skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The ACS LCID project. X. the star formation history of IC 1613: Revisiting the over-cooling problem

Abstract

We present an analysis of the star formation history (SFH) of a field near the half-light radius in the Local Group dwarf irregular galaxy IC 1613 based on deep Hubble Space Telescope Advanced Camera for Surveys imaging. Our observations reach the oldest main sequence turn-off, allowing a time resolution at the oldest ages of ∼1 Gyr. Our analysis shows that the SFH of the observed field in IC 1613 is consistent with being constant over the entire lifetime of the galaxy. These observations rule out an early dominant episode of star formation in IC 1613. We compare the SFH of IC 1613 with expectations from cosmological models. Since most of the mass is in place at early times for low-mass halos, a naive expectation is that most of the star formation should have taken place at early times. Models in which star formation follows mass accretion result in too many stars formed early and gas mass fractions that are too low today (the 'over-cooling problem'). The depth of the present photometry of IC 1613 shows that, at a resolution of ∼1 Gyr, the star formation rate is consistent with being constant, at even the earliest times, which is difficult tomore » achieve in models where star formation follows mass assembly.« less

Authors:
 [1]; ; ; ;  [2];
  1. Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States)
  2. Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38200 La Laguna, Tenerife, Canary Islands (Spain)
Publication Date:
OSTI Identifier:
22357015
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 786; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; COSMOLOGICAL MODELS; EVOLUTION; GALAXIES; LIFETIME; MASS; PHOTOMETRY; STARS; TELESCOPES; TIME RESOLUTION; UNIVERSE; VISIBLE RADIATION

Citation Formats

Skillman, Evan D., Hidalgo, Sebastian L., Monelli, Matteo, Gallart, Carme, Aparicio, Antonio, and others, and. The ACS LCID project. X. the star formation history of IC 1613: Revisiting the over-cooling problem. United States: N. p., 2014. Web. doi:10.1088/0004-637X/786/1/44.
Skillman, Evan D., Hidalgo, Sebastian L., Monelli, Matteo, Gallart, Carme, Aparicio, Antonio, & others, and. The ACS LCID project. X. the star formation history of IC 1613: Revisiting the over-cooling problem. United States. https://doi.org/10.1088/0004-637X/786/1/44
Skillman, Evan D., Hidalgo, Sebastian L., Monelli, Matteo, Gallart, Carme, Aparicio, Antonio, and others, and. 2014. "The ACS LCID project. X. the star formation history of IC 1613: Revisiting the over-cooling problem". United States. https://doi.org/10.1088/0004-637X/786/1/44.
@article{osti_22357015,
title = {The ACS LCID project. X. the star formation history of IC 1613: Revisiting the over-cooling problem},
author = {Skillman, Evan D. and Hidalgo, Sebastian L. and Monelli, Matteo and Gallart, Carme and Aparicio, Antonio and others, and},
abstractNote = {We present an analysis of the star formation history (SFH) of a field near the half-light radius in the Local Group dwarf irregular galaxy IC 1613 based on deep Hubble Space Telescope Advanced Camera for Surveys imaging. Our observations reach the oldest main sequence turn-off, allowing a time resolution at the oldest ages of ∼1 Gyr. Our analysis shows that the SFH of the observed field in IC 1613 is consistent with being constant over the entire lifetime of the galaxy. These observations rule out an early dominant episode of star formation in IC 1613. We compare the SFH of IC 1613 with expectations from cosmological models. Since most of the mass is in place at early times for low-mass halos, a naive expectation is that most of the star formation should have taken place at early times. Models in which star formation follows mass accretion result in too many stars formed early and gas mass fractions that are too low today (the 'over-cooling problem'). The depth of the present photometry of IC 1613 shows that, at a resolution of ∼1 Gyr, the star formation rate is consistent with being constant, at even the earliest times, which is difficult to achieve in models where star formation follows mass assembly.},
doi = {10.1088/0004-637X/786/1/44},
url = {https://www.osti.gov/biblio/22357015}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 786,
place = {United States},
year = {Thu May 01 00:00:00 EDT 2014},
month = {Thu May 01 00:00:00 EDT 2014}
}