The Astrophysical Journal Letters最新文献

{"title":"exoALMA. X. Channel Maps Reveal Complex 12CO Abundance Distributions and a Variety of Kinematic Structures with Evidence for Embedded Planets","authors":"Christophe Pinte, John D. Ilee, Jane Huang, Myriam Benisty, Stefano Facchini, Misato Fukagawa, Richard Teague, Jaehan Bae, Marcelo Barraza-Alfaro, Gianni Cataldi, Nicolás Cuello, Pietro Curone, Ian Czekala, Daniele Fasano, Mario Flock, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Iain Hammond, Caitlyn Hardiman, Thomas Hilder, Andrés F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Giuseppe Lodato, Cristiano Longarini, Ryan A. Loomis, Frédéric Masset, Francois Menard, Ryuta Orihara, Daniel J. Price, Giovanni Rosotti, Jochen Stadler, Hsi-Wei Yen, Gaylor Wafflard-Fernandez, David J. Wilner, Andrew J. Winter, Lisa Wölfer, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc433","DOIUrl":"https://doi.org/10.3847/2041-8213/adc433","url":null,"abstract":"We analyze the 12CO J = 3–2 data cubes of the disks in the exoALMA program. 13/15 disks reveal a variety of kinematic substructures in individual channels: large-scale arcs or spiral arms, localized velocity kinks, and/or multiple faints arcs that appear like filamentary structures on the disk surface. We find kinematic signatures that are consistent with planet wakes in six disks: AA Tau, SY Cha, J1842, J1615, LkCa 15, and HD 143006. Comparison with hydrodynamical and radiative transfer simulations suggests planets with orbital radii between 80 and 310 au and masses between 1 and 5 MJup. Additional kinematic substructures limit our ability to place tight constraints on the planet masses. When the inclination is favorable to separate the upper and lower surfaces (near 45°, i.e., in 7/15 disks), we always detect the vertical CO snowline and find that the 12CO freeze-out is partial in the disk midplane, with a depletion factor of ≈10−3 –10−2 compared to the warm molecular layer. In these same seven disks, we also systematically detect evidence of CO desorption in the outer regions.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884468","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}

{"title":"exoALMA. VI. Rotating under Pressure: Rotation Curves, Azimuthal Velocity Substructures, and Gas Pressure Variations","authors":"Jochen Stadler, Myriam Benisty, Andrew J. Winter, Andrés F. Izquierdo, Cristiano Longarini, Maria Galloway-Sprietsma, Pietro Curone, Sean M. Andrews, Jaehan Bae, Stefano Facchini, Giovanni Rosotti, Richard Teague, Marcelo Barraza-Alfaro, Gianni Cataldi, Nicolás Cuello, Ian Czekala, Daniele Fasano, Mario Flock, Misato Fukagawa, Himanshi Garg, Cassandra Hall, Iain Hammond, Thomas Hilder, Jane Huang, John D. Ilee, Kazuhiro Kanagawa, Geoffroy Lesur, Giuseppe Lodato, Ryan A. Loomis, Francois Menard, Ryuta Orihara, Christophe Pinte, Daniel J. Price, Hsi-Wei Yen, Gaylor Wafflard-Fernandez, David J. Wilner, Lisa Wölfer, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adb152","DOIUrl":"https://doi.org/10.3847/2041-8213/adb152","url":null,"abstract":"The bulk motion of the gas in protoplanetary disks around newborn stars is nearly Keplerian. By leveraging the high angular and spectral resolution of the Atacama Large Millimeter/submillimeter Array (ALMA), we can detect small-scale velocity perturbations in molecular line observations caused by local gas pressure variations in the disk, possibly induced by embedded protoplanets. This Letter presents the azimuthally averaged rotational velocity and its deviations from Keplerian rotation (δυϕ) for the exoALMA sample, as measured in the 12CO J = 3–2 and 13CO J = 3–2 emission lines. The rotation signatures show evidence for vertically stratified disks, in which 13CO rotates faster than 12CO due to a distinct thermal gas pressure gradient at their emitting heights. We find δυϕ substructures in the sample on both small (∼10 au) and large (∼100 au) radial scales, reaching deviations up to 15% from background Keplerian velocity in the most extreme cases. More than 75% of the rings and 80% of the gaps in the dust continuum emission resolved in δυϕ are colocated with gas pressure maxima and minima, respectively. Additionally, gas pressure substructures are observed far beyond the dust continuum emission. For the first time, we determined the gas pressure derivative at the midplane from observations, and found it to align well with the dust substructures within the given uncertainties. Based on our findings, we conclude that gas pressure variations are likely the dominant mechanism for ring and gap formation in the dust continuum.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"83 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884552","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}

{"title":"exoALMA. XV. Interpreting the Height of CO Emission Layer","authors":"Giovanni P. Rosotti, Cristiano Longarini, Teresa Paneque-Carreño, Gianni Cataldi, Maria Galloway-Sprietsma, Sean M. Andrews, Jaehan Bae, Marcelo Barraza-Alfaro, Myriam Benisty, Pietro Curone, Ian Czekala, Stefano Facchini, Daniele Fasano, Mario Flock, Misato Fukagawa, Himanshi Garg, Cassandra Hall, Jane Huang, John D. Ilee, Andrés F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Giuseppe Lodato, Ryan A. Loomis, Ryuta Orihara, Christophe Pinte, Daniel J. Price, Jochen Stadler, Richard Teague, Gaylor Wafflard- Fernandez, Andrew J. Winter, Lisa Wölfer, Hsi-Wei Yen, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc42e","DOIUrl":"https://doi.org/10.3847/2041-8213/adc42e","url":null,"abstract":"The availability of exquisite data and the development of new analysis techniques have enabled the study of emitting heights in protoplanetary disks. In this paper, we introduce a simple model linking the emitting height of CO to the disk surface density and temperature structure. We then apply the model to measurements of the emitting height and disk temperature conducted as part of exoALMA, integrated with additional legacy measurements from the MAPS Large Programme, to derive CO column densities and surface density profiles (assuming a CO abundance) for a total of 14 disks. A unique feature of the method we introduce to measure surface densities is that it can be applied to optically thick observations, rather than optically thin as conventionally done. While we use our method on a sample of well-studied disks where temperature structures have been derived using two emission lines, we show that reasonably accurate estimates can be obtained also when only one molecular transition is available. With our method, we obtain independent constraints from 12CO and 13CO, and we find they are in general good agreement using the standard 12C/13C isotopic ratio. The masses derived from our method are systematically lower compared with the values derived dynamically from the rotation curve if using an interstellar matter (ISM) CO abundance, implying that CO is depleted by a median factor ∼20 with respect to the ISM value, in line with other works that find that CO is depleted in protoplanetary disks.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884672","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}

{"title":"exoALMA. XII. Weighing and Sizing exoALMA Disks with Rotation Curve Modelling","authors":"Cristiano Longarini, Giuseppe Lodato, Giovanni Rosotti, Sean Andrews, Andrew Winter, Jochen Stadler, Andrés Izquierdo, Maria Galloway-Sprietsma, Stefano Facchini, Pietro Curone, Myriam Benisty, Richard Teague, Jaehan Bae, Marcelo Barraza-Alfaro, Gianni Cataldi, Ian Czekala, Nicolás Cuello, Daniele Fasano, Mario Flock, Misato Fukagawa, Himanshi Garg, Cassandra Hall, Iain Hammond, Caitlyn Hardiman, Thomas Hilder, Jane Huang, John D. Ilee, Andrea Isella, Kazuhiro Kanagawa, Geoffroy Lesur, Ryan A. Loomis, Francois Ménard, Ryuta Orihara, Christophe Pinte, Daniel Price, Leonardo Testi, Gaylor Wafflard- Fernandez, Lisa Wölfer, Hsi-Wei Yen, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc431","DOIUrl":"https://doi.org/10.3847/2041-8213/adc431","url":null,"abstract":"The exoALMA large program offers a unique opportunity to investigate the fundamental properties of protoplanetary disks, such as their masses and sizes, providing important insights into the mechanism responsible for the transport of angular momentum. In this work, we model the rotation curves of CO isotopologues 12CO and 13CO of 10 sources within the exoALMA sample, and we constrain the stellar mass, the disk mass, and the density scale radius through precise characterization of the pressure gradient and disk self-gravity. We obtain dynamical disk masses for our sample by measuring the self-gravitating contribution to the gravitational potential. We are able to parametrically describe their surface density, and all of them appear gravitationally stable. By combining dynamical disk masses with dust continuum emission data, we determine an averaged gas-to-dust ratio of approximately 400, not statistically consistent with the standard value of 100, assuming optically thin dust emission. In addition, the measurement of the dynamical scale radius allows for direct comparison with flux-based radii of gas and dust. This comparison suggests that substructures may influence the size of the dust disk and that CO depletion might reconcile our measurements with thermochemical models. Finally, with the stellar mass, disk mass, scale radius, and accretion rate, and assuming self-similar evolution of the surface density, we constrain the effective αS for these systems. We find a broad range of αS values ranging between 10−5 and 10−2.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884681","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}

{"title":"exoALMA. XI. ALMA Observations and Hydrodynamic Models of LkCa 15: Implications for Planetary Mass Companions in the Dust Continuum Cavity","authors":"Charles H. Gardner, Andrea Isella, Hui Li, Shengtai Li, Jaehan Bae, Marcelo Barraza-Alfaro, Myriam Benisty, Gianni Cataldi, Pietro Curone, Josh A. Eisner, Stefano Facchini, Daniele Fasano, Mario Flock, Katherine B. Follette, Misato Fukagawa, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Jane Huang, John D. Ilee, Michael J. Ireland, Andrés F. Izquierdo, Christopher M. Johns-Krull, Kazuhiro Kanagawa, Adam L. Kraus, Geoffroy Lesur, Shangfei Liu, Cristiano Longarini, Ryan A. Loomis, Francois Menard, Ryuta Orihara, Christophe Pinte, Daniel Price, Luca Ricci, Giovanni Rosotti, Steph Sallum, Jochen Stadler, Richard Teague, Gaylor Wafflard-Fernandez, David J. Wilner, Andrew J. Winter, Lisa Wölfer, Hsi-Wei Yen, Tomohiro C. Yoshida, Brianna Zawadzki and Zhaohuan Zhu","doi":"10.3847/2041-8213/adc432","DOIUrl":"https://doi.org/10.3847/2041-8213/adc432","url":null,"abstract":"In the past decade, the Atacama Large Millimeter/submillimeter Array (ALMA) has revealed a plethora of substructures in the disks surrounding young stars. These substructures have several proposed formation mechanisms, with one leading theory being the interaction between the disk and newly formed planets. In this Letter, we present high angular resolution ALMA observations of LkCa 15’s disk that reveal a striking difference in dust and CO emission morphology. The dust continuum emission shows a ringlike structure characterized by a dust-depleted inner region of ∼40 au in radius. Conversely, the CO emission is radially smoother and shows no sign of gas depletion within the dust cavity. We compare the observations with models for the disk–planet interaction, including radiative transfer calculation in the dust and CO emission. This source is particularly interesting, as the presence of massive planets within the dust cavity has been suggested based on previous near-IR observations. We find that the level of CO emission observed within the dust cavity is inconsistent with the presence of planets more massive than Jupiter orbiting between 10 and 40 au. Instead, we argue that the LkCa 15 innermost dust cavity might be created either by a chain of low-mass planets or by other processes that do not require the presence of planets.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884682","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}

{"title":"exoALMA. IX. Regularized Maximum Likelihood Imaging of Non-Keplerian Features","authors":"Brianna Zawadzki, Ian Czekala, Maria Galloway-Sprietsma, Jaehan Bae, Marcelo Barraza-Alfaro, Myriam Benisty, Gianni Cataldi, Pietro Curone, Stefano Facchini, Daniele Fasano, Mario Flock, Misato Fukagawa, Himanshi Garg, Cassandra Hall, Thomas Hilder, Jane Huang, John D. Ilee, Andrea Isella, Andrés F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Cristiano Longarini, Ryan A. Loomis, Ryuta Orihara, Christophe Pinte, Daniel J. Price, Giovanni Rosotti, Jochen Stadler, Richard Teague, Hsi-Wei Yen, Gaylor Wafflard-Fernandez, David J. Wilner, Andrew J. Winter, Lisa Wölfer and Tomohiro C. Yoshida","doi":"10.3847/2041-8213/adc434","DOIUrl":"https://doi.org/10.3847/2041-8213/adc434","url":null,"abstract":"The planet-hunting Atacama Large Millimeter/submillimeter Array (ALMA) large program exoALMA observed 15 protoplanetary disks at angular resolution and ∼100 m s−1 spectral resolution, characterizing disk structures and kinematics in enough detail to detect non-Keplerian features (NKFs) in the gas emission. As these features are often small and low-contrast, robust imaging procedures are critical for identifying and characterizing NKFs, including determining which features may be signatures of young planets. The exoALMA collaboration employed two different imaging procedures to ensure the consistent detection of NKFs: CLEAN, the standard iterative deconvolution algorithm, and regularized maximum likelihood (RML) imaging. This Letter presents the exoALMA RML images, obtained by maximizing the likelihood of the visibility data given a model image and subject to regularizer penalties. Crucially, in the context of exoALMA, RML images serve as an independent verification of marginal features seen in the fiducial CLEAN images. However, best practices for synthesizing RML images of multichanneled (i.e., velocity-resolved) data remain undefined, as prior work on RML imaging for protoplanetary disk data has primarily addressed single-image cases. We used the open-source Python package MPoL to explore RML image validation methods for multichanneled data and synthesize RML images from the exoALMA observations of seven protoplanetary disks with apparent NKFs in the 12CO J = 3–2 CLEAN images. We find that RML imaging methods independently reproduce the NKFs seen in the CLEAN images of these sources, suggesting that the NKFs are robust features rather than artifacts from a specific imaging procedure.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884689","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}

{"title":"Polytropic Behavior in Corotating Interaction Regions: Evidence of Alfvénic Heating","authors":"M. A. Dayeh, M. J. Starkey, G. Livadiotis, S. T. Hart, A. A. Shmies, R. C. Allen, R. Bučik and H. A. Elliott","doi":"10.3847/2041-8213/adc4d7","DOIUrl":"https://doi.org/10.3847/2041-8213/adc4d7","url":null,"abstract":"Corotating interaction regions (CIRs) are recurring structures in the solar wind, characterized by interactions between fast and slow solar wind streams that compress and heat plasma. This study investigates the polytropic behavior of distinct regions in and around CIRs: uncompressed slow solar wind, compressed slow solar wind, compressed fast solar wind, and uncompressed fast solar wind. Using Wind spacecraft data and an established methodology for calculating the polytropic index (γ), we analyze 117 CIR events. Results indicate varying γ values across regions, with heating observed in compressed regions driven by Alfvén wave dissipation originating from fast streams. In the uncompressed fast solar wind, γ exceeds adiabatic values the most and correlates well with strong Alfvénic wave activity.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884731","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}

{"title":"exoALMA. XVII. Characterizing the Gas Dynamics around Dust Asymmetries","authors":"Lisa Wölfer, Marcelo Barraza-Alfaro, Richard Teague, Pietro Curone, Myriam Benisty, Misato Fukagawa, Jaehan Bae, Gianni Cataldi, Ian Czekala, Stefano Facchini, Daniele Fasano, Mario Flock, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Jane Huang, John D. Ilee, Andrés F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Cristiano Longarini, Ryan A. Loomis, Francois Menard, Anika Nath, Ryuta Orihara, Christophe Pinte, Daniel J. Price, Giovanni Rosotti, Jochen Stadler, Gaylor Wafflard-Fernandez, Andrew J. Winter, Hsi-Wei Yen, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc42c","DOIUrl":"https://doi.org/10.3847/2041-8213/adc42c","url":null,"abstract":"The key planet-formation processes in protoplanetary disks remain an active matter of research. One promising mechanism to radially and azimuthally trap millimeter-emitting dust grains, enabling them to concentrate and grow into planetesimals, is anticyclonic vortices. While dust observations have revealed crescent structures in several disks, observations of their kinematic signatures are still lacking. Studying the gas dynamics is, however, essential to confirm the presence of a vortex and understand its dust trapping properties. In this work, we make use of the high-resolution and sensitivity observations conducted by the exoALMA large program to search for such signatures in the 12CO and 13CO molecular line emission of four disks with azimuthal dust asymmetries: HD 135344B, HD 143006, HD 34282, and MWC 758. To assess the vortex features, we constructed an analytical vortex model and performed hydrodynamical simulations. For the latter, we assumed two scenarios: a vortex triggered at the edge of a dead zone and of a gap created by a massive embedded planet. These models reveal a complex kinematical morphology of the vortex. When compared to the data, we find that none of the sources show a distinctive vortex signature around the dust crescents in the kinematics. HD 135344B exhibits a prominent feature similar to the predictions from the simulations, thus making this the most promising target for sensitive follow-up studies at higher resolution and in particular with less abundant molecules at higher resolution and sensitivity to trace closer to the disk midplane.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884666","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}

{"title":"exoALMA. III. Line-intensity Modeling and System Property Extraction from Protoplanetary Disks","authors":"Andrés F. Izquierdo, Jochen Stadler, Maria Galloway-Sprietsma, Myriam Benisty, Christophe Pinte, Jaehan Bae, Richard Teague, Stefano Facchini, Lisa Wölfer, Cristiano Longarini, Pietro Curone, Sean M. Andrews, Marcelo Barraza-Alfaro, Gianni Cataldi, Nicolás Cuello, Ian Czekala, Daniele Fasano, Mario Flock, Misato Fukagawa, Himanshi Garg, Cassandra Hall, Iain Hammond, Thomas Hilder, Jane Huang, John D. Ilee, Andrea Isella, Kazuhiro Kanagawa, Geoffroy Lesur, Giuseppe Lodato, Ryan A. Loomis, Ryuta Orihara, Daniel J. Price, Giovanni Rosotti, Leonardo Testi, Hsi-Wei Yen, Gaylor Wafflard-Fernandez, David J. Wilner, Andrew J. Winter, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc439","DOIUrl":"https://doi.org/10.3847/2041-8213/adc439","url":null,"abstract":"The ALMA large program exoALMA offers a unique window into the three-dimensional physical and dynamical properties of 15 circumstellar disks where planets may be actively forming. Here, we present an analysis methodology to map the gas disk structure and substructure encoded in 12CO, 13CO, and CS line emission from our targets. To model and characterize the disk structure probed by optically thin species, such as CS and, in some cases, 13CO, we introduce a composite line profile kernel that accounts for increased intensities caused by the projected overlap between the disk’s front and back side emission. Our workflow, built on the discminer modeling framework, incorporates an improved iterative two-component fitting method for inclined sources (i > 40∘) to mitigate the impact of the disk back side on the extraction of velocity maps. Also, we report best-fit parameters for the Keplerian stellar masses, as well as inclinations, position angles, systemic velocities, rotation direction, and emission surfaces of the disks in our sample.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884720","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}

{"title":"exoALMA. V. Gaseous Emission Surfaces and Temperature Structures","authors":"Maria Galloway-Sprietsma, Jaehan Bae, Andrés F. Izquierdo, Jochen Stadler, Cristiano Longarini, Richard Teague, Sean M. Andrews, Andrew J. Winter, Myriam Benisty, Stefano Facchini, Giovanni Rosotti, Brianna Zawadzki, Christophe Pinte, Daniele Fasano, Marcelo Barraza-Alfaro, Gianni Cataldi, Nicolás Cuello, Pietro Curone, Ian Czekala, Mario Flock, Misato Fukagawa, Charles H. Gardner, Himanshi Garg, Cassandra Hall, Jane Huang, John D. Ilee, Kazuhiro Kanagawa, Geoffroy Lesur, Giuseppe Lodato, Ryan A. Loomis, Francois Menard, Ryuta Orihara, Daniel J. Price, Gaylor Wafflard-Fernandez, David J. Wilner, Lisa Wölfer, Hsi-Wei Yen and Tomohiro C. Yoshida","doi":"10.3847/2041-8213/adc437","DOIUrl":"https://doi.org/10.3847/2041-8213/adc437","url":null,"abstract":"An analysis of the gaseous component in protoplanetary disks can inform us about their thermal and physical structure, chemical composition, and kinematic properties, all of which are crucial for understanding various processes within the disks. By exploiting the asymmetry of the line emission, or via line profile analysis, we can locate the emitting surfaces. Here, we present the emission surfaces of the exoALMA sources in 12CO J = 3–2, 13CO J = 3–2, and CS J = 7–6. We find that 12CO traces the upper disk atmosphere, with mean 〈z/r〉 values of ≈0.28, while 13CO and CS trace lower regions of the disk with mean 〈z/r〉 values of ≈0.16 and ≈0.18, respectively. We find that 12CO 〈z/r〉 and the disk mass are positively correlated with each other; this relationship offers a straightforward way to infer the disk mass. We derive 2D r – z temperature distributions of the disks. Additionally, we search for substructure in the surfaces and radial intensity profiles; we find evidence of localized substructure in the emission surfaces and peak intensity profiles of nearly every disk, with this substructure often being coincident between molecular tracers, intensity profiles, and kinematic perturbations. Four disks display evidence of potential photodesorption, implying that this effect may be common even in low far-ultraviolet star-forming regions. For most disks, we find that the physical and thermal structure is more complex than analytical models can account for, highlighting a need for more theoretical work and a better understanding of the role of projection effects on our observations.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884721","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}