Pub Date : 2024-06-05DOI: 10.1051/0004-6361/202348442
V. Jervci'c, J. M. Jenkins, R. K. C. F. M. Plasma-Astrophysics, K. Leuven, Belgium
Prominences and coronal rain are two forms of coronal condensations for which we still lack satisfactory details on the formation pathways and conditions under which the two come to exist. Even more so, it is unclear why prominences and filaments appear in so many different shapes and sizes, with a vertical rather than a horizontal structure or vice-versa. It is also not clear why coronal rain is present in some cases and not in others. Our aim is to understand the formation process of prominences and coronal rain in more detail by exploring what influence two specific heating prescriptions can have on the resulting formation and evolution, using simulations. We try to determine why we see prominences with such a variety in their properties, particularly by looking at the large-scale topology and dynamics. We attempted to recreate some of these aspects by simulating different types of localised heating. Besides the differences we see on a large scale, we also attempted to determine what the smaller-scale phenomena are, such as reconnection, the influence of resistivity (or lack thereof), the influence of flows and oscillations. We compared prominences that formed via a steady versus stochastic type of heating. We performed 2.5D simulations using the open-source MPI-AMRVAC code. To further extend the work and allow for future direct comparison with observations, we used Lightweaver to form spectra of the filament view of our steady case prominence. With that, we analysed a reconnection event that shares certain characteristics with nanojets. We show how different forms of localised heating that induce thermal instability result in prominences with different properties. The steady form of heating results in prominence with a clear vertical structure stretching across the magnetic field lines. On the other hand, stochastic heating produces many threads that predominantly have a horizontal motion along the field lines. Furthermore, the specific type of heating also influences the small-scale dynamics. In the steady heating case, the prominence is relatively static; however, there is evidence of reconnection happening almost the entire time the prominence is present. In the case of stochastic heating, the threads are highly dynamic, with them also exhibiting a form of transverse oscillation (strongly resembling the decayless type) similar to the vertically polarised oscillations previously found in observations. The fact that the threads in the stochastic heating case are constantly moving along the field lines suppresses any conditions for reconnection. It, therefore, appears that, to first order, the choice of heating prescription defines whether the prominence-internal dynamics are oriented vertically or horizontally. We closely inspected a sample reconnection event and computed the synthetic optically thick radiation using the open-source Lightweaver radiative transfer framework. We find the associated dynamics to imprint clear signatures, both in
{"title":"Prominence and coronal rain formation by steady versus stochastic heating and how we can relate it to observations","authors":"V. Jervci'c, J. M. Jenkins, R. K. C. F. M. Plasma-Astrophysics, K. Leuven, Belgium","doi":"10.1051/0004-6361/202348442","DOIUrl":"https://doi.org/10.1051/0004-6361/202348442","url":null,"abstract":"Prominences and coronal rain are two forms of coronal condensations for which we still lack satisfactory details on the formation pathways and conditions under which the two come to exist. Even more so, it is unclear why prominences and filaments appear in so many different shapes and sizes, with a vertical rather than a horizontal structure or vice-versa. It is also not clear why coronal rain is present in some cases and not in others. Our aim is to understand the formation process of prominences and coronal rain in more detail by exploring what influence two specific heating prescriptions can have on the resulting formation and evolution, using simulations. We try to determine why we see prominences with such a variety in their properties, particularly by looking at the large-scale topology and dynamics. We attempted to recreate some of these aspects by simulating different types of localised heating. Besides the differences we see on a large scale, we also attempted to determine what the smaller-scale phenomena are, such as reconnection, the influence of resistivity (or lack thereof), the influence of flows and oscillations. We compared prominences that formed via a steady versus stochastic type of heating. We performed 2.5D simulations using the open-source MPI-AMRVAC code. To further extend the work and allow for future direct comparison with observations, we used Lightweaver to form spectra of the filament view of our steady case prominence. With that, we analysed a reconnection event that shares certain characteristics with nanojets. We show how different forms of localised heating that induce thermal instability result in prominences with different properties. The steady form of heating results in prominence with a clear vertical structure stretching across the magnetic field lines. On the other hand, stochastic heating produces many threads that predominantly have a horizontal motion along the field lines. Furthermore, the specific type of heating also influences the small-scale dynamics. In the steady heating case, the prominence is relatively static; however, there is evidence of reconnection happening almost the entire time the prominence is present. In the case of stochastic heating, the threads are highly dynamic, with them also exhibiting a form of transverse oscillation (strongly resembling the decayless type) similar to the vertically polarised oscillations previously found in observations. The fact that the threads in the stochastic heating case are constantly moving along the field lines suppresses any conditions for reconnection. It, therefore, appears that, to first order, the choice of heating prescription defines whether the prominence-internal dynamics are oriented vertically or horizontally. We closely inspected a sample reconnection event and computed the synthetic optically thick radiation using the open-source Lightweaver radiative transfer framework. We find the associated dynamics to imprint clear signatures, both in","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"2 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141265717","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}
Pub Date : 2024-06-05DOI: 10.1051/0004-6361/202449585
Di Wang
A plausible origin for the quasi-periodic eruptions (QPEs) could be mass loss at the periastron of a body moving around the supermassive black hole (SMBH) on a highly eccentric orbit. This kind of tidally stripped star is expected to radiate gravitational waves, thereby leading to a shrinkage of the periastron distance. As a result, it will eventually be disrupted by the SMBH, as suggested by previous studies. This scenario predicts a gradually increasing mass transfer, contradicting the long-term evolution of the observed intensity of QPEs in GSN 069. In this work, we revisit the orbital evolution of the stripped star and we propose a model of a tidally stripped WD moving inside an accretion disk for QPEs, aimed at characterizing GSN 069. We found the effect of the mass transfer ultimately dominates the orbital evolution, resulting in the stripped star finally escaping the SMBH, rather than being disrupted by it. The drag force induced by the disk may effectively reduce the mass transfer and could thus explain the observed long-term evolution in the intensity of the QPEs in GSN 069. The disk is likely a fallback disk of the tidal disruption event in GSN 069. Considering the evolution of its accretion rate, this scenario could also explain the increase in the intensity of the latest eruption.
{"title":"Orbital evolution of a tidally stripped star and disk-driven stable mass transfer for QPEs in GSN 069","authors":"Di Wang","doi":"10.1051/0004-6361/202449585","DOIUrl":"https://doi.org/10.1051/0004-6361/202449585","url":null,"abstract":"A plausible origin for the quasi-periodic eruptions (QPEs) could be mass loss at the periastron of a body moving around the supermassive black hole (SMBH) on a highly eccentric orbit. This kind of tidally stripped star is expected to radiate gravitational waves, thereby leading to a shrinkage of the periastron distance. As a result, it will eventually be disrupted by the SMBH, as suggested by previous studies. This scenario predicts a gradually increasing mass transfer, contradicting the long-term evolution of the observed intensity of QPEs in GSN 069. In this work, we revisit the orbital evolution of the stripped star and we propose a model of a tidally stripped WD moving inside an accretion disk for QPEs, aimed at characterizing GSN 069. We found the effect of the mass transfer ultimately dominates the orbital evolution, resulting in the stripped star finally escaping the SMBH, rather than being disrupted by it. The drag force induced by the disk may effectively reduce the mass transfer and could thus explain the observed long-term evolution in the intensity of the QPEs in GSN 069. The disk is likely a fallback disk of the tidal disruption event in GSN 069. Considering the evolution of its accretion rate, this scenario could also explain the increase in the intensity of the latest eruption.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"2 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141265427","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}
Pub Date : 2024-06-05DOI: 10.1051/0004-6361/202348074
S. Musset, P. Jol, R. Sankar, S. Alnahari, C. Kapsiak, E. Ostlund, K. Lasko, L. Glesener, L. Fortson, G.D. Fleishman, K. Navdeep Panesar, Y. Zhang, M. Jeunon, N. Hurlburt
Solar coronal jets seen in extreme ultraviolet (EUV) are ubiquitous on the Sun, and they have been found in and at the edges of active regions, at the boundaries of coronal holes, and in the quiet Sun. Jets have various shapes, sizes, brightness, velocities, and durations in time, which complicates their detection by automated algorithms. So far, solar jets reported in the Heliophysics Event Knowledgebase (HEK) have been mostly reported by humans looking for them in the data, with different levels of precision regarding their timing and positions. We created a catalog of solar jets observed in EUV at 304 containing precise and consistent information on the jet timing, position, and extent. We designed a citizen science project, Solar Jet Hunter, on the Zooniverse platform, to analyze EUV observations at 304 from the Solar Dynamic Observatory/Atmospheric Imaging Assembly (SDO/AIA). We created movie strips for regions of the Sun in which jets have been reported in HEK and ask the volunteers to 1) confirm the presence of at least one jet in the data and 2) report the timing, position, and extent of the jet. We report here the design of the project and the results obtained after the analysis of data from 2011 to 2016. We note that 365 "coronal jet" events from HEK served as input for the citizen science project, equivalent to more than 120,000 images distributed into 9,689 "movie strips." Classification by the citizen scientists resulted in 883 individual jets being identified. We demonstrate how citizen science can enhance the analysis of solar data with the example of Solar Jet Hunter. The catalog of jets thusly created is publicly available and will enable statistical studies of jets and related phenomena. This catalog will also be used as a training set for machines to learn to recognize jets in further datasets.
{"title":"Solar Jet Hunter: a citizen science initiative to identify and characterize coronal jets at 304 AA","authors":"S. Musset, P. Jol, R. Sankar, S. Alnahari, C. Kapsiak, E. Ostlund, K. Lasko, L. Glesener, L. Fortson, G.D. Fleishman, K. Navdeep Panesar, Y. Zhang, M. Jeunon, N. Hurlburt","doi":"10.1051/0004-6361/202348074","DOIUrl":"https://doi.org/10.1051/0004-6361/202348074","url":null,"abstract":"Solar coronal jets seen in extreme ultraviolet (EUV) are ubiquitous on the Sun, and they have been found in and at the edges of active regions, at the boundaries of coronal holes, and in the quiet Sun. Jets have various shapes, sizes, brightness, velocities, and durations in time, which complicates their detection by automated algorithms. So far, solar jets reported in the Heliophysics Event Knowledgebase (HEK) have been mostly reported by humans looking for them in the data, with different levels of precision regarding their timing and positions. We created a catalog of solar jets observed in EUV at 304 containing precise and consistent information on the jet timing, position, and extent. We designed a citizen science project, Solar Jet Hunter, on the Zooniverse platform, to analyze EUV observations at 304 from the Solar Dynamic Observatory/Atmospheric Imaging Assembly (SDO/AIA). We created movie strips for regions of the Sun in which jets have been reported in HEK and ask the volunteers to 1) confirm the presence of at least one jet in the data and 2) report the timing, position, and extent of the jet. We report here the design of the project and the results obtained after the analysis of data from 2011 to 2016. We note that 365 \"coronal jet\" events from HEK served as input for the citizen science project, equivalent to more than 120,000 images distributed into 9,689 \"movie strips.\" Classification by the citizen scientists resulted in 883 individual jets being identified. We demonstrate how citizen science can enhance the analysis of solar data with the example of Solar Jet Hunter. The catalog of jets thusly created is publicly available and will enable statistical studies of jets and related phenomena. This catalog will also be used as a training set for machines to learn to recognize jets in further datasets.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141265656","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}
Pub Date : 2024-06-04DOI: 10.1051/0004-6361/202449817
Claude Bertout
Fluorescence of the optical FeI lines is observed in active T Tauri stars, and is considered a defining characteristic of this class of young stellar objects. The formation of optical fluorescent lines in moving media has not yet been studied in detail, so this work represents a first step in investigating the fluorescence process in different types of macroscopic velocity fields: (a) accelerated outflows, (b) accelerated infalls, and (c) non-monotonic velocity fields (such as an accelerating outflow followed by a deceleration region or an accretion shock front). We aim at developing a general computer code for studying the fluorescent emission in any 2D macroscopic velocity field. As an illustration, we consider FeI T Tauri-like fluorescent emission in these moving stellar envelopes. We solve the radiative transfer equations for the lines involved in the fluorescent process, assuming spherical symmetry and a simplified atomic model. We use the framework of the generalized Sobolev theory for computing the interacting, non-local source functions. The emergent line fluxes are then integrated exactly. Because of Doppler shifts in the moving gaseous envelope, photons of the three lines involved in TTS FeI fluorescence ( CaII H FeI and H interact with each other in a complex way, so that fluorescent amplification of the line flux occurs not only for FeI but also for the other two lines, in all velocity fields that we investigated. With the assumption of LTE populations, the line source functions of moderately optically thick lines are not strongly affected by line interactions, while they are depressed in the inner envelope for optically thick lines because of stellar photon absorption in the interaction regions. Fluorescent amplification takes place mainly in the observer's reference frame during the flux integration. We define a measure of fluorescence based on the line equivalent widths and perform a parameter study in an accretion flow over a broad range of envelope temperatures and densities. We include approximate collisional de-excitation rates in the source function computations. Significant fluorescence occurs over the entire temperature range investigated, but only in the higher density range, suggesting that relatively high mass accretion rates are needed to trigger the fluorescence process. Further comparison with observations will require solving the rate equations for the atomic populations involved, along with the radiation field computed with the method presented here. The main product of this research is the open-source computer code SLIM2 (Spectral Line Interactions in Moving Media), written in Python/Numpy, which numerically solves the fluorescence problem for arbitrary 2D velocities.
{"title":"Spectral line fluorescence in moving envelopes of stars","authors":"Claude Bertout","doi":"10.1051/0004-6361/202449817","DOIUrl":"https://doi.org/10.1051/0004-6361/202449817","url":null,"abstract":"Fluorescence of the optical FeI lines is observed in active T Tauri stars, and is considered a defining characteristic of this class of young stellar objects. The formation of optical fluorescent lines in moving media has not yet been studied in detail, so this work represents a first step in investigating the fluorescence process in different types of macroscopic velocity fields: (a) accelerated outflows, (b) accelerated infalls, and (c) non-monotonic velocity fields (such as an accelerating outflow followed by a deceleration region or an accretion shock front). We aim at developing a general computer code for studying the fluorescent emission in any 2D macroscopic velocity field. As an illustration, we consider FeI T Tauri-like fluorescent emission in these moving stellar envelopes. We solve the radiative transfer equations for the lines involved in the fluorescent process, assuming spherical symmetry and a simplified atomic model. We use the framework of the generalized Sobolev theory for computing the interacting, non-local source functions. The emergent line fluxes are then integrated exactly. Because of Doppler shifts in the moving gaseous envelope, photons of the three lines involved in TTS FeI fluorescence ( CaII H FeI and H interact with each other in a complex way, so that fluorescent amplification of the line flux occurs not only for FeI but also for the other two lines, in all velocity fields that we investigated. With the assumption of LTE populations, the line source functions of moderately optically thick lines are not strongly affected by line interactions, while they are depressed in the inner envelope for optically thick lines because of stellar photon absorption in the interaction regions. Fluorescent amplification takes place mainly in the observer's reference frame during the flux integration. We define a measure of fluorescence based on the line equivalent widths and perform a parameter study in an accretion flow over a broad range of envelope temperatures and densities. We include approximate collisional de-excitation rates in the source function computations. Significant fluorescence occurs over the entire temperature range investigated, but only in the higher density range, suggesting that relatively high mass accretion rates are needed to trigger the fluorescence process. Further comparison with observations will require solving the rate equations for the atomic populations involved, along with the radiation field computed with the method presented here. The main product of this research is the open-source computer code SLIM2 (Spectral Line Interactions in Moving Media), written in Python/Numpy, which numerically solves the fluorescence problem for arbitrary 2D velocities.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"244 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141386741","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}
Pub Date : 2024-06-04DOI: 10.1051/0004-6361/202348225
S. Moran, R. Kotak, M. Fraser, A. Pastorello, Y.-Z. Cai, G. Valerin, S. Mattila, E. Cappellaro, T. Kravtsov, C. P. Guti'errez, N. Elias-Rosa, A. Reguitti, P. Lundqvist, T. Brink, A. V. Filippenko, X. Wang
We present results from a five-month-long observing campaign of the unusual transient AT 2022fnm, which displays properties common to both luminous red novae (LRNe) and intermediate-luminosity red transients (ILRTs). Although its photometric evolution is broadly consistent with that of LRNe, no second peak is apparent in its light curve, and its spectral properties are more reminiscent of ILRTs. It has a fairly rapid rise time of 5.3pm 1.5,d, reaching a peak absolute magnitude of $-12.7 (in the ATLAS $o$ band). We find some evidence for circumstellar interaction, and a near-infrared excess becomes apparent at approximately +100,d after discovery. We attribute this to a dust echo. Finally, from an analytical diffusion toy model, we attempted to reproduce the pseudo-bolometric light curve and find that a mass of sim 4 is needed. Overall, the characteristics of AT 2022fnm are consistent with a weak stellar eruption or an explosion reminiscent of low-energy type IIP supernovae, which is compatible with expectations for ILRTs.
我们展示了对不寻常瞬变体 AT 2022fnm 长达五个月的观测结果，它显示出了发光红色新星（LRNe）和中等亮度红色瞬变体（ILRTs）的共同特性。虽然它的光度演化与红新星大致相同，但其光曲线中没有明显的第二峰值，其光谱特性更容易让人联想到中光度红瞬变体。它的上升时间相当快，为5.3pm 1.5,d，绝对星等达到峰值$-12.7（ATLAS $o$波段）。我们发现了一些星周相互作用的证据，并且在发现后大约+100,d处出现了明显的近红外过量。我们将其归因于尘埃回波。最后，我们试图通过一个分析扩散玩具模型来重现伪测辐射光曲线，结果发现需要模拟4的质量。总的来说，AT 2022fnm的特征与弱恒星爆发或爆炸相一致，让人联想到低能IIP型超新星，这与对ILRT的预期是一致的。
{"title":"Red eminence: The intermediate-luminosity red transient AT 2022fnm","authors":"S. Moran, R. Kotak, M. Fraser, A. Pastorello, Y.-Z. Cai, G. Valerin, S. Mattila, E. Cappellaro, T. Kravtsov, C. P. Guti'errez, N. Elias-Rosa, A. Reguitti, P. Lundqvist, T. Brink, A. V. Filippenko, X. Wang","doi":"10.1051/0004-6361/202348225","DOIUrl":"https://doi.org/10.1051/0004-6361/202348225","url":null,"abstract":"We present results from a five-month-long observing campaign of the \u0000 unusual transient AT 2022fnm, which displays properties common to both luminous red novae (LRNe) and intermediate-luminosity red transients (ILRTs).\u0000 Although its photometric evolution is broadly consistent with that of LRNe, no second peak is apparent in its light curve, and its spectral properties are more reminiscent of ILRTs. It has a fairly rapid rise time of 5.3pm 1.5,d, reaching a peak absolute magnitude of $-12.7 (in the ATLAS $o$ band). We find some evidence for circumstellar interaction, and a near-infrared excess becomes apparent at approximately +100,d after discovery. We attribute this to a dust echo. Finally, from an analytical diffusion toy model, we attempted to reproduce the pseudo-bolometric light curve and find that a mass of sim 4 is needed. Overall, the characteristics of AT 2022fnm are consistent with a weak stellar eruption or an explosion reminiscent of low-energy type IIP supernovae, which is compatible with expectations for ILRTs.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"40 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141387551","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}
Pub Date : 2024-06-04DOI: 10.1051/0004-6361/202449192
M. Solimano, J. González-López, M. Aravena, R. Herrera-Camus, I. de Looze, N. F. Förster Schreiber, J. Spilker, K. Tadaki, R. Assef, L. Barcos-Muñoz, R. Davies, T. Díaz-Santos, A. Ferrara, D. B. Fisher, L. Guaita, R. Ikeda, E. Johnston, D. Lutz, I. Mitsuhashi, C. Moya-Sierralta, M. Relaño, T. Naab, A. Posses, K. Telikova, H. Übler, S. van der Giessen, S. Veilleux, V. Villanueva
Massive star-forming galaxies in the high-redshift universe host large reservoirs of cold gas in their circumgalactic medium (CGM). Traditionally, these reservoirs have been linked to diffuse Lyman-alpha ( emission extending beyond approx parsec scales. In recent years, millimeter and submillimeter observations have started to identify even colder gas in the CGM through molecular and/or atomic tracers such as the transition. In this context, we studied the well-known system at $z=4.54$ that hosts a massive dusty star-forming galaxy (DSFG), a UV-bright companion, and a blob. We combined new ALMA line observations taken by the CRISTAL survey with data from previous programs targeting the system, and achieved a deep view into a DSFG and its rich environment at a $ parsec $ resolution. We identified an elongated structure with a projected size of parsec stemming from the bright DSFG at the center of the field, with no clear counterpart at any other wavelength. The plume is oriented approx away from the minor axis of the DSFG, and shows significant spatial variation of its spectral parameters. In particular, the emission shifts from second to second between the bottom and top of the plume, relative to the DSFG's systemic velocity. At the same time, the line width starts at $400- second $ but narrows down to second at the top end of the plume. We discuss four possible scenarios to interpret the plume: a conical outflow, a cold accretion stream, ram pressure stripping, and gravitational interactions. While we cannot strongly rule out any of these with the available data, we disfavor the ram pressure stripping scenario due to the requirement of special hydrodynamic conditions.
{"title":"The ALMA-CRISTAL survey. Discovery of a 15 kpc-long gas plume in a z=4.54 Lyman-alpha blob","authors":"M. Solimano, J. González-López, M. Aravena, R. Herrera-Camus, I. de Looze, N. F. Förster Schreiber, J. Spilker, K. Tadaki, R. Assef, L. Barcos-Muñoz, R. Davies, T. Díaz-Santos, A. Ferrara, D. B. Fisher, L. Guaita, R. Ikeda, E. Johnston, D. Lutz, I. Mitsuhashi, C. Moya-Sierralta, M. Relaño, T. Naab, A. Posses, K. Telikova, H. Übler, S. van der Giessen, S. Veilleux, V. Villanueva","doi":"10.1051/0004-6361/202449192","DOIUrl":"https://doi.org/10.1051/0004-6361/202449192","url":null,"abstract":"Massive star-forming galaxies in the high-redshift universe host large reservoirs of cold gas in their circumgalactic medium (CGM). Traditionally, these reservoirs have been linked to diffuse Lyman-alpha ( emission extending beyond approx parsec scales. In recent years, millimeter and submillimeter observations have started to identify even colder gas in the CGM through molecular and/or atomic tracers such as the transition. In this context, we studied the well-known system at $z=4.54$ that hosts a massive dusty star-forming galaxy (DSFG), a UV-bright companion, and a blob. We combined new ALMA line observations taken by the CRISTAL survey with data from previous programs targeting the system, and achieved a deep view into a DSFG and its rich environment at a $ parsec $ resolution. \u0000 We identified an elongated structure with a projected size of parsec stemming from the bright DSFG at the center of the field, with no clear counterpart at any other wavelength. The plume is oriented approx away from the minor axis of the DSFG, and shows significant spatial variation of its spectral parameters. In particular, the emission shifts from second to second between the bottom and top of the plume, relative to the DSFG's systemic velocity. At the same time, the line width starts at $400- second $ but narrows down to second at the top end of the plume. We discuss four possible scenarios to interpret the plume: a conical outflow, a cold accretion stream, ram pressure stripping, and gravitational interactions. While we cannot strongly rule out any of these with the available data, we disfavor the ram pressure stripping scenario due to the requirement of special hydrodynamic conditions.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"6 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141267842","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}
Pub Date : 2024-06-04DOI: 10.1051/0004-6361/202347345
C. Gapp, M. Rengel, P. Hartogh, H. Sagawa, H. Feuchtgruber, E. Lellouch, G. Villanueva
On October 31, 2009, the Photodetector Array Camera and Spectrometer (PACS) on board the Herschel Space Observatory observed far-infrared spectra of Jupiter in the wavelength range between 50 and 220$ as part of the program "Water and Related Chemistry in the Solar System". The spectra have an effective spectral resolution between 900 and 3500, depending on the wavelength and grating order. We investigate the disk-averaged chemical composition of Jupiter's atmosphere as a function of height using these observations. We used the Planetary Spectrum Generator (PSG) and the least-squares fitting technique to infer the abundances of trace constituents. The PACS data include numerous spectral lines attributable to ammonia (NH$_3$), methane (CH$_4$), phosphine (PH$_3$), water (H$_2$O), and deuterated hydrogen (HD) in the Jovian atmosphere and probe the chemical composition from $p 275$,mbar to $p 900$,mbar. From the observations, we infer an ammonia abundance profile that decreases from a mole fraction of $(1.7 $ at $p 900$,mbar to $(1.7 $ at $p 275$,mbar, following a fractional scale height of about $0.114$. For phosphine, we find a mole fraction of $(7.2 $ at pressures higher than $(550 100)$,mbar and a decrease of its abundance at lower pressures following a fractional scale height of $(0.09 0.02)$. Our analysis delivers a methane mole fraction of $(1.49 $. Analyzing the HD $R(0)$ line at $112.1 yields a new measurement of Jupiter's D/H ratio, $ D/H $. Finally, the PACS data allow us to put the most stringent $3 upper limits yet on the mole fractions of hydrogen halides in the Jovian troposphere. These new upper limits are $<1.1 $ for hydrogen fluoride (HF), $<6.0 $ for hydrogen chloride (HCl), $<2.3 $ for hydrogen bromide (HBr) and $<1.2 $ for hydrogen iodide (HI) and support the proposed condensation of hydrogen halides into ammonium halide salts in the Jovian troposphere.
{"title":"Abundances of trace constituents in Jupiter's atmosphere inferred from Herschel/PACS observations","authors":"C. Gapp, M. Rengel, P. Hartogh, H. Sagawa, H. Feuchtgruber, E. Lellouch, G. Villanueva","doi":"10.1051/0004-6361/202347345","DOIUrl":"https://doi.org/10.1051/0004-6361/202347345","url":null,"abstract":"On October 31, 2009, the Photodetector Array Camera and Spectrometer (PACS) on board the Herschel Space Observatory observed far-infrared spectra of Jupiter in the wavelength range between 50 and 220$ as part of the program \"Water and Related Chemistry in the Solar System\". The spectra have an effective spectral resolution between 900 and 3500, depending on the wavelength and grating order. We investigate the disk-averaged chemical composition of Jupiter's atmosphere as a function of height using these observations. We used the Planetary Spectrum Generator (PSG) and the least-squares fitting technique to infer the abundances of trace constituents. The PACS data include numerous spectral lines attributable to ammonia (NH$_3$), methane (CH$_4$), phosphine (PH$_3$), water (H$_2$O), and deuterated hydrogen (HD) in the Jovian atmosphere and probe the chemical composition from $p 275$,mbar to $p 900$,mbar. From the observations, we infer an ammonia abundance profile that decreases from a mole fraction of $(1.7 $ at $p 900$,mbar to $(1.7 $ at $p 275$,mbar, following a fractional scale height of about $0.114$. For phosphine, we find a mole fraction of $(7.2 $ at pressures higher than $(550 100)$,mbar and a decrease of its abundance at lower pressures following a fractional scale height of $(0.09 0.02)$. Our analysis delivers a methane mole fraction of $(1.49 $. Analyzing the HD $R(0)$ line at $112.1 yields a new measurement of Jupiter's D/H ratio, $ D/H $. Finally, the PACS data allow us to put the most stringent $3 upper limits yet on the mole fractions of hydrogen halides in the Jovian troposphere. These new upper limits are $<1.1 $ for hydrogen fluoride (HF), $<6.0 $ for hydrogen chloride (HCl), $<2.3 $ for hydrogen bromide (HBr) and $<1.2 $ for hydrogen iodide (HI) and support the proposed condensation of hydrogen halides into ammonium halide salts in the Jovian troposphere.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141268438","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}
Pub Date : 2024-06-04DOI: 10.1051/0004-6361/202450341
G. Valle, M. Dell'Omodarme, P. P. Prada Moroni, S. Degl'innocenti
We aim to investigate the theoretical possibility of accurately determining the helium-to-metal enrichment ratio $ Y/ Z$ from precise observations of double-lined eclipsing binary systems. Using Monte Carlo simulations, we drew synthetic binary systems with masses between 0.85 and 1.00 $M_ sun $ from a grid of stellar models. Both stars were sampled from a grid with $ Y/ Z = 2.0$, with a primary star at 80 of its main-sequence evolution. Subsequently, a broader grid with $ Y/ Z$ from 1.0 to 3.0 was used in the fitting process. To account for observational uncertainties, two scenarios were explored: S1, with realistic uncertainties of 100 K in temperature and 0.1 dex in Fe/H ; and S2, with halved uncertainties. We repeated the simulation at two baseline metallicities: Fe/H = 0.0 and $-0.3$. The posterior distributions of $ Y/ Z$ revealed significant biases. The distributions were severely biased towards the edge of the allowable range in the S1 error scenario. The situation only marginally improved when considering the S2 scenario. The effect is due to the impact of changing $ Y/ Z$ in the stellar effective temperature and its interplay with Fe/H observational error, and it is therefore not restricted to the specific fitting method. Despite the presence of these systematic discrepancies, the age of the systems were recovered unbiased with 10 precision. Our findings indicate that the observational uncertainty in effective temperature and metallicity significantly hinders the accurate determination of the $ Y/ Z$ parameter from main-sequence binary systems.
{"title":"Constraining the helium-to-metal enrichment ratio deltaY/deltaZ from main-sequence binary stars. Theoretical analysis of the accuracy and precision of the age and helium abundance estimates","authors":"G. Valle, M. Dell'Omodarme, P. P. Prada Moroni, S. Degl'innocenti","doi":"10.1051/0004-6361/202450341","DOIUrl":"https://doi.org/10.1051/0004-6361/202450341","url":null,"abstract":"We aim to investigate the theoretical possibility of accurately determining the helium-to-metal enrichment ratio $ Y/ Z$ from precise observations of double-lined eclipsing binary systems. Using Monte Carlo simulations, we drew synthetic binary systems with masses between 0.85 and 1.00 $M_ sun $ from a grid of stellar models. Both stars were sampled from a grid with $ Y/ Z = 2.0$, with a primary star at 80 of its main-sequence evolution. Subsequently, a broader grid with $ Y/ Z$ from 1.0 to 3.0 was used in the fitting process. To account for observational uncertainties, two scenarios were explored: S1, with realistic uncertainties of 100 K in temperature and 0.1 dex in Fe/H ; and S2, with halved uncertainties. We repeated the simulation at two baseline metallicities: Fe/H = 0.0 and $-0.3$. The posterior distributions of $ Y/ Z$ revealed significant biases. The distributions were severely biased towards the edge of the allowable range in the S1 error scenario. The situation only marginally improved when considering the S2 scenario. The effect is due to the impact of changing $ Y/ Z$ in the stellar effective temperature and its interplay with Fe/H observational error, and it is therefore not restricted to the specific fitting method. \u0000Despite the presence of these systematic discrepancies, the age of the systems were recovered unbiased with 10 precision. Our findings indicate that the observational uncertainty\u0000in effective temperature and metallicity significantly hinders the accurate determination of the $ Y/ Z$ parameter from main-sequence binary systems.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"17 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266403","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}
Pub Date : 2024-06-04DOI: 10.1051/0004-6361/202450100
J. Olofsson, P. Th'ebault, Amelia Bayo, T. Henning, J. Milli
Debris disks provide a unique opportunity to probe the properties of small mu m-sized particles, allowing us to peer into the constituents of their parent bodies, namely the young analogs of comets and the asteroids of our Solar System. In the past, studies of the total intensity phase function ---that is, the brightness of the disk as a function of the scattering angle--- have proven powerful in constraining the main characteristics of the dust particles in debris disks. Nonetheless, there can remain some degeneracies in the modeling, which can be alleviated when considering polarized intensity observations. We obtained new near-infrared scattered-light observations of four young debris disks, and used state-of-the-art algorithms to recover the total intensity and linear polarimetric images of the disks. These images allow us to constrain the degree of linear polarization as a function of the scattering angle. All four debris disks are detected in polarized intensity, and three are also recovered in total intensity. We measured a peak degree of polarization of $ 40$ for all three disks. For the disk around HD,129590, we are also able to determine the degree of polarization in the radiation-pressure-driven halo. To reproduce the observed polarization fractions, we find that the particles must consist of highly refractive and absorbing material. For HD,129590, by measuring the polarization fraction beyond the birth ring, we constrain the width of the size distribution to be increasingly small toward greater radii, which is compatible with the effect of radiation pressure. We put these findings to the test and present a self-consistent approach to producing synthetic images, assuming different profiles for the radiation pressure strength, and accounting for the presence of unbound grains. We find the contribution of these grains to be especially critical in order to reproduce the increasing degree of polarization with stellocentric distance. Some of our results ---namely a very small blow-out size and very large $(n,k)$ values for the optical constants, which are required to reproduce the observed degree of polarization--- might seem difficult to reconcile with our understanding of cosmic dust. Similar results have been obtained for other disks and we discuss the current limitation of available light-scattering models as well as possible avenues to alleviate these limitations.
{"title":"The near-infrared degree of polarization in debris disks. Toward a self-consistent approach to model scattered light observations","authors":"J. Olofsson, P. Th'ebault, Amelia Bayo, T. Henning, J. Milli","doi":"10.1051/0004-6361/202450100","DOIUrl":"https://doi.org/10.1051/0004-6361/202450100","url":null,"abstract":"Debris disks provide a unique opportunity to probe the properties of small mu m-sized particles, allowing us to peer into the constituents of their parent bodies, namely the young analogs of comets and the asteroids of our Solar System. In the past, studies of the total intensity phase function ---that is, the brightness of the disk as a function of the scattering angle--- have proven powerful in constraining the main characteristics of the dust particles in debris disks. Nonetheless, there can remain some degeneracies in the modeling, which can be alleviated when considering polarized intensity observations. We obtained new near-infrared scattered-light observations of four young debris disks, and used state-of-the-art algorithms to recover the total intensity and linear polarimetric images of the disks. These images allow us to constrain the degree of linear polarization as a function of the scattering angle. All four debris disks are detected in polarized intensity, and three are also recovered in total intensity. We measured a peak degree of polarization of $ 40$ for all three disks. For the disk around HD,129590, we are also able to determine the degree of polarization in the radiation-pressure-driven halo. To reproduce the observed polarization fractions, we find that the particles must consist of highly refractive and absorbing material. For HD,129590, by measuring the polarization fraction beyond the birth ring, we constrain the width of the size distribution to be increasingly small toward greater radii, which is compatible with the effect of radiation pressure. We put these findings to the test and present a self-consistent approach to producing synthetic images, assuming different profiles for the radiation pressure strength, and accounting for the presence of unbound grains. We find the contribution of these grains to be especially critical in order to reproduce the increasing degree of polarization with stellocentric distance. Some of our results ---namely a very small blow-out size and very large $(n,k)$ values for the optical constants, which are required to reproduce the observed degree of polarization--- might seem difficult to reconcile with our understanding of cosmic dust. Similar results have been obtained for other disks and we discuss the current limitation of available light-scattering models as well as possible avenues to alleviate these limitations.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"227 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141387038","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}
Pub Date : 2024-06-04DOI: 10.1051/0004-6361/202349137
A. Vazan, C. Ormel, M. Brouwers
The characterization of super-Earth- to Neptune-sized exoplanets relies heavily on our understanding of their formation and evolution. In this study, we link a model of planet formation by pebble accretion to the planets' long-term observational properties by calculating the interior evolution, starting from the dissipation of the protoplanetary disk. We investigate the evolution of the interior structure in 5--20 planets accounting for silicate redistribution caused by convective mixing, rainout (condensation and settling), and mass loss. Specifically, we have followed the fate of the hot silicate vapor that remained in the planet's envelope after planet formation as the planet cools. We find that disk dissipation is followed by a rapid contraction of the envelope from the Hill or Bondi radius to about one-tenth of that size within 10 Myr. Subsequent cooling leads to substantial growth of the planetary core through silicate rainout accompanied by inflated radii, in comparison to the standard models of planets that formed with core-envelope structure. We examined the dependence of rainout on the planet's envelope mass, on the distance from its host star, on its silicate mass, and on the atmospheric opacity. We find that the population of planets that formed with polluted envelopes can be roughly divided into three groups based on the mass of their gas envelopes: bare rocky cores that have shed their envelopes, super-Earth planets with a core-envelope structure, and Neptune-like planets with diluted cores that undergo gradual rainout. For polluted planets that formed with envelope masses below 0.4 we anticipate that the inflation of the planet's radius caused by rainout will enhance the mass loss by a factor of 2--8 compared to planets with unpolluted envelopes. Our model bridges the gap between the predicted composition gradients in massive planets and the core-envelope structure in smaller planets.
{"title":"How planets grow by pebble accretion. V. Silicate rainout delays the contraction of sub-Neptunes","authors":"A. Vazan, C. Ormel, M. Brouwers","doi":"10.1051/0004-6361/202349137","DOIUrl":"https://doi.org/10.1051/0004-6361/202349137","url":null,"abstract":"The characterization of super-Earth- to Neptune-sized exoplanets relies heavily on our understanding of their formation and evolution. In this study, we link a model of planet formation by pebble accretion to the planets' long-term observational properties by calculating the interior evolution, starting from the dissipation of the protoplanetary disk. We investigate the evolution of the interior structure in 5--20 planets accounting for silicate redistribution caused by convective mixing, rainout (condensation and settling), and mass loss. \u0000Specifically, we have followed the fate of the hot silicate vapor that remained in the planet's envelope after planet formation as the planet cools.\u0000We find that disk dissipation is followed by a rapid contraction of the envelope from the \u0000Hill or Bondi radius to about one-tenth of that size within 10 Myr. \u0000Subsequent cooling leads to substantial growth of the planetary core through silicate rainout accompanied by inflated radii, in comparison to the standard models of planets that formed with core-envelope structure. \u0000We examined the dependence of rainout on the planet's envelope mass, on the distance from its host star, on its silicate mass, and on the atmospheric opacity.\u0000We find that the population of planets that formed with polluted envelopes can be roughly divided into three groups based on the mass of their gas envelopes: bare rocky cores that have shed their envelopes, super-Earth planets with a core-envelope structure, and Neptune-like planets with diluted cores that undergo gradual rainout. For polluted planets that formed with envelope masses below 0.4 we anticipate that the inflation of the planet's radius caused by rainout will enhance the mass loss by a factor of 2--8 compared to planets with unpolluted envelopes. Our model bridges the gap between the predicted composition gradients in massive planets and the core-envelope structure in smaller planets.","PeriodicalId":505693,"journal":{"name":"Astronomy & Astrophysics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266519","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}
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