Clear Red Shift Research Articles

The Extreme Low-mass End of the Mass–Metallicity Relation at z ∼ 7

The mass–metallicity relation provides crucial insights into the baryon cycle in galaxies and strong constraints on galaxy formation models. We use JWST NIRSpec observations from the UNCOVER program to measure the gas-phase metallicity in a sample of eight galaxies during the epoch of reionization at z = 6–8. Thanks to the strong lensing of the galaxy cluster Abell 2744, we are able to probe extremely low stellar masses between 106 and 108 M ⊙. Using strong-line diagnostics and the most recent JWST calibrations, we derive extremely low oxygen abundances in the range of 12 + log(O/H) = 6.7–7.8. By combining this sample with more massive galaxies at similar redshifts, we derive a best-fit relation of 12 + log(O/H) = −0.076−0.03+0.03×(log(M⋆))2+1.61−0.52+0.52 × log(M⋆)−0.26−0.10+0.10 , which becomes steeper than determinations at z ∼ 3–6 toward low-mass galaxies. Our results show a clear redshift evolution in the overall normalization of the relation, galaxies at higher redshift having significantly lower metallicities at a given mass. A comparison with theoretical models provides important constraints on which physical processes, such as metal mixing, star formation or feedback recipes, are important in reproducing the observations. Additionally, these galaxies exhibit star formation rates that are higher by a factor of a few to tens compared to extrapolated relations at similar redshifts or theoretical predictions of main-sequence galaxies, pointing to a recent burst of star formation. All these observations are indicative of the highly stochastic star formation and interstellar medium enrichment expected in these low-mass systems, suggesting that feedback mechanisms in high-z dwarf galaxies might be different from those in place at higher masses.

Designing of new functionalized imidazolium based ionic liquids attached to the antracene derivatives and investigation on the influence of intramolecular hydrogen bondings in anions on their intermolecular hydrogen bondings and some of the other properties: A DFT M06-2X-GD3 study

To promote the development of new functionalized ionic liquids, it is necessary to get a deeper insight into their features of physicochemical and electronic and molecular structure. In this study, the interaction energies and structural and vibrational frequencies parameters in accompanied with some of the physiochemical, electronic and optic attributes of ionic liquids designed by the covalently attachement of imidazolium to anthracene derivatives ([X-AnMIM][A2] and [X-AnMIM][A3], X: NH2, OH, OMe, H, Cl, CHO, CN and NO2) ILs have been evaluated. Two conjugate bases of acids 1,3,5-pentanetriol (A2) and 3-(2-hydroxyethyl)-1,3,5-pentanetriol (A3) are used as anions which have two and three intramolecular hydrogen bonds, respectively. Based on the results of calculations at M06-2X-GD3/6–311++(d,p) level of theory, the differences in these properties in addition to the structural type of anions and cations can be attributed to the cation-anion, intra and intermolecular hydrogen bonding, interactions in ionic liquids. The results depict that the ILs based on A2 anions form stronger hydrogen bonds with [X-AnMIM]+ cations. The potency of interaction between cations and anion reduces with the increasement in the number of intramolecular hydrogen bonds and also decreasement in the basic strength in the anionic part. A clear red shift is observed between [X-AnMIM][A2] and [X-AnMIM][A3] ILs and isolated anthracene, which is a clear manifestation of the effect of the imidazolium cation on the electronic energy levels of anthracene. It can be expected that the studied ILs are not electrochemically stable during the electrochemistry applications.

Tin Gallium Oxide Epilayers on Different Substrates: Optical and Compositional Analysis

Electron beam techniques have been used to analyze the impact of substrate choice and growth parameters on the compositional and optical properties of tin gallium oxide [(SnxGa1−x)2O3] thin films grown by plasma‐assisted molecular beam epitaxy. Sn incorporation and film quality are found to be highly dependent on growth temperature and substrate material (silicon, sapphire, and bulk Ga2O3) with alloy concentrations varying up to an x value of 0.11. Room temperature cathodoluminescence spectra show the Sn alloying suppressing UV (3.3–3.0 eV), enhancing blue (2.8–2.4 eV), and generating green (2.4–2.0 eV) emission, indicative of the introduction of a high density of gallium vacancies (VGa) and subsequent VGa–Sn complexes. This behavior was further analyzed by mapping composition and luminescence across a cross section. Compared to Ga2O3, the spectral bands show a clear redshift due to bandgap reduction, confirmed by optical transmission measurements. The results show promise that the bandgap of gallium oxide can successfully be reduced through Sn alloying and used for bandgap engineering within UV optoelectronic devices.

Influence of star-forming galaxy selection on the galaxy main sequence

Aims. This work aims to determine how the galaxy main sequence (MS) changes using seven different commonly used methods to select the star-forming galaxies within VIPERS data over 0.5 ≤ z < 1.2. The form and redshift evolution of the MS was then compared between selection methods. Methods. The star-forming galaxies were selected using widely known methods: a specific star-formation rate (sSFR); Baldwin, Phillips, and Terlevich (BPT) diagram; a 4000 Å spectral break (D4000) cut; and four colour-colour cuts (near-ultra-violet – V verses r − J (NUVrJ), near-ultra-violet – V verses r − K (NUVrK), u − r, and U − V verses V − J (UVJ)). The main sequences were then fitted for each of the seven selection methods using a Markov chain Monte Carlo forward modelling routine, fitting both a linear main sequence and a MS with a high-mass turnover to the star-forming galaxies. This was done in four redshift bins of 0.50 ≤ z < 0.62, 0.62 ≤ z < 0.72, 0.72 ≤ z < 0.85, and 0.85 ≤ z < 1.20. Results. The slopes of all star-forming samples were found to either remain constant or increase with redshift, and the scatters were approximately constant. There is no clear redshift dependency of the presence of a high-mass turnover for the majority of samples, with the NUVrJ and NUVrK being the only samples with turnovers only at low redshift. No samples have turnovers at all redshifts. Star-forming galaxies selected with sSFR and u − r are the only samples to have no high-mass turnover in all redshift bins. The normalisation of the MS increases with redshift, as expected. The scatter around the MS is lower than the ≈0.3 dex typically seen in MS studies for all seven samples. Conclusions. The lack (or presence) of a high-mass turnover is at least partially a result of the method used to select star-forming galaxies. However, whether a turnover should be present or not is unclear.

Investigations of electronic, elastic, and optical properties of (Ag, Cd)-doped LaAlO3: a computational insight

In this study, we used density functional theory to examine how the wide band gap optoelectronic properties of pure, silver-, and cadmium-doped LaAlO3 perovskites changed. Structural, electrical, elastic, and mechanical properties were calculated using generalized gradient approximation. Silver and cadmium incorporated at Al site demonstrated a decreasing trend in the band gap. Both impurities showed the reduction in band gap from 2.98 to 0.468 eV and from 2.98 to 2.0238 eV. The density of states was examined for pristine and doped structures to understand behavioral change of LaAlO3. It was observed that p states in upper valance band and d states in lower conduction band were contributing toward the reduction of band gap. Elastic properties were computed. Elastic parameters were used to calculate Born’s stability and it is predicted that the material is stable mechanically for both pristine and doped forms. Mechanical properties were also predicted and brittle nature was found for both pristine and doped materials. Optical responses such as dielectric function, absorption, and refractive index were also predicted. The impurity inclusion in pristine structure not only reduces the bad gap but also alters the optical behavior. Absorption edge shifted toward lower energy shows a clear redshift, whereas refractive index also reduces from 2.4 to 1.9, making the material more transparent. The absorption spectrum as well as electronic band gap makes this material more useful for solar cell application as well as photocatalytic applications.

Dualistic influences of Pr3+ ions on the optical and radiation shielding characteristics of alumina bismuth – Sodium phosphate glasses

Using a standard melt quenching technique, alumina bismuth-sodium phosphate glasses doped with Pr2O3 were synthesized. The amorphous character of these glasses was confirmed by the XRD spectrum. The impact of Pr2O3 on optical and radiation-shielding characteristics has also been studied and linked to the structure. The optical characteristics show a decrement of the optical band gap from 3.72 to 3.48 eV, and an increment of the refractive index along with a clear red shift with the addition of Pr2O3 content. The refractive index of Pr2O3-based glasses was estimated with the help of the glass electronegativity (Δχ) and Eg values. The increment of Pr2O3 increases the mass attenuation coefficient (MAC) values and decreases the half-value layer (HVL) values, which improves the shielding ability of the manufactured glasses. The strongest interactions between photons and glass atoms occurred at about 100 keV, which causes the glass samples to exhibit remarkable photon-blocking characteristics, according to the effective atomic number (Zeff) data. The radiation shielding variables led to the finding that glass containing 2 mol% Pr2O3 provides better results among the samples that were synthesized.

Mid-Infrared Photothermal-Fluorescence In Situ Hybridization for Functional Analysis and Genetic Identification of Single Cells.

Simultaneous identification and metabolic analysis of microbes with single-cell resolution and high throughput are necessary to answer the question of "who eats what, when, and where" in complex microbial communities. Here, we present a mid-infrared photothermal-fluorescence in situ hybridization (MIP-FISH) platform that enables direct bridging of genotype and phenotype. Through multiple improvements of MIP imaging, the sensitive detection of isotopically labeled compounds incorporated into proteins of individual bacterial cells became possible, while simultaneous detection of FISH labeling with rRNA-targeted probes enabled the identification of the analyzed cells. In proof-of-concept experiments, we showed that the clear spectral red shift in the protein amide I region due to incorporation of 13C atoms originating from 13C-labeled glucose can be exploited by MIP-FISH to discriminate and identify 13C-labeled bacterial cells within a complex human gut microbiome sample. The presented methods open new opportunities for single-cell structure-function analyses for microbiology.

Importance of intracluster scattering and relativistic corrections from tSZ effect with cosmic infrared background

ABSTRACT The Sunyaev–Zeldovich effect towards clusters of galaxies has become a standard probe of cosmology. It is caused by the scattering of photons from the cosmic microwave background (CMB) by the hot cluster electron gas. In a similar manner, other photon backgrounds can be scattered when passing through the cluster medium. This problem has been recently considered for the radio and the cosmic infrared background. Here, we revisit the discussion of the cosmic infrared background (CIB) including several additional effects that were omitted before. We discuss the intracluster scattering of the CIB and the role of relativistic temperature corrections to the individual cluster and all-sky averaged signals. We show that the all-sky CIB distortion introduced by the scattering of the photon field was underestimated by a factor of ≃1.5 due to neglecting the intracluster scattering contribution. The CIB photons can scatter with the thermal electrons of both the parent halo or another halo, meaning that there are two ways to gain energy. Therefore, energy is essentially transferred twice from the thermal electrons to the CIB. We carefully clarify the origin of various effects in the calculation of the average CIB and also scattered signals. The single-cluster CIB scattering signal also exhibits a clear redshift dependence, which can be used in cosmological analyses, as we describe both analytically and numerically. This may open a new way for cosmological studies with future CMB experiments.

Synthesis of Fully Substituted Sumanenes at the Aromatic Periphery through Hexabromomethylation

Abstract2,3,5,6,8,9‐Hexakis(bromomethyl)sumanene, a hexa‐substituted sumanene with bromomethyl groups at the peripheral aromatic carbons, was successfully synthesized in 97% yield with a one‐step reaction. Single‐crystal X‐ray structural analysis showed a formation of a dimer structure. The nucleophilic substitution afforded the introduction of several substituents. These UV‐vis absorption and emission spectra showed clear redshift compared with pristine sumanene, indicating the extension of the conjugation system of hexa‐substituted sumanenes.

Nitrogen-doped, proton-exchanged Dion-Jacobson layered niobate perovskites for photocatalytic hydrogen generation in solar light

Wide band gap semiconductor niobate photocatalysts with Dion-Jacobson layered perovskite structure were nitrogen-doped via simple gas–solid reaction to extend their absorption into the visible light range. Nitrogen doping was performed using ammonia as precursor, resulting in decreased band gaps of doped AB2Nb3O10 compounds (A = Cs, Rb, K; B = Ca, Sr) down to 2.5 eV. The resulting materials were investigated concerning their chemical and electronic structures. Nitrogen-doped AB2Nb3O10 crystals showed a clear red shift in absorption. Photocatalytic performance tests for the doped materials evaluated the capability of H2 production under simulated solar irradiation. The addition of carbonates to the gas–solid reaction turned out to be advantageous for the reduction of defects and the preservation of photocatalytic activity of nitrogen-doped layered niobates AB2Nb3O10.Graphical

Thermal stability and high-temperature photoluminescence of chemical vapor deposited MoS2 in different atmosphere

Understanding the high-temperature behaviors of two-dimensional (2D) transition metal dichalcogenides under different environments will provide a directive guide for the fabrication and application of their nanoelectronic devices. In this study, we investigate the high-temperature properties of chemical vapor deposition grown molybdenum disulfide (MoS2) in different atmospheres through the ex situ and in situ morphological and spectroscopical characterizations. When the MoS2 is exposed to Ar, dry O2, and wet O2 at the temperature of 500, 350, and 300 °C, the etching process starts at the edge and inner regions simultaneously, and the etched trenches are opposite to the outline of the MoS2 triangular shape. We observe a clear redshift of MoS2 in the Raman peak position and the photoluminescence peak position by in situ spectroscopical characterizations as the temperature increases. Moreover, a strong photoluminescence enhancement of 24-fold of MoS2 is observed when exposing to O2 at 300 °C. This should be due to the chemical and physical adsorbed oxygen on the MoS2 surface. Moreover, we find that physical adsorption can be eliminated after vacuum annealing. This study provides a real-time strategy to study the morphology and property evolution of 2D materials at high temperature in different atmospheres. These results will contribute to the applications in future electronic and optoelectronic functional devices of 2D materials.

Synthesis, Characterization and Analytical Study of New Azo Dye

The azo dye ((E)-4-((4-aminophenyl) diazenyl) naphthalen-1-ol) was prepared by diazotization and coupling reaction with 1-naphthol. The azo dye was diagnosed by FT-IR, 1H-NMR, mass spectra and visible spectrometry. The acid and basic properties were studied by the visible absorption spectra of the dye at different pH values and appearance of a clear isobestic point and a high absorption peak at the maximum wavelength (595nm) which is due to the absorption of the negative formula of the dye in the basic medium and an absorption peak at the wavelength (477nm) that is due to the absorption of the proton formula of the dye in the acidic medium. The ionization and protonation constants were calculated and the extent of the indicator within pH (7.4 - 9.4). The effect of the solvents on the visible absorption spectra of the dye was studied, and a clear red shift of the dye spectra was observed in the polar solvents.

Absorption enhancement in visible range from Fano resonant silicon nanoparticle arrays embedded in single crystal Mg:Er:LiNbO3 synthesized by direct ion implantation

Fano resonant Si nanoparticles (NPs) are synthesized in single-crystal Mg:Er:LiNbO3 using ion implantation and subsequent thermal annealing. The structural and optical properties of the Si NPs embedded in the crystal have been investigated. Spherical particles with radius of about 60 nm are observed by cross-sectional transmission electron microscope, while ion beam analysis are used to characterize the NPs formation process. The absorption of the Mg:Er:LiNbO3 crystals have been enhanced significantly due to the embedded Si NPs, which are induced by the Fano resonance effect in the visible light wavelength band. Periodic structures of spherical Si particles model is proposed and analyzed using the Mie theory to study the optical response features and local fields. As a result, numerical simulations demonstrate that periodicities of the array of Si NPs can yield narrow resonant peaks connected with multiple light scattering by the NPs and displaying a Fano-type resonant profile. The wavelengths of the absorption peak show clear red shift with increasing the radius of NPs and the peak intensity can be enhanced by decreasing the array period. This work opens an avenue to modulate the optical filed by embedding Fano resonant Si NPs for potential application in optical devices.

Confined and synergistic effects between protonated amines and gases in the frameworks of lanthanum 1,3-propanediaminetetraacetates

Lanthanum microporous frameworks (Hdma) 2n [La 2 (1,3-pdta) 2 (H 2 O) 2 ] n ·5nH 2 O ( 1 , dma = dimethylamine, 1,3-pdta = 1,3-propanediaminetetraacetic acid) and (H 2 pn) n [La 2 (1,3-pdta) 2 (H 2 O) 2 ] n ·5nH 2 O ( 2 , pn = 1,3-propanediamine) with double channels have been template-synthesized by protonated dimethylamines and 1,3-propanediamines, respectively. While bulky product (H 2 bn)[La 2 (1,3-pdta) 2 (H 2 O) 4 ]·10H 2 O ( 3 , bn = 1,4-butanediamine) is isolated as a dinuclear species with tetrahydrates, whose main anion can be served as a precursor for 1 and 2 . Materials 1 – 3 are able to maintain their chemical and thermal stabilities to 200 °C based on TG and XRD analyses. Gas adsorptions demonstrate that MOFs 1 and 2 are amicable for O 2 and CO 2 , while no adsorption has been observed for CH 4 , N 2 or H 2 respectively. The amounts of encapsulated CO 2 in hydrophobic pores are dependent on the alkalinities of the diamines in the next confined hydrophilic holes, showing synergistic effects between double channels. For protonated dimethylamines and 1,3-propanediamines in 1 and 2 , obvious downfield shifts have been found by solid-state 13 C NMR spectroscopies, along with clear red shifts in FT-IR spectra compared with free species. Moreover, captured CO 2 inside 1 can be quantized by NMR measurements and IR spectroscopies under ambient condition. These all reflect the confinement effects of nano-environments. • Synergistic and confined effects in lanthanide MOFs with gases are quantized and discussed. • An interesting precursor is obtained when the synthetic template is 1,4-butanediamine. • CO 2 uptake and conversion in the hydrophobic channels can also be spectroscopic characterized.

Sensing Glucose Concentration Using Symmetric Metasurfaces under Oblique Incident Terahertz Waves

In this article, a planar metamaterial sensor designed at terahertz (THz) frequencies is utilized to sense glucose concentration levels that cover hypoglycemia, normal, and hyperglycemia conditions that vary from 54 to 342 mg/dL. The sensor was developed using a symmetric complementary split rectangular resonator at an oblique incidence angle. The resonance frequency shift was used as a measure of the changes in the glucose level of the samples. The increase in the glucose concentration level exhibited clear and noticeable redshifts in the resonance frequency. For instance, a 67.5 GHz redshift has been observed for a concentration level of 54 mg/dL and increased up to 122 GHz for the 342 mg/dL concentration level. Moreover, a high sensitivity level of 75,700 nm/RIU was observed for this design. In the future, the proposed THz sensors may have potential applications in diagnosing hypocalcemia and hyperglycemia cases.

Fluorescent detection of copper ions with acylhydrazine-based probes: Effects of substitute and its position

Four naphthalimide-based compounds (NHA, NHB, NHC and NHD) bearing carbazide or semi-carbazide at different positions were designed and synthesized for the detection of cooper ions. The presence of copper ions caused different spectral changes of the four compounds: the fluorescence of NHA and NHB were enhanced, while that of NHC was quenched, and little spectral changes of NHD were observed. The mechanism studies reveal that: copper ions promoted the hydrolysis of the probe containing semi-carbazide group (NHA), leading to evident fluorescence enhancement with clear red-shift; while it formed complex with the probes bearing carbazide (NHB and NHC), resulting in fluorescence “turn-on” or “turn-off”. The substituted position of carbazide group in naphthalimide affected the fluorescence significantly: strong photoinduced electron transfer occurred as it at 4-position (NHB), whereas the PET process was not easy to happen as the group at imine-N (NHC). Copper ions increased the fluorescence of NHB by blocking the PET process, while it could initiate a d-PET process and quenched the fluorescence of NHC. Fluorescence bio-imaging experiments demonstrate that both NHB and NHC exhibit good cell permeability and can monitor Cu2+ as well as thiols in living cells.

X-Ray Plateaus in Gamma-Ray Burst Afterglows and Their Application in Cosmology

Abstract For gamma-ray bursts (GRBs) with a plateau phase in the X-ray afterglow, a so-called L–T–E correlation that tightly connects the isotropic energy of the prompt GRB (E γ,iso) with the end time of the X-ray plateau (T a ) and the corresponding X-ray luminosity at the end time (L X) has been found. Here we show that there is a clear redshift evolution in the correlation. Furthermore, because the power-law indices of L X and E γ,iso in the correlation function are almost identical, the L–T–E correlation is insensitive to cosmological parameters and cannot be used as a satisfactory standard candle. On the other hand, based on a sample including 121 long GRBs, we establish a new three-parameter correlation that connects L X, T a , and the spectral peak energy E p, i.e., the L–T–E p correlation. This correlation strongly supports the so-called Combo-relation established by Izzo et al. After correcting for the redshift evolution, we show that the de-evolved L–T–E p correlation can be used as a standard candle. By using this correlation alone, we are able to constrain the cosmological parameters as Ω m = 0.389 − 0.141 + 0.202 (1σ) for the flat ΛCDM model, or Ω m = 0.369 − 0.191 + 0.217 and w = − 0.966 − 0.678 + 0.513 (1σ) for the flat wCDM model. Combining with other cosmological probes, more accurate constraints on the cosmology models are presented.

Aluminum to germanium inversion in mullite‐type RAlGeO5: Characterization of a rare phenomenon for R = Y, Sm–Lu

AbstractMullite‐type RMn2O5 (R = Y, rare‐earth element) ceramics are of ongoing research attentions because of their interesting crystal‐chemical, physical, and thermal properties. We report a detailed structural, spectroscopic and thermal analysis of the series of mullite‐type RAlGeO5 (R = Y, Sm‐Lu) phases. Polycrystalline samples are prepared by solid‐state synthesis methods. Each sample is characterized by X‐ray powder diffraction followed by Rietveld refinements, showing that they are isotypic and crystallize in the space group Pbam. The change of the metric parameters is explained in term of the lanthanide contraction effect. A rare inversion of Al/Ge between octahedral and pyramidal sites have been observed for these mullite‐type so called O10 compounds, and the inversion parameter found to be between 0.22(1) and 0.30(1) for different R‐cations. The <Al/Ge–O> bond distances and their bond valence sums (BVSs) support the respective inversions. Density functional theory (DFT) calculated phonon density of states (PDOS) and electronic band structures are compared for the vibrational and electronic band gap features respectively. Analysis of UV/Vis absorption spectra using both derivation of absorption spectra fitting (DASF) and Tauc's methods demonstrates that each of the RAlGeO5 O10 compounds is high bandgap semiconductor, possessing direct transition between 4.1(1) and 5.4(1) eV. Both Raman and Fourier transform infrared spectra show clear red shift (quasi‐harmonic) of the vibrational wavenumbers with respect to the ionic radii of the R‐cations. Selective Raman bands at higher wavenumber region further complement the inversion of Al/Ge between two coordination sites. The higher decomposition temperature of the RAlGeO5 compounds, compared to those of RMn2O5 phases, is explained in terms of higher bond strength of Al/Ge‐O than those of Mn‐O. Irrespective to the inversion between Al‐ and Ge‐sites, the decomposition temperature also depends on the type of R‐cation in RAlGeO5.

The clustering of galaxies in the DESI imaging legacy surveys DR8: I. The luminosity and color dependent intrinsic clustering

In a recent study, we developed a method that models the impact of photometric redshift uncertainty on the two-point correlation function (2PCF). Using this method, we simultaneously obtained both the intrinsic clustering strength and the photometric redshift errors by fitting the projected 2PCF with two integration depths along the line-of-sight. Herein, we apply this method to the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys Data Release 8 (LS DR8), which is the largest galaxy sample currently available. We separate the galaxies into 20 samples in eight redshift bins, from z = 0.1 to z = 1.0, and several z-band absolute magnitude bins, with Mz ≤ −20. These galaxies are further divided into red and blue subsamples according to their M r 0.5 - M z 0.5 colors. We measure the projected 2PCFs for all these galaxy subsamples and fit them using our photometric redshift 2PCF model. We find that the photometric redshift errors are smaller in the red subsamples than in the overall population. In contrast, some systematic photometric redshift errors exist in the blue subsamples, such that some of the subsamples show a significantly enhanced 2PCF on large scales. Therefore, separately focusing only on the red subsamples and on all the subsamples, we find that the biases of the galaxies in these subsamples exhibit clear color, redshift, and luminosity dependencies; the brighter red galaxies at higher redshift are more biased than their bluer and low-redshift counterparts. Apart from the best-fit set of parameters, σz and b, from this state-of-the-art photometric redshift survey, we obtain high-precision intrinsic clustering measurements for these 40 red- and all-galaxy subsamples. These measurements, on large and small scales, hold important information regarding cosmology and galaxy formation that will be used in our subsequent probes in this series.

Effect of silver iodide (AgI) on structural and optical properties of cobalt doped lead-borate glasses

Materials with distinct optical characteristics are still being explored. Hence, AgI doped cobalt-lead borate glasses of composition [29.7PbO – 0.3CoO – (70-x) B2O3 – xAgI (x = 0.0, 0.25, 0.5 and 1.0 mol%)] were synthesized via conventional melt quenching technique. XRD patterns and SEM micrographs confirmed the prepared glass system's amorphous nature; EDAX elemental analysis was also performed. According to increased density and decreased average boron-boron separation, AgI additives were found to enforce the glassy network's compactness. FT-IR analysis indicates the entry of AgI as a network modifier by converting the tetrahedral (BO4) to trigonal (BO3) units with NBO's ratio growth. The Raman data accords with FT-IR results and provides complementary information around these glasses by detecting additional structural groups. The ellipsometer spectroscopy technique confirmed the ability to control the refractive index of the current glassy system with the AgI addition. The absorption spectra clarified a gradual enhancement of Co3+/Co2+ ions at tetrahedral and/or octahedral sites by AgI additives. Ligand field parameters, such as crystal field intensity (10Dq)and Racah parameters(B&C), were accurately determined. The calculated nephelauxetic ratio (β)indicated a reducing covalent nature among Co2+ ions and the nearby bonds. Calculations of the UV absorption edges showed a clear red-shift by AgI additives with a remarkable gradual reduction of the optical band gap. Besides, the Urbach energy increased, and the metallization criterion varied from 0.394 to 0.391 eV-1, reflecting the semiconductor character of these glasses. The spectral tunability for optical absorption provided here by AgI additives qualifies present glasses as optically active materials for several potential applications in multi-functional optical devices operating in the visible and near-infrared (NIR) spectral regimes.