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Cenarro, A.J.; Gorgas, J.; Cardiel, N.; Pedraz, S.; Vazdekis, Alexandre; Peletier, Reynier F.

doi:10.1023/a:1012717019620

Cited by 218 publications

(421 citation statements)

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“…In the upper diagram of Fig. 5, we have plotted the index CaT measured by Cenarro et al (2001) against M V , using the distance moduli listed by Sandquist (2004) and by Harris (1996). This diagram shows that the red clump stars (or red HB stars) in M 67 and M 71 do not deviate systematically from the sequence of RGB stars.…”

Section: Estimate Of Metallicity From the Infrared Caii Linesmentioning

confidence: 97%

“…While this low S N would preclude measurement of the CaII line strengths in the low-resolution spectrograms (R ∼ 2000) normally employed to measure them, they are measurable in our much higher resolution spectrograms. The wavelength ranges used by Cenarro et al (2001) to define the CaT index extend both bluer and redder than the Whiting 1 spectrograms. The ranges used by Armandroff & Da Costa (1991, hereafter AD) to measure the two strongest of the CaII lines extend insignificant amounts beyond the limits of our spectrograms, and it is possible to measure their Ca II index.…”

Section: Estimate Of Metallicity From the Infrared Caii Linesmentioning

confidence: 99%

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Whiting 1: the youngest globular cluster associated with the Sagittarius dwarf spheroidal galaxy

Carraro¹,

Zinn²,

Bidin³

2007

A&A

120

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Context. Recently, Carraro (2005) drew attention to the remarkable star cluster Whiting 1 by showing that it lies about 40 kpc from the Sun and is therefore unquestionably a member of the Galactic halo (b = −60.6 deg). Its Color Magnitude Diagram (CMD) indicated that Whiting 1 is very young (∼5 Gyr) for a globular cluster. It is very likely that Whiting 1 originated in a dwarf galaxy that has since been disrupted by the Milky Way. Aims. The main goals of this investigation were to constrain better the age, metallicity, and distance of Whiting 1 and to assess whether it belongs to a stellar stream from the Sagittarius dwarf spheroidal galaxy (Sgr dSph). Methods. Deep CCD photometry in the BVI pass-bands obtained with the VLT is used to improve the quality of the CMD and to determine the cluster's luminosity function and surface density profile. High-resolution spectrograms obtained with Magellan are used to measure the cluster's radial velocity and to place limits on its possible metallicity. The measurements of distance and radial velocity are used to test the cluster's membership in the stellar streams from the Sgr dSph. Results. From our CMD of Whiting 1, we derive new estimates for the cluster's age (6.5 +1.0 −0.5 Gyr), metallicity (Z = 0.004 ± 0.001, [Fe/H] = -0.65), and distance (29.4 +1.8 −2.0 kpc). From echelle spectrograms of three stars, we obtain -130.6 ± 1.8 km s −1 for the cluster's radial velocity and show from measurements of two infra-red CaII lines that the [Fe/H] of the cluster probably lies in the range -1.1 to -0.4. Both the luminosity function and the surface density profile suggest that the cluster has undergone tidal stripping by the Milky Way. We demonstrate that the position of Whiting 1 on the sky, its distance from the Sun, and its radial velocity are identical to within the errors of both the theoretical predictions of the trailing stream of stars from the Sgr dSph galaxy and the previous observations of the M giant stars that delineate the streams. Conclusions. With the addition of Whiting 1, there is now strong evidence that 6 globular clusters formed within the Sgr dSph. Whiting 1 is particularly interesting because it is the youngest and among the most metal rich. The relatively young age of Whiting 1 demonstrates that this dwarf galaxy was able to form star clusters for a period of at least 6 Gyr, and the age and metallicity of Whiting 1 are consistent with the age-metallicity relationship in the main body of the Sgr dSph. The presence now of Whiting 1 in the Galactic halo provides additional support for the view that the young halo clusters originated in dwarf galaxies that have been accreted by the Milky Way.

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Section: Estimate Of Metallicity From the Infrared Caii Linesmentioning

confidence: 97%

Section: Estimate Of Metallicity From the Infrared Caii Linesmentioning

confidence: 99%

Whiting 1: the youngest globular cluster associated with the Sagittarius dwarf spheroidal galaxy

Carraro¹,

Zinn²,

Bidin³

2007

A&A

120

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“…A total of 37 B to M stars in common with the MILES library (Sánchez-Blázquez et al 2006) and the CaT library (Cenarro et al 2001) were observed to flux-calibrate our data and to use them as templates for velocity dispersion measurements. …”

Section: Observationsmentioning

confidence: 99%

“…The spectra was calibrated in relative flux using the observed stars in common with the MILES library (Sánchez-Blázquez et al 2006) for the optical spectra and with the CaT library (Cenarro et al 2001) for the near infrared. For each observed star we obtained a flux-calibration curve.…”

Section: Data Reductionmentioning

confidence: 99%

Formation and evolution of dwarf early-type galaxies in the Virgo cluster

Toloba

Boselli

Cenarro

et al. 2011

A&A

Self Cite

130

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We present new medium resolution kinematic data for a sample of 21 dwarf early-type galaxies (dEs) mainly in the Virgo cluster, obtained with the WHT and INT telescopes at the Roque de los Muchachos Observatory (La Palma, Spain). These data are used to study the origin of the dwarf elliptical galaxy population inhabiting clusters. We confirm that dEs are not dark matter dominated galaxies, at least not up to the half-light radius. We also find that the observed galaxies in the outer parts of the cluster are mostly rotationally supported systems with disky morphological shapes. Rotationally supported dEs have rotation curves similar to those of star-forming galaxies of similar luminosity and follow the Tully-Fisher relation. This is expected if dE galaxies are the descendants of low-luminosity star-forming systems that have recently entered the cluster environment and lost their gas due to a ram-pressure stripping event, quenching their star formation activity and transforming into quiescent systems, but conserving their angular momentum.

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“…Four types of IMFs are considered in this version: unimodal, bimodal, Kroupa universal, and Kroupa revised (Vazdekis et al 2003, and references therein). A revised version of the model of V96 and V99 was also presented (Vazdekis et al 2003), which replaced the database of Jones (1999) with Cenarro (2001), and replaced the isochrones of Bertelli (1994) with Pa 00. This model predicted both the strength of the Ca II triplet feature and SEDs in the range 8449-8952 Å at resolution 1.5 Å (FWHM), with metallicities −1.7 < [Fe/H] < +0.2, ages 0.1-18 Gyr, and 4 types of IMFs (as in V99).…”

Section: Vazdekis/milesmentioning

confidence: 99%

Comparing six evolutionary population synthesis models by performing spectral synthesis for galaxies

Chen

Liang

Hammer

et al. 2010

A&A

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Aims. We compare six popularly used evolutionary population synthesis (EPS) models by fitting the full optical spectra of six representative types of galaxies (star-forming and composite galaxies, Seyfert 2s, LINERs, E+A, and early-type galaxies) taken from the Sloan Digital Sky Survey (SDSS). We explore the dependence of stellar population synthesis results on the main ingredients of the EPS models and study whether there is an age sequence among these types of galaxies. Methods. We use the simple stellar populations (SSPs) of each EPS model and the software STARLIGHT to perform our fits. Firstly, we explore the dependence of stellar population synthesis on EPS models by fixing the age, metallicity, and initial mass function (IMF) to construct a standard SSP group. We then use the standard SSP group of each EPS model (BC03, CB07, Ma05, GALEV, GRASIL, and Vazdekis/Miles) to fit the spectra of star-forming and E+A galaxies. Secondly, we fix the IMF and alter the age and metallicity to construct eight additional SSP groups. We then use these SSP groups to fit the spectra of star-forming and E+A galaxies to verify the effects of age and metallicity on stellar populations. Finally, we study the effect of stellar evolution tracks and stellar spectral libraries on our results, and present a possible age sequence among these types of galaxies. Results. Using different EPS models, the numerical values of contributing light fractions obviously change, even though the dominant populations are unaltered. The stellar population synthesis does depend on the selection of age and metallicity, but does not depend significantly on the stellar evolution track. The importance of young populations decreases from star-forming, composite, Seyfert 2, LINER, to early-type galaxies, and the properties of E+A galaxies are between composite galaxies and Seyfert 2s in most cases. Conclusions. Different EPS models infer different stellar population parameters, so that it is not reasonable to directly compare stellar populations estimated from different EPS models. To obtain reliable results, we should use the same EPS model to derive the parameter values that we compare.

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Cited by 218 publications

References 0 publications

Whiting 1: the youngest globular cluster associated with the Sagittarius dwarf spheroidal galaxy

Whiting 1: the youngest globular cluster associated with the Sagittarius dwarf spheroidal galaxy

Formation and evolution of dwarf early-type galaxies in the Virgo cluster

Comparing six evolutionary population synthesis models by performing spectral synthesis for galaxies

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