2015AJ....149..198R


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.22CEST12:01:52

2015AJ....149..198R - Astron. J., 149, 198 (2015/June-0)

Metallicity distribution functions of four Local Group dwarf galaxies.

ROSS T.L., HOLTZMAN J., SAHA A. and ANTHONY-TWAROG B.J.

Abstract (from CDS):

We present stellar metallicities in Leo I, Leo II, IC 1613, and Phoenix dwarf galaxies derived from medium (F390M) and broad (F555W, F814W) band photometry using the Wide Field Camera 3 instrument on board the Hubble Space Telescope. We measured metallicity distribution functions (MDFs) in two ways, (1) matching stars to isochrones in color-color diagrams and (2) solving for the best linear combination of synthetic populations to match the observed color-color diagram. The synthetic technique reduces the effect of photometric scatter and produces MDFs 30%-50% narrower than the MDFs produced from individually matched stars. We fit the synthetic and individual MDFs to analytical chemical evolution models (CEMs) to quantify the enrichment and the effect of gas flows within the galaxies. Additionally, we measure stellar metallicity gradients in Leo I and II. For IC 1613 and Phoenix our data do not have the radial extent to confirm a metallicity gradient for either galaxy. We find the MDF of Leo I (dwarf spheroidal) to be very peaked with a steep metal-rich cutoff and an extended metal-poor tail, while Leo II (dwarf spheroidal), Phoenix (dwarf transition), and IC 1613 (dwarf irregular) have wider, less peaked MDFs than Leo I. A simple CEM is not the best fit for any of our galaxies; therefore we also fit the ''Best Accretion Model'' of Lynden-Bell. For Leo II, IC 1613, and Phoenix we find similar accretion parameters for the CEM even though they all have different effective yields, masses, star formation histories, and morphologies. We suggest that the dynamical history of a galaxy is reflected in the MDF, where broad MDFs are seen in galaxies that have chemically evolved in relative isolation and narrowly peaked MDFs are seen in galaxies that have experienced more complicated dynamical interactions concurrent with their chemical evolution.

Abstract Copyright:

Journal keyword(s): galaxies: abundances - galaxies: dwarf - galaxies: evolution - Local Group

Simbad objects: 24

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Number of rows : 24

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 NGC 104 GlC 00 24 05.359 -72 04 53.20   5.78 4.09     ~ 3463 0
2 NAME Cetus Dwarf Galaxy G 00 26 10.8 -11 03 14     13.2     ~ 194 0
3 NAME Andromeda III G 00 35 22.7 +36 30 17     14.4     ~ 259 0
4 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 10563 1
5 NAME Andromeda I G 00 45 39.8 +38 02 28   13.9 12.7     ~ 292 0
6 NAME Sculptor Dwarf Galaxy G 01 00 09.4 -33 42 32   9.79 8.6 8.81   ~ 1062 4
7 IC 1613 GiC 01 04 54.2 +02 08 00   10.42 10.01 9.77   ~ 1079 2
8 NAME Andromeda V G 01 10 17.1 +47 37 41     15.3     ~ 179 0
9 NAME Phoenix Dwarf Galaxy Sy1 01 51 06.3 -44 26 41   13.48 13.2 12.69   ~ 431 2
10 NAME Fornax Dwarf Spheroidal G 02 39 59.3 -34 26 57   9.02 7.4     ~ 1406 1
11 NAME Carina dSph G 06 41 36.7 -50 57 58   22.14 11.0 19.47   ~ 954 0
12 NAME Leo I dSph G 10 08 28.12 +12 18 23.4   11.3 10.0     ~ 1007 1
13 NAME Dwarf Elliptical Galaxy in Sex G 10 13 02.9 -01 36 53   12 10.4     ~ 667 0
14 NAME Leo B G 11 13 28.13 +22 09 10.1   12.9 12.0     ~ 702 0
15 NAME CVn I dSph G 13 28 03.5 +33 33 21     13.1     ~ 229 1
16 NAME UMi Galaxy G 15 09 11.34 +67 12 51.7   13.60 10.6     ~ 1136 0
17 NGC 5927 GlC 15 28 00.69 -50 40 22.9   10.13 8.86     ~ 388 0
18 M 92 GlC 17 17 07.39 +43 08 09.4     6.52     ~ 1866 0
19 NAME Dra dSph G 17 20 14.335 +57 55 16.39   12.40 10.6     ~ 1120 1
20 NGC 6752 GlC 19 10 52.11 -59 59 04.4   6.96 6.28     ~ 1764 0
21 NGC 6791 OpC 19 20 53 +37 46.3   10.52 9.5     ~ 841 0
22 NAME Tuc Galaxy G 22 41 49.6 -64 25 10   15.7 15.2     ~ 255 0
23 NAME Peg dSph GiG 23 51 46.4 +24 35 11   14.5 13.2     ~ 207 2
24 NAME Local Group GrG ~ ~           ~ 6661 0

    Equat.    Gal    SGal    Ecl

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2019.10.22-12:01:52

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