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The 111 and 129 GeV γ-ray lines from annihilations in the Milky Way dark matter halo, dark disk and subhalos 银河系暗物质晕、暗盘和亚晕中湮灭的111和129 GeV γ射线线
Astronomical Review Pub Date : 2013-03-22 DOI: 10.1080/21672857.2013.11519721
I. Cholis, Haril Nurbiantoro Santosa, M. Tavakoli, P. Ullio
{"title":"The 111 and 129 GeV γ-ray lines from annihilations in the Milky Way dark matter halo, dark disk and subhalos","authors":"I. Cholis, Haril Nurbiantoro Santosa, M. Tavakoli, P. Ullio","doi":"10.1080/21672857.2013.11519721","DOIUrl":"https://doi.org/10.1080/21672857.2013.11519721","url":null,"abstract":"Abstract Recently a series of indicati ons have been put forward suggesting the presence of two γ-ray lines at 110-130 GeV (centered at 111 and 129 GeV). Signals of these lines have been observed toward the Galactic center, at some galaxy clusters and among some of the unassociated point sources of the 2 years Fermi catalogue. Such a combination of signals could be generated by dark matter annihilations in the main dark matter halo, its substructures and nearby galaxy clusters. We discuss in this work the consistency between the number of events observed at the line energies in the sky and the predictions using results from the Via Lactea II nu numerical simulation and extrapolations below its mass resolution, taking into account that the annihilation cross-section to the lines can be estimated from the Galactic center signal. We find that some extrapolations to small substructures can naturally account for the point sources signal, although the hypothesis of background only cannot be rejected. We also study the morphology of the γ-ray sky at the 2 lines energies, testing different Galactic diffuse background models to account for interstellar medium uncertainties and different assumptions on the OM diffuse component profile. We find from template fits that within reasonable diffuse background uncertainties the presence of a spherical halo component is preferred with cuspier dark matter halo profiles being preferable even from the full sky fit. We finally check the impact of a dark disk component suggested by cosmological simulations that include baryons and find that thin dark disks can not be disfavored, thus possibly accounting for the preferentially closer to the Galactic disk distribution of the point sources lines signal.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121944543","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}
引用次数: 0
Hydrogen burning on massive binary white dwarfs: what we know from the observations 氢在大质量双白矮星上燃烧:我们从观测中知道的
Astronomical Review Pub Date : 2013-01-01 DOI: 10.1080/21672857.2013.11519714
M. Orio
{"title":"Hydrogen burning on massive binary white dwarfs: what we know from the observations","authors":"M. Orio","doi":"10.1080/21672857.2013.11519714","DOIUrl":"https://doi.org/10.1080/21672857.2013.11519714","url":null,"abstract":"","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115485202","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}
引用次数: 8
Eight Years of Swift and the Promise and Limitations of GRB High Energy Correlations 八年的雨燕和GRB高能相关性的希望与局限
Astronomical Review Pub Date : 2013-01-01 DOI: 10.1080/21672857.2013.11519716
N. Butler
{"title":"Eight Years of Swift and the Promise and Limitations of GRB High Energy Correlations","authors":"N. Butler","doi":"10.1080/21672857.2013.11519716","DOIUrl":"https://doi.org/10.1080/21672857.2013.11519716","url":null,"abstract":"Abstract I review the use of tantalizing correlations between high energy observables (flux, duration, and hardness) to potentially probe the intrinsic physical properties of GRBs and their host environments. Evidence from 77 GRBs with measured redshifts detected by the Swift experiment (and also from prior missions) suggests that these relations may have more to do with detection properties than physics. However, in the Fermi era, there has been strong use and continued interest in the GRB high energy correlations. Here I update the Swift study using the three times larger current Swift sample. I discuss the extent to which these relations appear to be intrinsic and the promise and limitations for using the relations to study the GRB intrinsic physics and, in particular, whether a common G RB energetics can be assumed in order to use the relations for cosmography. Even if GRBs do imprint information in these relations, separating out sample trends (ie., tendencies of the overall population) to tease out information applicable to one particular GRB (for example to infer its intrinsic flux for use in a Hubble diagram) may be very challenging.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125999896","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}
引用次数: 0
Connection between Gravity and Electromagnetism 重力与电磁学之间的联系
Astronomical Review Pub Date : 2013-01-01 DOI: 10.1080/21672857.2013.11519726
Octavian Balaci
{"title":"Connection between Gravity and Electromagnetism","authors":"Octavian Balaci","doi":"10.1080/21672857.2013.11519726","DOIUrl":"https://doi.org/10.1080/21672857.2013.11519726","url":null,"abstract":"Abstract A theoretical framework is presented which connect the electro-magnetic field with gravity considering the vacuum as a gravitational aether. The space and time are treated as imaginary and independent concepts. The aim is to explain electrodynamics and gravitational phenomena independent by the space-time system and also to better understand the cause of gravitational attraction.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132698341","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}
引用次数: 1
Low Ionization Emission Lines in Quasars: Clues from OI 8446 and the CaII Triplet 类星体中的低电离发射线:来自OI 8446和CaII三重态的线索
Astronomical Review Pub Date : 2013-01-01 DOI: 10.1080/21672857.2013.11519727
P. Marziani, M. Martínez-Aldama, D. Dultzin, J. Sulentic
{"title":"Low Ionization Emission Lines in Quasars: Clues from OI 8446 and the CaII Triplet","authors":"P. Marziani, M. Martínez-Aldama, D. Dultzin, J. Sulentic","doi":"10.1080/21672857.2013.11519727","DOIUrl":"https://doi.org/10.1080/21672857.2013.11519727","url":null,"abstract":"Abstract The formation of low emission lines in quasars and active galactic nuclei is still an open issue. Aided by the organizing power of the 4D eigenvector 1 scheme, we review basic developments since the 1980s, devoting special attention to the CaII IR triplet and the OI 8446 emission lines. Coverage of these lines is cumbersome since they are shifted in an inconvenient IR domain already at modest redshifts ( ≈ 0.2). Their detection is also difficult since they are faint and often buried in the CaII absorption of the host galaxy. We discuss how these lines can provide unambiguous constraints on the physical conditions of the broad line emitting regions of quasars when detected in emission, and summarise preliminary results for a sample of luminous, intermediate redshift quasars.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131737138","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}
引用次数: 1
Testing the space-time geometry around black hole candidates with the available radio and X-ray data 用可用的无线电和x射线数据测试候选黑洞周围的时空几何
Astronomical Review Pub Date : 2013-01-01 DOI: 10.1080/21672857.2013.11519712
C. Bambi
{"title":"Testing the space-time geometry around black hole candidates with the available radio and X-ray data","authors":"C. Bambi","doi":"10.1080/21672857.2013.11519712","DOIUrl":"https://doi.org/10.1080/21672857.2013.11519712","url":null,"abstract":"Abstract Astrophysical black hole candidates are thought to be the Kerr black holes predicted by General Relativity, but the actual nature of these objects has still to be proven. The Kerr black hole hypothesis can be tested by observing strong gravity features and check if they are in agreement with the predictions of General Relativity. In particular, the study of the properties of the electromagnetic radiation emitted by the gas of the accretion disk can provide information on the geometry of the space-time around these objects and constrain possible deviations from the Kerr background.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132710602","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}
引用次数: 32
X-ray morphological estimators for galaxy clusters 星系团的x射线形态估计
Astronomical Review Pub Date : 2012-11-29 DOI: 10.1080/21672857.2013.11519713
E. Rasia, M. Meneghetti, S. Ettori
{"title":"X-ray morphological estimators for galaxy clusters","authors":"E. Rasia, M. Meneghetti, S. Ettori","doi":"10.1080/21672857.2013.11519713","DOIUrl":"https://doi.org/10.1080/21672857.2013.11519713","url":null,"abstract":"Abstract The classification of galaxy clusters according to their X-ray appearance is a powerful tool to discriminate between regular clusters (associated to relaxed objects) and disturbed ones (linked to dynamically active systems). The compilation of the two subsamples is a necessary step both for cosmological studies- oriented towards spherical and virialized systems- and for astrophysical investigations - focused on phenomena typically present in highly disturbed galaxy clusters such as turbulence, particle re-acceleration, magneto-astrophysics. In this paper, we review several morphological parameters: asymmetry and fluctuation of the X-ray surface brightness, hardness ratios, X-ray surface-brightness concentration, centroid shift, and third-order power ratio. We test them against 60 Chandra-like images obtained from hydrodynamical simulations through the X-ray Map Simulator and visually classified as regular and disturbed. The best performances are registered when the parameters are computed using the largest possible region (either within R500 or 1000 kpc). The best indicators are the third-order power ratio, the asymmetry parameter, and the X-ray-surface-brightness concentration. All their combinations offer an efficient way to distinguish between the two morphological classes achieving values of purity extremely close to 1. A new parameter, M, is defined. It combines the strengths of the aforementioned indicators and, therefore, resulted to be the most effective parameter analyzed.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121965099","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}
引用次数: 34
Cosmology with Gamma-Ray Bursts: status and persp ectives 伽玛射线暴宇宙学:现状与展望
Astronomical Review Pub Date : 2012-10-01 DOI: 10.1080/21672857.2013.11519715
L. Amati, M. Valle
{"title":"Cosmology with Gamma-Ray Bursts: status and persp ectives","authors":"L. Amati, M. Valle","doi":"10.1080/21672857.2013.11519715","DOIUrl":"https://doi.org/10.1080/21672857.2013.11519715","url":null,"abstract":"Abstract Given their huge isotropic-equivalent radiated energies, up to more than 1054 erg s-1, and their redshift distribution extending up to more than z = 8, Gamma Ray Bursts (GRB) are in principle a powerful tool for measuring the geometry and expansion rate of the Universe. However, they are not standard candles given that t heir luminosities span several orders of magnitude, even when considering possible collimation angles. In the recent years, several attempts to exploit the correlation between the photon energy at which the νFν spectrum peaks (“peak energy”) and the radiated energy (or luminosity) for “standardizing” G RBs and using t hem as tools, complementary to other probes like SN Ia, BAO and the CMB, for the estimate of cosmological parameters have been made. These studies show that already with the present data set GRBs can provide a significant and independent confirmation of ΩM < 1 (and around ~.25) for a fiat ΛCDM universe and that the measurements expected from present and next GRB experiments (e.g. Swift, Fermi/GBM, SVOM, UFFO) will allow us to constrain ΩM, ΩA, and, in particular, to get clues on dark energy properties and evolution.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132566021","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}
引用次数: 0
Quasar Outflows: in the 4D Eigenvector 1 Context 类星体外流:在4D特征向量1背景下
Astronomical Review Pub Date : 2012-10-01 DOI: 10.1080/21672857.2012.11519710
P. Marziani, Jack W. Sulentict
{"title":"Quasar Outflows: in the 4D Eigenvector 1 Context","authors":"P. Marziani, Jack W. Sulentict","doi":"10.1080/21672857.2012.11519710","DOIUrl":"https://doi.org/10.1080/21672857.2012.11519710","url":null,"abstract":"Abstract Gas outflows appear to be a phenomenon shared by the vast majority of quasars. Observations indicate that there is a wide range in outflow prominence. In this paper, we review how the 4D eigenvector 1 scheme helps to organize observed properties and lead to a meaningful constraint on the outflow physical and dynamical processes.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122195533","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}
引用次数: 10
Cosmology with Gamma-Ray Bursts: status and perspectives. 伽玛射线暴宇宙学:现状与展望。
Astronomical Review Pub Date : 2012-10-01 DOI: 10.1080/21672857.2012.11519711
L. Amati
{"title":"Cosmology with Gamma-Ray Bursts: status and perspectives.","authors":"L. Amati","doi":"10.1080/21672857.2012.11519711","DOIUrl":"https://doi.org/10.1080/21672857.2012.11519711","url":null,"abstract":"Abstract “Given their huge isotropic-equivalent radiated energies, up to more than 1054 erg s−1, and their redshift distribution extending up to more than z = 9, Gamma Ray Bursts (GRB) are in principle a powerful tool for measuring the geometry and expansion rate of the Universe. However, they are not standard candles, given that their luminosities span several orders of magnitude, even when considering possible collimation angles. In the recent years, several attempts to exploit the correlation between the photon energy at which the vFv spectrum peaks (“peak energy”) and the radiated energy (or luminosity) for “standardizing” GRBs and using them as tools, complementary to other probes like SN Ia, BAO and the CMB, for the estimate of cosmological parameters have been made. These studies show that already with the present data set GRBs can provide a significant and independent confirmation of ΩM ~ 0.3 for a flat ACDM universe and that the measurements expected from present and next GRB experiments (e.g. Swift, Fermi/GBM, SVOM) will allow us to constrain ΩM, ΩA and, in particular, to get clues on dark energy properties and evolution.","PeriodicalId":204186,"journal":{"name":"Astronomical Review","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121674195","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}
引用次数: 0
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