Molecules with ALMA at Planet-forming Scales (MAPS) III: Characteristics of Radial Chemical Substructures
Charles J. Law, Ryan A. Loomis, Richard Teague, Karin I. Öberg, Ian Czekala, Sean M. Andrews, Jane Huang, Yuri Aikawa, Felipe Alarcón, Jaehan Bae, Edwin A. Berg… 展开作者
Charles J. Law, Ryan A. Loomis, Richard Teague, Karin I. Öberg, Ian Czekala, Sean M. Andrews, Jane Huang, Yuri Aikawa, Felipe Alarcón, Jaehan Bae, Edwin A. Bergin, Jennifer B. Bergner, Yann Boehler, Alice S. Booth, Arthur D. Bosman, Jenny K. Calahan, Gianni Cataldi, L. Ilsedore Cleeves, Kenji Furuya, Viviana V. Guzmán, John D. Ilee, Romane Le Gal, Yao Liu, Feng Long, François Ménard, Hideko Nomura, Chunhua Qi, Kamber R. Schwarz, Anibal Sierra, Takashi Tsukagoshi, Yoshihide Yamato, Merel L. R. van't Hoff, Catherine Walsh, David J. Wilner, Ke Zhang
备注：
62 pages, 31 figures, accepted for publication in ApJS, MAPS cross-references updated, corrected Figure 21, updated gas disk sizes (Table 2, Figures 15-16) from associated Erratum
The Molecules with ALMA at Planet-forming Scales (MAPS) Large Program provides a detailed, high resolution (${\sim}$10-20 au) view of molecular line emission in five protoplanetary disks at spatial scales relevant for planet formation. Here, we present a systematic analysis of chemical substructures in 18 molecular lines toward the MAPS sources: IM Lup, GM Aur, AS 209, HD 163296, and MWC 480. We identify more than 200 chemical substructures, which are found at nearly all radii where line emission is detected. A wide diversity of radial morphologies - including rings, gaps, and plateaus - is observed both within each disk and across the MAPS sample. This diversity in line emission profiles is also present in the innermost 50 au. Overall, this suggests that planets form in varied chemical environments both across disks and at different radii within the same disk. Interior to 150 au, the majority of chemical substructures across the MAPS disks are spatially coincident with substructures in the millimeter continuum, indicative of physical and chemical links between the disk midplane and warm, elevated molecular emission layers. Some chemical substructures in the inner disk and most chemical substructures exterior to 150 au cannot be directly linked to dust substructure, however, which indicates that there are also other causes of chemical substructures, such as snowlines, gradients in UV photon fluxes, ionization, and radially-varying elemental ratios. This implies that chemical substructures could be developed into powerful probes of different disk characteristics, in addition to influencing the environments within which planets assemble. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.
The recent ALMA DSHARP survey provided illuminating results on the diversity of substructures in planet forming disks. These substructures trace pebble-sized grains accumulated at local pressure maxima, possibly due to planet-disk interactions or other planet formation processes. DSHARP sources are heavily biased to large and massive disks that only represent the high (dust flux) tail end of the disk population. Thus it is unclear whether similar substructures and corresponding physical processes also occur in the majority of disks which are fainter and more compact. Here we explore the presen…
Recently, the Molecules with ALMA at Planet-forming Scales (MAPS) ALMA Large Program reported a high number of line emission substructures coincident with dust rings and gaps in the continuum emission, suggesting a causal link between these axisymmetric line emission and dust continuum substructures. To test the robustness of the claimed correlation, we compare the observed spatial overlap fraction in substructures with that from the null hypothesis, in which the overlap is assumed to arise from the random placement of line emission substructures. Our results reveal that there is no statistica…
We present a detailed multi-wavelength characterization of the multi-ring disk of HD 169142. We report new ALMA observations at 3 mm and analyze them together with archival 0.89 and 1.3 mm data. Our observations resolve three out of the four rings in the disk previously seen in high-resolution ALMA data. A simple parametric model is used to estimate the radial profile of the dust optical depth, temperature, density, and particle size distribution. We find that the multiple ring features of the disk are produced by annular accumulations of large particles, probably associated with gas pressure …
We present simulations of the capabilities of the Atacama Large Millimeter/submillimeter Array (ALMA) and of a Next Generation Very Large Array (ngVLA) to detect and resolve substructures due to terrestrial planets and Super-Earths in nearby planet-forming disks. We adopt the results of global 2-D hydrodynamical planet-disk simulations that account for the dynamics of gas and dust in a disk with an embedded planet. Our simulations follow the combined evolution of gas and dust for several thousand planetary orbits. We show that long integrations (several tens of hours) with the ngVLA can detect…
The protoplanetary disk around the T Tauri star GM Aur was one of the first hypothesized to be in the midst of being cleared out by a forming planet. As a result, GM Aur has had an outsized influence on our understanding of disk structure and evolution. We present 1.1 and 2.1 mm ALMA continuum observations of the GM Aur disk at a resolution of ~50 mas (~8 au), as well as HCO$^+$ $J=3-2$ observations at a resolution of ~100 mas. The dust continuum shows at least three rings atop faint, extended emission. Unresolved emission is detected at the center of the disk cavity at both wavelengths, likel…
The Disk Substructures at High Angular Resolution Project (DSHARP) is the largest homogeneous high-resolution ($\sim 0.035$ arcsec, or $\sim$ 5 au) disk continuum imaging survey with ALMA so far. In the coming years, many more disks will be mapped with ALMA at similar resolution. Interpreting the results in terms of the properties and quantities of the emitting dusty material is, however, a very non-trivial task. This is in part due to the uncertainty in the dust opacities, an uncertainty which is not likely to be resolved any time soon. It is also partly due to the fact that, as the DSHARP su…
In recent years, high-angular-resolution observations of the dust and gas in circumstellar discs have revealed a variety of morphologies, naturally triggering the question of whether these substructures are driven by forming planets. While it remains difficult to directly image embedded planets, a promising method to distinguish disc-shaping mechanisms is to study the gas kinematics as characterising deviations from Keplerian rotation can be used to probe underlying perturbations such as planets. Creating spiral structures, the latter can also be traced in the brightness temperature. Here we a…
Rings are the most frequently revealed substructure in ALMA dust observations of protoplanetary disks, but their origin is still hotly debated. In this paper, we identify dust substructures in 12 disks and measure their properties to investigate how they form. This subsample of disks is selected from a high-resolution ($\sim0.12''$) ALMA 1.33 mm survey of 32 disks in the Taurus star-forming region, which was designed to cover a wide range of sub-mm brightness and to be unbiased to previously known substructures. While axisymmetric rings and gaps are common within our sample, spiral patterns an…
We present 1.3 mm continuum ALMA long-baseline observations at 3-5 au resolution of 10 of the brightest discs from the Ophiuchus DIsc Survey Employing ALMA (ODISEA) project. We identify a total of 26 narrow rings and gaps distributed in 8 sources and 3 discs with small dust cavities (r $<$10 au). We find that two discs around embedded protostars lack the clear gaps and rings that are ubiquitous in more evolved sources with Class II SEDs. Our sample includes 5 objects with previously known large dust cavities (r $>$20 au). We find that the 1.3 mm radial profiles of these objects are in good agr…
In recent years, ALMA has been able to observe large-scale substructures within protoplanetary disks. Comparison with the predictions from models of planet-disk interaction has indicated that most of these disk substructures can be explained by the presence of planets with the mass of Neptune or larger at orbital radii of $\approx 5 - 100$ au. Better resolution is needed to observe structures closer to the star, where terrestrial planets are expected to form, as well as structures opened by planets with masses lower than Neptune. We investigate the capabilities of a possible extension to ALMA …
The Ophiuchus DIsc Survey Employing ALMA (ODISEA). Substructures as a function of SED Class and disc mass in 100 systems
Millennium Nucleus on Young Exoplanets and their Moons (YEMS)（年轻系外行星及其卫星千年核）；European Southern Observatory（欧洲南方天文台）；Joint ALMA Observatory（ALMA联合天文台）；Department of Physics and Astronomy, Texas A&M University（德克萨斯农工大学物理与天文学系）；Departamento de Física, Universidad de Santiago de Chile（智利圣地亚哥大学物理系）；Center for Interdisciplinary Research in Astrophysics Space Exploration (CIRAS), Universidad de Santiago de Chile（智利圣地亚哥大学天体物理学空间探索跨学科研究中心）；Mullard Space Science Laboratory, University College London（伦敦大学学院穆拉德太空科学实验室）；Universidad Nacional Autónoma de México. Instituto de Astronomía（墨西哥国立自治大学天文学研究所）
研究通过ALMA Band 8观测100个盘，探讨子结构与光谱能量分布类别及盘质量的关系，发现质量大于10地球质量的盘显示出与巨行星形成阶段相关的子结构特征。
The Ophiuchus DIsk Survey Employing ALMA (ODISEA): A Unified Evolutionary Sequence of Planet-Driven Substructures Explaining the Diversity of Disk Morphologies
We explore the dynamical structure of the protoplanetary disks surrounding HD 163296 and MWC 480 as part of the Molecules with ALMA at Planet Forming Scales (MAPS) large program. Using the $J = 2-1$ transitions of $^{12}$CO, $^{13}$CO and C$^{18}$O imaged at spatial resolutions of $\sim 0.^{\prime \prime}15$ and with a channel spacing of $200$ ${\rm m\,s^{-1}}$, we find perturbations from Keplerian rotation in the projected velocity fields of both disks ($\lesssim\!5\%$ of the local Keplerian velocity), suggestive of large-scale (10s of au in size), coherent flows. By accounting for the azimut…
We present a high-resolution ($\sim0.''12$, $\sim16$ au, mean sensitivity of $50~μ$Jy~beam$^{-1}$ at 225 GHz) snapshot survey of 32 protoplanetary disks around young stars with spectral type earlier than M3 in the Taurus star-forming region using Atacama Large Millimeter Array (ALMA). This sample includes most mid-infrared excess members that were not previously imaged at high spatial resolution, excluding close binaries and highly extincted objects, thereby providing a more representative look at disk properties at 1--2 Myr. Our 1.3 mm continuum maps reveal 12 disks with prominent dust gaps a…
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) IV: CO gas imaging and overview
Universidad de Santiago, Chile（圣地亚哥大学）；Department of Astronomy, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan（东京大学理学研究科天文学系）；Institute of Physics and Astronomy, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary（厄特沃什·罗兰大学物理与天文学研究所）；Max-Planck-Insitut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany（马克斯·普朗克天文研究所）；Department of Physics & Astronomy, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8P 5C2, Canada（维多利亚大学物理与天文学系）；Joint ALMA Observatory, Avenida Alonso de Córdova 3107, Vitacura 7630355, Santiago, Chile（ALMA联合天文台）；Departamento de Astrofísica, Universidad de La Laguna, La Laguna, E-38200, Teneri（拉帕尔马大学天体物理学系）
Turbulence is a crucial factor in many models of planet formation, but it has only been directly constrained among a small number of planet forming disks. Building on the upper limits on turbulence placed in disks around HD 163296 and TW Hya, we present ALMA CO J=2-1 line observations at $\sim0.3"$ (20-50 au) resolution and 80 ms$^{-1}$ channel spacing of the disks around DM Tau, MWC 480, and V4046 Sgr. Using parametric models of disk structure, we robustly detect non-thermal gas motions around DM Tau of between 0.25 c$_s$ and 0.33 c$_s$, with the range dominated by systematic effects, making …
We introduce the Disk Substructures at High Angular Resolution Project (DSHARP), one of the initial Large Programs conducted with the Atacama Large Millimeter/submillimeter Array (ALMA). The primary goal of DSHARP is to find and characterize substructures in the spatial distributions of solid particles for a sample of 20 nearby protoplanetary disks, using very high resolution (0.035 arcsec, or 5 au FWHM) observations of their 240 GHz (1.25 mm) continuum emission. These data provide a first homogeneous look at the small-scale features in disks that are directly relevant to the planet formation …
The 1.33 mm survey of protoplanetary discs in the Taurus molecular cloud found annular gaps and rings to be common in extended sources (>~55 au), when their 1D visibility distributions were fit parametrically. We first demonstrate the advantages and limitations of nonparametric visibility fits for data at the survey's 0.12" resolution. Then we use the nonparametric model in Frankenstein ('frank') to identify new substructure in three compact and seven extended sources. Among the new features we identify three trends: a higher occurrence rate of substructure in the survey's compact discs than p…
Constraining dust properties of planet-forming disks via high angular resolution observations is fundamental to understanding how solids are trapped in substructures and how dust growth may be favored or accelerated therein. We use ALMA dust continuum observations of the Molecules with ALMA at Planet-forming Scales (MAPS) disks and explore a large parameter space to constrain the radial distribution of solid mass and maximum grain size in each disk, including or excluding dust scattering. In the nonscattering model, the dust surface density and maximum grain size profiles decrease from the inn…
High angular resolution observations of discs at mm wavelengths (on scales of a few au) are now commonplace, but there is a current lack of a comparable angular resolution for observations at cm wavelengths. This presents a significant barrier to improving our understanding of planet formation, in particular how dust grains grow from mm to cm sizes. In this paper, we examine the ability of the Square Kilometre Array (SKA) to observe dust substructure in a young, planet-forming disc at cm wavelengths. We use dusty hydrodynamics and continuum radiative transfer to predict the distribution and em…
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) IX: Gas-driven origin for the continuum arc in the debris disc of HD 121617
Millennium Nucleus on Young Exoplanets and their Moons (YEMS)（年轻系外行星及其卫星千年核）；Center for Interdisciplinary Research in Astrophysics Space Exploration (CIRAS), Universidad de Santiago（圣地亚哥大学天体物理空间探索跨学科研究中心）；Department of Astronomy, Graduate School of Science, The University of Tokyo（东京大学理学研究科天文学系）；Departamento de Astrofísica, Universidad de La Laguna（拉帕鲁纳大学天体物理学系）；Institute of Physics and Astronomy, ELTE Eötvös Loránd University（罗兰·厄特沃什大学物理与天文学研究所）；Max-Planck-Insitut für Astronomie（马克斯·普朗克天文学研究所）
We investigate the potential of the Atacama Large Millimeter/submillimeter Array (ALMA) and the Next Generation Very Large Array (ngVLA) to observe substructures in nearby young disks which are due to the gravitational interaction between disk material and planets close to the central star. We simulate the gas and dust dynamics in the disk using the LA-COMPASS hydrodynamical code. We generate synthetic images for the dust continuum emission at sub-millimeter to centimeter wavelengths and simulate ALMA and ngVLA observations. We explore the parameter space of some of the main disk and planet pr…
UV photochemistry in the surface layers of protoplanetary disks dramatically alters their composition relative to previous stages of star formation. The abundance ratio CN/HCN has long been proposed to trace the UV field in various astrophysical objects, however to date the relationship between CN, HCN, and the UV field in disks remains ambiguous. As part of the ALMA Large Program MAPS (Molecules with ALMA at Planet-forming Scales), we present observations of CN N=1-0 transitions at 0.3'' resolution towards five disk systems. All disks show bright CN emission within $\sim$50-150 au, along with…
The Disk Substructures at High Angular Resolution Project used ALMA to map the 1.25 millimeter continuum of protoplanetary disks at a spatial resolution of ~5 au. We present a systematic analysis of annular substructures in the 18 single-disk systems targeted in this survey. No dominant architecture emerges from this sample; instead, remarkably diverse morphologies are observed. Annular substructures can occur at virtually any radius where millimeter continuum emission is detected and range in widths from a few au to tens of au. Intensity ratios between gaps and adjacent rings range from near-…
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) V: Comparison between scattered light and thermal emission
Univ. Grenoble Alpes（格勒诺布尔阿尔卑斯大学）；CNRS（法国国家科学研究中心）；IPAG（天体物理与行星学研究所）；European Southern Observatory（欧洲南方天文台）；Department of Physics and Astronomy, University of Exeter（埃克塞特大学物理与天文系）；Academia Sinica Institute of Astronomy and Astrophysics（中央研究院天文及天文物理研究所）；Aix Marseille Université（艾克斯-马赛大学）；LAM（地中海天文台）；Department of Astronomy and Steward Observatory, The University of Arizona（亚利桑那大学天文系和斯图尔德天文台）；Division of Geological and Planetary Sciences, California Institute of Technology（加州理工学院地质与行星科学系）；Department of Astronomy, Van Vleck Observatory, Wesleyan University（卫斯理大学天文系和范弗莱克天文台）；School of Physics, Trinity College Dublin, the University of Dublin（都柏林三一学院物理学院）；Instituto de Astrofísica de Canarias（加那利群岛天体物理研究所）
We analyze multi-frequency, high-resolution continuum data obtained by ALMA and JVLA to study detailed structure of the dust distribution in the infant disk of a Class~0/I source, L1527 IRS. We find three clumps aligning in the north-south direction in the $7 {\rm \,mm}$ radio continuum image. The three clumps remain even after subtracting free-free contamination, which is estimated from the $1.3{\rm \,cm}$ continuum observations. The northern and southern clumps are located at a distance of $\sim 15{\rm \,au}$ from the central clump and are likely optically thick at $7{\rm \,mm}$ wavelength. …
Protoplanetary disk surveys by the Atacama Large Millimeter/sub-millimeter Array (ALMA) are now probing a range of environmental conditions, from low-mass star-forming regions like Lupus to massive OB clusters like $σ$ Orionis. Here we conduct an ALMA survey of protoplanetary disks in $λ$ Orionis, a ~5 Myr old OB cluster in Orion, with dust mass sensitivities comparable to the surveys of nearby regions (~0.4 $M_\oplus$). We assess how massive OB stars impact planet formation, in particular from the supernova that may have occurred ~1 Myr ago in the core of $λ$ Orionis; studying these effects i…
The ALMA Survey of Gas Evolution of PROtoplanetary Disks (AGE-PRO): Constraints on disk turbulence, fragmentation velocity, and inner pebble fluxes
University College London（伦敦大学学院）；Universidad de Chile（智利大学）；European Southern Observatory（欧洲南方天文台）；Max Planck Institute for Extraterrestrial Physics（马克斯·普朗克地外物理研究所）；Max-Planck-Institut fur Astronomie (MPIA)（马克斯·普朗克天文学研究所）；Universidad Técnica Federico Santa María（费德里科·圣玛丽亚技术大学）；Università degli Studi di Milano（米兰大学）
The Molecules with ALMA at Planet-forming Scales (MAPS) Large Program provides a unique opportunity to study the vertical distribution of gas, chemistry, and temperature in the protoplanetary disks around IM Lup, GM Aur, AS 209, HD 163296, and MWC 480. By using the asymmetry of molecular line emission relative to the disk major axis, we infer the emission height ($z$) above the midplane as a function of radius ($r$). Using this method, we measure emitting surfaces for a suite of CO isotopologues, HCN, and C$_2$H. We find that $^{12}$CO emission traces the most elevated regions with $z/r > 0.3$…
Gas mass remains one of the most difficult protoplanetary disk properties to constrain. With much of the protoplanetary disk too cold for the main gas constituent, H2, to emit, alternative tracers such as dust, CO, or the H2 isotopolog HD are used. However, relying on disk mass measurements from any single tracer requires assumptions about the tracer's abundance relative to \hh\ and the disk temperature structure. Using new Atacama Large Millimeter/submillimeter Array (ALMA) observations from the Molecules with ALMA at Planet-forming Scales (MAPS) ALMA Large Program as well as archival ALMA ob…
We present a detailed analysis of new ALMA observations of the disk around the T-Tauri star HD 143006, which at 46 mas (7.6 au) resolution reveal new substructures in the 1.25 mm continuum emission. The disk resolves into a series of concentric rings and gaps together with a bright arc exterior to the rings that resembles hydrodynamics simulations of a vortex, and a bridge-like feature connecting the two innermost rings. Although our $^{12}$CO observations at similar spatial resolution do not show obvious substructure, they reveal an inner disk depleted of CO emission. From the continuum emiss…
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) III: The vertical structure of debris disks
Universidad de La Laguna（拉古纳大学）；The University of Tokyo（东京大学）；Large Binocular Telescope Observatory, The University of Arizona（亚利桑那大学大型双筒望远镜天文台）；University of Warwick（华威大学）；Max-Planck-Insitut für Astronomie（马克斯·普朗克天文学研究所）；ELTE Eötvös Loránd University（罗兰大学）；Universidad de Santiago（圣地亚哥大学）
Emission substructures in gas and dust are common in protoplanetary disks. Such substructures can be linked to planet formation or planets themselves. We explore the observed gas substructures in AS 209 using thermochemical modeling with RAC2D and high-spatial resolution data from the Molecules with ALMA at Planet-forming Scales(MAPS) program. The observations of C$^{18}$O J=2-1 emission exhibit a strong depression at 88 au overlapping with the positions of multiple gaps in millimeter dust continuum emission. We find that the observed CO column density is consistent with either gas surface-den…
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS): VI. Asymmetries and offsets
Joint ALMA Observatory（联合ALMA天文台）；Millennium Nucleus on Young Exoplanets and their Moons (YEMS)（年轻系外行星及其卫星千年核）；Department of Physics, University of Warwick（华威大学物理系）；Department of Physics & Astronomy, University of Victoria（维多利亚大学物理与天文学系）；Departamento de Astrofísica, Universidad de La Laguna（拉帕尔马大学天体物理学系）；Department of Astronomy, Graduate School of Science, The University of Tokyo（东京大学理学研究科天文学系）；Large Binocular Telescope Observatory, The University of Arizona（亚利桑那大学大双筒望远镜天文台）；Max-Planck-Insitut für Astronomie（马克斯·普朗克天文学研究所）；Institute of Physics and Astronomy, ELTE Eötvös Loránd University（厄特沃什·罗兰大学物理与天文学研究所）
We present mock observations of forming planets with ALMA. The possible detections of circumplanetary disks (CPDs) were investigated around planets of Saturn, 1, 3, 5, and 10 Jupiter-masses that are placed at 5.2 AU from their star. The radiative, three dimensional hydrodynamic simulations were then post-processed with RADMC3D and the ALMA Observation Simulator. We found that even though the CPDs are too small to be resolved, they are hot due to the accreting planet in the optically thick limit, therefore the best chance to detect them with continuum observations in this case is at the shortes…
Based on Atacama Large Millimeter/submillimeter Array (ALMA) observations, compact protoplanetary disks with dust radii of $r\lesssim 20-40$ au were found to be dominant in nearby low-mass star formation regions. However, their substructures have not been investigated because of the limited spatial resolution achieved so far. We apply a newly developed super-resolution imaging technique utilizing sparse modeling (SpM) to explore several au-scale structures in such compact disks. SpM imaging can directly solve for the incomplete sampling of visibilities in the spatial frequency and potentially …
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) I: Motivation, sample, data reduction, and results overview
University of Warwick（华威大学）；Universidad de La Laguna（拉古纳大学）；Millennium Nucleus on Young Exoplanets and their Moons (YEMS)（年轻系外行星及其卫星千年核）；Center for Interdisciplinary Research in Astrophysics Space Exploration (CIRAS), Universidad de Santiago, Chile（智利圣地亚哥大学天体物理学空间探索跨学科研究中心）；University of Victoria（维多利亚大学）；Institute for Astronomy (IfA), University of Vienna（维也纳大学天体物理研究所）；Institute of Physics and Astronomy, ELTE Eötvös Loránd University（罗兰·厄特沃什大学物理与天文学研究所）；Department of Astronomy, Graduate School of Science, The University of Tokyo（东京大学理学研究科天文学系）；Large Binocular Telescope Observatory, The University of Arizona（亚利桑那大学大双筒望远镜天文台）
We present Atacama Large Millimeter Array (ALMA) observations of TW Hya at 3.1 mm with $\sim50$ milliarcsecond resolution. These new data were combined with archival high angular resolution ALMA observations at 0.87 mm, 1.3 mm, and 2.1 mm. We analyze these multi-wavelength data to infer a disk radial profile of the dust surface density, maximum particle size, and slope of the particle size distribution. Most previously known annular substructures in the disk of TW Hya are resolved at the four wavelengths. Inside the inner 3 au cavity, the 2.1 mm and 3.1 mm images show a compact source of free-…
Small organic molecules, such as C2H, HCN, and H2CO, are tracers of the C, N, and O budget in protoplanetary disks. We present high angular resolution (10-50 au) observations of C2H, HCN, and H2CO lines in five protoplanetary disks from the Molecules with ALMA at Planet-forming Scales (MAPS) ALMA Large Program. We derive column density and excitation temperature profiles for HCN and C2H, and find that the HCN emission arises in a temperate (20-30 K) layer in the disk, while C2H is present in relatively warmer (20-60 K) layers. In the case of HD 163296, we find a decrease in column density for …
Planets form and obtain their compositions in dust and gas-rich disks around young stars, and the outcome of this process is intimately linked to the disk chemical properties. The distributions of molecules across disks regulate the elemental compositions of planets, including C/N/O/S ratios and metallicity (O/H and C/H), as well as access to water and prebiotically relevant organics. Emission from molecules also encodes information on disk ionization levels, temperature structures, kinematics, and gas surface densities, which are all key ingredients of disk evolution and planet formation mode…
ALMA observations of protoplanetary disks acquired by the Disk Substructure at High Angular Resolution Project (DSHARP) resolve the dust and gas emission on angular scales as small as 3 astronomical units, offering an unprecedented detailed view of the environment where planets form. In this article, we present and discuss observations of the HD 163296 protoplanetary disk that imaged the 1.25 mm dust continuum and $^{12}$CO J=2-1 rotational line emission at a spatial resolution of 4 and 10 au, respectively. The continuum observations resolve and allow us to characterize the previously discover…
The formation of planets occurs within protoplanetary disks surrounding young stars, resulting in perturbation of the gas and dust surface densities. Here, we report the first evidence of spatially resolved gas surface density ($Σ_{g}$) perturbation towards the AS~209 protoplanetary disk from the optically thin C$^{18}$O ($J=2-1$) emission. The observations were carried out at 1.3~mm with ALMA at a spatial resolution of about 0.3$\arcsec$ $\times$ 0.2$\arcsec$ (corresponding to $\sim$ 38 $\times$ 25 au). The C$^{18}$O emission shows a compact ($\le$60~au), centrally peaked emission and an oute…
ALMA 2D super-resolution imaging survey of Ophiuchus Class I/flat spectrum/II disks. II. Statistical analysis of stellar and disk properties
Kyushu University（九州大学）；Academia Sinica Institute of Astronomy and Astrophysics（中央研究院天文及天文物理研究所）；National Astronomical Observatory of Japan（日本国立天文台）；Kogakuin University（工学园大学）；The Graduate University for Advanced Studies (SOKENDAI)（综合研究大学院大学）
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) XI: Gas-dust interactions and radial offsets between micron and millimetre-sized grains
The University of Tokyo（东京大学）；Universidad de La Laguna（拉各拉纳加大学）；Millennium Nucleus on Young Exoplanets and their Moons (YEMS)（年轻系外行星及其卫星千年核）；Center for Interdisciplinary Research in Astrophysics Space Exploration (CIRAS), Universidad de Santiago（圣地亚哥大学天体物理与空间探索跨学科研究中心）；European Southern Observatory（欧洲南方天文台）；Institute of Physics Belgrade, University of Belgrade（贝尔格莱德大学物理研究所）；Department of Physics and Astronomy, University of Exeter（埃克塞特大学物理与天文学系）；Astrophysikalisches Institut und Universitätssternwarte, Friedrich-Schiller-Universität Jena（耶拿弗里德里希·席勒大学天体物理研究所及大学天文台）；Univ. Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学、法国国家科学研究中心、IPAG）；National Astronomical Observatory of Japan（日本国立天文台）
Here we present high resolution (15-24 au) observations of CO isotopologue lines from the Molecules with ALMA on Planet-forming Scales (MAPS) ALMA Large Program. Our analysis employs $^{13}$CO and C$^{18}$O ($J$=2-1), (1-0), and C$^{17}$O (1-0) line observations of five protoplanetary disks. We retrieve CO gas density distributions, using three independent methods: (1) a thermo-chemical modeling framework based on the CO data, the broadband spectral energy distribution, and the mm-continuum emission; (2) an empirical temperature distribution based on optically thick CO lines; and (3) a direct …
