相关论文: Calcium Triplet Synthesis

The near-infrared Calcium II Triplet (CaT), around 850nm, is a key metallicity indicator for red giant stars. We present a revised [Fe/H] calibration as a function of CaT line strengths and four luminosity indicators, including the $Gaia$…

Using data from the WiFeS Atlas of Galactic Globular cluster Spectra we study the behaviour of the calcium triplet (CaT), a popular metallicity indicator in extragalactic stellar population studies. A major caveat of these studies is that…

The metallicity distribution function of globular clusters (GCs) in galaxies is a key to understanding galactic formation and evolution. The calcium II triplet (CaT) index has recently become a popular metal abundance indicator thanks to…

Medium resolution (R=4,000 to 9,000) spectra of the near infrared Ca II lines (at 8498, 8542, and 8662 A) in M31 globular cluster integrated light spectra are presented. In individual stars the Ca II triplet (CaT) traces stellar…

We present a grid of theoretical models where the calculation of absorption line spectral indices in both the blue and red wavelength ranges is done with the same evolutionary synthesis code. We have computed some of these indices: CaT,…

We measure the central values (within Re/8) of the CaII triplet line indices CaT* and CaT and the Paschen index PaT at 8600 AA for a 93%-complete sample of 75 nearby early-type galaxies with BT<12 and Vgal<2490 km/s. We find that the values…

We present a new stellar population synthesis model, which predicts SEDs for single-age single-metallicity stellar populations, SSPs, at resolution 1.5A (FWHM) in the spectral region of the near-IR CaII triplet feature. The main ingredient…

The Ca triplet (CaT) feature in the near-infrared has been employed as a metallicity indicator for individual stars as well as integrated light of Galactic globular clusters (GCs) and galaxies with varying degrees of success, and sometimes…

We investigate techniques that can be used to determine ages of starburst regions containing populations beyond their early nebular phase. In particular, we study the strength of the CaII triplet (lambda 8498, 8542, 8662 Ang) and the CO…

Context. [...] One of the most efficient methods is the measurement of the equivalent width (EW) of the Calcium II Triplet (CaT), corrected for the luminosity and temperature effects via magnitude differences from the horizontal branch…

We present a new calibration of the Calcium II Triplet equivalent widths versus [Fe/H], constructed upon K giant stars in the Galactic bulge. This calibration will be used to derive iron abundances for the targets of the GIBS survey, and in…

We describe a new spectroscopic technique for measuring radial metallicity gradients out to large galactocentric radii. We use the DEIMOS multi-object spectrograph on the Keck telescope and the galaxy spectrum extraction technique of…

How can we accurately determine the metallicity of faint red giant stars in nearby galaxies? The equivalent widths of the broad absorption lines from Ca II at 8498, 8542, and 8662 Angstrom (the calcium triplet) have shown a smooth…

We present central CaT, PaT, and CaT* indices for a sample of fifteen dwarf elliptical galaxies (dEs). Twelve of these have CaT* ~ 7 A and extend the negative correlation between the CaT* index and central velocity dispersion sigma, which…

Aims. We use the spectra of more than 30,000 red giant branch (RGB) stars in 25 globular clusters (GC), obtained within the MUSE survey of Galactic globular clusters, to calibrate the Ca II triplet (CaT) metallicity relation and derive…

We present a spectroscopic atlas of active galactic nuclei covering the region around the 8498, 8542, 8662 Calcium triplet (CaT) lines. The sample comprises 78 objects, divided into 43 Seyfert 2s, 26 Seyfert 1s, 3 Starburst and 6 normal…

We present updated stellar population models appropriate for old ages (>1 Gyr) and covering a wide range in metallicities (-1.5<[Fe/H]<0.3). These models predict the full spectral variation associated with individual element abundance…

The number of methods used to study the properties of galaxies is increased, and testing these methods is very important. Galactic globular clusters (GCs) provide an excellent medium for such test, because they can be considered as simple…

We present measurements of the near-infrared Calcium II triplet (CaT, CaT*), Paschen (PaT) and Magnesium (MgI) indices for a well-studied sample of 19 bulges of early to intermediate spiral galaxies. We find that both the CaT* and CaT…

We probe the stellar population age and metallicity distributions in nearby elliptical galaxies over the largest extension to date. Long-slit spectroscopy is made by using the spectrograph SCORPIO of the 6-m telescope of the Special…