International Journal of Astronomy and Astrophysics最新文献_第9页

Static and Dynamic Components of the Redshift 红移的静态和动态分量

International Journal of Astronomy and Astrophysics Pub Date : 2018-08-08 DOI: 10.4236/IJAA.2018.83016

Rajendra P. Gupta

{"title":"Static and Dynamic Components of the Redshift","authors":"Rajendra P. Gupta","doi":"10.4236/IJAA.2018.83016","DOIUrl":"https://doi.org/10.4236/IJAA.2018.83016","url":null,"abstract":"We analyse the possibility that the observed cosmological redshift may be cumulatively due to the expansion of the universe and the tired light phenomenon. Since the source of both the redshifts is the same, they both independently relate to the same proper distance of the light source. Using this approach we have developed a hybrid model combining the Einstein de Sitter model and the tired light model that yields a slightly better fit to Supernovae Ia redshift data using one parameter than the standard ΛCDM model with two parameters. We have shown that the ratio of tired light component to the Einstein de Sitter component of redshift has evolved from 2.5 in the past, corresponding to redshift 1000, to its present value of 1.5. The hybrid model yields Hubble constant H0 =69.11(±0.53)km·s-1 ·Mpc-1 and the deceleration parameter q0 =-0.4. The component of Hubble constant responsible for expansion of the universe is 40% of H0 and for the tired light is 60% of H0. Consequently, the critical density is only 16% of its currently accepted value; a lot less dark matter is needed to make up the critical density. In addition, the best data fit yields the cosmological constant density parameter =0. The tired light effect may thus be considered equivalent to the cosmological constant in the hybrid model.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129082202","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

Possibility of Classical Entanglement at LIGO LIGO经典纠缠的可能性

International Journal of Astronomy and Astrophysics Pub Date : 2018-08-08 DOI: 10.4236/ijaa.2018.83019

P. Ghose, A. Rajagopal

引用次数: 0

Evolution of Angular Momentum and Orbital Period Changes in Close Double White Dwarf Binaries 近距离白矮星双星的角动量演化和轨道周期变化

International Journal of Astronomy and Astrophysics Pub Date : 2018-08-08 DOI: 10.4236/ijaa.2018.83020

S. H. Negu, S. B. Tessema

{"title":"Evolution of Angular Momentum and Orbital Period Changes in Close Double White Dwarf Binaries","authors":"S. H. Negu, S. B. Tessema","doi":"10.4236/ijaa.2018.83020","DOIUrl":"https://doi.org/10.4236/ijaa.2018.83020","url":null,"abstract":"We have presented the evolution of angular momentum and orbital period changes between the component spins and the orbit in close double white dwarf binaries undergoing mass transfer through direct impact accretion over a broad range of orbital parameter space. This work improves upon similar earlier studies in a number of ways: First, we calculate self-consistently the angular momentum of the orbit at all times. This includes gravitational, tides and mass transfer effects in the orbital evolution of the component structure models, and allow the Roche lobe radius of the donor star and the rotational angular velocities of both components to vary, and account for the exchange of angular momentum between the spins of the white dwarfs and the orbit. Second, we investigate the mass transfer by modeling the ballistic motion of a point mass ejected from the center of the donor star through the inner Lagrangian point. Finally, we ensure that the angular momentum is conserved, which requires the donor star spin to vary self-consistently. With these improvements, we calculate the angular momentum and orbital period changes of the orbit and each binary component across the entire parameter space of direct impact double white dwarf binary systems. We find a significant decrease in the amount of angular momentum removed from the orbit during mass transfer, as well as cases where this process increases the angular momentum and orbital period of the orbit at the expense of the spin angular momentum of the donor and accretor. We find that our analysis yields an increase in the predicted number of stable systems compared to that in the previous studies, survive the onset of mass transfer, even if this mass transfer is initially unstable. In addition, as a consequence of the tidal coupling, systems that come into contact near the mass transfer instability boundary undergo a phase of mass transfer with their orbital period.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131338315","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

The Geomagnetic Effects of Solar Activity as Measured at Ouagadougou Station 瓦加杜古站测量太阳活动的地磁效应

International Journal of Astronomy and Astrophysics Pub Date : 2018-05-09 DOI: 10.4236/IJAA.2018.82013

Aristide Marie Frédéric Gyébré, D. A. Gnabahou, F. Ouattara

{"title":"The Geomagnetic Effects of Solar Activity as Measured at Ouagadougou Station","authors":"Aristide Marie Frédéric Gyébré, D. A. Gnabahou, F. Ouattara","doi":"10.4236/IJAA.2018.82013","DOIUrl":"https://doi.org/10.4236/IJAA.2018.82013","url":null,"abstract":"The coronal mass ejections (CMEs) produce by Sun poloidal magnetic fields contribute to geomagnetic storms. The geomagnetic storm effects produced by one-day-shock, two-days-shock and three-days-shock activities on Ouagadougou station F2 layer critical frequency time variation are analyzed. It is found that during the solar minimum and the increasing phases, the shock activity produces both positive and negative storms. The positive storm is observed during daytime. At the solar maximum and the decreasing phases only the positive storm is produced. At the solar minimum there is no three-days-shock activity. During the solar increasing phase the highest amplitude of the storm effect is due to the one-day-shock activity and the lowest is produced by the two-days-shock activity. At the solar maximum phase the ionosphere electric current system is not affected by the shock activity. Nevertheless, the highest amplitude of the storm effect is caused by the two-days-shock activity and the lowest by the one-day-shock activity. During the solar decreasing phase, the highest amplitude provoked by the storm is due to the three-days-shock activity and the lowest by the one-day-shock activity.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114811646","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: 11

The Consequences of a Strengthened Newtonian Gravity at Short Distances 短距离增强牛顿引力的结果

International Journal of Astronomy and Astrophysics Pub Date : 2018-05-09 DOI: 10.4236/ijaa.2018.82014

L. Aghalovyan

引用次数: 1

The Fermi Bubbles as a Superbubble 费米气泡是一个超级气泡

International Journal of Astronomy and Astrophysics Pub Date : 2018-05-09 DOI: 10.4236/ijaa.2018.82015

L. Zaninetti

引用次数: 0

Modeling the Ionosphere during Quiet Time Variation at Ouagadougou in West Africa 西非瓦加杜古静时变化的电离层模拟

International Journal of Astronomy and Astrophysics Pub Date : 2018-05-09 DOI: 10.4236/IJAA.2018.82011

Emmanuel Nanéma, D. A. Gnabahou, Christian Zoundi, F. Ouattara

引用次数: 9

Change in Entropy of Spinning Black Holes Due to Corresponding Change in Mass in XRBs 由XRBs中相应质量变化引起的旋转黑洞熵的变化

International Journal of Astronomy and Astrophysics Pub Date : 2018-05-09 DOI: 10.4236/IJAA.2018.82012

Dipo Mahto, A. Kumari

引用次数: 0

Astronomy and Sun Cult in the Swedish Bronze Age 瑞典青铜时代的天文学和太阳崇拜

International Journal of Astronomy and Astrophysics Pub Date : 2018-05-09 DOI: 10.4236/IJAA.2018.82010

N. Mörner, Bob G. Lind

引用次数: 4

Multiphase ISM in Nearby Early Type Galaxy IC 5063 邻近早型星系IC 5063的多相ISM

International Journal of Astronomy and Astrophysics Pub Date : 2018-02-08 DOI: 10.4236/IJAA.2018.81006

B. T. Tate, A. Kyadampure, S. K. Pandey, M. Patil

{"title":"Multiphase ISM in Nearby Early Type Galaxy IC 5063","authors":"B. T. Tate, A. Kyadampure, S. K. Pandey, M. Patil","doi":"10.4236/IJAA.2018.81006","DOIUrl":"https://doi.org/10.4236/IJAA.2018.81006","url":null,"abstract":"A multiwavelength study of a nearby dust lane early-type galaxy IC 5063 is presented. The objectives are to investigate dust extinction properties and the association of interstellar dust with other phases of ISM. The color-index maps as well as the extinction maps derived from the analysis of deep CCD observations in optical passbands revealed a prominent dust lane along its optical major axis in the inner region. In addition, two more fainter and extended dust patterns are apparent in the color index map as well as extinction maps. These features are also evident in the smooth model subtracted residual maps. The extinction curve derived for this galaxy revealed that dust grains in it are identical to the canonical grains in the Milky Way with the dust grains little larger than the canonical grains. The total extinction measured in the V band extinction map enabled us to quantify the dust content of this galaxy to be equal to , an order of magnitude shorter than that estimated using the IRAS flux densities at 60 and 100 μm. A Multiphase ISM study revealed a surprising similarity in the morphologies of the Hα emitting ionized gas distribution and X-ray emitting gas. Systematic analysis of high resolution X-ray observations using Chandra telescope enabled us to detect 18 discrete X-ray sources within optical D25 region of IC 5063, out of which 17 sources were separated out as the low mass X-ray binaries and one as the high mass X-ray binary source in the X-ray color-color plot.","PeriodicalId":434427,"journal":{"name":"International Journal of Astronomy and Astrophysics","volume":"08 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129398270","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