- ID:
- ivo://CDS.VizieR/VI/148
- Title:
- Collision Strengths for [Co II] Forbidden Lines - SS4
- Short Name:
- VI/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The list presents electron collision strengths for the forbidden transitions between the fifteen lowest levels of the singly-ionized cobalt, Co^+^, as a function of the electron energy, in an intermediate coupling scheme using the Breit-Pauli relativistic terms as implemented in an R-matrix atomic scattering code. An atomic target for the R-matrix scattering defined by 26 atomic terms is used in these calculations. The data are particularly useful for analyzing the thermodynamic conditions of supernova ejecta.
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- ID:
- ivo://CDS.VizieR/VI/149
- Title:
- Collision Strengths for [Co III] Forbidden Lines - SS5
- Short Name:
- VI/149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The list presents electron collision strengths for the forbidden transitions between the fifteen lowest levels of the doubly-ionized cobalt, Co^2+^, as a function of the electron energy, in an intermediate coupling scheme using the Breit-Pauli relativistic terms as implemented in an R-matrix atomic scattering code. An atomic target for the R-matrix scattering defined by 36 atomic terms is used in these calculations. The data are particularly useful for analyzing the thermodynamic conditions of supernova ejecta.
- ID:
- ivo://CDS.VizieR/J/ApJ/788/24
- Title:
- Collision strengths for transitions in Fe VII
- Short Name:
- J/ApJ/788/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extensive calculations have been performed for electron impact excitation collision strengths and oscillator strengths for the Fe VII extreme ultraviolet lines of astrophysical importance. The collision strengths for fine-structure transitions are calculated in the B-spline Breit-Pauli R-matrix approach. The target wavefunctions have been calculated in the multiconfiguration Hartree-Fock method with term-dependent non-orthogonal orbitals. The close-coupling expansion includes 189 fine-structure levels of Fe VII belonging to terms of the ground 3p^6^ 3d^2^ and excited 3p^5^ 3d^3^, 3p^6^ 3d4l, 3p^6^ 3d5s, and 3p^6^ 3d5p configurations. The effective collision strengths are determined from the electron excitation collision strengths by integration over a Maxwellian distribution of electron velocities. The effective collision strengths are provided for 17766 fine-structure transitions at electron temperatures from 10^4^ to 10^7^ K. Our results normally agree with the previous R-matrix frame-transformation calculations by Witthoeft & Badnell (2008A&A...481..543W). However, there are important differences for some transitions with the previous calculations. The corrections to the previous results are mainly due to more extensive expansions for the Fe VII target states.
- ID:
- ivo://CDS.VizieR/J/ApJ/812/174
- Title:
- Collision strengths in FeIX
- Short Name:
- J/ApJ/812/174
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Collision strengths and thermally averaged collision strengths for a large number of extreme-ultraviolet lines of FeIX arising by electron impact have been reported. The thermally averaged collision strengths are calculated at electron temperatures in the range 10^4^-10^7^K for the 122043 forbidden and allowed transitions between the 370 fine-structure levels. The atomic parameters for FeIX play an important role in modeling of various astrophysical plasmas, including especially the solar corona. The B-spline Breit-Pauli R-matrix method has been used in the calculation of collision strengths. The target wave functions and transition probabilities have been determined by combining the multiconfiguration Hartree-Fock method with the B-spline box-based multichannel expansions. We have included 370 fine-structure levels of FeIX in the energy region up to 3s^2^3p^5^5s states. The close-coupling expansion includes levels of the 3s^2^3p^6^, 3s^2^3p^5^3d, 4l, 5s, 3s3p^6^3d, 4s, 4p, 3s^2^3p^4^3d^2^, 3s3p^5^3d^2^ configurations and some low-lying levels of the 3s^2^3p^3^3d^3^ configuration in our collision strengths and transition probabilities calculations. There is a good agreement with the previous R-matrix collision strength calculations by Storey et al. (2002, J/A+A/394/753) and Del Zanna et al. (2014, J/A+A/565/A77) for transitions between the lowest 17 levels of the 3s^2^3p^6^, 3s^2^3p^5^3d and 3s3p^6^3d configurations, especially for electron temperatures logT(K)>=5.0. The transitions between the first 17 levels are dominated by Rydberg series of resonances converging to the levels of the 3s^2^3p^4^3d^2^ configuration. The present results and the calculation of Del Zanna et al. show significant differences for many weaker forbidden and intercombination transitions with thermally averaged collision strengths smaller than 0.01.
- ID:
- ivo://CDS.VizieR/J/ApJ/526/544
- Title:
- Collision strengths in S III
- Short Name:
- J/ApJ/526/544
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Electron collisional excitation strengths for transitions between the 3s^2^3p^2^ ^3^P_0,1,2_, ^1^D_2_, and ^1^S_0_ levels and from these levels to the fine-structure levels of the excited 3s3p^3^, 3s^2^3p3d, 3s^2^3p4s, 3s^2^3p4p, and 3s^2^3p4d configurations of S III are calculated in R-matrix approach. We considered 49 fine-structure levels arising from the 27 LS 3s^2^3p^2^ ^3^P, ^1^D, ^1^S, 3s3p^3^ ^5,3^S_o_, ^1,3^D_o_, ^1,3^P_o_, 3s^2^3p3d ^1,3^P_o_, ^1,3^D_o_, ^1,3^F_o_, 3s^2^3p4s ^1,3^P_o_, 3s^2^3p4p ^1,3^S, ^1,3^P, ^1,3^D, 3s^2^3p4d ^1,3^P_o_, and ^1,3^D_o_ states. These target levels are represented by fairly extensive configuration-interaction wave functions. The collision strengths for transitions between fine-structure levels are calculated by transforming the LS-coupled K-matrices to K-matrices in an intermediate coupling scheme. Complicated resonance structures converging to excited state thresholds are explicitly included in collision strengths. The effective collision strengths are obtained from the total collision strengths by integrating over a Maxwellian velocity distribution. These are tabulated over a wide electron temperature range (0.5 - 10) x 10^4^ K.
- ID:
- ivo://CDS.VizieR/J/ApJ/766/109
- Title:
- Color/age/metallicity gradients of E galaxies
- Short Name:
- J/ApJ/766/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to understand the past merging history of elliptical galaxies, we studied the optical-near-infrared (NIR) color gradients of 204 elliptical galaxies. These galaxies are selected from the overlap region of the Sloan Digital Sky Survey (SDSS) Stripe 82 and the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). The use of optical and NIR data (g, r, and K) provides large wavelength baselines, and breaks the age-metallicity degeneracy, allowing us to derive age and metallicity gradients. The use of the deep SDSS Stripe 82 images makes it possible for us to examine how the color/age/metallicity gradients are related to merging features. We find that the optical-NIR color and the age/metallicity gradients of elliptical galaxies with tidal features are consistent with those of relaxed ellipticals, suggesting that the two populations underwent a similar merging history on average and that mixing of stars was more or less completed before the tidal features disappeared. Elliptical galaxies with dust features have steeper color gradients than the other two types, even after masking out dust features during the analysis, which can be due to a process involving wet merging. More importantly, we find that the scatter in the color/age/metallicity gradients of the relaxed and merging feature types decreases as their luminosities (or masses) increase at M>10^11.4^M_{sun}_ but stays large at lower luminosities. Mean metallicity gradients appear nearly constant over the explored mass range, but a possible flattening is observed at the massive end.
- ID:
- ivo://CDS.VizieR/J/A+A/397/361
- Title:
- 15-color BATC photometry of Landolt SA95 field
- Short Name:
- J/A+A/397/361
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present a set of photometric observations in 15 colors of stars in the Landolt SA95 field with the BATC (Beijing-Arizona-Taipei-Connecticut) system. The wavelengths covered by the system range from 300nm to 1000nm. Visual magnitudes of the stars studied in the field are from the 10th to 20th mag. The observational methodology and the data reduction procedures are described. The relationships between the BATC intermediate-band system and the Landolt UBVRI broad band system are obtained. A catalogue of the photometry has been produced which contains the spectral energy distributions (SEDs) of 3613 stars.
- ID:
- ivo://CDS.VizieR/J/A+A/478/701
- Title:
- Color excess of SDSS quasars with DLA systems
- Short Name:
- J/A+A/478/701
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyzed the spectroscopic and photometric database of the 5th data release of the Sloan Digital Sky Survey (SDSS) to search for evidence of the quasar reddening produced by dust embedded in intervening damped Ly{alpha} (DLA) systems. From a list of 5164 quasars in the interval of emission redshift 2.25<=z_e_<=3.5 and SDSS spectra with signal-to-noise ratio SNR>~4, we built up an "absorption sample" of 248 QSOs with a single DLA system in the interval of absorption redshift 2.2<z_a_<=3.5 and a "pool" of 1959 control QSOs without DLA systems or strong metal systems. For each QSO of the absorption sample we extracted from the pool a subset of control QSOs that are closest in redshift and magnitude.
- ID:
- ivo://CDS.VizieR/J/A+A/423/755
- Title:
- Color-Induced Displacement double stars in SDSS
- Short Name:
- J/A+A/423/755
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the first successful application of the astrometric color-induced displacement technique (CID, the displacement of the photocenter between different band-passes dur to a varying contribution of differently colored components to the total light), originally proposed by Wielen (1996A&A...314..679W) for discovering unresolved binary stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/500/714
- Title:
- Color-magnitude relation in CL 1358+62
- Short Name:
- J/ApJ/500/714
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use a large, multicolor mosaic of HST WFPC2 images to measure the colors and morphologies of 194 spectroscopically confirmed members of the rich galaxy cluster CL 1358+62 at z=0.33. We study the color-magnitude (CM) relation as a function of radius in the cluster to a limit of 4.6' from the center, equivalent to 1.6h^-1^_50_Mpc. The intrinsic scatter in the rest-frame B-V CM relation of the elliptical galaxies is very small, ~0.022mag. The CM relation of the ellipticals does not depend significantly on the distance from the cluster center. In contrast, the CM relation for the S0 galaxies does depend on radius: the S0's in the core follow a CM relation similar to that of the ellipticals, but at large radii (R>0.7h^-1^_50_Mpc) the S0's are systematically bluer and the scatter in the CM relation approximately doubles, to ~0.043mag. The blueing of the S0's at large radii is significant at the 95% confidence level. These results imply that the S0 galaxies in the outer parts of the cluster have formed stars more recently than the S0's in the inner parts.