CHEMICAL SIGNATURES OF THE FIRST SUPERNOVAE IN THE SCULPTOR DWARF SPHEROIDAL GALAXY
Name
Simon-2015-CHEMICAL SIGNATURES.pdf
Size
368.18 KB
Format
Adobe PDF
Checksum (MD5)
1596e51b7a36bca9e795afc29c161629
Author(s)
Simon, Joshua D.
Jacobson, Heather
Thompson, Ian B.
Adams, Joshua J.
Shectman, Stephen A.
Frebel, Anna L.
Date Issued
March 2015
Journal
The Astrophysical Journal
Publisher
IOP Publishing
Citation
Simon, Joshua D., Heather R. Jacobson, Anna Frebel, Ian B. Thompson, Joshua J. Adams, and Stephen A. Shectman. “CHEMICAL SIGNATURES OF THE FIRST SUPERNOVAE IN THE SCULPTOR DWARF SPHEROIDAL GALAXY.” The Astrophysical Journal 802, no. 2 (March 27, 2015): 93. © 2015 The American Astronomical Society
Version
Final published version
Abstract
We present a homogeneous chemical abundance analysis of five of the most metal-poor stars in the Sculptor dwarf spheroidal galaxy. We analyze new and archival high resolution spectroscopy from Magellan/MIKE and VLT/UVES and determine stellar parameters and abundances in a consistent way for each star. Two of the stars in our sample, at [Fe/H] = −3.5 and [Fe/H] = −3.8, are new discoveries from our Ca K survey of Sculptor, while the other three were known in the literature. We confirm that Scl 07-50 is the lowest metallicity star identified in an external galaxy, at [Fe/H] = −4.1. The two most metal-poor stars both have very unusual abundance patterns, with striking deficiencies of the α elements, while the other three stars resemble typical extremely metal-poor Milky Way halo stars. We show that the star-to-star scatter for several elements in Sculptor is larger than that for halo stars in the same metallicity range. This scatter and the uncommon abundance patterns of the lowest metallicity stars indicate that the oldest surviving Sculptor stars were enriched by a small number of earlier supernovae, perhaps weighted toward high-mass progenitors from the first generation of stars the galaxy formed.
MIT Department
Massachusetts Institute of Technology. Department of Physics
MIT Kavli Institute for Astrophysics and Space Research
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1088/0004-637x/802/2/93
