Sherwood-Relics simulation suite, consisting of diverse thermal histories, to generate mock spectra. Our convolutional and residual networks with likelihood metric predicts the Lyα optical depth-weighted density or temperature for each pixel in the Lyα forest skewer. We find that our network can successfully reproduce IGM conditions with high fidelity across range of instrumental signal-to-noise. These predictions are subsequently translated into the temperature-density plane, facilitating the derivation of reliable constraints on thermal parameters. This allows us to estimate temperature at mean cosmic density, T0 , with one sigma confidence, $delta {rm T_{rm 0}},$≲ 1000K, using only one 20h−1cMpc sightline (Δz ≃ 0.04) with a typical reionization history. Existing studies utilize redshift pathlength comparable to Δz ≃ 4 for similar constraints. We can also provide more stringent constraints on the slope (1σ confidence interval, δγ ≲ 0.1) of the IGM temperature-density relation as compared to other traditional approaches. We test the reconstruction on a single high signal-to-noise observed spectrum (20h−1cMpc segment), and recover thermal parameters consistent with current measurements. This machine learning approach has the potential to provide accurate yet robust measurements of IGM thermal history at the redshifts in question.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"33 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269284","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}
Scott T Kay, Joey Braspenning, Jens Chluba, John C Helly, Roi Kugel, Matthieu Schaller, Joop Schaye
The relativistic Sunyaev-Zel’dovich (SZ) effect can be used to measure intracluster gas temperatures independently of X-ray spectroscopy. Here, we use the large-volume FLAMINGO simulation suite to determine whether SZ y-weighted temperatures lead to more accurate hydrostatic mass estimates in massive ($M_{rm 500c} gt 7.5times 10^{14}, {rm M}_{odot }$) clusters than when using X-ray spectroscopic-like temperatures. We find this to be the case, on average. The median bias in the SZ mass at redshift zero is $leftlangle b rightrangle equiv 1-leftlangle M_{rm 500c,hse}/M_{rm 500c,true} rightrangle = -0.05 pm 0.01$, over 4 times smaller in magnitude than the X-ray spectroscopic-like case, $leftlangle b rightrangle = 0.22 pm 0.01$. However, the scatter in the SZ bias, $sigma _{b} approx 0.2$, is around 40 per cent larger than for the X-ray case. We show that this difference is strongly affected by clusters with large pressure fluctuations, as expected from shocks in ongoing mergers. Selecting the clusters with the best-fitting generalized NFW pressure profiles, the median SZ bias almost vanishes, $leftlangle b rightrangle = -0.009 pm 0.005$, and the scatter is halved to $sigma _{b} approx 0.1$. We study the origin of the SZ/X-ray difference and find that, at $R_{rm 500c}$ and in the outskirts, SZ weighted gas better reflects the hot, hydrostatic atmosphere than the X-ray weighted gas. The SZ/X-ray temperature ratio increases with radius, a result we find to be insensitive to variations in baryonic physics, cosmology, and numerical resolution.
相对论苏尼亚耶夫-泽尔多维奇（SZ）效应可用于测量星团内气体温度，而不依赖于X射线光谱。在这里，我们使用大容量的FLAMINGO模拟套件来确定SZ y加权温度是否会比使用类似X射线光谱的温度更准确地估计大质量（$M_{rm 500c} gt 7.5times 10^{14}}, {rm M}_{odot }$）星团的静水质量。我们发现平均来说情况就是这样。在红移为零时，SZ质量的中位偏差是 $leftlangle b rightrangle equiv 1-leftlangle M_{rm 500c,hse}/M_{rm 500c,true}.rightrangle = -0.05 pm 0.01$，比类似 X 射线光谱的情况（$leftlangle b rightrangle = 0.22 pm 0.01$）小 4 倍多。然而，SZ偏差的散度，$sigma _{b} （约 0.2约为 0.2$，比 X 射线情况下大 40%左右。我们的研究表明，这种差异在很大程度上受到了压力波动较大的星团的影响，如正在进行的合并中的冲击所预期的那样。选择具有最佳拟合广义NFW压力曲线的星团，SZ偏差的中值几乎消失了，$leftlangle b rightrangle = -0.009 pm 0.005$，散度减半，为$sigma _{b} （约0.1%）。大约 0.1$。我们研究了SZ/X射线差异的起源，发现在$R_{rm 500c}$和外围，SZ加权气体比X射线加权气体更好地反映了热的静压大气。SZ/X射线温度比随半径增加而增加，我们发现这一结果对重子物理学、宇宙学和数值分辨率的变化并不敏感。
{"title":"Relativistic SZ temperatures and hydrostatic mass bias for massive clusters in the FLAMINGO simulations","authors":"Scott T Kay, Joey Braspenning, Jens Chluba, John C Helly, Roi Kugel, Matthieu Schaller, Joop Schaye","doi":"10.1093/mnras/stae1991","DOIUrl":"https://doi.org/10.1093/mnras/stae1991","url":null,"abstract":"The relativistic Sunyaev-Zel’dovich (SZ) effect can be used to measure intracluster gas temperatures independently of X-ray spectroscopy. Here, we use the large-volume FLAMINGO simulation suite to determine whether SZ y-weighted temperatures lead to more accurate hydrostatic mass estimates in massive ($M_{rm 500c} gt 7.5times 10^{14}, {rm M}_{odot }$) clusters than when using X-ray spectroscopic-like temperatures. We find this to be the case, on average. The median bias in the SZ mass at redshift zero is $leftlangle b rightrangle equiv 1-leftlangle M_{rm 500c,hse}/M_{rm 500c,true} rightrangle = -0.05 pm 0.01$, over 4 times smaller in magnitude than the X-ray spectroscopic-like case, $leftlangle b rightrangle = 0.22 pm 0.01$. However, the scatter in the SZ bias, $sigma _{b} approx 0.2$, is around 40 per cent larger than for the X-ray case. We show that this difference is strongly affected by clusters with large pressure fluctuations, as expected from shocks in ongoing mergers. Selecting the clusters with the best-fitting generalized NFW pressure profiles, the median SZ bias almost vanishes, $leftlangle b rightrangle = -0.009 pm 0.005$, and the scatter is halved to $sigma _{b} approx 0.1$. We study the origin of the SZ/X-ray difference and find that, at $R_{rm 500c}$ and in the outskirts, SZ weighted gas better reflects the hot, hydrostatic atmosphere than the X-ray weighted gas. The SZ/X-ray temperature ratio increases with radius, a result we find to be insensitive to variations in baryonic physics, cosmology, and numerical resolution.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"109 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256369","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}
Annalisa Pillepich, Diego Sotillo-Ramos, Rahul Ramesh, Dylan Nelson, Christoph Engler, Vicente Rodriguez-Gomez, Martin Fournier, Martina Donnari, Volker Springel, Lars Hernquist
We present the properties of Milky Way- and Andromeda-like (MW/M31-like) galaxies simulated within TNG50, the highest-resolution run of the IllustrisTNG suite of ΛCDM magneto-hydrodynamical simulations. We introduce our fiducial selection for MW/M31 analogs, which we propose for direct usage as well as for reference in future analyses. TNG50 contains 198 MW/M31 analogs, i.e. galaxies with stellar disky morphology, with a stellar mass in the range of $M_* = 10^{10.5 - 11.2}~rm {rm M}_{odot }$, and within a MW-like 500 kpc-scale environment at z = 0. These are resolved with baryonic (dark matter) mass resolution of $8.5times 10^4rm {rm M}_{odot }$ ($4.5times 10^5rm {rm M}_{odot }$) and ∼150 pc of average gas spatial resolution in the star-forming regions. The majority of TNG50 MW/M31 analogs at z = 0 exhibit a bar, 60percnt are star-forming, the sample includes 3 Local Group (LG)-like systems, and a number of galaxies host one or more satellites as massive as e.g. the Magellanic Clouds. Even within such a relatively narrow selection, TNG50 reveals a great diversity in galaxy and halo properties, as well as in past histories. Within the TNG50 sample, it is possible to identify several simulated galaxies whose integral and structural properties are consistent, one or more at a time, with those measured for the Galaxy and Andromeda. With this paper, we document and release a series of broadly applicable data products that build upon the IllustrisTNG public release and aim to facilitate easy access and analysis by public users. These include datacubes across snapshots (0 ≤ z ≤ 7) for each TNG50 MW/M31-like galaxy, and a series of value-added catalogs.
{"title":"Milky Way and Andromeda analogs from the TNG50 simulation","authors":"Annalisa Pillepich, Diego Sotillo-Ramos, Rahul Ramesh, Dylan Nelson, Christoph Engler, Vicente Rodriguez-Gomez, Martin Fournier, Martina Donnari, Volker Springel, Lars Hernquist","doi":"10.1093/mnras/stae2165","DOIUrl":"https://doi.org/10.1093/mnras/stae2165","url":null,"abstract":"We present the properties of Milky Way- and Andromeda-like (MW/M31-like) galaxies simulated within TNG50, the highest-resolution run of the IllustrisTNG suite of ΛCDM magneto-hydrodynamical simulations. We introduce our fiducial selection for MW/M31 analogs, which we propose for direct usage as well as for reference in future analyses. TNG50 contains 198 MW/M31 analogs, i.e. galaxies with stellar disky morphology, with a stellar mass in the range of $M_* = 10^{10.5 - 11.2}~rm {rm M}_{odot }$, and within a MW-like 500 kpc-scale environment at z = 0. These are resolved with baryonic (dark matter) mass resolution of $8.5times 10^4rm {rm M}_{odot }$ ($4.5times 10^5rm {rm M}_{odot }$) and ∼150 pc of average gas spatial resolution in the star-forming regions. The majority of TNG50 MW/M31 analogs at z = 0 exhibit a bar, 60percnt are star-forming, the sample includes 3 Local Group (LG)-like systems, and a number of galaxies host one or more satellites as massive as e.g. the Magellanic Clouds. Even within such a relatively narrow selection, TNG50 reveals a great diversity in galaxy and halo properties, as well as in past histories. Within the TNG50 sample, it is possible to identify several simulated galaxies whose integral and structural properties are consistent, one or more at a time, with those measured for the Galaxy and Andromeda. With this paper, we document and release a series of broadly applicable data products that build upon the IllustrisTNG public release and aim to facilitate easy access and analysis by public users. These include datacubes across snapshots (0 ≤ z ≤ 7) for each TNG50 MW/M31-like galaxy, and a series of value-added catalogs.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"46 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269286","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}
Lee R Martin, Andrew W Blain, Tanio Díaz-Santos, Roberto J Assef, Chao-Wei Tsai, Hyunsung D Jun, Peter R M Eisenhardt, Jingwen Wu, Andrey Vayner, Román Fernández Aranda
We present observations of mid-J (J = 4–3 or J = 5–4) carbon monoxide (CO) emission lines and continuum emission from a sample of ten of the most luminous (Lbol ≥ 1014 L$rm odot$) Hot Dust-Obscured Galaxies (Hot DOGs) discovered by the Wide-field Infrared Survey Explorer (WISE) with redshifts up to 4.6. We uncover broad spectral lines (FWHM ≥ 400 km s−1) in these objects, suggesting a turbulent molecular interstellar medium (ISM) may be ubiquitous in Hot DOGs. A halo of molecular gas, extending out to a radius of 5 kpc is observed in W2305–0039, likely supplied by 940 km s−1 molecular outflows. W0831+0140 is plausibly the host of a merger between at least two galaxies, consistent with observations made using ionized gas. These CO(4–3) observations contrast with previous CO(1–0) studies of the same sources: the CO(4–3) to CO(1–0) luminosity ratios exceed 300 in each source, suggesting that the lowest excited states of CO are underluminous. These findings show that the molecular gas in Hot DOGs is consistently turbulent, plausibly a consequence of AGN feedback, triggered by galactic mergers.
{"title":"CO spectra of the ISM in the Host Galaxies of the most luminous WISE-selected AGNs","authors":"Lee R Martin, Andrew W Blain, Tanio Díaz-Santos, Roberto J Assef, Chao-Wei Tsai, Hyunsung D Jun, Peter R M Eisenhardt, Jingwen Wu, Andrey Vayner, Román Fernández Aranda","doi":"10.1093/mnras/stae2147","DOIUrl":"https://doi.org/10.1093/mnras/stae2147","url":null,"abstract":"We present observations of mid-J (J = 4–3 or J = 5–4) carbon monoxide (CO) emission lines and continuum emission from a sample of ten of the most luminous (Lbol ≥ 1014 L$rm odot$) Hot Dust-Obscured Galaxies (Hot DOGs) discovered by the Wide-field Infrared Survey Explorer (WISE) with redshifts up to 4.6. We uncover broad spectral lines (FWHM ≥ 400 km s−1) in these objects, suggesting a turbulent molecular interstellar medium (ISM) may be ubiquitous in Hot DOGs. A halo of molecular gas, extending out to a radius of 5 kpc is observed in W2305–0039, likely supplied by 940 km s−1 molecular outflows. W0831+0140 is plausibly the host of a merger between at least two galaxies, consistent with observations made using ionized gas. These CO(4–3) observations contrast with previous CO(1–0) studies of the same sources: the CO(4–3) to CO(1–0) luminosity ratios exceed 300 in each source, suggesting that the lowest excited states of CO are underluminous. These findings show that the molecular gas in Hot DOGs is consistently turbulent, plausibly a consequence of AGN feedback, triggered by galactic mergers.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"28 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256399","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}
Stellar mass and specific angular momentum are two properties of a galaxy that are directly related to its formation history, and hence morphology. In this work, the tight planar relationship between stellar specific angular momentum (j*), mass (M*) and mean effective surface brightness (<μeff >) that was recently constrained using ALFALFA galaxies is measured more accurately using galaxies from the Simba cosmological simulation. The distribution of 179 Simba galaxies in log10j* − log10M* - <μeff > space is shown to be very tightly planar with $j_*propto M_*^{0.694}$ and the distribution of perpendicular distances between the galaxies and the plane being approximately Gaussian with rms = 0.057 dex. The parameterised distribution is used with existing j* and <μeff > measurements of 3 607 ALFALFA galaxies and 84 SPARC galaxies to reliably predict their published stellar masses to within ∼0.1 to 0.2 dex over several decades of stellar mass. Thus, this work presents a new method of easily generating accurate galaxy stellar mass estimates for late-type galaxies and provides a new measurement of the fundamental link between galaxy morphology, mass and angular momentum.
{"title":"Using the Simba cosmological simulations to measure the planar relation between stellar specific angular momentum, mass and effective surface brightness","authors":"E Elson","doi":"10.1093/mnras/stae2145","DOIUrl":"https://doi.org/10.1093/mnras/stae2145","url":null,"abstract":"Stellar mass and specific angular momentum are two properties of a galaxy that are directly related to its formation history, and hence morphology. In this work, the tight planar relationship between stellar specific angular momentum (j*), mass (M*) and mean effective surface brightness (&lt;μeff &gt;) that was recently constrained using ALFALFA galaxies is measured more accurately using galaxies from the Simba cosmological simulation. The distribution of 179 Simba galaxies in log10j* − log10M* - &lt;μeff &gt; space is shown to be very tightly planar with $j_*propto M_*^{0.694}$ and the distribution of perpendicular distances between the galaxies and the plane being approximately Gaussian with rms = 0.057 dex. The parameterised distribution is used with existing j* and &lt;μeff &gt; measurements of 3 607 ALFALFA galaxies and 84 SPARC galaxies to reliably predict their published stellar masses to within ∼0.1 to 0.2 dex over several decades of stellar mass. Thus, this work presents a new method of easily generating accurate galaxy stellar mass estimates for late-type galaxies and provides a new measurement of the fundamental link between galaxy morphology, mass and angular momentum.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"34 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269287","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}
Zixian Wang, Sanjib Sharma, Michael R Hayden, Jesse van de Sande, Joss Bland-Hawthorn, Sam Vaughan, Marie Martig, Francesca Pinna
Ongoing deep IFS observations of disk galaxies provide opportunities for comparison with the Milky Way (MW) to understand galaxy evolution. However, such comparisons are marred by many challenges such as selection effects, differences in observations and methodology, and proper validation of full-spectrum fitting methods. In this study, we present a novel code GalCraft to address these challenges by generating mock IFS data cubes of the MW using simple stellar population models and a mock MW stellar catalog derived from E-Galaxia. We use the widely adopted full-spectrum fitting code pPXF to investigate the ability to recover kinematics and stellar populations for an edge-on mock MW IFS observation. We confirm that differences in kinematics, mean age, [M/H], and [α/Fe] between thin and thick disks can be distinguished. However, the age distribution is overestimated in the ranges between 2 − 4 and 12 − 14 Gyr compared to the expected values. This is likely due to the age spacing and degeneracy of SSP templates. We find systematic offsets in the recovered kinematics due to insufficient spectral resolution and the variation of line-of-sight velocity distribution with age and [M/H]. With future higher resolution and multi-[α/Fe] SSP templates, GalCraft will be useful to validate key signatures such as [α/Fe]-[M/H] distribution at different R and |z| and potentially infer radial migration and kinematic heating efficiency to study detailed chemodynamical evolution of MW-like galaxies.
{"title":"Validating full-spectrum fitting with a synthetic integral-field spectroscopic observation of the milky way","authors":"Zixian Wang, Sanjib Sharma, Michael R Hayden, Jesse van de Sande, Joss Bland-Hawthorn, Sam Vaughan, Marie Martig, Francesca Pinna","doi":"10.1093/mnras/stae2148","DOIUrl":"https://doi.org/10.1093/mnras/stae2148","url":null,"abstract":"Ongoing deep IFS observations of disk galaxies provide opportunities for comparison with the Milky Way (MW) to understand galaxy evolution. However, such comparisons are marred by many challenges such as selection effects, differences in observations and methodology, and proper validation of full-spectrum fitting methods. In this study, we present a novel code GalCraft to address these challenges by generating mock IFS data cubes of the MW using simple stellar population models and a mock MW stellar catalog derived from E-Galaxia. We use the widely adopted full-spectrum fitting code pPXF to investigate the ability to recover kinematics and stellar populations for an edge-on mock MW IFS observation. We confirm that differences in kinematics, mean age, [M/H], and [α/Fe] between thin and thick disks can be distinguished. However, the age distribution is overestimated in the ranges between 2 − 4 and 12 − 14 Gyr compared to the expected values. This is likely due to the age spacing and degeneracy of SSP templates. We find systematic offsets in the recovered kinematics due to insufficient spectral resolution and the variation of line-of-sight velocity distribution with age and [M/H]. With future higher resolution and multi-[α/Fe] SSP templates, GalCraft will be useful to validate key signatures such as [α/Fe]-[M/H] distribution at different R and |z| and potentially infer radial migration and kinematic heating efficiency to study detailed chemodynamical evolution of MW-like galaxies.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"187 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256115","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}
The vertical shear instability (VSI) is widely believed to be effective in driving turbulence in protoplanetary disks. Prior studies on VSI exclusively exploit the reflecting boundary conditions (BCs) at the disk surfaces. VSI depends critically on the boundary behaviors of waves at the disk surfaces. We extend earlier studies by performing a comprehensive numerical analysis of VSI with partially reflecting BCs for both the axisymmetric and non-axisymmetric unstable VSI modes. We find that the growth rates of the unstable modes diminish when the outgoing component of the flow is greater than the incoming one for high-order body modes. When the outgoing wave component dominates, the growth of VSI is notably suppressed. We find that the non-axisymmetric modes are unstable and they grow at a rate that decreases with the azimuthal wavenumber. The different BCs at the lower and upper disk surfaces naturally lead to non-symmetric modes relative to the disk midplane. The potential implications of our studies for further understanding planetary formation and evolution in protoplanetary disks (PPDs) are also briefly discussed.
人们普遍认为垂直剪切不稳定性（VSI）能有效地驱动原行星盘中的湍流。之前关于 VSI 的研究只利用了圆盘表面的反射边界条件（BCs）。VSI在很大程度上取决于磁盘表面波的边界行为。我们扩展了之前的研究，对轴对称和非轴对称不稳定 VSI 模式的部分反射边界条件进行了全面的数值分析。我们发现，对于高阶体模式，当流出分量大于流入分量时，不稳定模式的增长率会减小。当流出波分量占主导地位时，VSI 的增长明显受到抑制。我们发现，非轴对称模式是不稳定的，它们的增长速度随方位角波数的增加而减小。圆盘下表面和上表面不同的 BC 自然会导致相对于圆盘中平面的非对称模式。此外，还简要讨论了我们的研究对进一步理解原行星盘中行星形成和演化的潜在影响。
{"title":"Vertical Shear Instability with Partially Reflecting Boundary Conditions","authors":"Yuzi Wu, Cong Yu, Can Cui","doi":"10.1093/mnras/stae2141","DOIUrl":"https://doi.org/10.1093/mnras/stae2141","url":null,"abstract":"The vertical shear instability (VSI) is widely believed to be effective in driving turbulence in protoplanetary disks. Prior studies on VSI exclusively exploit the reflecting boundary conditions (BCs) at the disk surfaces. VSI depends critically on the boundary behaviors of waves at the disk surfaces. We extend earlier studies by performing a comprehensive numerical analysis of VSI with partially reflecting BCs for both the axisymmetric and non-axisymmetric unstable VSI modes. We find that the growth rates of the unstable modes diminish when the outgoing component of the flow is greater than the incoming one for high-order body modes. When the outgoing wave component dominates, the growth of VSI is notably suppressed. We find that the non-axisymmetric modes are unstable and they grow at a rate that decreases with the azimuthal wavenumber. The different BCs at the lower and upper disk surfaces naturally lead to non-symmetric modes relative to the disk midplane. The potential implications of our studies for further understanding planetary formation and evolution in protoplanetary disks (PPDs) are also briefly discussed.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"23 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256409","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}
Andrew M Miller, Alexander P Stephan, David V Martin
Many compact objects (black holes and neutron stars) exist in binaries. These binaries are normally discovered through their interactions, either from accretion as an X-ray binary or collisions as a gravitational wave source. However, the majority of compact objects in binaries should be non-interacting. Recently proposed discoveries have used radial velocities of a bright star (main sequence or evolved) that are indicative of a massive but dark companion, which is inferred to be a compact object. Unfortunately, this burgeoning new field has been hindered by false positives, including the “Unicorn” (V723 Mon) which was initially believed to be a red giant/black hole binary before being refuted. In this work, we investigate the evolution of stellar binary populations over time, using the binary evolution code COSMIC to simulate binary populations and determine the probability of a candidate object being either a “true Unicorn” (actual compact objects in binaries) or a false positive. We find that main sequence stars have a higher true Unicorn probability than red giants or naked helium stars (an exposed core of an evolved star), particularly if the companion is more massive and is ≥3 times less luminous than the MS star. We also find that a top-heavy initial mass function raises the true Unicorn probability further, that super-solar metallicity reduces the probability, and that most true Unicorns are found at periods ≤100 days. Finally, we find that a significant fraction of true Unicorns do not evolve into x-ray binaries during the age of the universe.
{"title":"True unicorns and false positives: Simulated probabilities of dark massive companions to bright stars","authors":"Andrew M Miller, Alexander P Stephan, David V Martin","doi":"10.1093/mnras/stae2146","DOIUrl":"https://doi.org/10.1093/mnras/stae2146","url":null,"abstract":"Many compact objects (black holes and neutron stars) exist in binaries. These binaries are normally discovered through their interactions, either from accretion as an X-ray binary or collisions as a gravitational wave source. However, the majority of compact objects in binaries should be non-interacting. Recently proposed discoveries have used radial velocities of a bright star (main sequence or evolved) that are indicative of a massive but dark companion, which is inferred to be a compact object. Unfortunately, this burgeoning new field has been hindered by false positives, including the “Unicorn” (V723 Mon) which was initially believed to be a red giant/black hole binary before being refuted. In this work, we investigate the evolution of stellar binary populations over time, using the binary evolution code COSMIC to simulate binary populations and determine the probability of a candidate object being either a “true Unicorn” (actual compact objects in binaries) or a false positive. We find that main sequence stars have a higher true Unicorn probability than red giants or naked helium stars (an exposed core of an evolved star), particularly if the companion is more massive and is ≥3 times less luminous than the MS star. We also find that a top-heavy initial mass function raises the true Unicorn probability further, that super-solar metallicity reduces the probability, and that most true Unicorns are found at periods ≤100 days. Finally, we find that a significant fraction of true Unicorns do not evolve into x-ray binaries during the age of the universe.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"17 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256401","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}
Yair Cohen, Sivan Ginzburg, Maya Levy, Tal Bar Shalom, Yoav Siman Tov
Millisecond pulsars with white dwarf companions have typical eccentricities $esim 10^{-6}{!-!}10^{-3}$. The eccentricities of helium white dwarfs are explained well by applying the fluctuation–dissipation theorem to convective eddies in their red giant progenitors. We extend this theory to more massive carbon–oxygen (CO) white dwarfs with asymptotic giant branch (AGB) progenitors. Due to the radiation pressure in AGB stars, the dominant factor in determining the remnant white dwarf’s eccentricity is the critical residual hydrogen envelope mass $m_{rm env}$ required to inflate the star to giant proportions. Using a suite of mesa stellar evolution simulations with $Delta m_{rm c}=10^{-3}, {rm M}_{odot }$ core-mass intervals, we resolved the AGB thermal pulses and found that the critical $m_{rm env}propto m_{rm c}^{-6}$. The resulting eccentricity $esim 3times 10^{-3}$ is almost independent of the remnant CO white dwarf’s mass $m_{rm c}$. Nearly all of the measured eccentricities lie below this robust theoretical limit, indicating that the eccentricity is damped during the common-envelope inspiral that follows the unstable Roche lobe overflow of the AGB star. Specifically, we focused on white dwarfs with median masses $m_{rm c}gt 0.6, {rm M}_{odot }$. These massive white dwarfs begin their inspiral with practically identical orbital periods and eccentricities, eliminating any dependence on the initial conditions. For this sub-sample, we find an empirical relation $epropto P^{3/2}$ between the final period and eccentricity that is much tighter than previous studies – motivating theoretical work on the eccentricity evolution during the common envelope phase. The eccentricities of lower mass CO white dwarfs may be explained by alternative formation channels.
{"title":"White dwarf eccentricity fluctuation and dissipation by AGB convection","authors":"Yair Cohen, Sivan Ginzburg, Maya Levy, Tal Bar Shalom, Yoav Siman Tov","doi":"10.1093/mnras/stae2136","DOIUrl":"https://doi.org/10.1093/mnras/stae2136","url":null,"abstract":"Millisecond pulsars with white dwarf companions have typical eccentricities $esim 10^{-6}{!-!}10^{-3}$. The eccentricities of helium white dwarfs are explained well by applying the fluctuation–dissipation theorem to convective eddies in their red giant progenitors. We extend this theory to more massive carbon–oxygen (CO) white dwarfs with asymptotic giant branch (AGB) progenitors. Due to the radiation pressure in AGB stars, the dominant factor in determining the remnant white dwarf’s eccentricity is the critical residual hydrogen envelope mass $m_{rm env}$ required to inflate the star to giant proportions. Using a suite of mesa stellar evolution simulations with $Delta m_{rm c}=10^{-3}, {rm M}_{odot }$ core-mass intervals, we resolved the AGB thermal pulses and found that the critical $m_{rm env}propto m_{rm c}^{-6}$. The resulting eccentricity $esim 3times 10^{-3}$ is almost independent of the remnant CO white dwarf’s mass $m_{rm c}$. Nearly all of the measured eccentricities lie below this robust theoretical limit, indicating that the eccentricity is damped during the common-envelope inspiral that follows the unstable Roche lobe overflow of the AGB star. Specifically, we focused on white dwarfs with median masses $m_{rm c}gt 0.6, {rm M}_{odot }$. These massive white dwarfs begin their inspiral with practically identical orbital periods and eccentricities, eliminating any dependence on the initial conditions. For this sub-sample, we find an empirical relation $epropto P^{3/2}$ between the final period and eccentricity that is much tighter than previous studies – motivating theoretical work on the eccentricity evolution during the common envelope phase. The eccentricities of lower mass CO white dwarfs may be explained by alternative formation channels.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"12 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142256404","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}
Modified theories of gravity predict deviations from General Relativity (GR) in the propagation of gravitational waves (GW) across cosmological distances. A key prediction is that the GW luminosity distance will vary with redshift, differing from the electromagnetic (EM) luminosity distance due to varying effective Planck mass. We introduce a model-independent, data-driven approach to explore these deviations using multi-messenger observations of dark standard sirens (Binary Black Holes, BBH). By combining GW luminosity distance measurements from dark sirens with Baryon Acoustic Oscillation (BAO) measurements, BBH redshifts inferred from cross-correlation with spectroscopic or photometric galaxy surveys, and sound horizon measurements from the Cosmic Microwave Background (CMB), we can make a data-driven test of GR (jointly with the Hubble constant) as a function of redshift. Using the multi-messenger technique with the spectroscopic DESI galaxy survey, we achieve precise measurements of deviations in the effective Planck mass variation with redshift. For the Cosmic Explorer and Einstein Telescope (CEET), the best precision is approximately 3.6%, and for LIGO-Virgo-KAGRA (LVK), it is 7.4% at a redshift of $rm {z = 0.425}$. Additionally, we can measure the Hubble constant with a precision of about 1.1% from CEET and 7% from LVK over five years of observation with a 75% duty cycle. We also explore the potential of cross-correlation with photometric galaxy surveys from the Rubin Observatory, extending measurements up to a redshift of $rm {z sim 2.5}$. This approach can reveal potential deviations from models affecting GW propagation using numerous dark standard sirens in synergy with DESI and the Rubin Observatory.
{"title":"Prospect of Precision Cosmology and Testing General Relativity using Binary Black Holes- Galaxies Cross-correlation","authors":"Samsuzzaman Afroz, Suvodip Mukherjee","doi":"10.1093/mnras/stae2139","DOIUrl":"https://doi.org/10.1093/mnras/stae2139","url":null,"abstract":"Modified theories of gravity predict deviations from General Relativity (GR) in the propagation of gravitational waves (GW) across cosmological distances. A key prediction is that the GW luminosity distance will vary with redshift, differing from the electromagnetic (EM) luminosity distance due to varying effective Planck mass. We introduce a model-independent, data-driven approach to explore these deviations using multi-messenger observations of dark standard sirens (Binary Black Holes, BBH). By combining GW luminosity distance measurements from dark sirens with Baryon Acoustic Oscillation (BAO) measurements, BBH redshifts inferred from cross-correlation with spectroscopic or photometric galaxy surveys, and sound horizon measurements from the Cosmic Microwave Background (CMB), we can make a data-driven test of GR (jointly with the Hubble constant) as a function of redshift. Using the multi-messenger technique with the spectroscopic DESI galaxy survey, we achieve precise measurements of deviations in the effective Planck mass variation with redshift. For the Cosmic Explorer and Einstein Telescope (CEET), the best precision is approximately 3.6%, and for LIGO-Virgo-KAGRA (LVK), it is 7.4% at a redshift of $rm {z = 0.425}$. Additionally, we can measure the Hubble constant with a precision of about 1.1% from CEET and 7% from LVK over five years of observation with a 75% duty cycle. We also explore the potential of cross-correlation with photometric galaxy surveys from the Rubin Observatory, extending measurements up to a redshift of $rm {z sim 2.5}$. This approach can reveal potential deviations from models affecting GW propagation using numerous dark standard sirens in synergy with DESI and the Rubin Observatory.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"41 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269289","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}
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