Stellar Populations at the Center of IC 1613 | Zendy

Andrew A. Cole | Zendy; Eline Tolstoy | Zendy; J. S. Gallagher | Zendy; J. G. Hoessel | Zendy; J. R. Mould | Zendy; Jon A. Holtzman | Zendy; Abhijit Saha | Zendy; G. E. Ballester | Zendy; Christopher J. Burrows | Zendy; J. T. Clarke | Zendy; David Crisp | Zendy; R. E. Griffiths | Zendy; Carl J. Grillmair | Zendy; J. J. Hester | Zendy; John Krist | Zendy; V. S. Meadows | Zendy; Paul A. Scowen | Zendy; Karl R. Stapelfeldt | Zendy; John T. Trauger | Zendy; A. M. Watson | Zendy; J. Westphal | Zendy

AI Assistant Blog Pricing

Home ZAIA Blog

Open Access

Stellar Populations at the Center of IC 1613

Author(s) -

Andrew A. Cole,

Eline Tolstoy,

J. S. Gallagher,

J. G. Hoessel,

J. R. Mould,

Jon A. Holtzman,

Abhijit Saha,

G. E. Ballester,

Christopher J. Burrows,

J. T. Clarke,

David Crisp,

R. E. Griffiths,

Carl J. Grillmair,

J. J. Hester,

John Krist,

V. S. Meadows,

Paul A. Scowen,

Karl R. Stapelfeldt,

John T. Trauger,

A. M. Watson,

J. Westphal

Publication year - 1999

Publication title -

the astronomical journal

Language(s) - English

Resource type - Journals

SCImago Journal Rank - 2.61

H-Index - 271

eISSN - 1538-3881

pISSN - 0004-6256

DOI - 10.1086/301042

Subject(s) - red giant branch , physics , astrophysics , stellar population , astronomy , galaxy , luminosity function , population , metallicity , dwarf galaxy , horizontal branch , luminosity , advanced camera for surveys , asymptotic giant branch , star formation , local group , red clump , stars , demography , sociology

We have observed the center of the Local Group dwarf irregular galaxy IC 1613with WFPC2 aboard the Hubble Space Telescope in the F439W, F555W, and F814Wfilters. We find a dominant old stellar population (aged ~7 Gyr), identifiableby the strong red giant branch (RGB) and red clump populations. From the (V-I)color of the RGB, we estimate a mean metallicity of the intermediate-agestellar population [Fe/H] = -1.38 +/- 0.31. We confirm a distance of 715 +/- 40kpc using the I-magnitude of the RGB tip. The main-sequence luminosity functiondown to I ~25 provides evidence for a roughly constant SFR of approximately0.00035 solar masses per year across the WFPC2 field of view (0.22 square kpc)during the past 250-350 Myr. Structure in the blue loop luminosity functionimplies that the SFR was ~50% higher 400-900 Myr ago than today. The mean heavyelement abundance of these young stars is 1/10th solar. The best explanationfor a red spur on the main-sequence at I = 24.7 is the blue horizontal branchcomponent of a very old stellar population at the center of IC 1613. We havealso imaged a broader area of IC 1613 using the 3.5-meter WIYN telescope underexcellent seeing conditions. The AGB-star luminosity function is consistentwith a period of continuous star formation over at least the age range 2-10Gyr. We present an approximate age-metallicity relation for IC 1613, whichappears similar to that of the Small Magellanic Cloud. We compare the Hessdiagram of IC 1613 to similar data for three other Local Group dwarf galaxies,and find that it most closely resembles the nearby, transition-type dwarfgalaxy Pegasus (DDO 216).Comment: To appear in the September 1999 Astronomical Journal. LaTeX, uses AASTeX v4.0, emulateapj style file, 19 pages, 12 postscript figures, 2 tables. 5 of the figures available separately via the WW

The content you want is available to Zendy users.

Already have an account? Click here to sign in.

Having issues? You can contact us here

Accelerating Research