Related papers: Enhanced methods for computing spectra from CO5BOL…
Stromgren indices v and b are combined with broad-band index I, and a new index p, the short wavelength half of the v band, to estimate CN 4215A molecular absorption in a sample of stars in M22. The results have been used to estimate carbon…
Computational methods that operate on three-dimensional molecular structure have the potential to solve important questions in biology and chemistry. In particular, deep neural networks have gained significant attention, but their…
Context : Star formation takes place in cold dense cores in molecular clouds. Earlier observations have found that dense cores exhibit subsonic non-thermal velocity dispersions. In contrast, CO observations show that the ambient large-scale…
The study of multiple molecular spectral lines in gas infalling sources can provide the physical and chemical properties of these sources and help us estimate their evolutionary stages. We report line detections within the 3 mm band using…
The increasing sensitivity and resolution of ground-based telescopes have enabled the detection of gas-phase complex organic molecules (COMs) across a variety of environments. Many of the detected species are expected to form on the icy…
We present a catalogue of H-band spectra for 85 stars of approximately solar abundance observed at a resolving power of 3000 with the KPNO Mayall 4m FTS. The atlas covers spectral types O7-M5 and luminosity classes I-V as defined on the MK…
A new method (NM) for filtering three-dimensional reconstructed densities is proposed. The algorithm is tested with simulated spectra and employed to study the electronic structure of the rare-earth compound LaB6. For this system, momentum…
While the best tracer of the molecular component and its dynamics in galaxies is the CO molecule, which excitation is revealed by its isotopic and (2-1)/(1-0) ratios, the denser gas is revealed by molecules such as HCN, HNC, HCO+ or CN,…
Any distortion of a chemical structure causes new features to appear in the absorption spectrum of the structure, especially in the visible and near UV (see Paper I). Chemical modeling, using molecular orbital theory, showed that the…
We are conducting a high-resolution follow-up of candidate EMP stars extracted from the Sloan Digital Sky Survey (SDSS; York et al. 2000) using UVES at the VLT. Three of the programme stars, SDSS J0912+0216, SDSS J1036+1212 and SDSS…
Spectra in the CH $^2\Pi_{1/2}$, J=1/2, F=1-1 transition at 3335 MHz were obtained in three 5-point crosses centered on the Galactic plane at $\ell =$ 50$\arcdeg$, 100$\arcdeg$, and 110$\arcdeg$. The lines of sight traverse both Giant…
The determination of chemical composition is crucial for investigating the formation and evolution of star forming galaxies and provides a powerful tool to constrain the effects of galactic winds and accretion from the cosmic web. In this…
We have observed several emission lines of two Nitrogen-bearing (C2H5CN and C2H3CN) and two Oxygen-bearing (CH3OCH3 and HCOOCH3) molecules towards a sample of well-known hot molecular cores (HMCs) in order to check whether the chemical…
Almost all the physics of star formation critically depends on the number density of the molecular gas. However, the methods to estimate this key property often rely on uncertain assumptions about geometry, depend on overly simplistic…
L-band spectroscopy is a powerful probe of cool low-gravity atmospheres: The P, Q, and R branch fundamental transitions of methane near 3.3 $\mu$m provide a sensitive probe of carbon chemistry; cloud thickness modifies the spectral slope…
A major limitation and a continuing source of confusion in the interpretation of molecular line observations has been the large degree of chemical complexity that is observed in star-forming molecular cores. The past decade has seen…
Observations to characterize planets larger than Earth but smaller than Neptune have led to largely inconclusive interpretations at low spectral resolution due to hazes or clouds that obscure molecular features in their spectra. However,…
Astronomical near-infrared Diffuse-Interstellar-Bands (DIBs) were characterized by pure carbon Fullerene and Graphene molecules comparing with laboratory experiment and with Time-Dependent Density-Functional-Theory (TD-DFT) analysis. It is…
This study presents a novel Machine Learning Algorithm, named Chemical Environment Graph Neural Network (ChemGNN), designed to accelerate materials property prediction and advance new materials discovery. Graphitic carbon nitride (g-C3N4)…
We describe a pseudo-3D photoionization code, NEBU_3D and its associated visualization tool, VIS_NEB3D, which are able to easily and rapidly treat a wide variety of nebular geometries, by combining models obtained with a 1D photoionization…