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Related papers: Hiding its age: the case for a younger bulge

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Colours of spiral galaxies generally are affected by the underlying old stellar population, younger stars, and extinction by dust. Old and young populations generally can be disentangled using a combination of blue and near-infrared…

Astrophysics · Physics 2019-07-31 R. F. Peletier , M. Balcells

We show that the factor $\sim$2 discrepancy between spectroscopic and photometric age determinations of the Galactic bulge main-sequence turnoff can be naturally explained by positing an elevated helium enrichment for the bulge relative to…

Astrophysics of Galaxies · Physics 2015-06-03 David M. Nataf , Andrew P. Gould

We employ optical photometry and high-resolution spectroscopy to study a field toward the open cluster Tombaugh 1, where we identify a complex population mixture, that we describe in terms of young and old Galactic thin disk. Of particular…

Astrophysics of Galaxies · Physics 2017-02-15 Giovanni Carraro , Joao Victor Sales Silva , Christian Moni Bidin , Ruben Vazquez

Hierarchical star formation leads to a progressive decrease in the clustering of star clusters both in terms of spatial scale and age. Consistently, the statistical analysis of positions and ages of clusters in the Milky Way disk strongly…

Astrophysics of Galaxies · Physics 2009-07-22 R. de la Fuente Marcos , C. de la Fuente Marcos

The radial profiles of the Hb, Mg, and Fe line-strength indices are presented for a sample of eight spiral galaxies with a low surface-brightness stellar disc and a bulge. The correlations between the central values of the line-strength…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 L. Morelli , E. M. Corsini , A. Pizzella , E. Dalla Bontà , L. Coccato , J. Méndez-Abreu , M. Cesetti

In the present work we analyzed seven globular clusters selected from their location in the Galactic bulge and with metallicity values in the range $-1.30\lesssim\rm{[Fe/H]}\lesssim-0.50$. The aim of this work is first to derive cluster…

We determined the age of the stellar content of the Galactic halo by considering main-sequence turn-off stars. From the large number of halo stars provided by Sloan Digital Sky Survey, we could accurately detect the turn-off as a function…

Astrophysics of Galaxies · Physics 2015-05-28 Paula Jofre , Achim Weiss

It is an observational fact that bulges of spiral galaxies contain a high fraction of old and metal-rich stars. Following this observational fact, we have investigated colors of 21 bulges hosted by a selected sample of high surface…

Astrophysics · Physics 2008-11-26 Gaspar Galaz , Alvaro Villalobos , Leopoldo Infante , Carlos Donzelli

We present a study of the properties of the star-cluster systems around pseudo-bulges of late-type spiral galaxies using a sample of 11 galaxies with distances from 17 to 37 Mpc. Star clusters are identified from multiband HST ACS and WFPC2…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Daiana Di Nino , Michele Trenti , Massimo Stiavelli , C. Marcella Carollo , Claudia Scarlata , Rosemary F. G. Wyse

Observations of the stellar content of the Milky Way's bulge helps to understand the stellar content and evolution of distant galaxies. In this brief overview I will first highlight some recent work directed towards measuring the history of…

Astrophysics · Physics 2007-05-23 Jay A. Frogel

We analyze high quality abundances data of solar neighborhood stars and show that there are two distinct regimes of [alpha/Fe] versus age which we identify as the epochs of the thick and thin disk formation. A tight correlation between…

Astrophysics of Galaxies · Physics 2015-06-16 M. Haywood , P. Di Matteo , M. Lehnert , D. Katz , A. Gomez

We present new spectroscopic data for 21 barred spiral galaxies, which we use to explore the effect of bars on disk star formation, and to place constraints on the characteristic lifetimes of bar episodes. The analysis centres on regions of…

Astrophysics of Galaxies · Physics 2017-12-27 P. A. James , S. M. Percival

The stellar density distribution of the bulge is analyzed through one of its tracers. We use oxygen-rich Miras variables from the Catchpole et al. (2016) survey and OGLE-III survey as standard candles. The average age of these stars is…

Astrophysics of Galaxies · Physics 2017-03-08 Martin Lopez-Corredoira

We present optical and near-infrared colour maps of the central regions of bulges of S0 and spiral galaxies obtained with WFPC2 and NICMOS on the HST. By combined use of HST and ground-based data the colour information spans from a few tens…

We compare the stellar population properties in the central regions of visually classified non-starforming spiral and elliptical galaxies from Galaxy Zoo and SDSS DR7. The galaxies lie in the redshift range $0.04<z<0.1$ and have stellar…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Aday R. Robaina , Ben Hoyle , Anna Gallazzi , Raul Jimenez , Arjen van der Wel , Licia Verde

The fundamental plane (FP) has an intrinsic scatter that can not be explained purely by observational errors. Using recently available age estimates for nearby early type galaxies, we show that a galaxy's position relative to the FP depends…

Astrophysics · Physics 2009-10-30 Duncan Forbes , Trevor Ponman , Richard Brown

Studying the resolved stellar populations of the different structural components which build massive galaxies directly unveils their assembly history. We aim at characterizing the stellar population properties of a representative sample of…

We investigate the nature of star-forming galaxies with reduced specific star formation rate (sSFR) and high stellar masses, those `green valley' objects that seemingly cause a reported bending, or flattening, of the star-forming main…

We have obtained long-slit spectroscopy for a sample of 20 early-type barred galaxies to study the influence of bars in the building of galaxy bulges. Line strength indices were measured and used to derive age and metallicity gradients in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Isabel Perez , Patricia Sanchez-Blazquez

Recent observations with the James Webb Space Telescope (JWST) have begun to reveal a surprising morphological diversity in galaxies within the first billion years after the Big Bang, including indications of structural maturity previously…

Astrophysics of Galaxies · Physics 2025-10-30 Anshuman Borgohain , Kanak Saha