The Dwarf Galaxy Leo A: A Survivor From the Epoch of Reionization

Bibcode
2006AAS...20917806C
Cole, Andrew A.; Skillman, E. D.; Dolphin, A. E.; Gallagher, J. S., III; Tolstoy, E.; Gallart, C.; Weisz, D.; Hidalgo, S. L.; Saha, A.; Stetson, P. B.; Aparicio, A.
Bibliographical reference

2007 AAS/AAPT Joint Meeting, American Astronomical Society Meeting 209, #178.06; Bulletin of the American Astronomical Society, Vol. 38, p.1156

Advertised on:
12
2006
Number of authors
11
IAC number of authors
0
Citations
0
Refereed citations
0
Description
We present the results of a program to derive the complete star-formation history of the Local Group dwarf irregular galaxy Leo A (DDO 69). Leo A is a low-luminosity (Mv = -11.7), very gas-rich (M(HI)/LB = 1.6) galaxy. Our analysis is based on color-magnitude diagrams derived from deep HST/ACS imaging; the CMDs reach well below the oldest main-sequence turnoff of Leo A, at I ≈ 28. Over 80% of all the stars ever created in Leo A were born more recently than 7.7 Gyr ago (redshift z = 1 in a flat ΛCDM universe). The star-formation rate from 8-12 Gyr ago is formally consistent with zero, but stars as old as the oldest globular clusters are present. These results are discussed in the context of the predicted effects of cosmological reionization on the evolution of dwarf galaxies.
Type
Non-refereed

It may interest you

  • Non-refereed
    ROSALIA: ROman Sky Analyst for Low surface brightness Imaging & Astronomy
    Diffuse emission in the outskirts of galaxies, such as stellar tidal streams, galaxy stellar halos and intracluster light, provides important constraints on the structure and evolution of the Universe. However, such low surface brightness diffuse emission can be up to thousands of times dimmer (>29 AB mag/[square arcseconds]) than the sky
    Laine, Seppo et al.

    Advertised on:

    6
    2024
    Bibcode
    2024AAS...24412902L
    Citations
    0
  • Non-refereed
    A Systematic Search for and Characterization of White Dwarf Binaries Across the H-R Diagram
    White dwarfs (WDs) are the endpoint of evolution for 97% of stars. Most of these stars are in multiple systems, and a significant fraction of those are compact enough to exchange mass, altering the structures and subsequent evolution of both stars. The physical mechanisms that facilitate these mass exchanges include common envelope evolution, Roche
    Anguiano, Borja et al.

    Advertised on:

    6
    2024
    Bibcode
    2024AAS...24410807A
    Citations
    0
  • Non-refereed
    The molecular gas perspective on the growth and death of H emitters in the Spiderweb protocluster at Alpha z=2.16
    Galaxy clusters at low redshift are dominated by massive quiescent galaxies hosting stellar populations 10 Gyrs old, indicating that they were formed in the early universe when clusters were still in the process of being assembled (i.e., protoclusters). The rapid growth of galaxies within protoclusters is driven by the efficient transformation of
    Martinez, J. M. P.

    Advertised on:

    3
    2024
    Bibcode
    2024aecc.conf...12M
    Citations
    0