Pub Date : 2021-06-01DOI: 10.1051/0004-6361/202140375
Yong Zhao, D. Ni
Context. Earth-sized exoplanets have been discovered and characterized thanks to new developments in observational techniques, particularly those planets that may have a rocky composition that is comparable to terrestrial planets of the Solar System. Characterizing the interiors of rocky exoplanets is one of the main objectives in investigations of their habitability. Theoretical mass-radius relations are often used as a tool to constrain the internal structure of rocky exoplanets. But one mass-radius curve only represents a single interior structure and a great deal of computation time is required to obtain all possible interior structures that comply with the given mass and radius of a planet.Aims. We apply a machine-learning approach based on mixture density networks (MDNs) to investigate the interiors of rocky exoplanets. We aim to provide a well-trained MDN model to quickly and efficiently predict the interior structure of rocky exoplanets.Methods. We presented a training data set of rocky exoplanets with masses between 0.1 and 10 Earth masses based on three-layer interior models by assuming Earth-like compositions. This data set was then used to train the MDN model to predict the layer thicknesses and core properties of rocky exoplanets, where planetary mass, radius, and water content are inputs to the MDN. The performance of the trained MDN model was investigated in order to discern its predictive ability.Results. The MDN model is found to show good performance in predicting the layer thicknesses and core properties of rocky exoplanets through a comparison with the real solutions obtained by solving the interior models. We also applied the MDN model to the Earth and the super-Earth exoplanet LHS 1140b. The MDN predictions are in good agreement with the interior model solutions within the uncertainties of planetary mass and radius. More importantly, the MDN model takes a much shorter computational time compared to the cost of the interior model calculations, offering a convenient and powerful tool for quickly obtaining information on planetary interiors.
{"title":"Machine learning techniques in studies of the interior structure of rocky exoplanets","authors":"Yong Zhao, D. Ni","doi":"10.1051/0004-6361/202140375","DOIUrl":"https://doi.org/10.1051/0004-6361/202140375","url":null,"abstract":"Context. Earth-sized exoplanets have been discovered and characterized thanks to new developments in observational techniques, particularly those planets that may have a rocky composition that is comparable to terrestrial planets of the Solar System. Characterizing the interiors of rocky exoplanets is one of the main objectives in investigations of their habitability. Theoretical mass-radius relations are often used as a tool to constrain the internal structure of rocky exoplanets. But one mass-radius curve only represents a single interior structure and a great deal of computation time is required to obtain all possible interior structures that comply with the given mass and radius of a planet.\u0000Aims. We apply a machine-learning approach based on mixture density networks (MDNs) to investigate the interiors of rocky exoplanets. We aim to provide a well-trained MDN model to quickly and efficiently predict the interior structure of rocky exoplanets.\u0000Methods. We presented a training data set of rocky exoplanets with masses between 0.1 and 10 Earth masses based on three-layer interior models by assuming Earth-like compositions. This data set was then used to train the MDN model to predict the layer thicknesses and core properties of rocky exoplanets, where planetary mass, radius, and water content are inputs to the MDN. The performance of the trained MDN model was investigated in order to discern its predictive ability.\u0000Results. The MDN model is found to show good performance in predicting the layer thicknesses and core properties of rocky exoplanets through a comparison with the real solutions obtained by solving the interior models. We also applied the MDN model to the Earth and the super-Earth exoplanet LHS 1140b. The MDN predictions are in good agreement with the interior model solutions within the uncertainties of planetary mass and radius. More importantly, the MDN model takes a much shorter computational time compared to the cost of the interior model calculations, offering a convenient and powerful tool for quickly obtaining information on planetary interiors.","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"7 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82906765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-01DOI: 10.1051/0004-6361/202040268
H. Gu, J. Cui, D. Niu, X. Wu, F. He, Yong Wei
{"title":"Non-thermal escape on Triton driven by atmospheric and ionospheric chemistry","authors":"H. Gu, J. Cui, D. Niu, X. Wu, F. He, Yong Wei","doi":"10.1051/0004-6361/202040268","DOIUrl":"https://doi.org/10.1051/0004-6361/202040268","url":null,"abstract":"","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"13 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74293013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-31DOI: 10.1051/0004-6361/202141452
R. Abbott, T. Abbott, F. Acernese, K. Ackley, C. Adams, N. Adhikari, R. Adhikari, V. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, S. Albanesi, A. Allocca, P. Altin, A. Amato, C. Anand, S. Anand, A. Ananyeva, S. Anderson, W. Anderson, M. Ando, T. Andrade, N. Andrés, S. Angelova, S. Ansoldi, J. Antelis, S. Antier, S. Appert, K. Arai, K. Arai, Y. Arai, S. Araki, A. Araya, M. Araya, J. Areeda, M. Arène, N. Aritomi, N. Arnaud, S. Aronson, K. Arun, H. Asada, Y. Asali, G. Ashton, Y. Aso, M. Assiduo, S. Aston, P. Astone, F. Aubin, C. Austin, S. Babak, F. Badaracco, M. Bader, C. Badger, S. Bae, Y. Bae, A. Baer, S. Bagnasco, Y. Bai, L. Baiotti, J. Baird, R. Bajpai, M. Ball, G. Ballardin, S. Ballmer, A. Balsamo, G. Baltus, S. Banagiri, D. Bankar, J. Barayoga, C. Barbieri, B. Barish, D. Barker, P. Barneo, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, D. Barta, J. Bartlett, M. Barton, I. Bartos, R. Bassiri, A. Basti, M. Bawaj, J. Bayley, A. Bay
Intermediate-mass black holes (IMBHs) span the approximate mass range 100−105 M , between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200 M and effective aligned spin 0.8 at 0.056 Gpc−3 yr−1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc−3 yr−1.
{"title":"Search for intermediate mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo","authors":"R. Abbott, T. Abbott, F. Acernese, K. Ackley, C. Adams, N. Adhikari, R. Adhikari, V. Adya, C. Affeldt, D. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. Aguiar, L. Aiello, A. Ain, P. Ajith, T. Akutsu, S. Albanesi, A. Allocca, P. Altin, A. Amato, C. Anand, S. Anand, A. Ananyeva, S. Anderson, W. Anderson, M. Ando, T. Andrade, N. Andrés, S. Angelova, S. Ansoldi, J. Antelis, S. Antier, S. Appert, K. Arai, K. Arai, Y. Arai, S. Araki, A. Araya, M. Araya, J. Areeda, M. Arène, N. Aritomi, N. Arnaud, S. Aronson, K. Arun, H. Asada, Y. Asali, G. Ashton, Y. Aso, M. Assiduo, S. Aston, P. Astone, F. Aubin, C. Austin, S. Babak, F. Badaracco, M. Bader, C. Badger, S. Bae, Y. Bae, A. Baer, S. Bagnasco, Y. Bai, L. Baiotti, J. Baird, R. Bajpai, M. Ball, G. Ballardin, S. Ballmer, A. Balsamo, G. Baltus, S. Banagiri, D. Bankar, J. Barayoga, C. Barbieri, B. Barish, D. Barker, P. Barneo, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, D. Barta, J. Bartlett, M. Barton, I. Bartos, R. Bassiri, A. Basti, M. Bawaj, J. Bayley, A. Bay","doi":"10.1051/0004-6361/202141452","DOIUrl":"https://doi.org/10.1051/0004-6361/202141452","url":null,"abstract":"Intermediate-mass black holes (IMBHs) span the approximate mass range 100−105 M , between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200 M and effective aligned spin 0.8 at 0.056 Gpc−3 yr−1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc−3 yr−1.","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"50 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80013192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-27DOI: 10.1051/0004-6361/202140801
A. Dundović, Carmelo Evoli, D. Gaggero, D. Grasso
The study of non-thermal processes such as synchrotron emission, inverse Compton scattering, bremsstrahlung and pion production is crucial to understand the properties of the Galactic cosmic-ray population, to shed light on their origin and confinement mechanisms, and to assess the significance of exotic signals possibly associated to new physics. We present a public code called HERMES aimed at generating sky maps associated to a variety of multi-messenger and multi-wavelength radiative processes, spanning from the radio domain all the way up to high-energy gamma-ray and neutrino production. We describe the physical processes under consideration, the code concept and structure, and the user interface, with particular focus on the python-based interactive mode. We especially present the modular and flexible design that allows to easily further extend the numerical package according to the user's needs. In order to demonstrate the capabilities of the code, we describe in detail a comprehensive set of sky maps and spectra associated to all physical processes included in the code. We comment in particular on the radio, gamma-ray, and neutrino maps, and mention the possibility to study signals stemming from dark matter annihilation. HERMES can be successfully applied to constrain the properties of the Galactic cosmic-ray population, improve our understanding of the diffuse Galactic radio, gamma--ray, and neutrino emission, and search for signals associated to particle dark matter annihilation or decay.
{"title":"Simulating the Galactic multi-messenger emissions with HERMES","authors":"A. Dundović, Carmelo Evoli, D. Gaggero, D. Grasso","doi":"10.1051/0004-6361/202140801","DOIUrl":"https://doi.org/10.1051/0004-6361/202140801","url":null,"abstract":"The study of non-thermal processes such as synchrotron emission, inverse Compton scattering, bremsstrahlung and pion production is crucial to understand the properties of the Galactic cosmic-ray population, to shed light on their origin and confinement mechanisms, and to assess the significance of exotic signals possibly associated to new physics. We present a public code called HERMES aimed at generating sky maps associated to a variety of multi-messenger and multi-wavelength radiative processes, spanning from the radio domain all the way up to high-energy gamma-ray and neutrino production. We describe the physical processes under consideration, the code concept and structure, and the user interface, with particular focus on the python-based interactive mode. We especially present the modular and flexible design that allows to easily further extend the numerical package according to the user's needs. In order to demonstrate the capabilities of the code, we describe in detail a comprehensive set of sky maps and spectra associated to all physical processes included in the code. We comment in particular on the radio, gamma-ray, and neutrino maps, and mention the possibility to study signals stemming from dark matter annihilation. HERMES can be successfully applied to constrain the properties of the Galactic cosmic-ray population, improve our understanding of the diffuse Galactic radio, gamma--ray, and neutrino emission, and search for signals associated to particle dark matter annihilation or decay.","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"3 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81584410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-26DOI: 10.1007/s00159-021-00132-9
Aldo Serenelli, Achim Weiss, Conny Aerts, George C. Angelou, David Baroch, Nate Bastian, Paul G. Beck, Maria Bergemann, Joachim M. Bestenlehner, Ian Czekala, Nancy Elias-Rosa, Ana Escorza, Vincent Van Eylen, Diane K. Feuillet, Davide Gandolfi, Mark Gieles, Léo Girardi, Yveline Lebreton, Nicolas Lodieu, Marie Martig, Marcelo M. Miller Bertolami, Joey S. G. Mombarg, Juan Carlos Morales, Andrés Moya, Benard Nsamba, Krešimir Pavlovski, May G. Pedersen, Ignasi Ribas, Fabian R. N. Schneider, Victor Silva Aguirre, Keivan G. Stassun, Eline Tolstoy, Pier-Emmanuel Tremblay, Konstanze Zwintz
The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning with the most direct and model-independent approach using detached eclipsing binaries. We then move to more indirect and model-dependent methods, such as the quite commonly used isochrone or stellar track fitting. The arrival of quantitative asteroseismology has opened a completely new approach to determine stellar masses and to complement and improve the accuracy of other methods. We include methods for different evolutionary stages, from the pre-main sequence to evolved (super)giants and final remnants. For all methods uncertainties and restrictions will be discussed. We provide lists of altogether more than 200 benchmark stars with relative mass accuracies between ([0.3,2]%) for the covered mass range of (Min [0.1,16],M_odot), (75%) of which are stars burning hydrogen in their core and the other (25%) covering all other evolved stages. We close with a recommendation how to combine various methods to arrive at a “mass-ladder” for stars.
{"title":"Weighing stars from birth to death: mass determination methods across the HRD","authors":"Aldo Serenelli, Achim Weiss, Conny Aerts, George C. Angelou, David Baroch, Nate Bastian, Paul G. Beck, Maria Bergemann, Joachim M. Bestenlehner, Ian Czekala, Nancy Elias-Rosa, Ana Escorza, Vincent Van Eylen, Diane K. Feuillet, Davide Gandolfi, Mark Gieles, Léo Girardi, Yveline Lebreton, Nicolas Lodieu, Marie Martig, Marcelo M. Miller Bertolami, Joey S. G. Mombarg, Juan Carlos Morales, Andrés Moya, Benard Nsamba, Krešimir Pavlovski, May G. Pedersen, Ignasi Ribas, Fabian R. N. Schneider, Victor Silva Aguirre, Keivan G. Stassun, Eline Tolstoy, Pier-Emmanuel Tremblay, Konstanze Zwintz","doi":"10.1007/s00159-021-00132-9","DOIUrl":"https://doi.org/10.1007/s00159-021-00132-9","url":null,"abstract":"<p>The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning with the most direct and model-independent approach using detached eclipsing binaries. We then move to more indirect and model-dependent methods, such as the quite commonly used isochrone or stellar track fitting. The arrival of quantitative asteroseismology has opened a completely new approach to determine stellar masses and to complement and improve the accuracy of other methods. We include methods for different evolutionary stages, from the pre-main sequence to evolved (super)giants and final remnants. For all methods uncertainties and restrictions will be discussed. We provide lists of altogether more than 200 benchmark stars with relative mass accuracies between <span>([0.3,2]%)</span> for the covered mass range of <span>(Min [0.1,16],M_odot)</span>, <span>(75%)</span> of which are stars burning hydrogen in their core and the other <span>(25%)</span> covering all other evolved stages. We close with a recommendation how to combine various methods to arrive at a “mass-ladder” for stars.</p>","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"29 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s00159-021-00132-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5015899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-24DOI: 10.1051/0004-6361/202140315
E. Asvestari, J. Pomoell, E. Kilpua, S. Good, T. Chatzistergos, M. Temmer, E. Palmerio, S. Poedts, J. Magdalenić
Coronal mass ejections (CMEs) are a manifestation of the Sun's eruptive nature. They can have a great impact on Earth, but also on human activity in space and on the ground. Therefore, modelling their evolution as they propagate through interplanetary space is essential. EUropean Heliospheric FORecasting Information Asset (EUHFORIA) is a data-driven, physics-based model, tracing the evolution of CMEs through background solar wind conditions. It employs a spheromak flux rope, which provides it with the advantage of reconstructing the internal magnetic field configuration of CMEs. This is something that is not included in the simpler cone CME model used so far for space weather forecasting. This work aims at assessing the spheromak CME model included in EUHFORIA. We employed the spheromak CME model to reconstruct a well observed CME and compare model output to in situ observations. We focus on an eruption from 6 January 2013 encountered by two radially aligned spacecraft, Venus Express and STEREO-A. We first analysed the observed properties of the source of this CME eruption and we extracted the CME properties as it lifted off from the Sun. Using this information, we set up EUHFORIA runs to model the event. The model predicts arrival times from half to a full day ahead of the in situ observed ones, but within errors established from similar studies. In the modelling domain, the CME appears to be propagating primarily southward, which is in accordance with white-light images of the CME eruption close to the Sun. In order to get the observed magnetic field topology, we aimed at selecting a spheromak rotation angle for which the axis of symmetry of the spheromak is perpendicular to the direction of the polarity inversion line (PIL). The modelled magnetic field profiles, their amplitude, arrival times, and sheath region length are all affected by the choice of radius of the modelled spheromak.
{"title":"Modelling a multi-spacecraft coronal mass ejection encounter with EUHFORIA","authors":"E. Asvestari, J. Pomoell, E. Kilpua, S. Good, T. Chatzistergos, M. Temmer, E. Palmerio, S. Poedts, J. Magdalenić","doi":"10.1051/0004-6361/202140315","DOIUrl":"https://doi.org/10.1051/0004-6361/202140315","url":null,"abstract":"Coronal mass ejections (CMEs) are a manifestation of the Sun's eruptive nature. They can have a great impact on Earth, but also on human activity in space and on the ground. Therefore, modelling their evolution as they propagate through interplanetary space is essential. EUropean Heliospheric FORecasting Information Asset (EUHFORIA) is a data-driven, physics-based model, tracing the evolution of CMEs through background solar wind conditions. It employs a spheromak flux rope, which provides it with the advantage of reconstructing the internal magnetic field configuration of CMEs. This is something that is not included in the simpler cone CME model used so far for space weather forecasting. This work aims at assessing the spheromak CME model included in EUHFORIA. We employed the spheromak CME model to reconstruct a well observed CME and compare model output to in situ observations. We focus on an eruption from 6 January 2013 encountered by two radially aligned spacecraft, Venus Express and STEREO-A. We first analysed the observed properties of the source of this CME eruption and we extracted the CME properties as it lifted off from the Sun. Using this information, we set up EUHFORIA runs to model the event. The model predicts arrival times from half to a full day ahead of the in situ observed ones, but within errors established from similar studies. In the modelling domain, the CME appears to be propagating primarily southward, which is in accordance with white-light images of the CME eruption close to the Sun. In order to get the observed magnetic field topology, we aimed at selecting a spheromak rotation angle for which the axis of symmetry of the spheromak is perpendicular to the direction of the polarity inversion line (PIL). The modelled magnetic field profiles, their amplitude, arrival times, and sheath region length are all affected by the choice of radius of the modelled spheromak.","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"64 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80340520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-12DOI: 10.1051/0004-6361/202040213
E. Pointecouteau, I. Santiago-Bautista, M. Douspis, N. Aghanim, D. Crichton, J. Diego, G. Hurier, J. Macías-Pérez, T. Marriage, M. Remazeilles, C. Caretta, H. Bravo-Alfaro
The pressure of hot gas in groups and clusters of galaxies is a key physical quantity, which is directly linked to the total mass of the halo and several other thermodynamical properties. In the wake of previous observational works on the hot gas pressure distribution in massive halos, we have investigated a sample of 31 clusters detected in both the Planck and Atacama Cosmology Telescope (ACT), MBAC surveys. We made use of an optimised Sunyaev-Zeldovich (SZ) map reconstructed from the two data sets and tailored for the detection of the SZ e ff ect, taking advantage of both Planck coverage of large scales and the ACT higher spatial resolution. Our average pressure profile covers a radial range going from 0 . 04 × R 500 in the central parts to 2 . 5 × R 500 in the outskirts. In this way, it improves upon previous pressure-profile reconstruction based on SZ measurements. It is compatible, as well as competitive, with constraints derived from joint X-ray and SZ analysis. This work demonstrates the possibilities o ff ered by large sky surveys of the SZ e ff ect with multiple experiments with di ff erent spatial resolutions and spectral coverages, such as ACT and Planck .
星系群和星系团中热气体的压力是一个关键的物理量，它直接关系到光晕的总质量和其他几个热力学性质。在之前对大质量晕中热气体压力分布的观测工作之后，我们研究了在普朗克和阿塔卡马宇宙学望远镜(ACT) MBAC巡天中探测到的31个星团样本。我们利用了从两个数据集重建的优化的Sunyaev-Zeldovich (SZ)地图，并针对SZ效应的检测进行了定制，利用了普朗克大尺度覆盖和ACT更高的空间分辨率。我们的平均压力分布图涵盖了从0开始的径向范围。04 × r500在中心部位要2个。5 × R 500在郊区。通过这种方式，改进了以前基于SZ测量的压力剖面重建。它是兼容的，也是竞争的，从联合x射线和SZ分析得出的约束。这项工作证明了通过不同空间分辨率和光谱覆盖范围(如ACT和普朗克)的多个实验，对SZ效应进行大规模巡天所提供的可能性。
{"title":"PACT. II. Pressure profiles of galaxy clusters using Planck and ACT","authors":"E. Pointecouteau, I. Santiago-Bautista, M. Douspis, N. Aghanim, D. Crichton, J. Diego, G. Hurier, J. Macías-Pérez, T. Marriage, M. Remazeilles, C. Caretta, H. Bravo-Alfaro","doi":"10.1051/0004-6361/202040213","DOIUrl":"https://doi.org/10.1051/0004-6361/202040213","url":null,"abstract":"The pressure of hot gas in groups and clusters of galaxies is a key physical quantity, which is directly linked to the total mass of the halo and several other thermodynamical properties. In the wake of previous observational works on the hot gas pressure distribution in massive halos, we have investigated a sample of 31 clusters detected in both the Planck and Atacama Cosmology Telescope (ACT), MBAC surveys. We made use of an optimised Sunyaev-Zeldovich (SZ) map reconstructed from the two data sets and tailored for the detection of the SZ e ff ect, taking advantage of both Planck coverage of large scales and the ACT higher spatial resolution. Our average pressure profile covers a radial range going from 0 . 04 × R 500 in the central parts to 2 . 5 × R 500 in the outskirts. In this way, it improves upon previous pressure-profile reconstruction based on SZ measurements. It is compatible, as well as competitive, with constraints derived from joint X-ray and SZ analysis. This work demonstrates the possibilities o ff ered by large sky surveys of the SZ e ff ect with multiple experiments with di ff erent spatial resolutions and spectral coverages, such as ACT and Planck .","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"295 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89067185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-05DOI: 10.1051/0004-6361/202140493
J. Gonz'alez-Payo, M. Cort'es-Contreras, N. Lodieu, E. Solano, Z. Zhang, M. G'alvez-Ortiz
Aims. The aim of the project is to identify wide common proper motion companions to a sample of spectroscopically confirmed M and L metal-poor dwarfs (also known as subdwarfs) to investigate the impact of metallicity on the binary fraction of low-mass metal-poor binaries and to improve the determination of their metallicity from the higher-mass binary. Methods. We made use of Virtual Observatory tools and large-scale public surveys to look in Gaia for common proper motion companions to a well-defined sample of ultracool subdwarfs with spectral types later than M5 and metallicities below or equal to −0.5 dex. We collected low-resolution optical spectroscopy for our best system, which is a binary composed of one sdM1.5 subdwarf and one sdM5.5 subdwarf located at ∼1 360 au, and for another two likely systems separated by more than 115 000 au. Results. We confirm one wide companion to an M subdwarf, and infer a multiplicity for M subdwarfs (sdMs) of 1.0+2.0 −1.0% for projected physical separations of up to 743 000 au. We also find four M–L systems, three of which are new detections. No colder companion was identified in any of the 219 M and L subdwarfs of the sample, mainly because of limitations on the detection of faint sources with Gaia. We infer a frequency of wide systems for sdM5–9.5 of 0.60+1.17 −0.60% for projected physical separations larger than 1 360 au (up to 142 400 au). This study shows a multiplicity rate of 1.0+2.0 −1.0% in sdMs, and 1.9 +3.7 −1.9% in extreme M subdwarfs (esdMs). We did not find any companion for the ultra M subdwarfs (usdMs) of our sample, establishing an upper limit of 5.3% on binarity for these objects.
{"title":"Wide companions to M and L subdwarfs with Gaia and the Virtual Observatory","authors":"J. Gonz'alez-Payo, M. Cort'es-Contreras, N. Lodieu, E. Solano, Z. Zhang, M. G'alvez-Ortiz","doi":"10.1051/0004-6361/202140493","DOIUrl":"https://doi.org/10.1051/0004-6361/202140493","url":null,"abstract":"Aims. The aim of the project is to identify wide common proper motion companions to a sample of spectroscopically confirmed M and L metal-poor dwarfs (also known as subdwarfs) to investigate the impact of metallicity on the binary fraction of low-mass metal-poor binaries and to improve the determination of their metallicity from the higher-mass binary. Methods. We made use of Virtual Observatory tools and large-scale public surveys to look in Gaia for common proper motion companions to a well-defined sample of ultracool subdwarfs with spectral types later than M5 and metallicities below or equal to −0.5 dex. We collected low-resolution optical spectroscopy for our best system, which is a binary composed of one sdM1.5 subdwarf and one sdM5.5 subdwarf located at ∼1 360 au, and for another two likely systems separated by more than 115 000 au. Results. We confirm one wide companion to an M subdwarf, and infer a multiplicity for M subdwarfs (sdMs) of 1.0+2.0 −1.0% for projected physical separations of up to 743 000 au. We also find four M–L systems, three of which are new detections. No colder companion was identified in any of the 219 M and L subdwarfs of the sample, mainly because of limitations on the detection of faint sources with Gaia. We infer a frequency of wide systems for sdM5–9.5 of 0.60+1.17 −0.60% for projected physical separations larger than 1 360 au (up to 142 400 au). This study shows a multiplicity rate of 1.0+2.0 −1.0% in sdMs, and 1.9 +3.7 −1.9% in extreme M subdwarfs (esdMs). We did not find any companion for the ultra M subdwarfs (usdMs) of our sample, establishing an upper limit of 5.3% on binarity for these objects.","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"1 1","pages":"143"},"PeriodicalIF":25.8,"publicationDate":"2021-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89159673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-04DOI: 10.1051/0004-6361/202140829
L. Moscadelli, R. Cesaroni, M. Beltr'an, V. Rivilla
The study of hyper-compact (HC) or ultra-compact (UC) HII regions isfundamental to understanding the process of massive (> 8 M_sun) star formation.We employed Atacama Large Millimeter/submillimeter Array (ALMA) 1.4 mm Cycle 6observations to investigate at high angular resolution (~0.050", correspondingto 330 au) the HC HII region inside molecular core A1 of the high-massstar-forming cluster G24.78+0.08. We used the H30alpha emission and differentmolecular lines of CH3CN and 13CH3CN to study the kinematics of the ionized andmolecular gas, respectively. At the center of the HC HII region, at radii <~500au, we observe two mutually perpendicular velocity gradients, which aredirected along the axes at PA = 39 deg and PA = 133 deg, respectively. Thevelocity gradient directed along the axis at PA = 39 deg has an amplitude of 22km/s mpc^(-1), which is much larger than the other's, 3 km/s mpc^(-1). Weinterpret these velocity gradients as rotation around, and expansion along, theaxis at PA = 39 deg. We propose a scenario where the H30alpha line traces theionized heart of a disk-jet system that drives the formation of the massivestar (~20 M_sun) responsible for the HC HII region. Such a scenario is alsosupported by the position-velocity plots of the CH3CN and 13CH3CN lines alongthe axis at PA = 133 deg, which are consistent with Keplerian rotation around a20 M_sun star. Toward the HC HII region in G24.78+0.08, the coexistence of massinfall (at radii of ~5000 au), an outer molecular disk (from ~500au), and an inner ionized disk (<~500 au) indicates that the massive ionizingstar is still actively accreting from its parental molecular core. To ourknowledge, this is the first example of a molecular disk around a high-massforming star that, while becoming internally ionized after the onset of the HIIregion, continues to accrete mass onto the ionizing star.
{"title":"The ionized heart of a molecular disk","authors":"L. Moscadelli, R. Cesaroni, M. Beltr'an, V. Rivilla","doi":"10.1051/0004-6361/202140829","DOIUrl":"https://doi.org/10.1051/0004-6361/202140829","url":null,"abstract":"The study of hyper-compact (HC) or ultra-compact (UC) HII regions is\u0000fundamental to understanding the process of massive (> 8 M_sun) star formation.\u0000We employed Atacama Large Millimeter/submillimeter Array (ALMA) 1.4 mm Cycle 6\u0000observations to investigate at high angular resolution (~0.050\", corresponding\u0000to 330 au) the HC HII region inside molecular core A1 of the high-mass\u0000star-forming cluster G24.78+0.08. We used the H30alpha emission and different\u0000molecular lines of CH3CN and 13CH3CN to study the kinematics of the ionized and\u0000molecular gas, respectively. At the center of the HC HII region, at radii <~500\u0000au, we observe two mutually perpendicular velocity gradients, which are\u0000directed along the axes at PA = 39 deg and PA = 133 deg, respectively. The\u0000velocity gradient directed along the axis at PA = 39 deg has an amplitude of 22\u0000km/s mpc^(-1), which is much larger than the other's, 3 km/s mpc^(-1). We\u0000interpret these velocity gradients as rotation around, and expansion along, the\u0000axis at PA = 39 deg. We propose a scenario where the H30alpha line traces the\u0000ionized heart of a disk-jet system that drives the formation of the massive\u0000star (~20 M_sun) responsible for the HC HII region. Such a scenario is also\u0000supported by the position-velocity plots of the CH3CN and 13CH3CN lines along\u0000the axis at PA = 133 deg, which are consistent with Keplerian rotation around a\u000020 M_sun star. Toward the HC HII region in G24.78+0.08, the coexistence of mass\u0000infall (at radii of ~5000 au), an outer molecular disk (from ~500\u0000au), and an inner ionized disk (<~500 au) indicates that the massive ionizing\u0000star is still actively accreting from its parental molecular core. To our\u0000knowledge, this is the first example of a molecular disk around a high-mass\u0000forming star that, while becoming internally ionized after the onset of the HII\u0000region, continues to accrete mass onto the ionizing star.","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"24 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83443778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-01DOI: 10.1051/0004-6361/202040055E
A. Noll, S. Deheuvels, J. Ballot
{"title":"Probing core overshooting using subgiant asteroseismology: The case of KIC10273246 (Corrigendum)","authors":"A. Noll, S. Deheuvels, J. Ballot","doi":"10.1051/0004-6361/202040055E","DOIUrl":"https://doi.org/10.1051/0004-6361/202040055E","url":null,"abstract":"","PeriodicalId":785,"journal":{"name":"The Astronomy and Astrophysics Review","volume":"283 1","pages":""},"PeriodicalIF":25.8,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76836948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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