| 1. |
- Abolfathi, Bela, et al.
(författare)
-
The Fourteenth Data Release of the Sloan Digital Sky Survey : First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment
- 2018
-
Ingår i: Astrophysical Journal Supplement Series. - : IOP Publishing Ltd. - 0067-0049 .- 1538-4365. ; 235:2
-
Tidskriftsartikel (refereegranskat)abstract
- The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014-2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V.
|
|
| 2. |
-
The Seventeenth Data Release of the Sloan Digital Sky Surveys : Complete Release of MaNGA, MaStar, and APOGEE-2 Data
- 2022
-
Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics (IOP). - 0067-0049 .- 1538-4365. ; 259:2
-
Tidskriftsartikel (refereegranskat)abstract
- This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.
|
|
| 3. |
- Aguado, D. S., et al.
(författare)
-
The Fifteenth Data Release of the Sloan Digital Sky Surveys : First Release of MaNGA-derived Quantities, Data Visualization Tools, and Stellar Library
- 2019
-
Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics Publishing (IOPP). - 0067-0049 .- 1538-4365. ; 240:2
-
Tidskriftsartikel (refereegranskat)abstract
- Twenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 July-2017 July). This is the third data release for SDSS-IV, and the 15th from SDSS (Data Release Fifteen; DR15). New data come from MaNGA-we release 4824 data cubes, as well as the first stellar spectra in the MaNGA Stellar Library (MaStar), the first set of survey-supported analysis products (e.g., stellar and gas kinematics, emission-line and other maps) from the MaNGA Data Analysis Pipeline, and a new data visualization and access tool we call "Marvin." The next data release, DR16, will include new data from both APOGEE-2 and eBOSS; those surveys release no new data here, but we document updates and corrections to their data processing pipelines. The release is cumulative; it also includes the most recent reductions and calibrations of all data taken by SDSS since first light. In this paper, we describe the location and format of the data and tools and cite technical references describing how it was obtained and processed. The SDSS website (www.sdss.org) has also been updated, providing links to data downloads, tutorials, and examples of data use. Although SDSS-IV will continue to collect astronomical data until 2020, and will be followed by SDSS-V (2020-2025), we end this paper by describing plans to ensure the sustainability of the SDSS data archive for many years beyond the collection of data.
|
|
| 4. |
- Zhang, X. H., et al.
(författare)
-
Benchmarking Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics : Si-like Ions from Cr xi to Zn xvii
- 2021
-
Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics Publishing (IOPP). - 0067-0049 .- 1538-4365. ; 257:2
-
Tidskriftsartikel (refereegranskat)abstract
- The multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction methods are used to provide excitation energies, lifetimes, and radiative transition data for the 604 (699, 702, 704, 704, 704, and 699) lowest levels of the 3s (2)3p (2), 3s3p (3), 3s (2)3p3d, 3p (4), 3s3p (2)3d, 3s (2)3d (2), 3p (3)3d, 3s3p3d (2), 3s3d (3), 3p3d (3), 3p (2)3d (2), 3s (2)3p4s, 3s (2)3p4p, 3s (2)3p4d, 3s (2)3p4f, 3s3p (2)4s, 3s3p (2)4p, 3s3p (2)4d, 3s3p (2)4f, 3s (2)3d4s, 3s (2)3d4p, 3p (3)4s, 3p (3)4p, 3s3p3d4s, 3s (2)3p5s, and 3s (2)3p5p configurations in Cr xi, (Mn xii, Fe xiii, Co xiv, Ni xv, Cu xvi, and Zn xvii). Previous line identifications of Fe xiii and Ni xv in the EUV and X-ray wavelength ranges are reviewed by comprehensively comparing the MCDHF theoretical results with available experimental data. Many recent identifications of Fe xiii and Ni xv lines are confirmed, and several new identifications for these two ions are proposed. A consistent atomic data set with spectroscopic accuracy is provided for the lowest hundreds of levels for Si-like ions of iron-group elements of astrophysical interest, for which experimental values are scarce. The uncertainty estimation method suggested by Kramida, applied to the comparison of the length and velocity line strength values, is used for ranking the transition data. The correlation of the latter with the gauge dependency patterns of the line strengths is investigated.
|
|
| 5. |
- Wang, Kai, et al.
(författare)
-
Calculations with spectroscopic accuracy : Energies and transition rates in the nitrogen isoelectronic sequence from Ar XII to Zn XXIV
- 2016
-
Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 223:1
-
Tidskriftsartikel (refereegranskat)abstract
- Combined relativistic configuration interaction and many-body perturbation calculations are performed for the 359 fine-structure levels of the 2s2 2p3, 2 s2p4, 2p5, 2s2 2p2 3l, 2 s2p3 3l, 2p4 3l, and 2s2 2p2 4l configurations in N-like ions from Ar XII to Zn XXIV. Complete and consistent data sets of energies, wavelengths, radiative rates, oscillator strengths, and line strengths for all possible electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions among the 359 levels are given for each ion. The present work significantly increases the amount of accurate data for ions in the nitrogen-like sequence, and the accuracy of the energy levels is high enough to enable the identification and interpretation of observed spectra involving the n=3, 4 levels, for which experimental values are largely scarce. Meanwhile, the results should be of great help for modeling and diagnosing astrophysical and fusion plasmas.
|
|
| 6. |
- Wang, Kai, et al.
(författare)
-
Energy levels, lifetimes and radiative rates for transitions in the bromine isoelectronic sequence La XXIII-Dy XXXII, W XL
- 2018
-
Ingår i: Atomic Data and Nuclear Data Tables. - : Elsevier. - 0092-640X .- 1090-2090. ; 123, s. 114-167
-
Tidskriftsartikel (refereegranskat)abstract
- Using the multiconfiguration Dirac-Fock method, calculations for the lowest 62 levels of the ([Ar] 3d(10))4s(2) 4p(5), ([Ar] 3d(10))4s(2)4p(3)4d(2), ([Ar] 3d(10))4s(2)4p(4)4d, ([Ar] 3d(10))4s4p(6), and ([Ar] 3d(10))4s4p(5)4d configurations are performed for the bromine isoelectronic sequence La XXIII-Dy XXXII, W XL. Results of energy levels, lifetimes, wavelengths, and electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole radiative rates are presented. In order to assess the accuracy of results, independent calculations for W XL have been carried out using the many-body perturbation theory (MBPT) method. Comparisons are made with available theoretical results from other calculations and the observed values of the Atomic Spectra Database of the National Institute of Standards and Technology. Energy levels are estimated to be accurate to better than 1%, and radiative rates (and lifetimes) are accurate to better than 20% for a majority of strong transitions. These results should be useful in many applications of lanthanide ions related to broad area of research such as applied physics, laser physics and fusion science. (C) 2017 Elsevier Inc. All rights reserved.
|
|
| 7. |
- Wang, Kai, et al.
(författare)
-
Extended calculations of energy levels, radiative properties, A(J), B-J hyperfine interaction constants, and Lande g(J)-factors for nitrogen-like Ge XXVI
- 2018
-
Ingår i: Journal of Quantitative Spectroscopy and Radiative Transfer. - : Pergamon Press. - 0022-4073 .- 1879-1352. ; 208, s. 134-151
-
Tidskriftsartikel (refereegranskat)abstract
- Employing two state-of-the-art methods, multiconfiguration Dirac-Hartree-Fock and second-order many body perturbation theory, highly accurate calculations are performed for the lowest 272 fine -structure levels arising from the 2s(2)2p(3), 2s(2)p(4), 2p(5), 2s(2)2p(2)3l (l = s, p, d), 2s2p(3)3l (l = s, p, d), and 2p(4)3l (l = s, p. d) configurations in nitrogen-like Ge XXVI. Complete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Lande g(J)-factors, and E1, E2, M1, M2 line strengths, oscillator strengths, and transition rates among these 272 levels are provided. Comparisons are made between the present two data sets, as well as with other available experimental and theoretical values. The present data are accurate enough for identification and deblending of emission lines involving the n = 3 levels, and are also useful for modeling and diagnosing fusion plasmas. (C) 2018 Elsevier Ltd. All rights reserved.
|
|
| 8. |
- Wang, Kai, et al.
(författare)
-
Extended calculations of energy levels, radiative properties, A(J), B-J hyperfine interaction constants, and Lande g(J)-factors for oxygen-like Kr XXIX
- 2017
-
Ingår i: Journal of Quantitative Spectroscopy and Radiative Transfer. - : Elsevier. - 0022-4073 .- 1879-1352. ; 194, s. 108-112
-
Tidskriftsartikel (refereegranskat)abstract
- Using the multiconfiguration Dirac-Fock method and the second-order many-body perturbation theory method, highly accurate calculations are performed for the lowest 344 fine-structure levels arising from the 2s(2)2p(4), 2s2p(5), 2p(6), 2s(2)2p(3)3s, 2s(2)2p(3)3p, 2s(2)2p(3)3d, 2s2p(4)3s, 2s2p(4)3p, 2s2p(4)3d, 2p(5)3s, 2p(5)3p, 2p(5)3d, 2s(2)2p(3)4s, 2s(2)2p(3)4p, 2s(2)2p(3)4d, 2s(2)2p(3)4f, and 2s2p(4)4s configurations in O-like Kr XXIX. Complete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Lande g(J)-factors, and E1, M1, E2, M2 transition rates, line strengths, and oscillator strengths among these 344 levels are obtained. Comparisons are made between our two different sets of results, as well as with the other available experimental and theoretical values. For O-like Kr only a few levels have been experimentally established. The accuracy of our calculated energies is however high enough to facilitate identifications of observed lines involving the n = 3,4 levels. The calculated data are also useful for modeling and diagnosing fusion plasmas. (C) 2017 Elsevier Ltd. All rights reserved.
|
|
| 9. |
- Wang, Kai, et al.
(författare)
-
Extended Calculations of Spectroscopic Data : Energy Levels, Lifetimes, and Transition Rates for O-like Ions from Cr XVII to ZnXXIII
- 2017
-
Ingår i: Astrophysical Journal Supplement Series. - : Bibliopolis, Edizioni di Filosofia e Scienze. - 0067-0049 .- 1538-4365. ; 229:2
-
Tidskriftsartikel (refereegranskat)abstract
- Employing two state-of-the-art methods, multiconfiguration Dirac-Hartree-Fock and second-order many-body perturbation theory, the excitation energies and lifetimes for the lowest 200 states of the 2 s(2)2p(4), 2s2p(5), 2p(6), 2s(2)2p(3)3s, 2s(2)2p(3)3p, 2s(2)2p(3)3d, 2s(2)p(4)3s, 2s2p(4)3p, and 2s2p(4)3d configurations, and multipole (electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2)) transition rates, line strengths, and oscillator strengths among these states are calculated for each O-like ion, from Cr XVII to Zn XXIII. Our two data sets are compared with the National Institute of Standards and Technology and CHIANTI compiled values, and previous calculations. The data are accurate enough for identification and deblending of new emission lines from the Sun and other astrophysical sources. The amount of high-accuracy data is significantly increased for the n. =. 3 states of several O-like ions of astrophysical interest, where experimental data are very scarce.
|
|
| 10. |
- Wang, K., et al.
(författare)
-
Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics : Cl-like Ions from Cr VIII to ZnXIV
- 2020
-
Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics Publishing (IOPP). - 0067-0049 .- 1538-4365. ; 246:1
-
Tidskriftsartikel (refereegranskat)abstract
- We use the multiconfiguration Dirac-Hartree-Fock (MCDHF) method combined with the relativistic configuration interaction approach (GRASP2K) to provide a consistent set of transition energies and radiative transition data for the lower n = 3 states in all Cl-like ions of astrophysical importance, from Cr VIII to Zn XIV. We also provide excitation energies calculated for Fe X using the many-body perturbation theory (MBPT, implemented within FAC). The comparison of the present MCDHF results with MBPT and with the available experimental energies indicates that the theoretical excitation energies are highly accurate, with uncertainties of only a few hundred cm(-1). Detailed comparisons for Fe X and Ni XII highlight discrepancies in the experimental energies found in the literature. Several new identifications are proposed.
|
|
