scholarly journals The star-formation history of the Universe from the stellar populations of nearby galaxies

Nature ◽  
2004 ◽  
Vol 428 (6983) ◽  
pp. 625-627 ◽  
Author(s):  
Alan Heavens ◽  
Benjamin Panter ◽  
Raul Jimenez ◽  
James Dunlop
Keyword(s):  
Star Formation ◽  
Stellar Populations ◽  
Star Formation History ◽  
Formation History ◽  
History Of ◽  
Nearby Galaxies ◽  
The Universe

Recovering the star formation history of galaxies through spectral fitting: Current challenges

2019 ◽  
Vol 15 (S359) ◽  
pp. 386-390
Author(s):  
Lucimara P. Martins
Keyword(s):  
Star Formation ◽  
Mass Function ◽  
Initial Mass Function ◽  
Star Formation History ◽  
Stellar Spectra ◽  
Spectral Fitting ◽  
Formation History ◽  
History Of ◽  
Nearby Galaxies ◽  
Extract Information

AbstractWith the exception of some nearby galaxies, we cannot resolve stars individually. To recover the galaxies star formation history (SFH), the challenge is to extract information from their integrated spectrum. A widely used tool is the full spectral fitting technique. This consists of combining simple stellar populations (SSPs) of different ages and metallicities to match the integrated spectrum. This technique works well for optical spectra, for metallicities near solar and chemical histories not much different from our Galaxy. For everything else there is room for improvement. With telescopes being able to explore further and further away, and beyond the optical, the improvement of this type of tool is crucial. SSPs use as ingredients isochrones, an initial mass function, and a library of stellar spectra. My focus are the stellar libraries, key ingredient for SSPs. Here I talk about the latest developments of stellar libraries, how they influence the SSPs and how to improve them.

scholarly journals Dissecting the Formation Histories of Galaxies with Stellar Populations Models

2009 ◽  
Vol 5 (S262) ◽  
pp. 153-163
Author(s):  
Ivo Labbé
Keyword(s):  
Star Formation ◽  
Current Knowledge ◽  
High Redshift ◽  
Local Environment ◽  
Stellar Populations ◽  
Current Data ◽  
Star Formation History ◽  
Spectral Energy ◽  
Formation History ◽  
History Of

AbstractHow did galaxies evolve from primordial fluctuations to the well-ordered but diverse population of disk and elliptical galaxies that we observe today? Stellar populations synthesis models have become a crucial tool in addressing this question by helping us to interpret the spectral energy distributions of present-day galaxies and their high redshift progenitors in terms of fundamental characteristics such as stellar mass and age. I will review our current knowledge on the evolution of stellar populations in early- and late type galaxies at z < 1 and the tantalizing – but incomplete – view of the stellar populations in galaxies at 1 < z < 3, during the global peak of star formation. Despite great progress, many fundamental questions remain: what processes trigger episodes of galaxy-scale star formation and what quenches them? To what degree does the star formation history of galaxies depend on the merger history, (halo) mass, or local environment? I will discuss some of the challenges posed in interpreting current data and what improved results might be expected from new observational facilities in the near- and more distant future.

scholarly journals HUBBLE SPACE TELESCOPEGRISM SPECTROSCOPY OF EXTREME STARBURSTS ACROSS COSMIC TIME: THE ROLE OF DWARF GALAXIES IN THE STAR FORMATION HISTORY OF THE UNIVERSE

2014 ◽  
Vol 789 (2) ◽  
pp. 96 ◽  
Author(s):  
Hakim Atek ◽  
Jean-Paul Kneib ◽  
Camilla Pacifici ◽  
Matthew Malkan ◽  
Stephane Charlot ◽  
...  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxies ◽  
Cosmic Time ◽  
Star Formation History ◽  
Formation History ◽  
History Of ◽  
The Universe

scholarly journals Cosmic Star Formation from the Milky Way and its Satellites

1999 ◽  
Vol 190 ◽  
pp. 8-14
Author(s):  
F.D.A. Hartwick
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Star Formation History ◽  
Evolutionary Models ◽  
Disk Mass ◽  
Formation History ◽  
History Of ◽  
The Universe

We use observations and evolutionary models of local objects to interpret a recent determination of the star-formation history of the universe. By fitting the global star-formation rate, the model predicts the ratio of spheroid to disk mass of ~1, an intergalactic medium (IGM) whose mass is ~2.3 times the mass in stars, and whose metallicity is ~0.1 Z⊙.

scholarly journals A gamma-ray determination of the Universe’s star formation history

Science ◽  
2018 ◽  
Vol 362 (6418) ◽  
pp. 1031-1034 ◽  
Author(s):  
Keyword(s):  
Star Formation ◽  
Gamma Ray ◽  
Cosmic Time ◽  
Star Formation History ◽  
Large Area ◽  
Extragalactic Background Light ◽  
Galaxy Surveys ◽  
Formation History ◽  
History Of ◽  
The Universe

The light emitted by all galaxies over the history of the Universe produces the extragalactic background light (EBL) at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for gamma rays via photon-photon interactions, leaving an imprint in the spectra of distant gamma-ray sources. We measured this attenuation using 739 active galaxies and one gamma-ray burst detected by the Fermi Large Area Telescope. This allowed us to reconstruct the evolution of the EBL and determine the star formation history of the Universe over 90% of cosmic time. Our star formation history is consistent with independent measurements from galaxy surveys, peaking at redshiftz~ 2. Upper limits of the EBL at the epoch of reionization suggest a turnover in the abundance of faint galaxies atz~ 6.

scholarly journals Galaxies in the first billion years: implications for re-ionization and the star formation history at z>6

2006 ◽  
Vol 2 (14) ◽  
pp. 248-248
Author(s):  
Andrew J. Bunker ◽  
Elizabeth R. Stanway ◽  
Laurence P. Eyles ◽  
Richard S. Ellis ◽  
Richard G. McMahon ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Stellar Populations ◽  
Star Formation History ◽  
Star Forming ◽  
Formation History ◽  
Stellar Masses ◽  
The Universe ◽  
Selection Of

AbstractWe discuss the selection of star-forming galaxies at z≃6 through the Lyman-break technique. Spitzer imaging implies many of these contain older stellar populations (>200Myr) which produce detectable Balmer breaks. The ages and stellar masses (∼1010M⊙) imply that the star formation rate density at earlier epochs may have been significantly higher than at z≃6, and might have played a key role in re-ionizing the universe.

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