- ID:
- ivo://CDS.VizieR/J/ApJS/106/1
- Title:
- EFAR cluster and galaxy selection
- Short Name:
- J/ApJS/106/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The EFAR project is a study of 736 candidate elliptical galaxies in 84 clusters lying in two regions, toward Hercules-Corona Borealis and Perseus-Pisces-Cetus, at distances cz~6000-15000km/s. In this paper (the first of a series), we present an introduction to the EFAR project and describe in detail the selection of the clusters and galaxies in our sample. Fundamental data for the galaxies and clusters are given, including accurate new positions for each galaxy and redshifts for each cluster. The galaxy selection functions are determined by using diameters measured from Schmidt sky survey images for 2185 galaxies in the cluster fields. Future papers in this series will present the spectroscopic and photometric observations of this sample, investigate the properties of the fundamental plane for elliptical galaxies, and determine the large-scale peculiar velocity fields in these two regions of the universe.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/305/259
- Title:
- EFAR galaxies redshifts & velocity dispersions
- Short Name:
- J/MNRAS/305/259
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the spectroscopic data for the galaxies studied in the EFAR project, which is designed to measure the properties and peculiar motions of early-type galaxies in two distant regions. We have obtained 1319 spectra of 714 early-type galaxies over 33 observing runs on 10 different telescopes. We describe the observations and data reductions used to measure redshifts, velocity dispersions and the Mgb and Mg_2_ Lick linestrength indices. Detailed simulations and intercomparison of the large number of repeat observations lead to reliable error estimates for all quantities. The measurements from different observing runs are calibrated to a common zero-point or scale before being combined, yielding a total of 706 redshifts, 676 velocity dispersions, 676 Mgb linestrengths and 582 Mg_2_ linestrengths. The median estimated errors in the combined measurements are {Delta}cz=20km/s, {Delta}sigma/sigma=9.1%, {Delta}Mgb/Mgb=7.2% and {Delta}Mg_2_=0.015mag. Comparison of our measurements with published data sets shows no systematic errors in the redshifts or velocity dispersions, and only small zero-point corrections to bring our linestrengths on to the standard Lick system. We have assigned galaxies to physical clusters by examining the line-of-sight velocity distributions based on EFAR and ZCAT redshifts, together with the projected distributions on the sky. We derive mean redshifts and velocity dispersions for these clusters, which will be used in estimating distances and peculiar velocities and to test for trends in the galaxy population with cluster mass. The spectroscopic parameters presented here for 706 galaxies combine high-quality data, uniform reduction and measurement procedures, and detailed error analysis. They form the largest single set of velocity dispersions and linestrengths for early-type galaxies published to date.
4863. EFAR photometric data
- ID:
- ivo://CDS.VizieR/J/MNRAS/292/499
- Title:
- EFAR photometric data
- Short Name:
- J/MNRAS/292/499
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present R-band CCD photometry for 776 galaxies observed in the EFAR (Elliptical FAR away) project. The photometry is compared with photoelectric data, showing that a common zero-point good to better than 1% and a precision of 0.03mag per zero-point have been achieved. We give the circularly averaged surface brightness profiles and the photometric parameters of the 762 program galaxies, D(n) diameters (at 20.5mag/arcsec^2^), half-luminosity radii Re, total magnitudes m_T_, and average effective surface brightnesses <SBe>. More than 80% of the profiles have a global S/N ratio larger than 300. The extrapolation needed to derive total magnitudes is less than 10% for 80% of the fits. More than 80% of the galaxies have mean effective surface brightness larger than the observed sky brightness. In 90% of the profiles the estimate of the contamination of the sky by the galaxy light is less than 1%. We derive total magnitudes and half-luminosity radii to better than 0.15mag and 25%, respectively, for 90% of our sample. In contrast, external comparisons show that data in the literature can be strongly affected by systematic errors due to large extrapolations, small radial range, sky subtraction errors, seeing effects, and the use of a simple R^1/4^ fit. The resulting errors can easily amount to more than 0.5mag in the total magnitudes and 50% in the half-luminosity radii.
- ID:
- ivo://CDS.VizieR/J/AN/333/209
- Title:
- Effective area of X-ray microcalorimeter
- Short Name:
- J/AN/333/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The historical development of ground based astronomical telescopes leads us to expect that space-based astronomical telescopes will need to be operational for many decades. The exchange of scientific instruments in space will be a prerequisite for the long lasting scientific success of such missions. Operationally, the possibility to repair or replace key spacecraft components in space will be mandatory. We argue that these requirements can be fulfilled with robotic missions and see the development of the required engineering as the main challenge. Ground based operations, scientifically and technically, will require a low operational budget of the running costs. These can be achieved through enhanced autonomy of the spacecraft and mission independent concepts for the support of the software. This concept can be applied to areas where the mirror capabilities do not constrain the lifetime of the mission.
- ID:
- ivo://CDS.VizieR/J/A+A/493/697
- Title:
- Effective collision strength of Mg IX
- Short Name:
- J/A+A/493/697
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Electron impact excitation collision strengths are required for analysing and interpreting stellar observations. This calculation aims to provide fine-structure effective collision strengths for the Mg IX ion using a method that includes contributions from resonances. A 26-state Breit-Pauli R-matrix calculation has been performed.
- ID:
- ivo://CDS.VizieR/J/A+A/494/729
- Title:
- Effective collision strength of Mg V
- Short Name:
- J/A+A/494/729
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Electron-impact excitation collision strengths are required for the analysis and interpretation of stellar observations. This calculation aims to provide effective collision strengths for the MgV ion for a larger number of transitions and for a greater temperature range than previously available, using collision strength data that include contributions from resonances.
- ID:
- ivo://CDS.VizieR/J/A+A/537/A12
- Title:
- Effective collision strength of Ni XVII
- Short Name:
- J/A+A/537/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Electron-impact excitation collision strengths are required for the analysis and interpretation of stellar observations. This calculation aims to provide effective collision strengths for the Ni XVII ion using collision strength data which include contributions from resonances.
- ID:
- ivo://CDS.VizieR/J/A+A/436/1131
- Title:
- Effective collision strengths for Al III
- Short Name:
- J/A+A/436/1131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Effective collision strengths are presented for all the transitions among the 17 fine-structure levels arising from the 10 lowest LS states of Al III, i.e. those with configurations: 2p(6)3l (l=s,p,d); 2p(6)4l (l=s,p,d,f); 2p(6)5l (l=s,p,d). The effective collision strengths have been calculated using the R-matrix method. Each fine-structure level is assigned an index number ranging from 1 to 17, which are noted in the file 'j-index.dat'. The index values are used here in Table 7 to refer to particular transitions, eg. Index 1-3 denotes the 2p(6)3s 2SE(J=1/2) -- 2p(6)3p 2PO(J=3/2) transition.The effective collision strengths for each transition are presented for electron temperatures ranging from log10(T)=3.6 to log10(T)=5.60 in steps of 0.1.
- ID:
- ivo://CDS.VizieR/J/A+A/486/629
- Title:
- Effective collision strengths for C II
- Short Name:
- J/A+A/486/629
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Oscillator strengths and electron impact excitation collision strengths for CII lines among the fine-structure levels are calculated. Thermally averaged collision strengths are presented as a function of electron temperature for application to astrophysical plasmas. An accurate description of the target wave functions has been obtained in the multiconfiguration Hartree-Fock approach with flexible non-orthogonal orbitals. The 42 fine-structure levels of the 2s^2^2p, 2s2p^2^, 2s^2^3l (l=0-2), 2p^3^, 2s^2^4l (l=0-3), 2s2p3s and 2s^2^5l (l=0-2) configurations have been included in the scattering calculation. A second calculation with lowest 35 levels in the close-coupling expansion has also been carried out to check channel coupling effects on collision strengths. The continuum functions have been represented by the use of B-spline basis. The B-spline R-matrix method in the framework of Breit-Pauli approximation has been used to investigate the electron impact excitation of forbidden and allowed transitions in CII.
- ID:
- ivo://CDS.VizieR/J/A+A/432/731
- Title:
- Effective collision strengths for C II
- Short Name:
- J/A+A/432/731
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The effective collision strengths are presented in this table for all transitions among the lowest 30 fine-structure levels belonging to the 2s^2^2p, 2s2p^2^, 2p^3^, 2s2p3s, 2s^2^3l (l=s,p,d) and 2s^2^4l (l=s,p,d,f) configurations of C II. The effective collision strengths have been calculated using the R-matrix method. Each fine-structure level is assigned an index number in Table 1 of the manuscript ranging from 1 to 30. These index values are used here in Table 2 to refer to particular transitions, eg. Index 2-8 denotes the transition 2s^2^2p 2PO(J=3/2) - 2s2p^2^ 3SE(J=1/2). The effective collision strengths for each transition are presented in rows for a number of electron temperatures ranging from log10(T)=3.00 to log10(T)=5.50.