Astronomische Nachrichten最新文献

The composite image shows highlights of select papers from the Proceedings of the Scientific Detector Workshop 2022. From top left, clockwise: The Euclid NISP Near-Infrared Focal Plane under test at the CEA/LAM facility in Marseilles, France (see J. Beletic et al., e230136); The Acuros CQD sensors from SWIR Vision Systems (see C. Mackay, e230104); The Original lab book entry made at Bell Labs by Willard S. Boyle and George E. Smith on October 19th, 1969 (see M.M. Roth, e230066); The focal plane of the Dark Energy Survey (see S.E. Holland, p. xx4); The DECam CCD wafer (see S.E. Holland, e230072); The 2048 × 2048 detector array of JWST NIRCam supplied by Teledyne (see G. Rieke, e230065); Mosaic of three integrated FPA + Linear variable filters (see, J. Beletic et al., e230136).

In the present work, we employ a nonlocal Nambu–Jona–Lasinio (NJL) model with a Gaussian form factor that is dependent on the spatial components of the momentum (3D-FF). Focusing on the temperature-baryon chemical potential plane, we investigate some aspects of the phase diagram. Initially, we propose an assumption that the range of interactions in momentum space may be modified by temperature, allowing us to obtain the critical temperature values based on lattice QCD (LQCD) predictions. Subsequently, we consider this model within a hybrid framework to examine the effects of temperature, together with neutrino trapping, in compact object configurations.

We examine the behavior of highly magnetized two-light-flavor quark matter within the context of a nonlocal NJL-type model. This analysis assumes the chiral limit $��\left(�m_c�=�0�\right)�$ and incorporates the interaction between fermions and the Polyakov loop. Our calculations utilize a covariant Gaussian form factor. We present phase diagrams on the $��T�-�\mu �$ plane, illustrating different magnetic field strengths. Additionally, we examine the critical endpoint's placement and the de Haas-Van Alphen transitions within the chiral restored phase, observing their temperature-dependent characteristics.

We investigate the surface and curvature tensions of three-flavor cold quark matter in a state of electric charge neutrality and chemical equilibrium under weak interactions, employing the Nambu–Jona–Lasinio model with the inclusion of vector interactions. To account for finite-size effects we adopt the multiple-reflection expansion framework and present our results for various input parameters. Our results indicate that both surface and curvature tensions increase with heightened vector interactions and density. Furthermore, we note that the restoration of chiral symmetry in the strange quark sector leads to a modest reduction in curvature tension and a substantial increase in surface tension.

This article focuses on the implications of a noncommutative formulation of branch-cut quantum gravity. Based on a mini-superspace structure that obeys the noncommutative Poisson algebra, combined with the Wheeler–DeWitt equation and Hořava–Lifshitz quantum gravity, we explore the impact of a scalar field of the inflaton-type in the evolution of the Universe's wave function. Taking as a starting point the Hořava–Lifshitz action, which depends on the scalar curvature of the branched Universe and its derivatives, the corresponding wave equations are derived and solved. The noncommutative quantum gravity approach adopted preserves the diffeomorphism property of General Relativity, maintaining compatibility with the Arnowitt–Deser–Misner Formalism. In this work we delve deeper into a mini-superspace of noncommutative variables, incorporating scalar inflaton fields and exploring inflationary models, particularly chaotic and nonchaotic scenarios. We obtained solutions to the wave equations without resorting to numerical approximations. The results indicate that the noncommutative algebraic space captures low and high spacetime scales, driving the exponential acceleration of the Universe.

The exclusive photo- and electroproduction of light vector mesons like $��\rho �,�\omega �,�$ and $��\varphi �$ is studied in $��\gamma �p�$ collisions within the color dipole formalism with vector meson wave functions obtained using the AdS/QCD holographic approach. This setup provides a good description of the existing data for the ground vector mesons $��\rho �\left(�1�S�\right)�,��\omega �\left(�1�S�\right)�,��\text{and}��\varphi �\left(�1�S�\right)�$ and permits us to make predictions for the corresponding excited states. The results show significant theoretical uncertainties related to modeling the partial dipole amplitude, which can be constrained with upcoming measurements in future hadron colliders.

With the present first issue of volume 345 in 2024, we enter the 203rd year of continuous appearance of Astronomische Nachrichten/Astronomical Notes (AN). Not bad, even by astronomical standards. Needless to recall the changes that scientific publishing had gone through over the years and currently still is, and thus also changed AN. Myself being an active researcher/author and flooded daily with article-submission invitations from journals and places I never heard of, I state here that I ever more appreciate a simple and concise research paper where I know that other folks have already had a critical look, and which I can download for no extra charge. The tricky part for our journal is to be of high standard on the one hand while also being openly accessible at the same time, preferably without costs. The end product, your research paper, shall nevertheless be a peer-reviewed, content-, and thus a user-oriented, widely distributed and easily retrievable article that I am, as maybe a typical astro author, keen and happy to cite. AN's aim is nothing less.

The editorial changes in the recent years consolidated the above aim. We now rely on the ScholarOne submission platform for user interaction, eLocators instead of the sequential page numbers for easy identification, a modern web appearance where you can find the latest but also all historical volumes of AN, and open access as part of the European DEAL treaty. AN's most recent ISI-Journal Impact Factor is 0.95. We hope to improve this. In any case, the editorial team of AN is eagerly looking forward to another year of your valuable submissions. Papers are welcomed in all fields of astronomy, astrophysics, and solar-system research as well as related aspects in instrumentation, astrobiologic, and historic studies. Many thanks in advance.

As before, the Leibniz-Institute for Astrophysics Potsdam (AIP) continues hosting the editorial office in close collaboration with Wiley. The editorial team can be contacted through our usual e-mail address [email protected].

This paper focuses on the implications of a commutative formulation that integrates branch-cutting cosmology, the Wheeler–DeWitt equation, and Hořava–Lifshitz quantum gravity. Building on a mini-superspace structure, we explore the impact of an inflaton-type scalar field on the wave function of the Universe. Specifically analyzing the dynamical solutions of branch-cut gravity within a mini-superspace framework, we emphasize the scalar field's influence on the evolution of the evolution of the wave function of the Universe. Our research unveils a helix-like function that characterizes a topologically foliated spacetime structure. The starting point is the Hořava–Lifshitz action, which depends on the scalar curvature of the branched Universe and its derivatives, with running coupling constants denoted as $��{�g�}_{�i�}�$. The corresponding wave equations are derived and are resolved. The commutative quantum gravity approach preserves the diffeomorphism property of General Relativity, maintaining compatibility with the Arnowitt–Deser–Misner formalism. Additionally, we delve into a mini-superspace of variables, incorporating scalar-inflaton fields and exploring inflationary models, particularly chaotic and nonchaotic scenarios. We obtained solutions for the wave equations without recurring to numerical approximations.

There exist isolated elliptical galaxies, whose dynamics can be modeled without resorting to dark matter or MOND, for example, NGC 7507. Such objects lack understanding within the current framework of galaxy formation. The isolated elliptical NGC 5812 is another object to investigate a possible role of isolation. We use globular clusters (GCs) and the galaxy light itself as dynamical tracers to constrain its mass profile. We employ Gemini/GMOS mask spectroscopy, apply the GMOS reduction procedures provided within IRAF, measure GC velocities by cross correlation methods and extract the line-of-sight kinematics of galaxy spectra using the tool pPXF. We identify 28 GCs with an outermost galactocentric distance of 20 kpc, for which velocities could be obtained. Furthermore, 16 spectra of the integrated galaxy light out to 6 kpc have been used to model the central kinematics. These spectra provide evidence for a disturbed velocity field, which is plausible given the disturbed morphology of the galaxy. We construct spherical Jeans models for the galaxy light and apply tracer mass estimators for the globular clusters. With the assumptions inherent to the mass estimators, MOND is compatible with the mass out to 20 kpc. However, a dark matter free galaxy is not excluded, given the uncertainties related to a possible nonsphericity and a possible nonequilibrium state. We find one globular cluster with an estimated mass of $��1�.�6�\times �1�{�0�}^{�7�}�{�M�}_{�\odot �}�$, the first Ultra Compact Dwarf in an isolated elliptical. We put NGC 5812 into the general context of dark matter or alternative ideas in elliptical galaxies. The case for a MONDian phenomenology also among early-type galaxies has become so strong that deviating cases appear astrophysically more interesting than agreements. The baryonic Tully Fisher relation (BTFR) as predicted by MOND is observed in some samples of early-type galaxies, in others not. However, in cases of galaxies that deviate from the MONDian prediction, data quality and data completeness are often problematic.