- ID:
- ivo://CDS.VizieR/J/ApJ/768/81
- Title:
- Ethyl cyanide, CH_3_CH_2_CN, vibrational states
- Short Name:
- J/ApJ/768/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Ethyl cyanide, CH_3_CH_2_CN, is an important interstellar molecule with a very dense rotational-vibrational spectrum. On the basis of new laboratory data in the range of 17-605GHz and ab initio calculations, two new vibrational states, {nu}_12_ and {nu}_20_, have been detected in molecular clouds of Orion. Laboratory data consist of Stark spectroscopy (17-110GHz) and frequency-modulated spectrometers (GEM laboratory in Valladolid: 17-170, 270-360GHz; Toyama: 26-200GHz; Emory: 200-240GHz; Ohio State: 258-368GHz; and JPL: 270-318, 395-605GHz). More than 700 distinct lines of each species were measured in J up to 71 and in K_a_ up to 25. The states were fitted with Watson's S-reduction Hamiltonian. The two new states have been identified in the interstellar medium toward the Orion Nebula (Orion KL). The ground state, the isotopologues of CH_3_CH_2_CN, and the vibrationally excited states have been fitted to obtain column densities and to derive vibrational temperatures. All together, ethyl cyanide is responsible for more than 2000 lines in the observed frequency range of 80-280GHz.
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5722. Ethylene oxide spectrum
- ID:
- ivo://CDS.VizieR/J/ApJ/499/517
- Title:
- Ethylene oxide spectrum
- Short Name:
- J/ApJ/499/517
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The cyclic molecule ethylene oxide (c-C_2_H_4_O) has recently been detected in the interstellar source Sgr B2N. Previous laboratory work on the rotational spectrum of this molecule extends only to a frequency of 123GHz. We report here the extension of the laboratory rotational spectrum of this species through the frequency range 262358GHz using a new fast scan spectrometer (fast scan submillimeter spectroscopic technique, FASSST). The newly measured lines have been combined with previous data at lower frequencies to form a data set consisting of 662 lines that has been assigned and fitted via a standard semirigid asymmetric top analysis. The spectral constants obtained from the fit have allowed us to predict the frequencies of many additional lines.
- ID:
- ivo://CDS.VizieR/J/A+A/610/A44
- Title:
- Ethyl isocyanide submillimeter wave spectroscopy
- Short Name:
- J/A+A/610/A44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- About 40 cyanide molecules have been detected in the interstellar medium, but only 3 examples of organic isocyanide molecules were observed in this medium. Ethyl isocyanide is one of the best candidates for possible detection. To date, measurements of rotational spectra are limited to 40 GHz. The extrapolation of the prediction in the millimeter wave domain is inaccurate and does not permit an unambiguous detection. The rotational spectra were reinvestigated from 0.15 to 1THz. Using the new prediction, we searched for the compound ethyl isocyanide in Orion KL and Sgr B2. We newly assigned 2906 transitions and fitted these new data with those from previous studies, reaching quantum numbers up to J=103 and Ka=30. The asymmetric top Hamiltonian proposed by Watson in the Ir representation was used for the analysis, and both reductions A and S were tested. The search for CH_3_CH_2_NC in SgrB2 (IRAM 30m) and Orion KL (IRAM 30m, ALMA Science Verification) result in a non-detection; upper limits to the column density were derived.
- ID:
- ivo://CDS.VizieR/J/A+A/639/A129
- Title:
- Ethyl methyl sulfide rotational spectroscopy
- Short Name:
- J/A+A/639/A129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sulfur-containing molecules constitute only 8% of the molecules observed in the interstellar medium (ISM) in spite that sulfur has been shown to be an abundant element in the ISM. In order to understand the chemical behaviour of the ISM and specific cases like the missing sulfur reservoir, a detailed chemical molecular composition in the ISM must be mapped out. Our goal is the investigation of the rotational spectrum of ethyl methyl sulfide, CH_3_CH_2_SCH_3_, which seems to be a potential candidate to be observed in the ISM since the simpler analogs, CH_3_SH and CH_3_CH_2_SH, have been already detected. Rotational spectrum of ethyl methyl sulfide has been observed before, but its experimental rotational parameters are not precise enough to allow its detection in the ISM. The rotational spectrum of ethyl methyl sulfide in the frequency range 72-116.5GHz was measured using a broadband millimeter-wave spectrometer based on radio astronomy receivers with fast Fourier transform backends. The spectral searches and identification of the vibrational excited states of ethyl methyl sulfide was supported by high-level ab initio calculations on the harmonic and anharmonic force fields. The rotational spectra for the trans and gauche conformers of ethyl methyl sulfide was analyzed and a total of 172 and 259 rotational transitions were observed for each one, respectively. The observation of A-E internal rotation splittings allowed the experimental determination of the V3 hindered internal rotation barrier height for both trans and gauche species. In addition, the vibrational excited states, resulting from the lowest frequency vibrational mode nu30 were identified for both conformers. The new experimental rotational parameters were employed to search for ethyl methyl sulfide in the cold and warm molecular clouds Orion KL, Sgr B2(N), B1-b and TMC-1, using the spectral surveys captured by IRAM 30m at 3mm and 2mm.
- ID:
- ivo://CDS.VizieR/J/A+A/381/500
- Title:
- Eu abundances in F and G disk stars
- Short Name:
- J/A+A/381/500
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Europium abundances for 74 F and G dwarf stars of the galactic disk have been determined. The stars were selected from the sample of Edvardsson et al. (1993, Cat. <J/A+A/275/101>) and [Eu/Fe] shows a smaller scatter and a slightly weaker trend with [Fe/H] than found by Woolf et al. (1995ApJ...453..660W). The data of the two analyses are homogeneized and merged.
- ID:
- ivo://CDS.VizieR/J/MNRAS/444/744
- Title:
- EUADP sample. [N/{alpha}] distribution
- Short Name:
- J/MNRAS/444/744
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report here a study of nitrogen and {alpha}-capture element (O, S, and Si) abundances in 18 damped Ly{alpha} absorbers (DLAs) and sub-DLAs drawn from the European Southern Observatory's Ultraviolet Visual Echelle Spectrograph (ESO-UVES) Advanced Data Products (EUADP) data base. We report nine new measurements, five upper and four lower limits of nitrogen that when compiled with available nitrogen measurements from the literature makes a sample of 10^8^ systems. The extended sample presented here confirms the [N/{alpha}] bimodal behaviour suggested in previous studies. Three-quarter of the systems show <[N/{alpha}]>=-0.85 (+/-0.20dex) and one-quarter of the systems show that ratios are clustered at <[N/{alpha}]>=-1.41 (+/-0.14dex). The high [N/{alpha}] plateau is consistent with the Hii regions of dwarf irregular and blue compact dwarf galaxies although extended to lower metallicities and could be interpreted as the result of a primary nitrogen production by intermediate mass stars. The low [N/{alpha}] values are the lowest ever observed in any astrophysical site. In spite of this fact, even lower values could be measured with the present instrumentation, but we do not find them below [N/{alpha}]~-1.7. This suggests the presence of a floor in [N/{alpha}] abundances, which along with the lockstep increase of N and Si may indicate a primary nitrogen production from fast rotating, massive stars in relatively young or unevolved systems.
- ID:
- ivo://CDS.VizieR/J/ApJS/256/9
- Title:
- Euclid preparation. XIV. C3R2 survey DR3
- Short Name:
- J/ApJS/256/9
- Date:
- 18 Jan 2022 14:01:22
- Publisher:
- CDS
- Description:
- The Complete Calibration of the Color-Redshift Relation (C3R2) survey is obtaining spectroscopic redshifts in order to map the relation between galaxy color and redshift to a depth of i~24.5 (AB). The primary goal is to enable sufficiently accurate photometric redshifts for Stage IV dark energy projects, particularly Euclid and the Nancy Grace Roman Space Telescope (Roman), which are designed to constrain cosmological parameters through weak lensing. We present 676 new high-confidence spectroscopic redshifts obtained by the C3R2 survey in the 2017B-2019B semesters using the DEIMOS, LRIS, and MOSFIRE multiobject spectrographs on the Keck telescopes. Combined with the 4454 redshifts previously published by this project, the C3R2 survey has now obtained and published 5130 high-quality galaxy spectra and redshifts. If we restrict consideration to only the 0.2<z_p_<2.6 range of interest for the Euclid cosmological goals, then with the current data release, C3R2 has increased the spectroscopic redshift coverage of the Euclid color space from 51% (as reported by Masters+ 2017, J/ApJ/841/111) to the current 91%. Once completed and combined with extensive data collected by other spectroscopic surveys, C3R2 should provide the spectroscopic calibration set needed to enable photometric redshifts to meet the cosmology requirements for Euclid, and make significant headway toward solving the problem for Roman.
- ID:
- ivo://CDS.VizieR/J/PAZh/28/41
- Title:
- Eu III oscillator strengths
- Short Name:
- J/PAZh/28/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The calculations of the spectrum and oscillator strengths for the 4f^7^-(4f^6^5d+4f^6^6s) Eu III transitions. The calculations were performed with Cowan's RCN-RCG-RCE codes in the single-configuration approximation. The new oscillator strengths were tested by analyzing the Europium abundances using Eu II and Eu III lines in the spectra of hot peculiar stars ({alpha}^2^ CVn is a typical representative) and a cool peculiar stars ({beta} CrB is a typical representative).
5729. European HST Archive TAP
- ID:
- ivo://esavo/ehst/tap
- Title:
- European HST Archive TAP
- Short Name:
- Hubble/TAP
- Date:
- 06 Sep 2024 06:58:18
- Publisher:
- European Space Agency
- Description:
- This service provides access to observations and catalogs from the ESA Hubble Space Observatory mission hosted at the ESAC Science Data Centre
- ID:
- ivo://esavo/jwst/tap
- Title:
- European JWST Archive TAP
- Short Name:
- JWST
- Date:
- 06 Sep 2024 06:58:39
- Publisher:
- European Space Agency
- Description:
- This service provides access to observations from the European JWST Science Archive hosted at the ESAC Science Data Centre.