Ancient Universe Research Articles

Fossil group origins

Aims. In this work we study the large-scale structure around a sample of non-fossil systems and compare the results with earlier findings for a sample of genuine fossil systems selected using their magnitude gap. Methods. We computed the distance from each system to the closest filament and intersection as obtained from a catalogue of galaxies in the redshift range 0.05 ≤ z ≤ 0.7. We then estimated the average distances and the distributions of cumulative distances to filaments and intersections for different magnitude-gap bins. Results. We find that the average distance to filaments is (3.0 ± 0.8) R200 for fossil systems, whereas it is (1.1 ± 0.1) R200 for non-fossil systems. Similarly, the average distance to intersections is larger in fossil than in non-fossil systems, with values of (16.3 ± 3.2) and (8.9 ± 1.1) R200, respectively. Moreover, the cumulative distributions of distances to intersections are statistically different for fossil and non-fossil systems. Conclusions. Fossil systems selected using the magnitude gap appear to be, on average, more isolated from the cosmic web than non-fossil systems. No dependence is found on the magnitude gap (i.e. non-fossil systems behave in a similar manner independently of their magnitude gap, and only fossils are found at larger average distances from the cosmic web). This result supports a formation scenario for fossil systems in which the lack of infalling galaxies from the cosmic web, due to their peculiar position, favours the growing of the magnitude gap via the merging of all the massive satellites with the central galaxy. Comparison with numerical simulations suggests that fossil systems selected using the magnitude gap are not old fossils of the ancient Universe, but rather systems located in regions of the cosmic web not influenced by the presence of intersections.

L’antagonisme du féminin et du masculin dans Salammbô de Flaubert

"In Salammbô by Flaubert, the representation of the ancient universe reveals a struggle between two opposing principles, masculine and feminine, which takes on a character that is both mythological and cosmological. While revealing the dangers of the encounter between these two poles, the story stages a fierce confrontation between these two imaginaries presenting themselves as mutually exclusive. This antithetical construction will give rise to a whirlwind of passion and cruelty that will consecrate the triumph of monstrosity over amorous emotions. In the Punic work, the language of violence prevails over that of love so much so that the deep energy that nourishes amorous desire is transformed into a veritable force of generalized annihilation. Flaubert’s nihilism strives to undermine the highest values of bourgeois culture, which disgusts it, and reaches its peak when it attacks the roles it assigns to the opposite sexes."

New telescopes seek the cosmic dark ages

Radio astronomers look to far-flung locations to detect low-frequency signals that emanate from the ancient universe.

INSPIRE: INvestigating Stellar Population In RElics

Context. The INvestigating Stellar Population In RElics (INSPIRE) is an ongoing project targeting 52 ultra-compact massive galaxies at 0.1 < z < 0.5 with the X-shooter at VLT spectrograph (XSH). These objects are the ideal candidates to be ‘relics’, massive red nuggets that have formed at high redshift (z > 2) through a short and intense star formation burst, and then have evolved passively and undisturbed until the present day. Relics provide a unique opportunity to study the mechanisms of star formation at high-z. Aims.INSPIRE is designed to spectroscopically confirm and fully characterise a large sample of relics, computing their number density in the redshift window 0.1 < z < 0.5 for the first time, thus providing a benchmark for cosmological galaxy formation simulations. In this paper, we present the INSPIRE Data Release (DR1), comprising 19 systems with observations completed in 2020. Methods. We use the methods already presented in the INSPIRE Pilot, but revisiting the 1D spectral extraction. For the 19 systems studied here, we obtain an estimate of the stellar velocity dispersion, fitting the two XSH arms (UVB and VIS) separately at their original spectral resolution to two spectra extracted in different ways. We estimate [Mg/Fe] abundances via line-index strength and mass-weighted integrated stellar ages and metallicities with full spectral fitting on the combined (UVB+VIS) spectrum. Results. For each system, different estimates of the velocity dispersion always agree within the errors. Spectroscopic ages are very old for 13/19 galaxies, in agreement with the photometric ones, and metallicities are almost always (18/19) super-solar, confirming the mass–metallicity relation. The [Mg/Fe] ratio is also larger than solar for the great majority of the galaxies, as expected. We find that ten objects formed more than 75% of their stellar mass (M⋆) within 3 Gyr from the big bang and classify them as relics. Among these, we identify four galaxies that had already fully assembled their M⋆ by that time and are therefore ‘extreme relics’ of the ancient Universe. Interestingly, relics, overall, have a larger [Mg/Fe] and a more metal-rich stellar population. They also have larger integrated velocity dispersion values compared to non-relics (both ultra-compact and normal-size) of similar stellar mass. Conclusions. The INSPIRE DR1 catalogue of ten known relics is the largest publicly available collection, augmenting the total number of confirmed relics by a factor of 3.3, and also enlarging the redshift window. The resulting lower limit for the number density of relics at 0.17 < z < 0.39 is ρ ∼ 9.1 × 10−8 Mpc−3.

The Spitzer Space Telescope: Exploring the Infrared Universe

From 2003 until 2020, NASA’s Spitzer Space Telescope provided an unprecedented view of our universe in infrared. One of the most important instruments aboard the telescope was the Infrared Array Camera (IRAC), which was designed and operated by a team led by Dr Giovanni Fazio at the Center for Astrophysics | Harvard & Smithsonian. Across its 16-year run, the camera gave crucial insights into processes ranging from galaxy formation in the ancient universe, to emissions from supermassive black holes. The discoveries enabled by Dr Fazio and his colleagues could soon be instrumental in aiding observations from even more advanced telescopes.

Nucleosynthetic yields of Z = 10−5 intermediate-mass stars

Context. Observed abundances of extremely metal-poor stars in the Galactic halo hold clues for understanding the ancient universe. Interpreting these clues requires theoretical stellar models in a wide range of masses in the low-metallicity regime. The existing literature is relatively rich with extremely metal-poor massive and low-mass stellar models. However, relatively little information is available on the evolution of intermediate-mass stars of Z ≲ 10−5, and the impact of the uncertain input physics on the evolution and nucleosynthesis has not yet been systematically analysed. Aims. We aim to provide the nucleosynthetic yields of intermediate-mass Z = 10−5 stars between 3 and 7.5 M⊙, and quantify the effects of the uncertain wind rates. We expect these yields could eventually be used to assess the contribution to the chemical inventory of the early universe, and to help interpret abundances of selected C-enhanced extremely metal-poor (CEMP) stars. Methods. We compute and analyse the evolution of surface abundances and nucleosynthetic yields of Z = 10−5 intermediate-mass stars from their main sequence up to the late stages of their thermally pulsing (Super) AGB phase, with different prescriptions for stellar winds. We use the postprocessing code MONSOON to compute the nucleosynthesis based on the evolution structure obtained with the Monash-Mount Stromlo stellar evolution code MONSTAR. By comparing our models and others from the literature, we explore evolutionary and nucleosynthetic trends with wind prescriptions and with initial metallicity (in the very low-Z regime). We also compare our nucleosynthetic yields to observations of CEMP-s stars belonging to the Galactic halo. Results. The yields of intermediate-mass extremely metal-poor stars reflect the effects of very deep or corrosive second dredge-up (for the most massive models), superimposed with the combined signatures of hot-bottom burning and third dredge-up. Specifically, we confirm the reported trend that models with initial metallicity Zini ≲ 10−3 give positive yields of 12C, 15N, 16O, and 26Mg. The 20Ne, 21Ne, and 24Mg yields, which were reported to be negative at Zini ≳ 10−4, become positive for Z = 10−5. The results using two different prescriptions for mass-loss rates differ widely in terms of the duration of the thermally pulsing (Super) AGB phase, overall efficiency of the third dredge-up episode, and nucleosynthetic yields. We find that the most efficient of the standard wind rates frequently used in the literature seems to favour agreement between our yield results and observational data. Regardless of the wind prescription, all our models become N-enhanced EMP stars.

Josephson Junctions and Cosmic Microwave Background

The implementation of utilizing superconducting quantum interference device (SQUID) readout for constant voltage biased transition edge sensors (TES) has enabled the detection of the infinitesimal fluctuation in cosmic microwave background (CMB). The properties of the fluctuations will provide us the information of the universe at the time that this light was first emitted. In short, by measuring the CMB today, we learn about the distant, ancient universe—how the universe began, what it is made of, and how it evolved to its current state. Over the past 20 years, we have achieved many successful CMB measurements with Josephson junctions. Brian, I offer my congratulations on your eight decades of life—Happy 80th birthday!

Rational theology: The case of Philo of Alexandria

The phenomenon of rational theology arises at the moment when there is a need to adapt traditional or new religious ideas to contemporary and characteristic intellectual practices. The case of Philo of Alexandria can serve as a good example of what happens when two different cultural traditions begin the mutual translation of discourses. We analyze how this affects the most important theological concepts of Philo on the basis of the treatise De opificio mundi. We pay attention to three points: 1. Philo’s assessment of the cosmogonic and historical narrative of Moses as a metaphysical prologue to his legislation; 2. Philo’s interpretation of natural law and natural being as an allegory of metaphysical and moral law; 3. Aristotle’s “motives” in Philo’s description of the activities of God the Creator. It can be concluded that Philo interprets the Greek philosophical language as a completely acceptable way of reading both the laws of nature and the Jewish Scriptures (he explains this through the “borrowing hypothesis”). As a result, the legislation of Moses appears to be included in the structure of the ancient universe reformed by Philo. Greek philosophical discourse is interpreted as one of the manifestations of Divine Revelation— a point of view that will later be inherent in some early Christian authors (for example, Clement of Alexandria).

Astronomical Context of Georgian Folklore

Objectives: The religious Ancient megalithic monuments are accordingly o/riente to the ancient Gods – The Sun, Moon, luminaries. The aim of this work to research the ethnographic data, current folklore and based on the results, harmonize the ancient Gods and the orientations of the religious megalithic complexes. Methods/Statistical Analysis: We harmonized the ethnographical, folklore and historical information and restoration of ancient celestial sphere (using special astronomy application) and identified the correlations between the some acronychal or helical rising/set of luminaries and orientations of megalithic objects. Such connections are stored in a folklore. Findings: This technique of investigations gives us more clear understanding of ancient universe. Using this method, we can receive additional information about the ancient Gods – Luminaries, clarify current mythology, date the megalithic complex. Application/Improvements: This method of investigation - Harmonization cultural astronomy and archae or astronomy with the archeological investigations will be more fruitful, because it gives us reliable information concerning the ancient culture, ancient religion and ancient people.

Megalithic Monument of Abuli, Georgia, and Possible Astronomical Significance

Background/Objectives: In recent years, in purpose of investigation of the artefacts, the ancient culture and religion, based on the astronomy knowledge play significant role. The aim of this work is to identify the orientations of the religious megalithic complexes and their correlation to the celestial luminaries. Methods/Statistical Analysis: We harmonized the archeological data, ethnographical, historical information and restoration of ancient celestial sphere (using special astronomy application), which give us possibility to identify the correlations between the acronychal or helical rising/ set of luminaries and directions of megalithic objects. Very often such connections are stored in a current folklore too. Findings: This technique of investigations give us more clear understanding of ancient universe. Using this method, we can receive latent information about the ancient Gods – Luminaries, clarify current mythology, date of the megalithic complex. Application/Improvements: This method of investigation is an additional instrument for archeological investigations, because it gives us more reliable information concerning the ancient culture, religion and people.

Time, Space, Gravity and Spacetime Based on Yangton & Yington Theory, and Spacetime Shrinkage Versus Universe Expansion

Wu’s Particle is proposed as the building block of all Matters, therefore Time and Length can be measured by the Period and Size of the circulation of Wu’s Particle. For a local event, object and process, the Time, Length and Velocity measured by the Period and Size of Wu’s Particle have equal values as that of the identical events, objects and processes occurred at different locations measured by the corresponding Periods and Sizes of Wu’s Particles. However, for a remote event, object and process, the Time, Length and Velocity change with the Period and Size of Wu’s Particle at observation. For an event, object and process occurred in a large Gravitational Field and an ancient Universe, Time runs slower, Length gets longer and Velocity is smaller observed on Earth. As a result, light travels at lower speed with lower frequency and larger wavelength from a large Gravitational Field known as Gravitational Red Shift; also from a star of a few millions light years away known as Cosmological Red Shift. Spacetime is a four dimensional system based on the Period and Size of Wu’s Particle. Since the Period and Size of Wu’s Particle change with Gravitational Field and Concentration of Higgs Bosons, Spacetime is a function of Gravitational Field and Concentration of Higgs Bosons. In Wu’s Particle, Time is proportional to 3/2 power of Length which is named as “Wu’s Spacetime Theory”. Furthermore, instead of “Universe Accelerating Expansion Theory” which is based on the non-existing Dark Energy, “Spacetime Accelerating Shrinkage Theory” is proposed to explain the accelerating expansion of the Universe.

Impact of star formation inhomogeneities on merger rates and interpretation of LIGO results

Within the next decade, ground based gravitational-wave detectors are in principle capable of determining the compact object merger rate per unit volume of the local universe to better than 20% with more than 30 detections. These measurements will constrain our models of stellar, binary and star cluster evolution in the nearby present-day and ancient universe. We argue that the stellar models are sensitive to heterogeneities (in age and metallicity at least) in such a way that the predicted merger rates are subject to an additional 30–50% systematic errors unless these heterogeneities are taken into account. Without adding new electromagnetic constraints on massive binary evolution or relying on more information from each merger (e.g., binary masses and spins), as few as the ≃ 5 merger detections could exhaust the information available in a naive comparison to merger rate predictions. As a concrete example immediately relevant to analysis of initial and enhanced LIGO results, we use a nearby-universe catalog to demonstrate that no one tracer of stellar content can be consistently used to constrain merger rates without introducing a systematic error of order O(30%) at 90% confidence (depending on the type of binary involved). For example, though binary black holes typically take many Gyr to merge, binary neutron stars often merge rapidly; different tracers of stellar content are required for these two types. More generally, we argue that theoretical binary evolution can depend sufficiently sensitively on star-forming conditions—even assuming no uncertainty in binary evolution model—that the distribution of star-forming conditions must be incorporated to reduce the systematic error in merger rate predictions below roughly 40%. We emphasize that the degree of sensitivity to star-forming conditions depends on the binary evolution model and on the amount of relevant variation in star-forming conditions. For example, if after further comparison with electromagnetic and gravitational-wave observations future population synthesis models suggest all BH-BH binary mergers occur promptly and therefore are associated with well-studied present-day star formation, the associated composition-related systematic uncertainty could be lower than the pessimistic value quoted above. Further, as gravitational-wave detectors will make available many properties of each merger—binary component masses, spins and even short GRB associations and host galaxies could be available—many detections can still be exploited to create high-precision constraints on binary compact object formation models.