Pub Date : 2020-08-31DOI: 10.1103/physrevc.102.055807
T. Fischer, S. Typel, G. Röpke, N. Bastian, G. Mart'inez-Pinedo
The present article investigates the role of heavy nuclear clusters and weakly bound light nuclear clusters based on a newly developed equation of state for core collapse supernova studies. A novel approach is brought forward for the description of nuclear clusters, taking into account the quasiparticle approach and continuum correlations. It demonstrates that the commonly employed nuclear statistical equilibrium approach, based on non-interacting particles, for the description of light and heavy clusters becomes invalid for warm nuclear matter near the saturation density. This has important consequences for studies of core collapse supernovae. To this end, we implement this nuclear equation of state provided for arbitrary temperature, baryon density and isospin asymmetry, to spherically symmetric core collapse supernova simulations in order to study the impact on the dynamics as well as on the neutrino emission. For the inclusion of a set of weak processes involving light clusters the rate expressions are derived, including medium modifications at the mean field level. A substantial impact from the inclusion of a variety of weak reactions involving light clusters on the post bounce dynamics nor on the neutrino emission could not be found.
{"title":"Medium modifications for light and heavy nuclear clusters in simulations of core collapse supernovae: Impact on equation of state and weak interactions","authors":"T. Fischer, S. Typel, G. Röpke, N. Bastian, G. Mart'inez-Pinedo","doi":"10.1103/physrevc.102.055807","DOIUrl":"https://doi.org/10.1103/physrevc.102.055807","url":null,"abstract":"The present article investigates the role of heavy nuclear clusters and weakly bound light nuclear clusters based on a newly developed equation of state for core collapse supernova studies. A novel approach is brought forward for the description of nuclear clusters, taking into account the quasiparticle approach and continuum correlations. It demonstrates that the commonly employed nuclear statistical equilibrium approach, based on non-interacting particles, for the description of light and heavy clusters becomes invalid for warm nuclear matter near the saturation density. This has important consequences for studies of core collapse supernovae. To this end, we implement this nuclear equation of state provided for arbitrary temperature, baryon density and isospin asymmetry, to spherically symmetric core collapse supernova simulations in order to study the impact on the dynamics as well as on the neutrino emission. For the inclusion of a set of weak processes involving light clusters the rate expressions are derived, including medium modifications at the mean field level. A substantial impact from the inclusion of a variety of weak reactions involving light clusters on the post bounce dynamics nor on the neutrino emission could not be found.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75536051","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}
The observed X-ray pulse period of OB-type high-mass X-ray binary (HMXB) pulsars are typically longer than 100 seconds. It is considered that the interaction between the strong magnetic field of neutron star and the wind matter could cause such a long pulse period. In this study, we follow the spin evolution of NS, taking into account the interaction between the magnetic field and wind matter. In this line, as new challenges, we solve the evolution of the magnetic field of the neutron star at the same time, and additionally we focus on the effects of wind properties of the donor. As the result, evolutionary tracks were obtained in which the neutron star spends some duration in the ejector phase after birth, then rapidly spins down, becomes quasi-equilibrium, and gradually spins up. Such evolution is similar to previous studies, but we found that its dominant physics depends on the velocity of the donor wind. When the wind velocity is fast, the spin-down occurs due to magnetic inhibition, while the classical propeller effect and settling accretion shell causes rapid spin-down in the slow wind accretion. Since the wind velocity of the donor could depend on the irradiated X-ray luminosity, the spin evolution track of the neutron star in wind-fed HMXB could be more complicated than considered.
{"title":"Spin evolution of neutron stars in wind-fed high-mass X-ray binaries","authors":"S. Karino","doi":"10.1093/pasj/psaa087","DOIUrl":"https://doi.org/10.1093/pasj/psaa087","url":null,"abstract":"The observed X-ray pulse period of OB-type high-mass X-ray binary (HMXB) pulsars are typically longer than 100 seconds. It is considered that the interaction between the strong magnetic field of neutron star and the wind matter could cause such a long pulse period. \u0000In this study, we follow the spin evolution of NS, taking into account the interaction between the magnetic field and wind matter. In this line, as new challenges, we solve the evolution of the magnetic field of the neutron star at the same time, and additionally we focus on the effects of wind properties of the donor. As the result, evolutionary tracks were obtained in which the neutron star spends some duration in the ejector phase after birth, then rapidly spins down, becomes quasi-equilibrium, and gradually spins up. Such evolution is similar to previous studies, but we found that its dominant physics depends on the velocity of the donor wind. When the wind velocity is fast, the spin-down occurs due to magnetic inhibition, while the classical propeller effect and settling accretion shell causes rapid spin-down in the slow wind accretion. Since the wind velocity of the donor could depend on the irradiated X-ray luminosity, the spin evolution track of the neutron star in wind-fed HMXB could be more complicated than considered.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89573935","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 : 2020-08-24DOI: 10.1103/physrevd.102.081501
R. Buscicchio, C. Moore, G. Pratten, P. Schmidt, A. Vecchio
Gravitational wave (GW) transients from binary neutron star (BNS) coalescences can, in principle, be subject to gravitational lensing thereby increasing the amplitude and signal-to-noise ratio. We estimate the rate of lensed BNS events resolvable by LIGO and Virgo and find that it is constrained by the current non-detection of a stochastic GW background. Following closely the formalism we developed previously (arXiv:2006.04516v2 [this http URL]) in the context of binary black hole lensing, we show that at current sensitivities the fraction of BNS coalescences with lensing magnifications $mu> 1.02$ is less than $sim 7times 10^{-8}$ and therefore such events should not be expected in the near future. We also make predictions for projected future sensitivities.
{"title":"Constraining the lensing of binary neutron stars from their stochastic background","authors":"R. Buscicchio, C. Moore, G. Pratten, P. Schmidt, A. Vecchio","doi":"10.1103/physrevd.102.081501","DOIUrl":"https://doi.org/10.1103/physrevd.102.081501","url":null,"abstract":"Gravitational wave (GW) transients from binary neutron star (BNS) coalescences can, in principle, be subject to gravitational lensing thereby increasing the amplitude and signal-to-noise ratio. We estimate the rate of lensed BNS events resolvable by LIGO and Virgo and find that it is constrained by the current non-detection of a stochastic GW background. Following closely the formalism we developed previously (arXiv:2006.04516v2 [this http URL]) in the context of binary black hole lensing, we show that at current sensitivities the fraction of BNS coalescences with lensing magnifications $mu> 1.02$ is less than $sim 7times 10^{-8}$ and therefore such events should not be expected in the near future. We also make predictions for projected future sensitivities.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"17 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82569973","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 : 2020-08-19DOI: 10.1103/physrevd.102.123003
C. Thorpe-Morgan, D. Malyshev, A. Santangelo, J. Jochum, B. Jäger, M. Sasaki, S. Saeedi
Through a series of simulated observations, we investigate the capability of the instruments aboard the forthcoming THESEUS mission for the detection of a characteristic signal from decaying dark matter (DM) in the keV-MeV energy range. We focus our studies on three well studied Standard Model extensions hosting axion-like particles, dark photon, and sterile neutrino DM candidates. We show that, due to the sensitivity of THESEUS' X and Gamma Imaging Spectrometer (XGIS) instrument, existing constraints on dark matter parameters can be improved by a factor of up to around 300, depending on the considered DM model and assuming a zero level of systematic uncertainty. We also show that even a minimal level of systematic uncertainty of 1% can impair potential constraints by one to two orders of magnitude. We argue that nonetheless, the constraints imposed by THESEUS will be substantially better than existing ones and will well complement the constraints of upcoming missions such as eXTP and Athena. Ultimately, the limits imposed by THESEUS and future missions will ensure a robust and thorough coverage of the parameter space for decaying DM models, enabling either a detection of dark matter or a significant improvement of relevant limits.
{"title":"THESEUS insights into axionlike particles, dark photon, and sterile neutrino dark matter","authors":"C. Thorpe-Morgan, D. Malyshev, A. Santangelo, J. Jochum, B. Jäger, M. Sasaki, S. Saeedi","doi":"10.1103/physrevd.102.123003","DOIUrl":"https://doi.org/10.1103/physrevd.102.123003","url":null,"abstract":"Through a series of simulated observations, we investigate the capability of the instruments aboard the forthcoming THESEUS mission for the detection of a characteristic signal from decaying dark matter (DM) in the keV-MeV energy range. We focus our studies on three well studied Standard Model extensions hosting axion-like particles, dark photon, and sterile neutrino DM candidates. We show that, due to the sensitivity of THESEUS' X and Gamma Imaging Spectrometer (XGIS) instrument, existing constraints on dark matter parameters can be improved by a factor of up to around 300, depending on the considered DM model and assuming a zero level of systematic uncertainty. We also show that even a minimal level of systematic uncertainty of 1% can impair potential constraints by one to two orders of magnitude. We argue that nonetheless, the constraints imposed by THESEUS will be substantially better than existing ones and will well complement the constraints of upcoming missions such as eXTP and Athena. Ultimately, the limits imposed by THESEUS and future missions will ensure a robust and thorough coverage of the parameter space for decaying DM models, enabling either a detection of dark matter or a significant improvement of relevant limits.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90966470","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}
A. Jana, A. Chatterjee, N. Kumari, P. Nandi, S. Naik, D. Patra
We present the results obtained from a detailed X-ray timing and spectral analysis of Seyfert 2 galaxy NGC 6300 by using observations with the {it Suzaku}, {it Chandra} and {it NuSTAR} observatories between 2007 and 2016. We calculate variance, rms fractional variability of the source in different energy bands and find variabilities in various energy bands. Spectral properties of the source are studied by using various phenomenological and physical models. The properties of the Compton clouds, reflection, Fe K$alpha$ line emission and soft X-ray excess are studied in detail. Several physical parameters of the source are extracted and investigated to establish the presence/absence of any correlation between them. We also investigate the nature of the circumnuclear `torus' and find that the torus is not uniform, rather clumpy. The observed changes in the line-of-sight column density can be explained in terms of transiting clouds. The iron line emitting region is found to be different in the different epoch of observations. We also observe that the torus and the nucleus independently evolve over the years.
{"title":"Probing the nuclear and circumnuclear properties of NGC 6300 using X-ray observations","authors":"A. Jana, A. Chatterjee, N. Kumari, P. Nandi, S. Naik, D. Patra","doi":"10.1093/mnras/staa2552","DOIUrl":"https://doi.org/10.1093/mnras/staa2552","url":null,"abstract":"We present the results obtained from a detailed X-ray timing and spectral analysis of Seyfert 2 galaxy NGC 6300 by using observations with the {it Suzaku}, {it Chandra} and {it NuSTAR} observatories between 2007 and 2016. We calculate variance, rms fractional variability of the source in different energy bands and find variabilities in various energy bands. Spectral properties of the source are studied by using various phenomenological and physical models. The properties of the Compton clouds, reflection, Fe K$alpha$ line emission and soft X-ray excess are studied in detail. Several physical parameters of the source are extracted and investigated to establish the presence/absence of any correlation between them. We also investigate the nature of the circumnuclear `torus' and find that the torus is not uniform, rather clumpy. The observed changes in the line-of-sight column density can be explained in terms of transiting clouds. The iron line emitting region is found to be different in the different epoch of observations. We also observe that the torus and the nucleus independently evolve over the years.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85484436","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 : 2020-08-12DOI: 10.1103/PHYSREVD.103.063038
Hector O. Silva, G. Pappas, N. Yunes, Kent Yagi
The Neutron star Interior Composition Explorer (NICER) is currently observing the x-ray pulse profiles emitted by hot spots on the surface of rotating neutron stars allowing for an inference of their radii with unprecedented precision. A critical ingredient in the pulse profile model is an analytical formula for the oblate shape of the star. These formulas require a fitting over a large ensemble of neutron star solutions, which cover a wide set of equations of state, stellar compactnesses and rotational frequencies. However, this procedure introduces a source of systematic error, as (i) the fits do not describe perfectly the surface of all stars in the ensemble and (ii) neutron stars are described by a single equation of state, whose influence on the surface shape is averaged out during the fitting procedure. Here we perform a first study of this systematic error, finding evidence that it is subdominant relative to the statistical error in the radius inference by NICER. We also find evidence that the formula currently used by NICER can be used in the inference of the radii of rapidly rotating stars, outside of the formula's domain of validity. Moreover, we employ an accurate enthalpy-based method to locate the surface of numerical solutions of rapidly rotating neutron stars and a new highly-accurate formula to describe their surfaces. These results can be used in applications that require an accurate description of oblate surfaces of rapidly rotating neutron stars.
{"title":"Surface of rapidly-rotating neutron stars: Implications to neutron star parameter estimation","authors":"Hector O. Silva, G. Pappas, N. Yunes, Kent Yagi","doi":"10.1103/PHYSREVD.103.063038","DOIUrl":"https://doi.org/10.1103/PHYSREVD.103.063038","url":null,"abstract":"The Neutron star Interior Composition Explorer (NICER) is currently observing the x-ray pulse profiles emitted by hot spots on the surface of rotating neutron stars allowing for an inference of their radii with unprecedented precision. A critical ingredient in the pulse profile model is an analytical formula for the oblate shape of the star. These formulas require a fitting over a large ensemble of neutron star solutions, which cover a wide set of equations of state, stellar compactnesses and rotational frequencies. However, this procedure introduces a source of systematic error, as (i) the fits do not describe perfectly the surface of all stars in the ensemble and (ii) neutron stars are described by a single equation of state, whose influence on the surface shape is averaged out during the fitting procedure. Here we perform a first study of this systematic error, finding evidence that it is subdominant relative to the statistical error in the radius inference by NICER. We also find evidence that the formula currently used by NICER can be used in the inference of the radii of rapidly rotating stars, outside of the formula's domain of validity. Moreover, we employ an accurate enthalpy-based method to locate the surface of numerical solutions of rapidly rotating neutron stars and a new highly-accurate formula to describe their surfaces. These results can be used in applications that require an accurate description of oblate surfaces of rapidly rotating neutron stars.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75129443","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}
In this dissertation, we estimate the population of different classes of BNS systems that are visible to gravitational-wave observatories. Given that no ultra-compact BNS systems have been discovered in pulsar radio surveys, we place a 95% confidence upper limit of $sim$850 and $sim$1100 ultra-compact neutron star--white dwarf and double neutron star (DNS) systems that are beaming towards the Earth, respectively. We show that among all of the current radio pulsar surveys, the ones at the Arecibo radio telescope have the best chance of detecting an ultra-compact BNS system. We also show that adopting a survey integration time of $t_{rm int} sim 1$~min will maximize the signal-to-noise ratio, and thus, the probability of detecting an ultra-compact BNS system. Similarly, we use the sample of nine observed DNS systems to derive a Galactic DNS merger rate of $mathcal{R}_{rm MW} = 37^{+24}_{-11}$~Myr$^{-1}$, where the errors represent 90% confidence intervals. Extrapolating this rate to the observable volume for LIGO, we derive a merger detection rate of $mathcal{R} = 1.9^{+1.2}_{-0.6} times left(D_{rm r}/100 rm Mpc right)^3 rm yr^{-1}$, where $D_{rm r}$ is the range distance for LIGO. This rate is consistent with that derived using the DNS mergers observed by LIGO. Finally, we measure the sense of rotation of the older millisecond pulsar, pulsar A, in the DNS J0737--3039 system and find that it rotates prograde with respect to its orbit. This is the first direct measurement of the sense of rotation of a pulsar and a direct confirmation of the rotating lighthouse model for pulsars. This result confirms that the spin angular momentum vector is closely aligned with the orbital angular momentum, suggesting that kick of the supernova producing the second born pulsar J0737--3039B was small.
{"title":"Modeling the Galactic Compact Binary Neutron Star Population and Studying the Double Pulsar System","authors":"N. Pol","doi":"10.33915/etd.7691","DOIUrl":"https://doi.org/10.33915/etd.7691","url":null,"abstract":"In this dissertation, we estimate the population of different classes of BNS systems that are visible to gravitational-wave observatories. Given that no ultra-compact BNS systems have been discovered in pulsar radio surveys, we place a 95% confidence upper limit of $sim$850 and $sim$1100 ultra-compact neutron star--white dwarf and double neutron star (DNS) systems that are beaming towards the Earth, respectively. We show that among all of the current radio pulsar surveys, the ones at the Arecibo radio telescope have the best chance of detecting an ultra-compact BNS system. We also show that adopting a survey integration time of $t_{rm int} sim 1$~min will maximize the signal-to-noise ratio, and thus, the probability of detecting an ultra-compact BNS system. Similarly, we use the sample of nine observed DNS systems to derive a Galactic DNS merger rate of $mathcal{R}_{rm MW} = 37^{+24}_{-11}$~Myr$^{-1}$, where the errors represent 90% confidence intervals. Extrapolating this rate to the observable volume for LIGO, we derive a merger detection rate of $mathcal{R} = 1.9^{+1.2}_{-0.6} times left(D_{rm r}/100 rm Mpc right)^3 rm yr^{-1}$, where $D_{rm r}$ is the range distance for LIGO. This rate is consistent with that derived using the DNS mergers observed by LIGO. Finally, we measure the sense of rotation of the older millisecond pulsar, pulsar A, in the DNS J0737--3039 system and find that it rotates prograde with respect to its orbit. This is the first direct measurement of the sense of rotation of a pulsar and a direct confirmation of the rotating lighthouse model for pulsars. This result confirms that the spin angular momentum vector is closely aligned with the orbital angular momentum, suggesting that kick of the supernova producing the second born pulsar J0737--3039B was small.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76652432","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 : 2020-08-05DOI: 10.1103/PhysRevD.103.103024
M. Chan, K. Hayama
The circular polarisation of gravitational waves from core collapse supernovae has been proposed as a probe to investigate the rotation and physical features inside the core of the supernovae. However, it is still unclear as to how detectable the circular polarisation of gravitational waves will be. We developed an algorithm referred to as the Stokes Circular Polarisation algorithm for the computation of the Stokes parameters that works with the burst search pipeline coherent WaveBurst. Employing the waveform SFHx and the algorithm, we estimate the detectability of the circular polarisation signatures (V mode of the Stokes parameters) for sources across the sky at three different distances 2, 5, and 10 kpc, for a network of gravitational wave detectors consisted of advanced LIGO, advanced VIRGO and KAGRA. Using the Bayes factor, we found that for 2 kpc and 5 kpc, the majority of the sources (99.9% and 58.2% respectively) will have their V mode detectable, while for 10 kpc, no significant V mode is detectable. In addition, the significance of the V mode signature are consistent with the recoverability of the two polarisations of gravitational waves with respect to the network.
{"title":"Estimate of the detectability of the circular polarization signature of supernova gravitational waves using the Stokes parameters","authors":"M. Chan, K. Hayama","doi":"10.1103/PhysRevD.103.103024","DOIUrl":"https://doi.org/10.1103/PhysRevD.103.103024","url":null,"abstract":"The circular polarisation of gravitational waves from core collapse supernovae has been proposed as a probe to investigate the rotation and physical features inside the core of the supernovae. However, it is still unclear as to how detectable the circular polarisation of gravitational waves will be. We developed an algorithm referred to as the Stokes Circular Polarisation algorithm for the computation of the Stokes parameters that works with the burst search pipeline coherent WaveBurst. Employing the waveform SFHx and the algorithm, we estimate the detectability of the circular polarisation signatures (V mode of the Stokes parameters) for sources across the sky at three different distances 2, 5, and 10 kpc, for a network of gravitational wave detectors consisted of advanced LIGO, advanced VIRGO and KAGRA. Using the Bayes factor, we found that for 2 kpc and 5 kpc, the majority of the sources (99.9% and 58.2% respectively) will have their V mode detectable, while for 10 kpc, no significant V mode is detectable. In addition, the significance of the V mode signature are consistent with the recoverability of the two polarisations of gravitational waves with respect to the network.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73039331","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}
Recent studies of the effects on the Earth's atmosphere by astrophysical sources, such as nearby gamma-ray bursts or supernovae, have shown that these events could lead to severe changes in atmospheric composition. Depletion of ozone, the most notable of these changes, is extremely dangerous to living organisms as any decrease in ozone levels leads to an increase in the irradiance of harmful solar radiation at the Earth's surface. In this work we consider dark matter as an astrophysical source of gamma rays, by the annihilation and decay of WIMPs found within dark compact halo objects known as UltraCompact Minihaloes (UCMHs). We calculate the fluence of gamma rays produced in this way and simulate the resulting changes to terrestrial ozone levels using the Goddard Space Flight Center 2D Atmospheric Model. We also calculate the rate at which such events would occur, using estimates for the mass distribution of these haloes within the Milky Way. We find that the ozone depletion from UCMHs can be significant, and even of similar magnitude to the levels which have been linked to the cause of the Late-Ordovician mass extinction event. However, the probability of such encounters over the Earth's entire history is relatively low. This suggests that, while dark compact objects like UCMHs could have had an impact on the Earth's biosphere, other astrophysical phenomena like gamma-ray bursts or supernovae seem a more likely source of these effects.
{"title":"Gamma-rays from ultracompact minihaloes: effects on the Earth’s atmosphere and links to mass extinction events","authors":"M. Sarkis, G. Beck, B. Thomas","doi":"10.1093/MNRAS/STAB1074","DOIUrl":"https://doi.org/10.1093/MNRAS/STAB1074","url":null,"abstract":"Recent studies of the effects on the Earth's atmosphere by astrophysical sources, such as nearby gamma-ray bursts or supernovae, have shown that these events could lead to severe changes in atmospheric composition. Depletion of ozone, the most notable of these changes, is extremely dangerous to living organisms as any decrease in ozone levels leads to an increase in the irradiance of harmful solar radiation at the Earth's surface. In this work we consider dark matter as an astrophysical source of gamma rays, by the annihilation and decay of WIMPs found within dark compact halo objects known as UltraCompact Minihaloes (UCMHs). We calculate the fluence of gamma rays produced in this way and simulate the resulting changes to terrestrial ozone levels using the Goddard Space Flight Center 2D Atmospheric Model. We also calculate the rate at which such events would occur, using estimates for the mass distribution of these haloes within the Milky Way. We find that the ozone depletion from UCMHs can be significant, and even of similar magnitude to the levels which have been linked to the cause of the Late-Ordovician mass extinction event. However, the probability of such encounters over the Earth's entire history is relatively low. This suggests that, while dark compact objects like UCMHs could have had an impact on the Earth's biosphere, other astrophysical phenomena like gamma-ray bursts or supernovae seem a more likely source of these effects.","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85863410","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 : 2020-07-28DOI: 10.5958/0976-5506.2018.02034.X
Hassanen Abdulhussaen Jassim, A. AL-RUBAIEE, I. Al-Alawy
Extensive air showers (EAS) are a cascade of electromagnetic radiation and ionized particles that produced in the atmosphere through the interaction of a primary cosmic ray with the atom of nucleus in the air producing a huge amount of secondary particles such as X-ray, electrons, neutrons, muons, alpha particles, etc. In this work, EAS effects were demonstrated by estimating the lateral distribution function (LDF) at ultrahigh energies of the various cosmic ray particles. The LDF of charged particles such as electron and positron pair production, gamma and muons particles was simulated at ultrahigh energies 10^16, 10^18 and 10^19 eV. The simulation was carried out using an air shower simulator called AIRES system version 2.6.0. The effect of the primary particles, energies and zenith angle on the LDF of charged particles produced in the EAS was taken into account. Comparison of LDF for charged particles and experimental results gave good agreement for electron and positron pair production and muons particles at 10^19 eV for 0 and 10 zenith angles
{"title":"Theoretical Study of Extensive Air Shower Effects in Atmosphere by Simulating the Lateral structure of Several Cosmic Radiations","authors":"Hassanen Abdulhussaen Jassim, A. AL-RUBAIEE, I. Al-Alawy","doi":"10.5958/0976-5506.2018.02034.X","DOIUrl":"https://doi.org/10.5958/0976-5506.2018.02034.X","url":null,"abstract":"Extensive air showers (EAS) are a cascade of electromagnetic radiation and ionized particles that produced in the atmosphere through the interaction of a primary cosmic ray with the atom of nucleus in the air producing a huge amount of secondary particles such as X-ray, electrons, neutrons, muons, alpha particles, etc. In this work, EAS effects were demonstrated by estimating the lateral distribution function (LDF) at ultrahigh energies of the various cosmic ray particles. The LDF of charged particles such as electron and positron pair production, gamma and muons particles was simulated at ultrahigh energies 10^16, 10^18 and 10^19 eV. The simulation was carried out using an air shower simulator called AIRES system version 2.6.0. The effect of the primary particles, energies and zenith angle on the LDF of charged particles produced in the EAS was taken into account. Comparison of LDF for charged particles and experimental results gave good agreement for electron and positron pair production and muons particles at 10^19 eV for 0 and 10 zenith angles","PeriodicalId":8437,"journal":{"name":"arXiv: High Energy Astrophysical Phenomena","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88359881","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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