The star-formation histories of early-type galaxies from ATLAS3D

2011 ◽  
Vol 7 (S284) ◽  
pp. 244-247 ◽  
Author(s):  
Richard M. McDermid ◽  
Katherine Alatalo ◽  
Leo Blitz ◽  
Maxime Bois ◽  
Frédéric Bournaud ◽  
...  
Keyword(s):  
Star Formation ◽  
Stellar Population ◽  
Abundance Ratio ◽  
Star Formation History ◽  
Early Type ◽  
Solar Abundance ◽  
Formation History ◽  
History Of ◽  
Free Parameters ◽  
Star Formation Histories

AbstractWe present an exploration of the integrated stellar populations of early-type galaxies (ETGs) from the ATLAS3D survey. We use two approaches: firstly the application of line-indices interpreted through single stellar population (SSP) models, which provide a single value of age, metallicity and abundance ratio. And secondly, by fitting a linear combination of SSP spectra to our data, smoothly weighted in the free parameters of age and metallicity, thereby inferring a star-formation history of these galaxies. Despite the significant differences in these approaches, we obtain generally consistent results, such that galaxies that are more massive appear older with enhanced abundance ratios using line indices, and have shorter star-formation histories weighted to early times. We highlight two limitations of the index-SSP approach. Firstly the SSP-equivalent ages belie the fact that ETGs are overwhelmingly composed of ancient stars. Secondly, the young stellar contributions implied in our star formation histories are required to obtain realistic UV-optical colours. We remark that, even fitting solar-abundance models, we can recover a star-formation duration that correlates with the measured alpha-enhancement, in agreement with other recent work.

scholarly journals The Structure and Star Formation History of Early‐Type Galaxies in the Ultra Deep Field/GRAPES Survey

2006 ◽  
Vol 636 (1) ◽  
pp. 115-133 ◽  
Author(s):  
A. Pasquali ◽  
I. Ferreras ◽  
N. Panagia ◽  
E. Daddi ◽  
S. Malhotra ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation History ◽  
Early Type ◽  
Formation History ◽  
History Of

scholarly journals Spatial variations in the star formation history of the Large Magellanic Cloud

2008 ◽  
Vol 4 (S256) ◽  
pp. 281-286
Author(s):  
Carme Gallart ◽  
Ingrid Meschin ◽  
Antonio Aparicio ◽  
Peter B. Stetson ◽  
Sebastián L. Hidalgo
Keyword(s):  
Star Formation ◽  
Outer Part ◽  
Large Magellanic Cloud ◽  
Star Formation History ◽  
Wide Field ◽  
Galactocentric Distance ◽  
Formation History ◽  
The Galaxy ◽  
History Of ◽  
Star Formation Histories

AbstractBased on the quantitative analysis of a set of wide-field color—magnitude diagrams reaching the old main sequence-turnoffs, we present new LMC star-formation histories, and their variation with galactocentric distance. Some coherent features are found, together with systematic variations of the star-formation history among the three fields analyzed. We find two main episodes of star formation in all three fields, from 1 to 4 and 7 to 13 Gyr ago, with relatively low star formation around ≃ 4–7 Gyr ago. The youngest age in each field gradually increases with galactocentric radius; in the innermost field, LMC 0514–6503, an additional star formation event younger than 1 Gyr is detected, with star formation declining, however, in the last ≃ 200 Myr. The population is found to be older on average toward the outer part of the galaxy, although star formation in all fields seems to have started around 13 Gyr ago.

scholarly journals The star formation history of the Fornax dwarf spheroidal galaxy

2009 ◽  
Vol 5 (S262) ◽  
pp. 353-354
Author(s):  
Enrico V. Held ◽  
Eline Tolstoy ◽  
Luca Rizzi ◽  
Mary Cesetti ◽  
Andrew A. Cole ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Stellar Population ◽  
Main Sequence ◽  
Dwarf Galaxy ◽  
Star Formation History ◽  
Stellar Content ◽  
Formation History ◽  
First Results ◽  
History Of

AbstractWe present the first results of a comprehensive HST study of the star-formation history of Fornax dSph, based on WFPC2 imaging of 7 Fornax fields. Our observations reach the oldest main-sequence turnoffs, allowing us to address fundamental questions of dwarf galaxy evolution, such as the spatial variations in the stellar content, and whether the old stellar population is made up of stars formed in a very early burst or the result of a more continuous star formation.

scholarly journals Stellar Populations and the Star Formation Histories of LSB Galaxies—Part I: Optical and HαImaging

2011 ◽  
Vol 2011 ◽  
pp. 1-18 ◽  
Author(s):  
James Schombert ◽  
Tamela Maciel ◽  
Stacy McGaugh
Keyword(s):  
Star Formation ◽  
Data Storage ◽  
Star Formation History ◽  
Star Forming ◽  
Reduction Techniques ◽  
Formation History ◽  
History Of ◽  
Star Formation Histories ◽  
Baryonic Mass ◽  
Lsb Galaxies

This paper presents optical and Hαimaging for a large sample of LSB galaxies selected from the PSS-II catalogs (Schombert et al., 1992). As noted in previous work, LSB galaxies span a range of luminosities () and sizes (), although they are consistent in their irregular morphology. Their Hαluminosities (L(Hα)) range from 1036to 1041 ergs s−1(corresponding to a range in star formation, using canonical prescriptions, from 10−5to 1  yr−1). Although their optical colors are at the extreme blue edge for galaxies, they are similar to the colors of dwarf galaxies (Van Zee, 2001) and gas-rich irregulars (Hunter and Elmegreen, 2006). However, their star formation rates per unit stellar mass are a factor of ten less than other galaxies of the same baryonic mass, indicating that they are not simply quiescent versions of more active star-forming galaxies. This paper presents the data, reduction techniques, and new philosophy of data storage and presentation. Later papers in this series will explore the stellar population and star formation history of LSB galaxies using this dataset.

VIPERS view of the star formation history of early-type galaxies

2015 ◽  
Author(s):  
M. Siudek ◽  
K. Malek ◽  
B. Garilli ◽  
M. Scodeggio ◽  
A. Fritz ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation History ◽  
Early Type ◽  
Formation History ◽  
History Of

scholarly journals SDSS-IV MaNGA: the [α/Fe] of early-type galaxies

2020 ◽  
Vol 497 (3) ◽  
pp. 3011-3025
Author(s):  
Yiqing Liu
Keyword(s):  
Star Formation ◽  
Stellar Population ◽  
Signal To Noise Ratio ◽  
Abundance Ratio ◽  
Star Formation History ◽  
High Signal ◽  
Early Type ◽  
Iron Abundance ◽  
Nearby Galaxies ◽  
The Mean

ABSTRACT The mean stellar alpha-to-iron abundance ratio ([α/Fe]) of a galaxy is an indicator of galactic star formation time-scale. It is important for understanding the star formation history of early-type galaxies (ETGs) as their star formation processes have basically stopped. Using the model templates that are made by Vazdekis et al., we apply the pPXF-based spectral fitting method to estimate the [α/Fe] of 196 high-signal-to-noise ratio ETGs from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. The velocity dispersions within 1Re (σe) range from 27 to 270 km s−1. We find a flat relation between the mean [α/Fe] within the 1$R_\mathrm{ e}^{\mathrm{ maj}}$ ellipses and log(σe), even if limiting to the massive sample with log(σe/km s−1) > 1.9. However, the relation becomes positive after we exclude the Mg1 feature in our fits, which agrees with the results from the previous work with other stellar population models, albeit with relatively large scatter. It indicates that the Vazdekis models have self-inconsistency and do not actually cover the observations in Mg1. For reference, we also measure the stellar population radial gradients within 1$R_\mathrm{ e}^{\mathrm{ maj}}$ ellipses. Due to the low resolution of age estimations for old objects and the Mg1 issue, the uncertainties of these gradients cannot be neglected.

scholarly journals Compact Binaries as Tracers of Star Formation Histories: the XMM Survey of M31

1999 ◽  
Vol 192 ◽  
pp. 496-502
Author(s):  
U. Kolb ◽  
J. Osborne ◽  
M. G. Watson
Keyword(s):  
Star Formation ◽  
Evolutionary History ◽  
Star Formation History ◽  
X Ray ◽  
Compact Binaries ◽  
Normal Galaxies ◽  
Formation History ◽  
History Of ◽  
Star Formation Histories ◽  
X Ray Binaries

X-ray binaries (XBs) dominate the X-ray emission of normal galaxies. The new X-ray satellite XMM will study the XB population of M31 in detail. The resulting M31 sample will significantly advance our understanding of the evolutionary history of XBs, and ultimately allow us to probe the star formation history of stellar populations by X-ray observations.

Sign in / Sign up

Export Citation Format

Share Document