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Version 11 of the CHIANTI database and software package is presented. Advanced ionization equilibrium models have been added for low charge states of seven elements (C, N, O, Ne, Mg, Si and S), and represent a significant improvement…

Solar and Stellar Astrophysics · Physics 2024-03-26 R. P. Dufresne , G. Del Zanna , P. R. Young , K. P. Dere , E. Deliporanidou , W. T. Barnes , E. Landi

Based on the earlier papers in this series, we discuss here the errors in the prediction of the model, and compare with the error ranges in the spectra for individual elements. The predictions are spectra of $E^{-2.75 \pm 0.04}$ for…

Astrophysics · Physics 2007-05-23 Barbara Wiebel-Sooth , Peter L. Biermann , Hinrich Meyer

The Solar X-ray Spectrometer (XSM) payload onboard Chandrayaan-2 provides disk-integrated solar spectra in the 1-15 keV energy range with an energy resolution of 180 eV (at 5.9 keV) and a cadence of 1~second. During the period from…

In this paper, we calculate new line lists and opacities for the 12 bands of the A$^6\Sigma^{+}$ -- X$^6\Sigma^{+}$ transitions of the CrH molecule. Identified in objects of the new L dwarf spectroscopic class (many of which are brown…

Astrophysics · Physics 2009-11-07 Adam Burrows , R. S. Ram , Peter Bernath , C. M. Sharp , J. A. Milsom

The high-velocity cloud (HVC) Complex A is a probe of the physical conditions in the Galactic halo. The kinematics, morphology, distance, and metallicity of Complex A indicate that it represents new material that is accreting onto the…

Astrophysics of Galaxies · Physics 2013-08-06 Kathleen A. Barger , Lawrence M. Haffner , Bart P. Wakker , Alex S. Hill , Greg J. Madsen , Allison K. Duncan

It is shown that above the temperature of maximum abundance, recombination rates into the excited states of He-like ions that are calculated using earlier, more approximate methods differ markedly from rates obtained from recent…

Astrophysics · Physics 2007-11-26 J. Oelgoetz , C. J. Fontes , H. L. Zhang , M. Montenegro , S. N. Nahar , A. K. Pradhan

Coalescence of binary neutron star give rise to electromagnetic emission, kilonova, powered by radioactive decays of r-process nuclei. Observations of kilonova associated with GW170817 provided unique opportunity to study the heavy element…

Solar and Stellar Astrophysics · Physics 2019-02-13 Gediminas Gaigalas , Daiji Kato , Pavel Rynkun , Laima Radziute , Masaomi Tanaka

In a previous paper, we assembled a collection of medium-resolution spectra of 35 carbon stars, covering optical and near-infrared wavelengths from 400 to 2400 nm. The sample includes stars from the Milky Way and the Magellanic Clouds, with…

Solar and Stellar Astrophysics · Physics 2017-05-24 A. Gonneau , A. Lançon , S. C. Trager , B. Aringer , W. Nowotny , R. F. Peletier , P. Prugniel , Y. -P. Chen , M. Lyubenova

In this paper, we discuss atomic processes modifying the soft X-ray spectra in from optical depth effects like photoelectric absorption and electron scattering suppressing the soft X-ray lines. We also show the enhancement in soft X-ray…

High Energy Astrophysical Phenomena · Physics 2022-08-24 Priyanka Chakraborty , Gary Ferland , Marios Chatzikos , Andrew Fabian , Stefano Bianchi , Francisco Guzmán , Yuanyuan Su

High-resolution absorption and laser spectroscopy are used to determine electronic energy levels for Ho$^{3+}$ ions in K$_2$YF$_5$ microparticles. A total of 72 crystal-field energy levels, distributed among 8 multiplets, are assigned. This…

Materials Science · Physics 2025-10-21 Pakwan Chanprakhon , Michael F. Reid , Jon-Paul R. Wells

We describe an instrument which can be used to analyze complex chemical mixtures at high resolution and high sensitivity. Molecules are collisionally cooled with helium gas at cryogenic temperatures (~ 4-7 K), and subsequently detected…

Instrumentation and Detectors · Physics 2019-05-22 Jessica P. Porterfield , Lincoln Satterthwaite , Sandra Eibenberger , David Patterson , Michael C. McCarthy

Ever since the pioneering study of Spitzer, it has been widely recognized that grains play an important role in the heating and cooling of photo-ionized environments. This includes the diffuse ISM, as well as H II regions, planetary…

Astrophysics · Physics 2007-05-23 P. A. M. van Hoof , J. C. Weingartner , P. G. Martin , K. Volk , G. J. Ferland

The addition of metals to any gas can significantly alter its evolution by increasing the rate of radiative cooling. In star-forming environments, enhanced cooling can potentially lead to fragmentation and the formation of low-mass stars,…

Astrophysics · Physics 2009-11-13 Britton D. Smith , Steinn Sigurdsson , Tom Abel

This paper presents a study of the dependence of the simulated intensities of recombination lines from hydrogen and helium atoms on the number of $n\ell$-resolved principal quantum numbers included in the calculations. We simulate hydrogen…

Astrophysics of Galaxies · Physics 2025-04-15 F. Guzmán , M. Chatzikos , G. Ferland

Recent state-of-the-art calculations of A-values and electron impact excitation rates for Fe III are used in conjunction with the Cloudy modeling code to derive emission line intensity ratios for optical transitions among the fine-structure…

A novel, to the best of our knowledge, ultralow-temperature luminescence thermometry strategy is proposed, based on a measurement of relative intensities of hyperfine components in the spectra of Ho$^{3+}$ ions doped into a crystal. A…

Optics · Physics 2025-11-25 Marina N. Popova , Mosab Diab , Boris Z. Malkin

Cosmological datasets have great potential to elucidate the nature of dark energy and test gravity on the largest scales available to observation. Theoretical predictions can be computed with hi_class (www.hiclass-code.net), an accurate,…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-13 Emilio Bellini , Ignacy Sawicki , Miguel Zumalacárregui

The $m \alpha^6$ correction to energy is expressed in terms of an effective Hamiltonian $H^{(6)}$ for an arbitrary state of helium. Numerical calculations are performed for $n=2$ levels, and the previous result for the $2^3P$ centroid is…

Atomic Physics · Physics 2009-11-13 Krzysztof Pachucki

Brown dwarf spectra are rich in information revealing of the chemical and physical processes operating in their atmospheres. We apply a recently developed atmospheric retrieval tool to an ensemble of late T-dwarf (600-800K) near infrared…

The Particle Flow Algorithms adopted for future $e^{+}e^{-}$ colliders detectors and phase-II CMS upgrade require very high granularity calorimeters to deconvolve the individual contributions of particles in jets. This is especially true…

Instrumentation and Detectors · Physics 2017-11-27 Kostiantyn Shpak