The star formation histories of local group dwarf galaxies. I. Hubble space telescope/wide field planetary camera 2 observations
Daniel R. Weisz,Daniel R. Weisz,Andrew E. Dolphin,Evan D. Skillman,Jon Holtzman,Karoline M. Gilbert,Karoline M. Gilbert,Julianne J. Dalcanton,Benjamin F. Williams +8 more
TLDR
In this article, the authors presented uniformly measured star formation histories (SFHs) of 40 Local Group (LG) dwarf galaxies based on color-magnitude diagram (CMD) analysis from archival Hubble Space Telescope imaging.Abstract:
We present uniformly measured star formation histories (SFHs) of 40 Local Group (LG) dwarf galaxies based on color-magnitude diagram (CMD) analysis from archival Hubble Space Telescope imaging. We demonstrate that accurate SFHs can be recovered from CMDs that do not reach the oldest main sequence turn-off (MSTO), but emphasize that the oldest MSTO is critical for precisely constraining the earliest epochs of star formation. We find that: (1) the average lifetime SFHs of dwarf spheroidals (dSphs) can be approximated by an exponentially declining SFH with τ ∼ 5 Gyr; (2) lower luminosity dSphs are less likely to have extended SFHs than more luminous dSphs; (3) the average SFHs of dwarf irregulars (dIrrs), transition dwarfs, and dwarf ellipticals can be approximated by the combination of an exponentially declining SFH (τ ∼ 3-4 Gyr) for lookback ages >10-12 Gyr ago and a constant SFH thereafter; (4) the observed fraction of stellar mass formed prior to z = 2 ranges considerably (80% for galaxies with M 10{sup 7} M{sub ☉}) and is largely explained by environment; (5) the distinction between 'ultra-faint' and 'classical' dSphs is arbitrary; (6) LG dIrrs formed amore » significantly higher fraction of stellar mass prior to z = 2 than the Sloan Digital Sky Survey galaxies from Leitner and the SFHs from the abundance matching models of Behroozi et al. This may indicate higher than expected star formation efficiencies at early times in low mass galaxies. Finally, we provide all the SFHs in tabulated electronic format for use by the community.« lessread more
Citations
More filters
Dwarf galaxies, cold dark matter, and biased galaxy formation
Avishai Dekel,Joseph Silk +1 more
TL;DR: In this article, a reexamination is conducted of the formation of dwarf, diffuse, metal-poor galaxies due to supernova-driven winds, in view of data on the systematic properties of dwarfs in the Local Group and Virgo Cluster.
Journal ArticleDOI
Reconciling dwarf galaxies with λcdm cosmology: simulating a realistic population of satellites around a milky way–mass galaxy
Andrew Wetzel,Andrew Wetzel,Andrew Wetzel,Philip F. Hopkins,Ji-hoon Kim,Ji-hoon Kim,Claude André Faucher-Giguère,Dušan Kereš,Eliot Quataert +8 more
TL;DR: In this paper, the Milky Way on Feedback in Realistic Environments (FIRE) model was used to simulate the formation of a small-scale galaxy to z = 0 within the cold dark matter (CDM) model.
Journal ArticleDOI
Reconciling dwarf galaxies with LCDM cosmology: Simulating a realistic population of satellites around a Milky Way-mass galaxy
Andrew Wetzel,Philip F. Hopkins,Ji Hoon Kim,Claude André Faucher-Giguère,Dušan Kereš,Eliot Quataert +5 more
TL;DR: In this paper, the Milky Way on FIRE (Feedback in Realistic Environments) model was used to simulate the formation of a MW-mass galaxy to z = 0 within LCDM cosmology, including dark matter, gas, and stars at unprecedented resolution.
Journal ArticleDOI
Forged in FIRE: cusps, cores and baryons in low-mass dwarf galaxies
Jose Oñorbe,Jose Oñorbe,Michael Boylan-Kolchin,Michael Boylan-Kolchin,James S. Bullock,Philip F. Hopkins,Dušan Kereš,Claude André Faucher-Giguère,Eliot Quataert,Norman Murray +9 more
TL;DR: In this article, the authors present multiple ultrahigh resolution cosmological hydrodynamic simulations of M_★ ≃ 10^(4-6.3) and M_⊙ dwarfs that form within two M_(vir) = 10.5-10.5
Journal ArticleDOI
The quenching of the ultra-faint dwarf galaxies in the reionization era ∗
Thomas M. Brown,Jason Tumlinson,Marla Geha,Joshua D. Simon,Luis C. Vargas,Don A. VandenBerg,Evan N. Kirby,Jason S. Kalirai,Jason S. Kalirai,Roberto J. Avila,Mario Gennaro,Henry C. Ferguson,Ricardo R. Muñoz,Puragra Guhathakurta,Alvio Renzini +14 more
TL;DR: In this paper, the star formation histories of six ultra-faint dwarf galaxies, Bootes I, Canes Venatici II, Coma Berenices, Hercules, Leo IV, and Ursa Major I, were analyzed using a combination of high-precision photometry obtained with the Advanced Camera for Surveys on the Hubble Space Telescope, medium-resolution spectroscopy obtained with DEep Imaging Multi-Object Spectrograph on the W. M. Keck Observatory, and updated Victoria-Regina isochrones tailored to the abundance patterns appropriate for these
References
More filters
Journal ArticleDOI
Astropy: A community Python package for astronomy
Thomas P. Robitaille,Erik Tollerud,Perry Greenfield,Michael Droettboom,Erik Bray,Tom Aldcroft,Matt Davis,Adam Ginsburg,Adrian M. Price-Whelan,Wolfgang Kerzendorf,A. Conley,Neil H. M. Crighton,Kyle Barbary,Demitri Muna,Henry C. Ferguson,Frédéric Grollier,Madhura Parikh,Prasanth H. Nair,Hans Moritz Günther,Christoph Deil,Julien Woillez,Simon Conseil,Roban Kramer,J. Turner,Leo Singer,R. T. Fox,Benjamin A. Weaver,Victor Zabalza,Zachary I. Edwards,K. Azalee Bostroem,Douglas Burke,Andrew R. Casey,Steven M. Crawford,Nadia Dencheva,Justin Ely,Tim Jenness,Kathleen Labrie,Pey Lian Lim,Francesco Pierfederici,Andrew Pontzen,Andy Ptak,Brian L. Refsdal,Mathieu Servillat,Ole Streicher +43 more
TL;DR: Astropy as discussed by the authors is a Python package for astronomy-related functionality, including support for domain-specific file formats such as flexible image transport system (FITS) files, Virtual Observatory (VO) tables, common ASCII table formats, unit and physical quantity conversions, physical constants specific to astronomy, celestial coordinate and time transformations, world coordinate system (WCS) support, generalized containers for representing gridded as well as tabular data, and a framework for cosmological transformations and conversions.
Journal ArticleDOI
On the variation of the initial mass function
TL;DR: In this paper, the uncertainty inherent in any observational estimate of the IMF is investigated by studying the scatter introduced by Poisson noise and the dynamical evolution of star clusters, and it is found that this apparent scatter reproduces quite well the observed scatter in power-law index determinations, thus defining the fundamental limit within which any true variation becomes undetectable.
Journal ArticleDOI
Measuring Reddening with Sloan Digital Sky Survey Stellar Spectra and Recalibrating SFD
TL;DR: In this paper, the authors measured the difference between the measured and predicted colors of a star, as derived from stellar parameters from the Sloan Extension for Galactic Understanding and Exploration Stellar Parameter Pipeline, and achieved uncertainties of 56, 34, 25, and 29 mmag in the colors u − g, g − r, r − i, and i − z, per star.
Journal ArticleDOI
Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
TL;DR: Lee et al. as discussed by the authors measured the difference between the measured and predicted colors of a star, as derived from stellar parameters from the SEGUE Stellar Parameter Pipeline, and achieved uncertainties of 56, 34, 25, and 29 mmag in the colors u-g, g-r, r-i, and i-z, per star.
Journal ArticleDOI
parsec: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
Alessandro Bressan,Paola Marigo,Léo Girardi,Bernardo Salasnich,Claudia Dal Cero,Stefano Rubele,Ambra Nanni +6 more
TL;DR: In this article, the authors present an updated version of the AESOPUS code used to compute stellar evolutionary tracks in Padova, which is the result of a thorough revision of put physics, together with the inclusion of the pre-main sequence phase.
Related Papers (5)
Measuring Reddening with Sloan Digital Sky Survey Stellar Spectra and Recalibrating SFD
Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
Astropy: A community Python package for astronomy
Thomas P. Robitaille,Erik Tollerud,Perry Greenfield,Michael Droettboom,Erik Bray,Tom Aldcroft,Matt Davis,Adam Ginsburg,Adrian M. Price-Whelan,Wolfgang Kerzendorf,A. Conley,Neil H. M. Crighton,Kyle Barbary,Demitri Muna,Henry C. Ferguson,Frédéric Grollier,Madhura Parikh,Prasanth H. Nair,Hans Moritz Günther,Christoph Deil,Julien Woillez,Simon Conseil,Roban Kramer,J. Turner,Leo Singer,R. T. Fox,Benjamin A. Weaver,Victor Zabalza,Zachary I. Edwards,K. Azalee Bostroem,Douglas Burke,Andrew R. Casey,Steven M. Crawford,Nadia Dencheva,Justin Ely,Tim Jenness,Kathleen Labrie,Pey Lian Lim,Francesco Pierfederici,Andrew Pontzen,Andy Ptak,Brian L. Refsdal,Mathieu Servillat,Ole Streicher +43 more