T Collins, G Rowell, S Einecke, F Voisin, Y Fukui, H Sano
HESS J1825-137 is one of the most powerful and luminous TeV gamma-ray pulsar wind nebulae (PWNe), making it an excellent laboratory to study particle transportation around pulsars. We present a model of the (diffusive and advective) transport and radiative losses of electrons from the pulsar PSR J1826-1334 powering HESS J1825-137 using interstellar medium gas (ISM) data, soft photon fields and a spatially varying magnetic field.We find that for the characteristic age of 21 kyr, PSR J1826-1334 is unable to meet the energy requirements to match the observed X-ray and gamma-ray emission. An older age of 40 kyr, together with an electron conversion efficiency of 0.14 and advective flow of E = 0.0022, can reproduce the observed multi-wavelengh emission towards HESS J1825-137. A turbulent ISM with magnetic field of B=20 μG to 60 μG to the north of HESS J1825-137 (as suggested by ISM observations) is required to prevent significant gamma-ray contamination towards the northern TeV source HESS J1826-130.
{"title":"A 3D Diffusive and Advective Model of Electron Transport Applied to the Pulsar Wind Nebula HESS J1825-137","authors":"T Collins, G Rowell, S Einecke, F Voisin, Y Fukui, H Sano","doi":"10.1093/mnras/stae139","DOIUrl":"https://doi.org/10.1093/mnras/stae139","url":null,"abstract":"HESS J1825-137 is one of the most powerful and luminous TeV gamma-ray pulsar wind nebulae (PWNe), making it an excellent laboratory to study particle transportation around pulsars. We present a model of the (diffusive and advective) transport and radiative losses of electrons from the pulsar PSR J1826-1334 powering HESS J1825-137 using interstellar medium gas (ISM) data, soft photon fields and a spatially varying magnetic field.We find that for the characteristic age of 21 kyr, PSR J1826-1334 is unable to meet the energy requirements to match the observed X-ray and gamma-ray emission. An older age of 40 kyr, together with an electron conversion efficiency of 0.14 and advective flow of E = 0.0022, can reproduce the observed multi-wavelengh emission towards HESS J1825-137. A turbulent ISM with magnetic field of B=20 μG to 60 μG to the north of HESS J1825-137 (as suggested by ISM observations) is required to prevent significant gamma-ray contamination towards the northern TeV source HESS J1826-130.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"88 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rhythm Shimakawa, Jose Manuel Pérez-Martínez, Yusei Koyama, Masayuki Tanaka, Ichi Tanaka, Tadayuki Kodama, Nina A Hatch, Huub J A Röttgering, Helmut Dannerbauer, Jaron D Kurk
As a considerable investment of time from various telescope facilities were dedicated toward studying the Spiderweb protocluster at z = 2.2, it so far remains one of the most extensively studied protocluster. We report here the latest results in this field, adding a new dimension to previous research on cluster formation at high redshift. Previous studies have reported a significant overdensity (δ ∼ 10) of massive Hα (+ [N ii]) -emitting galaxies in 3700 comoving Mpc3. Many of these were previously considered to be dusty, actively star-forming galaxies, given their rest-frame optical and infrared features. However, this study argues that a third of them are more likely to be “passively-evolving” galaxies with low-luminosity active galactic nuclei (AGNs) rather than star-forming galaxies, given the multi-wavelength spectral energy distribution (SED) fitting including an AGN component. For their SED-based star formation rates to be valid, bulk of their Hα + [N ii] emission should come from the central AGNs. This difference in interpretation between this work and past studies, including ours, is particularly supported by the recent deep Chandra/X-ray observation. Furthermore, we have spectroscopically confirmed a quiescent nature for one of these AGNs, with its multiple stellar absorption lines but also low ionisation emission lines. This important update provides new insights into the role of AGNs in forming the cluster red sequence observed in the present-day universe.
{"title":"New insights into the role of AGNs in forming the cluster red sequence","authors":"Rhythm Shimakawa, Jose Manuel Pérez-Martínez, Yusei Koyama, Masayuki Tanaka, Ichi Tanaka, Tadayuki Kodama, Nina A Hatch, Huub J A Röttgering, Helmut Dannerbauer, Jaron D Kurk","doi":"10.1093/mnras/stae118","DOIUrl":"https://doi.org/10.1093/mnras/stae118","url":null,"abstract":"As a considerable investment of time from various telescope facilities were dedicated toward studying the Spiderweb protocluster at z = 2.2, it so far remains one of the most extensively studied protocluster. We report here the latest results in this field, adding a new dimension to previous research on cluster formation at high redshift. Previous studies have reported a significant overdensity (δ ∼ 10) of massive Hα (+ [N ii]) -emitting galaxies in 3700 comoving Mpc3. Many of these were previously considered to be dusty, actively star-forming galaxies, given their rest-frame optical and infrared features. However, this study argues that a third of them are more likely to be “passively-evolving” galaxies with low-luminosity active galactic nuclei (AGNs) rather than star-forming galaxies, given the multi-wavelength spectral energy distribution (SED) fitting including an AGN component. For their SED-based star formation rates to be valid, bulk of their Hα + [N ii] emission should come from the central AGNs. This difference in interpretation between this work and past studies, including ours, is particularly supported by the recent deep Chandra/X-ray observation. Furthermore, we have spectroscopically confirmed a quiescent nature for one of these AGNs, with its multiple stellar absorption lines but also low ionisation emission lines. This important update provides new insights into the role of AGNs in forming the cluster red sequence observed in the present-day universe.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"26 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Supergiant fast X-ray transients are wind-fed binaries hosting neutron star accretors, which display a peculiar variability in the X-ray domain. Different models have been proposed to explain this variability and the strength of the compact object magnetic field is generally considered a key parameter to discriminate among possible scenarios. We present here the analysis of two simultaneous observational campaigns carried out with Swift and NuSTAR targeting the supergiant fast X-ray transient sources AX J1841.0-0536 and SAX J1818.6-1703. A detailed spectral analysis is presented for both sources, with the main goal of hunting for cyclotron resonant scattering features that can provide a direct measurement of the neutron star magnetic field intensity. AX J1841.0-0536 was caught during the observational campaign at a relatively low flux. The source broad-band spectrum was featureless and could be well described by using a combination of a hot blackbody and a power-law component with no measurable cut-off energy. In the case of SAX J1818.6-1703, the broad-band spectrum presented a relatively complex curvature which could be described by an absorbed cut-off power-law (including both a cut-off and a folding energy) and featured a prominent edge at ∼7 keV, compatible with being associated to the presence of a ‘screen’ of neutral material partly obscuring the X-ray source. The fit to the broad-band spectrum also required the addition of a moderately broad (∼1.6 keV) feature centered at ∼14 keV. If interpreted as a cyclotron resonant scattering feature, our results would indicate for SAX J1818.6-1703 a relatively low magnetized neutron star (∼1.2 × 1012 G).
超巨星快速 X 射线瞬变体是寄存有中子星吸积器的风力双星，在 X 射线领域显示出奇特的可变性。人们提出了不同的模型来解释这种变异性，而紧凑天体磁场强度通常被认为是区分各种可能情况的关键参数。我们在此介绍对 Swift 和 NuSTAR 针对超巨型快速 X 射线瞬变源 AX J1841.0-0536 和 SAX J1818.6-1703 同时进行的两次观测活动的分析。本文对这两个源进行了详细的光谱分析，主要目的是寻找回旋共振散射特征，从而直接测量中子星的磁场强度。AX J1841.0-0536 是在观测活动期间以相对较低的磁通量捕获到的。源宽带光谱没有特征，可以用热黑体和幂律分量（没有可测量的截止能量）的组合来很好地描述。在 SAX J1818.6-1703 的情况下，宽带光谱呈现出相对复杂的曲率，可以用吸收截止幂律（包括截止能量和折叠能量）来描述，并在∼7 keV 处有一个突出的边缘，这与部分遮挡 X 射线源的中性物质 "屏幕 "的存在有关。为了拟合宽波段光谱，还需要增加一个中等宽（∼1.6 keV）的特征，其中心为∼14 keV。如果将其解释为回旋共振散射特征，我们的结果将表明 SAX J1818.6-1703 是一颗磁化率相对较低的中子星（∼1.2 × 1012 G）。
{"title":"NuSTAR and Swift observations of two supergiant fast X-ray transients: AX J1841.0-0536 and SAX J1818.6-1703","authors":"E Bozzo, C Ferrigno, P Romano","doi":"10.1093/mnras/stae061","DOIUrl":"https://doi.org/10.1093/mnras/stae061","url":null,"abstract":"Supergiant fast X-ray transients are wind-fed binaries hosting neutron star accretors, which display a peculiar variability in the X-ray domain. Different models have been proposed to explain this variability and the strength of the compact object magnetic field is generally considered a key parameter to discriminate among possible scenarios. We present here the analysis of two simultaneous observational campaigns carried out with Swift and NuSTAR targeting the supergiant fast X-ray transient sources AX J1841.0-0536 and SAX J1818.6-1703. A detailed spectral analysis is presented for both sources, with the main goal of hunting for cyclotron resonant scattering features that can provide a direct measurement of the neutron star magnetic field intensity. AX J1841.0-0536 was caught during the observational campaign at a relatively low flux. The source broad-band spectrum was featureless and could be well described by using a combination of a hot blackbody and a power-law component with no measurable cut-off energy. In the case of SAX J1818.6-1703, the broad-band spectrum presented a relatively complex curvature which could be described by an absorbed cut-off power-law (including both a cut-off and a folding energy) and featured a prominent edge at ∼7 keV, compatible with being associated to the presence of a ‘screen’ of neutral material partly obscuring the X-ray source. The fit to the broad-band spectrum also required the addition of a moderately broad (∼1.6 keV) feature centered at ∼14 keV. If interpreted as a cyclotron resonant scattering feature, our results would indicate for SAX J1818.6-1703 a relatively low magnetized neutron star (∼1.2 × 1012 G).","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"249 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It has been claimed that the variability of field quasars resembles gravitational lensing by a large cosmological population of free-floating planets with mass ∼10 M⊕. But Galactic photometric monitoring experiments, on the other hand, exclude a large population of such planetary-mass gravitational lenses. These apparently contradictory pieces of evidence can be reconciled if the objects under consideration have a mean column-density that lies between the critical column-densities for gravitational lensing in these two contexts. Dark matter in that form is known to be weakly collisional, so that a core develops in galaxy halo density profiles, and a preferred model has already been established. Here we consider what such a model implies for Q2237+0305, which is the best-studied example of a quasar that is strongly lensed by an intervening galaxy. We construct microlensing magnification maps appropriate to the four macro-images of the quasar — all of which are seen through the bulge of the galaxy. Each of these maps exhibits a caustic network arising from the stars, plus many small, isolated caustics arising from the free-floating “planets” in the lens galaxy. The “planets” have little influence on the magnification histograms but a large effect on the statistics of the magnification gradients. We compare our predictions to the published OGLE photometry of Q2237+0305 and find that these data are consistent with the presence of the hypothetical “planets”. However, the evidence is relatively weak because the OGLE dataset is not well suited to testing our predictions and requires low-pass filtering for this application. New data from a large, space-based telescope are desirable to address this issue.
{"title":"Free-floating ‘planets’ in the macrolensed quasar Q2237+0305","authors":"Artem V Tuntsov, Geraint F Lewis, Mark A Walker","doi":"10.1093/mnras/stae133","DOIUrl":"https://doi.org/10.1093/mnras/stae133","url":null,"abstract":"It has been claimed that the variability of field quasars resembles gravitational lensing by a large cosmological population of free-floating planets with mass ∼10 M⊕. But Galactic photometric monitoring experiments, on the other hand, exclude a large population of such planetary-mass gravitational lenses. These apparently contradictory pieces of evidence can be reconciled if the objects under consideration have a mean column-density that lies between the critical column-densities for gravitational lensing in these two contexts. Dark matter in that form is known to be weakly collisional, so that a core develops in galaxy halo density profiles, and a preferred model has already been established. Here we consider what such a model implies for Q2237+0305, which is the best-studied example of a quasar that is strongly lensed by an intervening galaxy. We construct microlensing magnification maps appropriate to the four macro-images of the quasar — all of which are seen through the bulge of the galaxy. Each of these maps exhibits a caustic network arising from the stars, plus many small, isolated caustics arising from the free-floating “planets” in the lens galaxy. The “planets” have little influence on the magnification histograms but a large effect on the statistics of the magnification gradients. We compare our predictions to the published OGLE photometry of Q2237+0305 and find that these data are consistent with the presence of the hypothetical “planets”. However, the evidence is relatively weak because the OGLE dataset is not well suited to testing our predictions and requires low-pass filtering for this application. New data from a large, space-based telescope are desirable to address this issue.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"53 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mai Liao, Junxian Wang, Jialai Kang, Xiaofeng Li, Minhua Zhou
Compact radio AGN are thought to be young radio active galactic nuclei (AGN) at the early stage of AGN evolution, thus are ideal laboratory to study the high-energy emission throughout the evolution of radio AGN. In this work, we report for the first time the detection of the high-energy cutoff (Ecut), a direct indicator of thermal coronal radiation, of X-ray emission in Mrk 348 (z = 0.015), a young radio galaxy classified as compact symmetric object. With a 100 ks NuSTAR exposure, we find that the high-energy cutoff (Ecut ) is firmly detected ($218^{+124}_{-62}$ keV). Fitting with various Comptonization models indicates the presence of a hot corona with temperature kTe = 35 – 40 keV. These strongly support the corona origin for its hard X-ray emission. The comparison in the Ecut – spectra index Γ plot of Mrk 348 with normal large-scale radio galaxies (mostly FR II) yields no difference between them. This suggests the corona properties in radio sources may not evolve over time (i.e., from the infant stage to mature stage), which is to-be-confirmed with future sample studies of young radio AGN.
{"title":"The X-ray high-energy cutoff in Compact Symmetric Object Mrk 348","authors":"Mai Liao, Junxian Wang, Jialai Kang, Xiaofeng Li, Minhua Zhou","doi":"10.1093/mnras/stae122","DOIUrl":"https://doi.org/10.1093/mnras/stae122","url":null,"abstract":"Compact radio AGN are thought to be young radio active galactic nuclei (AGN) at the early stage of AGN evolution, thus are ideal laboratory to study the high-energy emission throughout the evolution of radio AGN. In this work, we report for the first time the detection of the high-energy cutoff (Ecut), a direct indicator of thermal coronal radiation, of X-ray emission in Mrk 348 (z = 0.015), a young radio galaxy classified as compact symmetric object. With a 100 ks NuSTAR exposure, we find that the high-energy cutoff (Ecut ) is firmly detected ($218^{+124}_{-62}$ keV). Fitting with various Comptonization models indicates the presence of a hot corona with temperature kTe = 35 – 40 keV. These strongly support the corona origin for its hard X-ray emission. The comparison in the Ecut – spectra index Γ plot of Mrk 348 with normal large-scale radio galaxies (mostly FR II) yields no difference between them. This suggests the corona properties in radio sources may not evolve over time (i.e., from the infant stage to mature stage), which is to-be-confirmed with future sample studies of young radio AGN.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"8 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Here we consider the general radiative transfer theory in a magnetized atmosphere for any value of parameter $x=omega _B/omega simeq 0.933times 10^{-8}lambda (mu mathrm{m}) B(text{G})$, where ωB is the cyclotron frequency of electron rotation and ω is the angular frequency of considered monochromatic radiation. The main term of the radiative transfer equations $textbf {J}_{alpha beta }$ for the Stokes parameters I, V, U and Q describes the scattering of radiation coming from all directions and distances. All Stokes parameters of the incident radiation mutually transform into each other along their path due to interference and different cross-sections for them. To find this transformation of the Stokes parameters one has to solve the complex system of transfer equations without the sources and term $textbf {J}_{alpha beta }$. This is done in our paper. Firstly, we present the general solution and then give the solution for the case of a homogeneous magnetic field, where the formulas have clear algebraic form. We note that for small parameter x our formulas describe the known Faraday rotation. Our formulas allow us to derive an integral equation for the density of polarized radiation, multiple scattered in a magnetized atmosphere for any values of the parameter x. The obtained correct radiation transfer equation allows us to calculate the Stokes parameters of radiation emerging from an atmosphere, in particular, for the Milne problem.
{"title":"General theory of radiative transfer in a magnetized atmosphere with scattering by electrons","authors":"N A Silant’ev, G A Alekseeva, Yu K Ananjevskaja","doi":"10.1093/mnras/stae111","DOIUrl":"https://doi.org/10.1093/mnras/stae111","url":null,"abstract":"Here we consider the general radiative transfer theory in a magnetized atmosphere for any value of parameter $x=omega _B/omega simeq 0.933times 10^{-8}lambda (mu mathrm{m}) B(text{G})$, where ωB is the cyclotron frequency of electron rotation and ω is the angular frequency of considered monochromatic radiation. The main term of the radiative transfer equations $textbf {J}_{alpha beta }$ for the Stokes parameters I, V, U and Q describes the scattering of radiation coming from all directions and distances. All Stokes parameters of the incident radiation mutually transform into each other along their path due to interference and different cross-sections for them. To find this transformation of the Stokes parameters one has to solve the complex system of transfer equations without the sources and term $textbf {J}_{alpha beta }$. This is done in our paper. Firstly, we present the general solution and then give the solution for the case of a homogeneous magnetic field, where the formulas have clear algebraic form. We note that for small parameter x our formulas describe the known Faraday rotation. Our formulas allow us to derive an integral equation for the density of polarized radiation, multiple scattered in a magnetized atmosphere for any values of the parameter x. The obtained correct radiation transfer equation allows us to calculate the Stokes parameters of radiation emerging from an atmosphere, in particular, for the Milne problem.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"5 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139460529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joseph F V Allingham, Céline Bœhm, Dominique Eckert, Mathilde Jauzac, David Lagattuta, Guillaume Mahler, Matt Hilton, Geraint F Lewis, Stefano Ettori
Whilst X-rays and Sunyaev-Zel’dovich observations allow to study the properties of the intra-cluster medium (ICM) of galaxy clusters, their gravitational potential may be constrained using strong gravitational lensing. Although being physically related, these two components are often described with different physical models. Here, we present a unified technique to derive the ICM properties from strong lensing for clusters in hydrostatic equilibrium. In order to derive this model, we present a new universal and self-similar polytropic temperature profile, which we fit using the X-COP sample of clusters. We subsequently derive an analytical model for the electron density, which we apply to strong lensing clusters MACS J0242.5-2132 and MACS J0949.8+1708. We confront the inferred ICM reconstructions to XMM-Newton and ACT observations. We contrast our analytical electron density reconstructions with the best canonical β-model. The ICM reconstructions obtained prove to be compatible with observations. However they appear to be very sensitive to various dark matter halo parameters constrained through strong lensing (such as the core radius), and to the halo scale radius (fixed in the lensing optimisations). With respect to the important baryonic effects, we make the sensitivity on the scale radius of the reconstruction an asset, and use the inferred potential to constrain the dark matter density profile using ICM observations. The technique here developed should allow to take a new, and more holistic path to constrain the content of galaxy clusters.
{"title":"A full reconstruction of two galaxy clusters intra-cluster medium with strong gravitational lensing","authors":"Joseph F V Allingham, Céline Bœhm, Dominique Eckert, Mathilde Jauzac, David Lagattuta, Guillaume Mahler, Matt Hilton, Geraint F Lewis, Stefano Ettori","doi":"10.1093/mnras/stae107","DOIUrl":"https://doi.org/10.1093/mnras/stae107","url":null,"abstract":"Whilst X-rays and Sunyaev-Zel’dovich observations allow to study the properties of the intra-cluster medium (ICM) of galaxy clusters, their gravitational potential may be constrained using strong gravitational lensing. Although being physically related, these two components are often described with different physical models. Here, we present a unified technique to derive the ICM properties from strong lensing for clusters in hydrostatic equilibrium. In order to derive this model, we present a new universal and self-similar polytropic temperature profile, which we fit using the X-COP sample of clusters. We subsequently derive an analytical model for the electron density, which we apply to strong lensing clusters MACS J0242.5-2132 and MACS J0949.8+1708. We confront the inferred ICM reconstructions to XMM-Newton and ACT observations. We contrast our analytical electron density reconstructions with the best canonical β-model. The ICM reconstructions obtained prove to be compatible with observations. However they appear to be very sensitive to various dark matter halo parameters constrained through strong lensing (such as the core radius), and to the halo scale radius (fixed in the lensing optimisations). With respect to the important baryonic effects, we make the sensitivity on the scale radius of the reconstruction an asset, and use the inferred potential to constrain the dark matter density profile using ICM observations. The technique here developed should allow to take a new, and more holistic path to constrain the content of galaxy clusters.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"1 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Attila Moór, Péter Ábrahám, Kate Y L Su, Thomas Henning, Sebastian Marino, Lei Chen, Ágnes Kóspál, Nicole Pawellek, József Varga, Krisztián Vida
Extreme debris discs (EDDs) are bright and warm circumstellar dusty structures around main sequence stars. They may represent the outcome of giant collisions occuring in the terrestrial region between large planetesimals or planetary bodies, and thus provide a rare opportunity to peer into the aftermaths of these events. Here, we report on results of a mini-survey we conducted with the aim to increase the number of known EDDs, investigate the presence of solid-state features around 10 μm in eight EDDs, and classify them into the silica or silicate dominated groups. We identify four new EDDs and derive their fundamental properties. For these, and for four other previously known discs, we study the spectral energy distribution around 10 μm by means of VLT/VISIR photometryin three narrow-band filters and conclude that all eight objects likely exhibit solid-state emission features from sub-micron grains. We find that four discs probably belong to the silicate dominated subgroup. Considering the age distribution of the entire EDD sample, we find that their incidence begins to decrease only after 300 Myr, suggesting that the earlier common picture that these objects are related to the formation of rocky planets may not be exclusive, and that other processes may be involved for older objects (≳100 Myr). Because most of the older EDD systems have wide, eccentric companions, we suggest that binarity may play a role in triggering late giant collisions.
{"title":"Abundant sub-micron grains revealed in newly discovered extreme debris discs","authors":"Attila Moór, Péter Ábrahám, Kate Y L Su, Thomas Henning, Sebastian Marino, Lei Chen, Ágnes Kóspál, Nicole Pawellek, József Varga, Krisztián Vida","doi":"10.1093/mnras/stae155","DOIUrl":"https://doi.org/10.1093/mnras/stae155","url":null,"abstract":"Extreme debris discs (EDDs) are bright and warm circumstellar dusty structures around main sequence stars. They may represent the outcome of giant collisions occuring in the terrestrial region between large planetesimals or planetary bodies, and thus provide a rare opportunity to peer into the aftermaths of these events. Here, we report on results of a mini-survey we conducted with the aim to increase the number of known EDDs, investigate the presence of solid-state features around 10 μm in eight EDDs, and classify them into the silica or silicate dominated groups. We identify four new EDDs and derive their fundamental properties. For these, and for four other previously known discs, we study the spectral energy distribution around 10 μm by means of VLT/VISIR photometryin three narrow-band filters and conclude that all eight objects likely exhibit solid-state emission features from sub-micron grains. We find that four discs probably belong to the silicate dominated subgroup. Considering the age distribution of the entire EDD sample, we find that their incidence begins to decrease only after 300 Myr, suggesting that the earlier common picture that these objects are related to the formation of rocky planets may not be exclusive, and that other processes may be involved for older objects (≳100 Myr). Because most of the older EDD systems have wide, eccentric companions, we suggest that binarity may play a role in triggering late giant collisions.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"41 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Austen Fourkas, Dary Ruíz-Rodríguez, Lee G Mundy, Jonathan P Williams
We present Atacama Large Millimeter/sub-millimeter Array (ALMA) Cycle-5 observations of HBC 494, as well as calculations of the kinematic and dynamic variables which represent the object’s wide-angle bipolar outflows. HBC 494 is a binary FU Orionis type object located in the Orion A molecular cloud. We take advantage of combining the ALMA main array, Atacama Compact Array (ACA), and Total Power (TP) array in order to map HBC 494’s outflows and thus, estimate their kinematic parameters with higher accuracy in comparison to prior publications. We use 12CO, 13CO, C18O, and SO observations to describe the object’s outflows, envelope, and disc, as well as estimate the mass, momentum, and kinetic energy of the outflows. After correcting for optical opacity near systemic velocities, we estimate a mass of 3.0 × 10−2 M⊙ for the southern outflow and 2.8 × 10−2 M⊙ for northern outflow. We report the first detection of a secondary outflow cavity located approximately 15″ north of the central binary system, which could be a remnant of a previous large-scale accretion outburst. Furthermore, we find CO spatial features in HBC 494’s outflows corresponding to position angles of ∼35○ and ∼145○. This suggests that HBC 494’s outflows are most likely a composite of overlapping outflows from two different sources, i.e., HBC 494a and HBC 494b, the two objects in the binary system.
我们介绍了阿塔卡马大型毫米波/亚毫米波阵列（ALMA）对HBC 494的第5周期观测结果，以及代表该天体广角双极外流的运动学和动力学变量的计算结果。HBC 494 是位于猎户座 A 分子云中的猎户座 FU 型双星。我们利用 ALMA 主阵列、阿塔卡马紧凑阵列（ACA）和全功率（TP）阵列的组合优势，绘制了 HBC 494 的外流图，从而比以前的出版物更精确地估算了其运动学参数。我们利用 12CO、13CO、C18O 和 SO 观测数据来描述该天体的外流、包膜和圆盘，并估算外流的质量、动量和动能。在校正了系统速度附近的光学不透明度之后，我们估计南侧外流的质量为 3.0 × 10-2 M⊙，北侧外流的质量为 2.8 × 10-2 M⊙。我们首次探测到了位于中央双星系统以北约15″处的次级流出腔，它可能是先前大规模吸积爆发的残余物。此外，我们还在 HBC 494 的外流中发现了 CO 空间特征，其位置角分别为 ∼35○和 ∼145○。这表明，HBC 494 的外溢流很可能是来自两个不同来源的重叠外溢流的复合体，即双星系统中的两个天体 HBC 494a 和 HBC 494b。
{"title":"The kinematic and dynamic properties of HBC 494’s wide-angle outflows","authors":"Austen Fourkas, Dary Ruíz-Rodríguez, Lee G Mundy, Jonathan P Williams","doi":"10.1093/mnras/stae085","DOIUrl":"https://doi.org/10.1093/mnras/stae085","url":null,"abstract":"We present Atacama Large Millimeter/sub-millimeter Array (ALMA) Cycle-5 observations of HBC 494, as well as calculations of the kinematic and dynamic variables which represent the object’s wide-angle bipolar outflows. HBC 494 is a binary FU Orionis type object located in the Orion A molecular cloud. We take advantage of combining the ALMA main array, Atacama Compact Array (ACA), and Total Power (TP) array in order to map HBC 494’s outflows and thus, estimate their kinematic parameters with higher accuracy in comparison to prior publications. We use 12CO, 13CO, C18O, and SO observations to describe the object’s outflows, envelope, and disc, as well as estimate the mass, momentum, and kinetic energy of the outflows. After correcting for optical opacity near systemic velocities, we estimate a mass of 3.0 × 10−2 M⊙ for the southern outflow and 2.8 × 10−2 M⊙ for northern outflow. We report the first detection of a secondary outflow cavity located approximately 15″ north of the central binary system, which could be a remnant of a previous large-scale accretion outburst. Furthermore, we find CO spatial features in HBC 494’s outflows corresponding to position angles of ∼35○ and ∼145○. This suggests that HBC 494’s outflows are most likely a composite of overlapping outflows from two different sources, i.e., HBC 494a and HBC 494b, the two objects in the binary system.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"82 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J Hoffmann, C W James, H Qiu, M Glowacki, K W Bannister, V Gupta, J X Prochaska, A Bera, A T Deller, K Gourdji, L Marnoch, S D Ryder, D R Scott, R M Shannon, N Tejos
Fast radio bursts (FRBs) are transient radio signals of extragalactic origins that are subjected to propagation effects such as dispersion and scattering. It follows then that these signals hold information regarding the medium they have traversed and are hence useful as cosmological probes of the Universe. Recently, FRBs were used to make an independent measure of the Hubble Constant H0, promising to resolve the Hubble tension given a sufficient number of detected FRBs. Such cosmological studies are dependent on FRB population statistics, cosmological parameters and detection biases, and thus it is important to accurately characterise each of these. In this work, we empirically characterise the sensitivity of the Fast Real-time Engine for Dedispersing Amplitudes (FREDDA) which is the current detection system for the Australian Square Kilometer Array Pathfinder (ASKAP). We coherently redisperse high-time resolution data of 13 ASKAP-detected FRBs and inject them into FREDDA to determine the recovered signal-to-noise ratios as a function of dispersion measure (DM). We find that for 11 of the 13 FRBs, these results are consistent with injecting idealised pulses. Approximating this sensitivity function with theoretical predictions results in a systematic error of 0.3 km s−1 Mpc−1 on H0 when it is the only free parameter. Allowing additional parameters to vary could increase this systematic by up to ∼1 km s−1 Mpc−1. We estimate that this systematic will not be relevant until ∼400 localised FRBs have been detected, but will likely be significant in resolving the Hubble tension.
{"title":"The impact of the FREDDA dedispersion algorithm on H0 estimations with FRBs","authors":"J Hoffmann, C W James, H Qiu, M Glowacki, K W Bannister, V Gupta, J X Prochaska, A Bera, A T Deller, K Gourdji, L Marnoch, S D Ryder, D R Scott, R M Shannon, N Tejos","doi":"10.1093/mnras/stae131","DOIUrl":"https://doi.org/10.1093/mnras/stae131","url":null,"abstract":"Fast radio bursts (FRBs) are transient radio signals of extragalactic origins that are subjected to propagation effects such as dispersion and scattering. It follows then that these signals hold information regarding the medium they have traversed and are hence useful as cosmological probes of the Universe. Recently, FRBs were used to make an independent measure of the Hubble Constant H0, promising to resolve the Hubble tension given a sufficient number of detected FRBs. Such cosmological studies are dependent on FRB population statistics, cosmological parameters and detection biases, and thus it is important to accurately characterise each of these. In this work, we empirically characterise the sensitivity of the Fast Real-time Engine for Dedispersing Amplitudes (FREDDA) which is the current detection system for the Australian Square Kilometer Array Pathfinder (ASKAP). We coherently redisperse high-time resolution data of 13 ASKAP-detected FRBs and inject them into FREDDA to determine the recovered signal-to-noise ratios as a function of dispersion measure (DM). We find that for 11 of the 13 FRBs, these results are consistent with injecting idealised pulses. Approximating this sensitivity function with theoretical predictions results in a systematic error of 0.3 km s−1 Mpc−1 on H0 when it is the only free parameter. Allowing additional parameters to vary could increase this systematic by up to ∼1 km s−1 Mpc−1. We estimate that this systematic will not be relevant until ∼400 localised FRBs have been detected, but will likely be significant in resolving the Hubble tension.","PeriodicalId":18930,"journal":{"name":"Monthly Notices of the Royal Astronomical Society","volume":"6 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139459612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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