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Start Over Subject atomic physics Result Type text/xml+votable
751. VUV absorption cross section of CO_2_
ID:
ivo://CDS.VizieR/J/A+A/609/A34
Title:
VUV absorption cross section of CO_2_
Short Name:
J/A+A/609/A34
Date:
21 Oct 2021
Publisher:
CDS
Description:
We quantify the temperature dependency of the VUV absorption cross section of carbon dioxide. The VUV absorption cross section of CO_2_ increases with the temperature. The absorption we measured at 150K seems to be close to the absorption of CO_2_ in the fundamental ground state. The absorption cross section can be separated in two parts: a continuum and a fine structure superimposed on the continuum. The variation of the continuum of absorption can be represented by the sum of three gaussian functions. We used these data in our 1D thermo-photochemical model in order to study their impact on the predicted atmospheric composition of warm exoplanets. Using data at high temperature in thermo-photochemical models modifies significantly the abundance and the photodissociation rates of many species, in addition to carbon dioxide, such as methane and ammonia. These deviations have an impact on synthetic transmission spectra, leading to variations of up to 5ppm.
752. Warm ISM in the Sagittarius A Complex
ID:
ivo://CDS.VizieR/J/A+A/588/A131
Title:
Warm ISM in the Sagittarius A Complex
Short Name:
J/A+A/588/A131
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the spatial and spectral distribution of the local standard of rest (LSR) velocity resolved submillimetre emission from the warm (25-90K) gas in the Sgr A Complex, located in the Galactic centre. We present large-scale submillimetre heterodyne observations towards the Sgr A Complex covering ~300-arcmin2. These data were obtained in the frame of the Herschel EXtraGALactic guaranteed time key program (HEXGAL) with the Herschel-HIFI satellite and are complemented with submillimetre observations obtained with the NANTEN2/SMART telescope as part of the NANTEN2/SMART Central Nuclear Zone Survey. The observed species are CO(J=4-3) at 461.0GHz observed with the NANTEN2/SMART telescope, and [CI] 3P1-3P0 at 492.2GHz, [CI] 3P2-3P1 at 809.3GHz, [NII] 3P1-3P0 at 1461.1GHz, and [CII] 2P3/2-2P1/2 at 1900.5GHz observed with the Herschel-HIFI satellite. The observations are presented in a 1km/s spectral resolution and a spatial resolution ranging from 46-arcsec to 28-arcsec. The spectral coverage of the three lower frequency lines is +/-200km/s, while in the two high frequency lines, the upper LSR velocity limit is +94km/s and +145km/s for the [NII] and [CII] lines, respectively. The spatial distribution of the emission in all lines is very widespread. The bulk of the carbon monoxide emission is found towards Galactic latitudes below the Galactic plane, and all the known molecular clouds are identified. Both neutral atomic carbon lines have their brightest emission associated with the +50km/s cloud. Their spatial distribution at this LSR velocity describes a crescent-shape structure, which is probably the result of interaction with the energetic event (one or several supernovae explosions) that gave origin to the non-thermal Sgr A-East source. The [CII] and [NII] emissions have most of their flux associated with the thermal arched-filaments and the H region and bright spots in [CII] emission towards the central nuclear disk (CND) are detected. Warm Gas at very high (|Vlsr|>100km/s) LSR velocities is also detected towards the line of sight to the Sgr A Complex, and it is most probably located outside the region, in the X1 orbits.
753. Warm molecular hydrogen in nearby LIRGs
ID:
ivo://CDS.VizieR/J/AJ/156/295
Title:
Warm molecular hydrogen in nearby LIRGs
Short Name:
J/AJ/156/295
Date:
21 Oct 2021
Publisher:
CDS
Description:
Mid-infrared molecular hydrogen (H_2_) emission is a powerful cooling agent in galaxy mergers and in radio galaxies; it is a potential key tracer of gas evolution and energy dissipation associated with mergers, star formation, and accretion onto supermassive black holes. We detect mid-IR H_2_ line emission in at least one rotational transition in 91% of the 214 Luminous Infrared Galaxies (LIRGs) observed with Spitzer as part of the Great Observatories All-sky LIRG Survey. We use H_2_ excitation diagrams to estimate the range of masses and temperatures of warm molecular gas in these galaxies. We find that LIRGs in which the IR emission originates mostly from the Active Galactic Nuclei (AGN) have about 100 K higher H_2_ mass-averaged excitation temperatures than LIRGs in which the IR emission originates mostly from star formation. Between 10% and 15% of LIRGs have H_2_ emission lines that are sufficiently broad to be resolved or partially resolved by the high-resolution modules of Spitzer's Infrared Spectrograph (IRS). Those sources tend to be mergers and contain AGN. This suggests that a significant fraction of the H_2_ line emission is powered by AGN activity through X-rays, cosmic rays, and turbulence. We find a statistically significant correlation between the kinetic energy in the H_2_ gas and the H_2_ to IR luminosity ratio. The sources with the largest warm gas kinetic energies are mergers. We speculate that mergers increase the production of bulk inflows leading to observable broad H_2_ profiles and possibly denser gas.
755. Xe II lines Stark broadening
ID:
ivo://CDS.VizieR/J/A+AS/116/359
Title:
Xe II lines Stark broadening
Short Name:
J/A+AS/116/359
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present here Stark widths and shifts for 20 Xe II multiplets which are of interest for laboratory plasma research as well as for the analysis of Hg-Mn stars spectra. For calculations the modified semiempirical approach was used. The obtained results are compared with the available experimental data.
756. X-ray line ratios for diverse ion collisions
ID:
ivo://CDS.VizieR/J/ApJ/844/7
Title:
X-ray line ratios for diverse ion collisions
Short Name:
J/ApJ/844/7
Date:
21 Oct 2021
Publisher:
CDS
Description:
Charge exchange (CX) has emerged in X-ray emission modeling as a significant process that must be considered in many astrophysical environments- particularly comets. Comets host an interaction between solar wind ions and cometary neutrals to promote solar wind charge exchange (SWCX). X-ray observatories provide astronomers and astrophysicists with data for many X-ray emitting comets that are impossible to accurately model without reliable CX data. Here, we utilize a streamlined set of computer programs that incorporate the multi-channel Landau-Zener theory and a cascade model for X-ray emission to generate cross sections and X-ray line ratios for a variety of bare and non-bare ion single electron capture (SEC) collisions. Namely, we consider collisions between the solar wind constituent bare and H-like ions of C, N, O, Ne, Na, Mg, Al, and Si and the cometary neutrals H2O, CO, CO2, OH, and O. To exemplify the application of this data, we model the X-ray emission of Comet C/2000 WM1 (linear) using the CX package in SPEX and find excellent agreement with observations made with the XMM-Newton RGS detector. Our analyses show that the X-ray intensity is dominated by SWCX with H, while H2O plays a secondary role. This is the first time, to our knowledge, that CX cross sections have been implemented into a X-ray spectral fitting package to determine the H to H2O ratio in cometary atmospheres. The CX data sets are incorporated into the modeling packages SPEX and Kronos.
757. Zeeman effect in sulfur monoxide (SO)
ID:
ivo://CDS.VizieR/J/A+A/605/A20
Title:
Zeeman effect in sulfur monoxide (SO)
Short Name:
J/A+A/605/A20
Date:
21 Oct 2021
Publisher:
CDS
Description:
Magnetic fields play a fundamental role in star formation processes and the best method to evaluate their intensity is to measure the Zeeman effect of atomic and molecular lines. However, a direct measurement of the Zeeman spectral pattern from interstellar molecular species is challenging due to the high sensitivity and high spectral resolution required. So far, the Zeeman effect has been detected unambiguously in star forming regions for very few non-masing species, such as OH and CN. We decided to investigate the suitability of sulfur monoxide (SO), which is one of the most abundant species in star forming regions, for probing the intensity of magnetic fields via the Zeeman effect. We investigated the Zeeman effect for several rotational transitions of SO in the (sub-)mm spectral regions by using a frequency-modulated, computer-controlled spectrometer, and by applying a magnetic field parallel to the radiation propagation (i.e., perpendicular to the oscillating magnetic field of the radiation). To support the experimental determination of the g factors of SO, a systematic quantum-chemical investigation of these parameters for both SO and O_2_ has been carried out.
758. ZnI atomic data
ID:
ivo://CDS.VizieR/J/A+A/536/A51
Title:
ZnI atomic data
Short Name:
J/A+A/536/A51
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present our calculated data including energy levels of 235 bound terms, oscillator strength gf-values of E1 transitions between these bound states and photoionization cross sections of all the terms for Zn I. The energy levels are listed in the file "znibound.dat" by symmetries in Ry, and the oscillator strength gf-values are listed in the file "gfvalues.dat". The photoionization cross section of each bound states is listed in an individual file named by the corresponding state. In each file, the first column is the photon energy in Ry, and other columns are photoionization cross section in Mb.
759. ZnII lines and collision strengths
ID:
ivo://CDS.VizieR/J/ApJ/804/76
Title:
ZnII lines and collision strengths
Short Name:
J/ApJ/804/76
Date:
21 Oct 2021
Publisher:
CDS
Description:
Damped Ly{alpha} (DLA) and sub-DLA absorbers in quasar spectra provide the most sensitive tools for measuring the element abundances of distant galaxies. The estimation of abundances from absorption lines depends sensitively on the accuracy of the atomic data used. We have started a project to produce new atomic spectroscopic parameters for optical and UV spectral lines using state-of-the-art computer codes employing a very broad configuration interaction (CI) basis. Here we report our results for ZnII, an ion used widely in studies of the interstellar medium (ISM) as well as DLAs and sub-DLAs. We report new calculations of many energy levels of Zn II and the line strengths of the resulting radiative transitions. Our calculations use the CI approach within a numerical Hartree-Fock framework. We use both nonrelativistic and quasi-relativistic one-electron radial orbitals. We have incorporated the results of these atomic calculations into the plasma simulation code Cloudy and applied them to a lab plasma and examples of a DLA and a sub-DLA. Our values of the ZnII {lambda}{lambda}2026,2062 oscillator strengths are higher than previous values by 0.10dex. The Cloudy calculations for representative absorbers with the revised Zn atomic data imply ionization corrections lower than calculated earlier by 0.05dex. The new results imply that Zn metallicities should be lower by 0.1dex for DLAs and by 0.13-0.15dex for sub-DLAs than in past studies. Our results can be applied to other studies of ZnII in the Galactic and extragalactic ISM.
760. ZnIV and ZnV oscillator strengths
ID:
ivo://CDS.VizieR/J/A+A/564/A41
Title:
ZnIV and ZnV oscillator strengths
Short Name:
J/A+A/564/A41
Date:
21 Oct 2021
Publisher:
CDS
Description:
For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. In a recent analysis of the ultraviolet (UV) spectrum of the DA-type white dwarf G191-B2B, 21 ZnIV lines were newly identified. Because of the lack of ZnIV data, transition probabilities of the isoelectronic GeVI were adapted for a first, coarse determination of the photospheric Zn abundance. Reliable ZnIV and ZnV oscillator strengths are used to improve the Zn abundance determination and to identify more Zn lines in the spectra of G191-B2B and the DO-type white dwarf RE 0503-289.

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