Universe最新文献_第10页

Surveying the Onset and Evolution of Supermassive Black Holes at High-z with AXIS 用 AXIS 勘测高兹超大质量黑洞的发生与演化

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-25 DOI: 10.3390/universe10070276

Nico Cappelluti, Adi Foord, Stefano Marchesi, Fabio Pacucci, Angelo Ricarte, Melanie Habouzit, Fabio Vito, Meredith Powell, Michael Koss, Richard Mushotzky

{"title":"Surveying the Onset and Evolution of Supermassive Black Holes at High-z with AXIS","authors":"Nico Cappelluti, Adi Foord, Stefano Marchesi, Fabio Pacucci, Angelo Ricarte, Melanie Habouzit, Fabio Vito, Meredith Powell, Michael Koss, Richard Mushotzky","doi":"10.3390/universe10070276","DOIUrl":"https://doi.org/10.3390/universe10070276","url":null,"abstract":"The nature and origin of supermassive black holes (SMBHs) remain an open matter of debate within the scientific community. While various theoretical scenarios have been proposed, each with specific observational signatures, the lack of sufficiently sensitive X-ray observations hinders the progress of observational tests. In this white paper, we present how AXIS will contribute to solving this issue. With an angular resolution of 1.5′′ on-axis and minimal off-axis degradation, we designed a deep survey capable of reaching flux limits in the [0.5–2] keV range of approximately 2 × 10−18 erg s−1 cm−2 over an area of 0.13 deg2 in approximately 7 million seconds (7 Ms). Furthermore, we planned an intermediate depth survey covering approximately 2 deg2 and reaching flux limits of about 2 × 10−17 erg s−1 cm−2 in order to detect a significant number of SMBHs with X-ray luminosities (LX) of approximately 1042 erg s−1 up to z ∼ 10. These observations will enable AXIS to detect SMBHs with masses smaller than 105 M⊙, assuming Eddington-limited accretion and a typical bolometric correction for Type II AGN. AXIS will provide valuable information on the seeding and population synthesis models of SMBHs, allowing for more accurate constraints on their initial mass function (IMF) and accretion history from z∼0–10. To accomplish this, AXIS will leverage the unique synergy of survey telescopes such as the JWST, Roman, Euclid, Vera Rubin Telescope, and the new generation of 30 m class telescopes. These instruments will provide optical identification and redshift measurements, while AXIS will discover the smoking gun of nuclear activity, particularly in the case of highly obscured AGN or peculiar UV spectra as predicted and recently observed by the JWST in the early Universe.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"79 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Fitting the Crab Supernova with a Gamma-Ray Burst 用伽马射线暴拟合蟹状超新星

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-25 DOI: 10.3390/universe10070275

Remo Ruffini, Costantino Sigismondi

引用次数: 0

Serendipitous Discovery of a 431 ms Pulsar in the Background of Westerlund 1 偶然发现维斯特伦德 1 背景中的 431 毫秒脉冲星

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-25 DOI: 10.3390/universe10070274

Viviana Piga, Marta Burgay, Andrea Possenti, Alessandro Ridolfi, Maura Pilia, Nanda Rea, Rosalba Perna, Monica Colpi, Gianluca Israel

引用次数: 0

FLRW Transit Cosmological Model in f(R,T) Gravity f(R,T) 引力下的 FLRW 穿越宇宙学模型

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-24 DOI: 10.3390/universe10070272

Vijay Singh, Siwaphiwe Jokweni, Aroonkumar Beesham

引用次数: 0

The de Sitter Swampland Conjectures in the Context of Chaplygin-Inspired Inflation 查普利金启发的通货膨胀背景下的德西特沼泽地猜想

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-23 DOI: 10.3390/universe10070271

Orfeu Bertolami, Robertus Potting, Paulo M. Sá

引用次数: 0

Non-Minimally Coupled Electromagnetic Fields and Observable Implications for Primordial Black Holes 非微量耦合电磁场及其对原始黑洞的可观测影响

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-22 DOI: 10.3390/universe10070270

Susmita Jana, S. Shankaranarayanan

{"title":"Non-Minimally Coupled Electromagnetic Fields and Observable Implications for Primordial Black Holes","authors":"Susmita Jana, S. Shankaranarayanan","doi":"10.3390/universe10070270","DOIUrl":"https://doi.org/10.3390/universe10070270","url":null,"abstract":"General relativity (GR) postulates have been verified with high precision, yet our understanding of how gravity interacts with matter fields remains incomplete. Various modifications to GR have been proposed in both classical and quantum realms to address these interactions within the strong gravity regime. One such approach is non-minimal coupling (NMC), where the space-time curvature (scalar and tensor) interacts with matter fields, resulting in matter fields not following the geodesics. To probe the astrophysical implications of NMC, in this work, we investigate non-minimally coupled electromagnetic (EM) fields in the presence of black holes. Specifically, we show that primordial black holes (PBHs) provide a possible tool to constrain the NMC parameter. PBHs represent an intriguing cosmological black hole class that does not conform to the no-hair theorem. We model the PBH as a Sultana–Dyer black hole and compare it with Schwarzschild. We examine observables such as the radius of the photon sphere, critical impact parameter, and total deflection angles for non-minimally coupled photons for Schwarzschild and Sultana–Dyer black holes. Both the black hole space-times lead to similar constraints on the NMC parameter. For a PBH of mass M=10−5M⊙, the photon sphere will not be formed for one mode. Hence, the photons forming the photon sphere will be highly polarized, potentially leading to observable implications.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"71 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Effects of Impurities and Deformations on Electronic Effective Mass in Quantum Revival Time within the Infinite Square Well 杂质和变形对无限方井量子复兴时间中电子有效质量的影响

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-20 DOI: 10.3390/universe10060269

Cleverson Filgueiras, Luiz H. C. Borges, Moises Rojas

引用次数: 0

Constraints on the Minimally Extended Varying Speed of Light Model Using Pantheon Dataset+ 利用潘神数据集对最小扩展光速变化模型的约束+

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-19 DOI: 10.3390/universe10060268

Seokcheon Lee

{"title":"Constraints on the Minimally Extended Varying Speed of Light Model Using Pantheon Dataset+","authors":"Seokcheon Lee","doi":"10.3390/universe10060268","DOIUrl":"https://doi.org/10.3390/universe10060268","url":null,"abstract":"In the context of the minimally extended varying speed of light (meVSL) model, both the absolute magnitude and the luminosity distance of type Ia supernovae (SNe Ia) deviate from those predicted by general relativity (GR). Using data from the Pantheon+ survey, we assess the plausibility of various dark energy models within the framework of meVSL. Both the constant equation of state (EoS) of the dark energy model (ωCDM) and the Chevallier–Polarski–Linder (CPL) parameterization model (ω=ω0+ωa(1−a)) indicate potential variations in the cosmic speed of light at the 1−σ confidence level. For Ωm0=0.30,0.31, and 0.32 with (ω0,ωa)=(−1,0), the 1−σ range of c˙0/c0(10−13yr−1) is (−8.76, −0.89), (−11.8, 3.93), and (−14.8, −6.98), respectively. Meanwhile, the 1−σ range of c˙0/c0(10−12yr−1) for CPL dark energy models with −1.05≤ω0≤−0.95 and 0.28≤Ωm0≤0.32 is (−6.31, −2.98). The value of c at z=3 can exceed that of the present by 0.2∼3% for ωCDM models and 5∼13% for CPL models. Additionally, for viable models except for the CPL model with Ωm0=0.28, we find −25.6≤G˙0/G0(10−12yr−1)≤−0.36. For this particular model, we obtain an increasing rate of the gravitational constant within the range 1.65≤G˙0/G0(10−12yr−1)≤3.79. We obtain some models that do not require dark matter energy density through statistical interpretation. However, this is merely an effect of the degeneracy between model parameters and energy density and does not imply that dark matter is unnecessary.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"24 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

On the Five-Dimensional Non-Extremal Reissner–Nordström Black Hole: Retractions and Scalar Quasibound States 论五维非极端赖斯纳-诺德斯特伦黑洞：回缩与标量准边界态

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-19 DOI: 10.3390/universe10060267

Mohammed Abu-Saleem, Horacio Santana Vieira, Luiz Henrique Campos Borges

引用次数: 0

On Dark Matter and Dark Energy in CCC+TL Cosmology 论 CCC+TL 宇宙学中的暗物质和暗能量

IF 2.9 4区物理与天体物理

Universe Pub Date : 2024-06-18 DOI: 10.3390/universe10060266

Rajendra P. Gupta

{"title":"On Dark Matter and Dark Energy in CCC+TL Cosmology","authors":"Rajendra P. Gupta","doi":"10.3390/universe10060266","DOIUrl":"https://doi.org/10.3390/universe10060266","url":null,"abstract":"Relaxing the temporal constancy constraint on coupling constants in an expanding universe results in Friedmann equations containing terms that may be interpreted as dark energy and dark matter. When tired light (TL) was considered to complement the redshift due to the expanding universe, the resulting covarying coupling constants (CCC+TL) model not only fit the Type Ia supernovae data as precisely as the ΛCDM model, but also resolved concerns about the angular size of cosmic dawn galaxies observed by the James Webb Space Telescope. The model was recently shown to be compliant with the baryon acoustic oscillation features in the galaxy distribution and the cosmic microwave background (CMB). This paper demonstrates that dark energy and dark matter of the standard ΛCDM model are not arbitrary but can be derived from the CCC approach based on Dirac’s 1937 hypothesis. The energy densities associated with dark matter and dark energy turn out to be about the same in the ΛCDM and the CCC+TL models. However, the critical density in the new model can only account for the baryonic matter in the universe, raising concerns about how to account for observations requiring dark matter. We therefore analyze some key parameters of structure formation and show how they are affected in the absence of dark matter in the CCC+TL scenario. It requires reconsidering alternatives to dark matter to explain observations on gravitationally bound structures. The model’s consistency with the CMB power spectrum, BBN element abundances, and other critical observations is yet to be established.","PeriodicalId":48646,"journal":{"name":"Universe","volume":"79 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0