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

Title: Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III

Abstract

We present herein the first detailed elemental abundances in the ultra-faint Magellanic satellite galaxies Carina II (Car II) and Carina III (Car III). With high-resolution Magellan/MIKE spectroscopy, we determined the abundances of nine stars in Car II, including the first abundances of an RR Lyrae star in an ultra-faint dwarf galaxy (UFD), and two stars in Car III. The chemical abundances demonstrate that both systems are clearly galaxies and not globular clusters. The stars in these galaxies mostly display abundance trends matching those of other similarly faint dwarf galaxies: enhanced but declining [α/Fe] ratios, iron-peak elements matching the stellar halo, and unusually low neutron-capture element abundances. One star displays a low outlying [Sc/Fe] = -1.0. We detect a large Ba scatter in Car II, likely due to inhomogeneous enrichment by low-mass asymptotic giant branch star winds. The most striking abundance trend is for [Mg/Ca] in Car II, which decreases from +0.4 to -0.4 and indicates clear variation in the initial progenitor masses of enriching core-collapse supernovae. So far, the only UFDs displaying a similar [Mg/Ca] trend are likely satellites of the Large Magellanic Cloud. We find two stars with [Fe/H] ≤ -3.5 whose abundances likely trace the first generation ofmore » metal-free Population III stars and are well fit by Population III core-collapse supernova yields. An appendix describes our new abundance uncertainty analysis that propagates line-by-line stellar parameter uncertainties.« less

Authors:
ORCiD logo; ORCiD logo; ; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ORCiD logo; ; ; ; ; ORCiD logo
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP); National Aeronautics and Space Administration (NASA); National Science Foundation (NSF)
Contributing Org.:
MagLiteS Collaboration
OSTI Identifier:
1615361
Report Number(s):
arXiv:1912.04963; FERMILAB-PUB-19-691-AE
Journal ID: ISSN 1538-4357; oai:inspirehep.net:1791080
Grant/Contract Number:  
AC02-07CH11359; HST-HF2-51393.001; HST-HF2-51439.001; NAS5-26555; AST-1714873; AST-1813881; AST- 1909584; AST- 1813881
Resource Type:
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 889; Journal Issue: 1; Journal ID: ISSN 1538-4357
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; Stellar abundances; Dwarf galaxies

Citation Formats

Ji, A. P., Li, T. S., Simon, J. D., Marshall, J., Vivas, A. K., Pace, A. B., Bechtol, K., Drlica-Wagner, A., Koposov, S. E., Hansen, T. T., Allam, S., Gruendl, R. A., Johnson, M. D., McNanna, M., Noël, N. E. D., Tucker, D. L., and Walker, A. R. Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III. United States: N. p., 2020. Web. https://doi.org/10.3847/1538-4357/ab6213.
Ji, A. P., Li, T. S., Simon, J. D., Marshall, J., Vivas, A. K., Pace, A. B., Bechtol, K., Drlica-Wagner, A., Koposov, S. E., Hansen, T. T., Allam, S., Gruendl, R. A., Johnson, M. D., McNanna, M., Noël, N. E. D., Tucker, D. L., & Walker, A. R. Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III. United States. https://doi.org/10.3847/1538-4357/ab6213
Ji, A. P., Li, T. S., Simon, J. D., Marshall, J., Vivas, A. K., Pace, A. B., Bechtol, K., Drlica-Wagner, A., Koposov, S. E., Hansen, T. T., Allam, S., Gruendl, R. A., Johnson, M. D., McNanna, M., Noël, N. E. D., Tucker, D. L., and Walker, A. R. Wed . "Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III". United States. https://doi.org/10.3847/1538-4357/ab6213. https://www.osti.gov/servlets/purl/1615361.
@article{osti_1615361,
title = {Detailed Abundances in the Ultra-faint Magellanic Satellites Carina II and III},
author = {Ji, A. P. and Li, T. S. and Simon, J. D. and Marshall, J. and Vivas, A. K. and Pace, A. B. and Bechtol, K. and Drlica-Wagner, A. and Koposov, S. E. and Hansen, T. T. and Allam, S. and Gruendl, R. A. and Johnson, M. D. and McNanna, M. and Noël, N. E. D. and Tucker, D. L. and Walker, A. R.},
abstractNote = {We present herein the first detailed elemental abundances in the ultra-faint Magellanic satellite galaxies Carina II (Car II) and Carina III (Car III). With high-resolution Magellan/MIKE spectroscopy, we determined the abundances of nine stars in Car II, including the first abundances of an RR Lyrae star in an ultra-faint dwarf galaxy (UFD), and two stars in Car III. The chemical abundances demonstrate that both systems are clearly galaxies and not globular clusters. The stars in these galaxies mostly display abundance trends matching those of other similarly faint dwarf galaxies: enhanced but declining [α/Fe] ratios, iron-peak elements matching the stellar halo, and unusually low neutron-capture element abundances. One star displays a low outlying [Sc/Fe] = -1.0. We detect a large Ba scatter in Car II, likely due to inhomogeneous enrichment by low-mass asymptotic giant branch star winds. The most striking abundance trend is for [Mg/Ca] in Car II, which decreases from +0.4 to -0.4 and indicates clear variation in the initial progenitor masses of enriching core-collapse supernovae. So far, the only UFDs displaying a similar [Mg/Ca] trend are likely satellites of the Large Magellanic Cloud. We find two stars with [Fe/H] ≤ -3.5 whose abundances likely trace the first generation of metal-free Population III stars and are well fit by Population III core-collapse supernova yields. An appendix describes our new abundance uncertainty analysis that propagates line-by-line stellar parameter uncertainties.},
doi = {10.3847/1538-4357/ab6213},
journal = {The Astrophysical Journal (Online)},
number = 1,
volume = 889,
place = {United States},
year = {2020},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 4 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Chemical Enrichment in the Faintest Galaxies: the Carbon and iron Abundance Spreads in the BoÖTes i Dwarf Spheroidal Galaxy and the Segue 1 System
journal, October 2010


Gaia Data Release 2 : Specific characterisation and validation of all-sky Cepheids and RR Lyrae stars★
journal, January 2019


MIKE: A Double Echelle Spectrograph for the Magellan Telescopes at Las Campanas Observatory
conference, March 2003

  • Bernstein, Rebecca; Shectman, Stephen A.; Gunnels, Steven M.
  • Astronomical Telescopes and Instrumentation, SPIE Proceedings
  • DOI: 10.1117/12.461502

Satellite Dwarf Galaxies in a Hierarchical Universe: Infall Histories, Group Preprocessing, and Reionization
journal, June 2015

  • Wetzel, Andrew R.; Deason, Alis J.; Garrison-Kimmel, Shea
  • The Astrophysical Journal, Vol. 807, Issue 1
  • DOI: 10.1088/0004-637X/807/1/49

Mg line formation in late-type stellar atmospheres: I. The model atom
journal, June 2015


The Chemical Compositions of Variable Field Horizontal-Branch Stars: rr Lyrae Stars
journal, November 2011

  • For, Bi-Qing; Sneden, Christopher; Preston, George W.
  • The Astrophysical Journal Supplement Series, Vol. 197, Issue 2
  • DOI: 10.1088/0067-0049/197/2/29

The predicted luminous satellite populations around SMC- and LMC-mass galaxies – a missing satellite problem around the LMC?
journal, August 2017

  • Dooley, Gregory A.; Peter, Annika H. G.; Carlin, Jeffrey L.
  • Monthly Notices of the Royal Astronomical Society, Vol. 472, Issue 1
  • DOI: 10.1093/mnras/stx2001

Chemical Abundance Signature of J0023+0307: A Second-generation Main-sequence Star with [Fe/H] < −6
journal, January 2019

  • Frebel, Anna; Ji, Alexander P.; Ezzeddine, Rana
  • The Astrophysical Journal, Vol. 871, Issue 2
  • DOI: 10.3847/1538-4357/aae848

Observational Clues to the Progenitors of Type Ia Supernovae
journal, August 2014


“Galaxy,” Defined
journal, August 2012


Non-LTE analysis of K I in late-type stars
journal, July 2019


Chemical Signatures of the First Galaxies: Criteria for One-Shot Enrichment
journal, October 2012


Recovery from Population III supernova explosions and the onset of second-generation star formation
journal, November 2014

  • Jeon, Myoungwon; Pawlik, Andreas H.; Bromm, Volker
  • Monthly Notices of the Royal Astronomical Society, Vol. 444, Issue 4
  • DOI: 10.1093/mnras/stu1980

CHEMISTRY OF THE SAGITTARIUS DWARF GALAXY: A TOP-LIGHT INITIAL MASS FUNCTION, OUTFLOWS, AND THE R -PROCESS
journal, November 2013


Abundance ratios of red giants in low-mass ultra-faint dwarf spheroidal galaxies
journal, March 2016


Metal Mixing and Ejection in Dwarf Galaxies Are Dependent on Nucleosynthetic Source
journal, December 2018

  • Emerick, Andrew; Bryan, Greg L.; Low, Mordecai-Mark Mac
  • The Astrophysical Journal, Vol. 869, Issue 2
  • DOI: 10.3847/1538-4357/aaec7d

The Chemical Compositions of Non-Variable red and blue Field Horizontal Branch Stars
journal, October 2010


Non-LTE calculations for neutral Na in late-type stars using improved atomic data
journal, March 2011


The Faintest Dwarf Galaxies
journal, August 2019


Ultra metal-poor stars: improved atmospheric parameters and NLTE abundances of magnesium and calcium
journal, March 2019

  • Sitnova, T. M.; Mashonkina, L. I.; Ezzeddine, R.
  • Monthly Notices of the Royal Astronomical Society, Vol. 485, Issue 3
  • DOI: 10.1093/mnras/stz626

Carbon-Enhanced Metal-Poor Stars: Relics from the dark ages
journal, August 2014


Statistics of Satellite Galaxies Around Milky-Way-Like Hosts
journal, November 2011

  • Busha, Michael T.; Wechsler, Risa H.; Behroozi, Peter S.
  • The Astrophysical Journal, Vol. 743, Issue 2
  • DOI: 10.1088/0004-637X/743/2/117

A New Milky Way Companion: Unusual Globular Cluster or Extreme Dwarf Satellite?
journal, June 2005

  • Willman, Beth; Blanton, Michael R.; West, Andrew A.
  • The Astronomical Journal, Vol. 129, Issue 6
  • DOI: 10.1086/430214

JINAbase—A Database for Chemical Abundances of Metal-poor Stars
journal, October 2018

  • Abohalima, Abdu; Frebel, Anna
  • The Astrophysical Journal Supplement Series, Vol. 238, Issue 2
  • DOI: 10.3847/1538-4365/aadfe9

Eight new Milky way Companions Discovered in First-Year dark Energy Survey data
journal, June 2015


VLT/UVES Abundances in Four Nearby Dwarf Spheroidal Galaxies. II. Implications for Understanding Galaxy Evolution
journal, February 2003

  • Tolstoy, Eline; Venn, Kim A.; Shetrone, Matthew
  • The Astronomical Journal, Vol. 125, Issue 2
  • DOI: 10.1086/345967

The birth of a galaxy – III. Propelling reionization with the faintest galaxies
journal, June 2014

  • Wise, John H.; Demchenko, Vasiliy G.; Halicek, Martin T.
  • Monthly Notices of the Royal Astronomical Society, Vol. 442, Issue 3
  • DOI: 10.1093/mnras/stu979

Connecting the First Galaxies with Ultrafaint Dwarfs in the Local Group: Chemical Signatures of Population III Stars
journal, October 2017

  • Jeon, Myoungwon; Besla, Gurtina; Bromm, Volker
  • The Astrophysical Journal, Vol. 848, Issue 2
  • DOI: 10.3847/1538-4357/aa8c80

A NEW FAINT MILKY WAY SATELLITE DISCOVERED IN THE PAN-STARRS1 3 π SURVEY
journal, March 2015

  • Laevens, Benjamin P. M.; Martin, Nicolas F.; Ibata, Rodrigo A.
  • The Astrophysical Journal, Vol. 802, Issue 2
  • DOI: 10.1088/2041-8205/802/2/L18

A Deeper Look at the New Milky Way Satellites: Sagittarius II, Reticulum II, Phoenix II, and Tucana III
journal, August 2018

  • Mutlu-Pakdil, Burçin; Sand, David J.; Carlin, Jeffrey L.
  • The Astrophysical Journal, Vol. 863, Issue 1
  • DOI: 10.3847/1538-4357/aacd0e

Tracing the first stars and galaxies of the Milky Way
journal, October 2017

  • Griffen, Brendan F.; Dooley, Gregory A.; Ji, Alexander P.
  • Monthly Notices of the Royal Astronomical Society, Vol. 474, Issue 1
  • DOI: 10.1093/mnras/stx2749

Chemical Abundances of New Member Stars in the Tucana II Dwarf Galaxy
journal, April 2018

  • Chiti, Anirudh; Frebel, Anna; Ji, Alexander P.
  • The Astrophysical Journal, Vol. 857, Issue 1
  • DOI: 10.3847/1538-4357/aab4fc

Non-LTE line formation of Fe in late-type stars – I. Standard stars with 1D and 〈3D〉 model atmospheres: Fe in late-type stars – I
journal, October 2012


A Magellanic origin of the DES dwarfs
journal, June 2016

  • Jethwa, P.; Erkal, D.; Belokurov, V.
  • Monthly Notices of the Royal Astronomical Society, Vol. 461, Issue 2
  • DOI: 10.1093/mnras/stw1343

An Ultra-Faint Galaxy Candidate Discovered in Early data from the Magellanic Satellites Survey
journal, November 2016


Optimal Techniques in Two‐dimensional Spectroscopy: Background Subtraction for the 21st Century
journal, June 2003

  • Kelson, Daniel D.
  • Publications of the Astronomical Society of the Pacific, Vol. 115, Issue 808
  • DOI: 10.1086/375502

The Kinematics of the Ultra‐faint Milky Way Satellites: Solving the Missing Satellite Problem
journal, November 2007

  • Simon, Joshua D.; Geha, Marla
  • The Astrophysical Journal, Vol. 670, Issue 1
  • DOI: 10.1086/521816

The Stellar Initial mass Function of Ultra-Faint Dwarf Galaxies: Evidence for imf Variations with Galactic Environment
journal, June 2013


Mg line formation in late-type stellar atmospheres: II. Calculations in a grid of 1D models⋆
journal, February 2016


Identifying true satellites of the Magellanic Clouds
journal, November 2016

  • Sales, Laura V.; Navarro, Julio F.; Kallivayalil, Nitya
  • Monthly Notices of the Royal Astronomical Society, Vol. 465, Issue 2
  • DOI: 10.1093/mnras/stw2816

Chemical Abundance Analysis of Three α -poor, Metal-poor Stars in the Ultrafaint Dwarf Galaxy Horologium I
journal, January 2018

  • Nagasawa, D. Q.; Marshall, J. L.; Li, T. S.
  • The Astrophysical Journal, Vol. 852, Issue 2
  • DOI: 10.3847/1538-4357/aaa01d

Elemental Abundances and Their Implications for the Chemical Enrichment of the BoÖTes i Ultrafaint Galaxy
journal, January 2013


Preserving chemical signatures of primordial star formation in the first low-mass stars
journal, September 2015

  • Ji, Alexander P.; Frebel, Anna; Bromm, Volker
  • Monthly Notices of the Royal Astronomical Society, Vol. 454, Issue 1
  • DOI: 10.1093/mnras/stv2052

Computational issues in chemo-dynamical modelling of the formation and evolution of galaxies
journal, March 2016


Near-Field Cosmology with Extremely Metal-Poor Stars
journal, August 2015


Carbon‐enhanced Metal‐poor Stars. I. Chemical Compositions of 26 Stars
journal, January 2007

  • Aoki, Wako; Beers, Timothy C.; Christlieb, Norbert
  • The Astrophysical Journal, Vol. 655, Issue 1
  • DOI: 10.1086/509817

Stellar Yields from Metal-Rich Asymptotic Giant Branch Models
journal, June 2016


Gemini/GRACES spectroscopy of stars in Tri II
journal, December 2016

  • Venn, K. A.; Starkenburg, E.; Malo, L.
  • Monthly Notices of the Royal Astronomical Society, Vol. 466, Issue 3
  • DOI: 10.1093/mnras/stw3198

COMPLETE ELEMENT ABUNDANCES OF NINE STARS IN THE r -PROCESS GALAXY RETICULUM II
journal, October 2016


The galaxy-wide initial mass function of dwarf late-type to massive early-type galaxies
journal, October 2013

  • Weidner, C.; Kroupa, P.; Pflamm-Altenburg, J.
  • Monthly Notices of the Royal Astronomical Society, Vol. 436, Issue 4
  • DOI: 10.1093/mnras/stt1806

Chemical compositions of six metal-poor stars in the ultra-faint dwarf spheroidal galaxy Boötes I
journal, February 2014


The first carbon-enhanced metal-poor star found in the Sculptor dwarf spheroidal
journal, February 2015


Na-O anticorrelation and HB: III. The abundances of NGC 6441 from FLAMES-UVES spectra
journal, July 2006


The Abundances of Neutron-Capture Species in the very Metal-Poor Globular Cluster m15: a Uniform Analysis of red Giant Branch and red Horizontal Branch Stars
journal, April 2011

  • Sobeck, Jennifer S.; Kraft, Robert P.; Sneden, Christopher
  • The Astronomical Journal, Vol. 141, Issue 6
  • DOI: 10.1088/0004-6256/141/6/175

Deriving Stellar Effective Temperatures of Metal-Poor Stars with the Excitation Potential Method
journal, May 2013

  • Frebel, Anna; Casey, Andrew R.; Jacobson, Heather R.
  • The Astrophysical Journal, Vol. 769, Issue 1
  • DOI: 10.1088/0004-637X/769/1/57

The Initial Mass Function in the Coma Berenices Dwarf Galaxy from Deep Near-infrared HST Observations
journal, August 2018

  • Gennaro, Mario; Geha, Marla; Tchernyshyov, Kirill
  • The Astrophysical Journal, Vol. 863, Issue 1
  • DOI: 10.3847/1538-4357/aaceff

The Missing Satellites of the Magellanic Clouds? Gaia Proper Motions of the Recently Discovered Ultra-faint Galaxies
journal, October 2018

  • Kallivayalil, Nitya; Sales, Laura V.; Zivick, Paul
  • The Astrophysical Journal, Vol. 867, Issue 1
  • DOI: 10.3847/1538-4357/aadfee

Non-LTE aluminium abundances in late-type stars
journal, November 2017


Extremely Metal‐poor Stars. II. Elemental Abundances and the Early Chemical Enrichment of the Galaxy
journal, November 1996

  • Ryan, Sean G.; Norris, John E.; Beers, Timothy C.
  • The Astrophysical Journal, Vol. 471, Issue 1
  • DOI: 10.1086/177967

Are the Magellanic Clouds on Their First Passage about the Milky Way?
journal, October 2007

  • Besla, Gurtina; Kallivayalil, Nitya; Hernquist, Lars
  • The Astrophysical Journal, Vol. 668, Issue 2
  • DOI: 10.1086/521385

The upper bound on the lowest mass halo
journal, September 2017

  • Jethwa, P.; Erkal, D.; Belokurov, V.
  • Monthly Notices of the Royal Astronomical Society, Vol. 473, Issue 2
  • DOI: 10.1093/mnras/stx2330

The effects of photoionization on galaxy formation - II. Satellite galaxies in the Local Group
journal, June 2002


Matplotlib: A 2D Graphics Environment
journal, January 2007


How low does it go? Too few Galactic satellites with standard reionization quenching
journal, July 2019

  • Graus, Andrew S.; Bullock, James S.; Kelley, Tyler
  • Monthly Notices of the Royal Astronomical Society, Vol. 488, Issue 4
  • DOI: 10.1093/mnras/stz1992

Zinc abundances in Galactic bulge field red giants: Implications for damped Lyman- α systems
journal, July 2015


HIGH-RESOLUTION SPECTROSCOPY OF EXTREMELY METAL-POOR STARS IN THE LEAST EVOLVED GALAXIES: URSA MAJOR II and COMA BERENICES
journal, December 2009


A MegaCam Survey of Outer Halo Satellites. III. Photometric and Structural Parameters
journal, June 2018

  • Muñoz, Ricardo R.; Côté, Patrick; Santana, Felipe A.
  • The Astrophysical Journal, Vol. 860, Issue 1
  • DOI: 10.3847/1538-4357/aac16b

Beasts of the Southern Wild: Discovery of nine Ultra Faint Satellites in the Vicinity of the Magellanic Clouds
journal, May 2015

  • Koposov, Sergey E.; Belokurov, Vasily; Torrealba, Gabriel
  • The Astrophysical Journal, Vol. 805, Issue 2
  • DOI: 10.1088/0004-637X/805/2/130

The NumPy Array: A Structure for Efficient Numerical Computation
journal, March 2011

  • van der Walt, Stéfan; Colbert, S. Chris; Varoquaux, Gaël
  • Computing in Science & Engineering, Vol. 13, Issue 2
  • DOI: 10.1109/MCSE.2011.37

Dynamics of radiative supernova remnants
journal, November 1988

  • Cioffi, Denis F.; McKee, Christopher F.; Bertschinger, Edmund
  • The Astrophysical Journal, Vol. 334
  • DOI: 10.1086/166834

The Discovery and Analysis of Very Metal-Poor Stars in the Galaxy
journal, September 2005


Predicting the locations of possible long-lived low-mass first stars: importance of satellite dwarf galaxies
journal, October 2017

  • Magg, Mattis; Hartwig, Tilman; Agarwal, Bhaskar
  • Monthly Notices of the Royal Astronomical Society, Vol. 473, Issue 4
  • DOI: 10.1093/mnras/stx2729

Small Dwarf Galaxies within Larger Dwarfs: Why Some Are Luminous while Most Go Dark
journal, September 2008

  • D'Onghia, Elena; Lake, George
  • The Astrophysical Journal, Vol. 686, Issue 2
  • DOI: 10.1086/592995

Chemical Abundances in the Ultra-faint Dwarf Galaxies Grus I and Triangulum II: Neutron-capture Elements as a Defining Feature of the Faintest Dwarfs
journal, January 2019

  • Ji, Alexander P.; Simon, Joshua D.; Frebel, Anna
  • The Astrophysical Journal, Vol. 870, Issue 2
  • DOI: 10.3847/1538-4357/aaf3bb

Na-O anticorrelation and HB: VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra
journal, July 2009


Chemical Abundance Analysis of Tucana III, the Second r -process Enhanced Ultra-faint Dwarf Galaxy
journal, September 2019


The first stars: CEMP-no stars and signatures of spinstars
journal, March 2015


Gaia Data Release 2 : Summary of the contents and survey properties
journal, August 2018


Cats and Dogs, Hair and a Hero: A Quintet of New Milky Way Companions
journal, January 2007

  • Belokurov, V.; Zucker, D. B.; Evans, N. W.
  • The Astrophysical Journal, Vol. 654, Issue 2
  • DOI: 10.1086/509718

The Chemical Evolution of the BoÖTes i Ultra-Faint Dwarf Galaxy
journal, July 2016


News from the Galactic suburbia: the chemical composition of the remote globular cluster NGC 2419: Chemical composition of NGC 2419
journal, October 2012


Na-O anticorrelation and horizontal branches: VI. The chemical composition of the peculiar bulge globular cluster NGC 6388
journal, January 2007


The very Faint end of the uv Luminosity Function over Cosmic Time: Constraints from the Local Group Fossil Record
journal, September 2014

  • Weisz, Daniel R.; Johnson, Benjamin D.; Conroy, Charlie
  • The Astrophysical Journal, Vol. 794, Issue 1
  • DOI: 10.1088/2041-8205/794/1/L3

NORMAL AND OUTLYING POPULATIONS OF THE MILKY WAY STELLAR HALO AT [Fe/H] <–2
journal, November 2013

  • Cohen, Judith G.; Christlieb, Norbert; Thompson, Ian
  • The Astrophysical Journal, Vol. 778, Issue 1
  • DOI: 10.1088/0004-637X/778/1/56

Multi-Element Abundance Measurements from Medium-Resolution Spectra. iv. Alpha Element Distributions in Milky way Satellite Galaxies
journal, January 2011

  • Kirby, Evan N.; Cohen, Judith. G.; Smith, Graeme H.
  • The Astrophysical Journal, Vol. 727, Issue 2
  • DOI: 10.1088/0004-637X/727/2/79

Gaia DR 2 and VLT/FLAMES search for new satellites of the LMC
journal, March 2019


Detailed abundance analysis of the brightest star in Segue 2, the least massive galaxy★
journal, April 2014

  • Roederer, Ian U.; Kirby, Evan N.
  • Monthly Notices of the Royal Astronomical Society, Vol. 440, Issue 3
  • DOI: 10.1093/mnras/stu491

Discovery of two neighbouring satellites in the Carina constellation with MagLiteS
journal, January 2018

  • Torrealba, G.; Belokurov, V.; Koposov, S. E.
  • Monthly Notices of the Royal Astronomical Society, Vol. 475, Issue 4
  • DOI: 10.1093/mnras/sty170

Eight Ultra-Faint Galaxy Candidates Discovered in year two of the dark Energy Survey
journal, November 2015


The dark Energy Camera
journal, October 2015


Evidence for Sub-Chandrasekhar Type Ia Supernovae from Stellar Abundances in Dwarf Galaxies
journal, August 2019

  • Kirby, Evan N.; Xie, Justin L.; Guo, Rachel
  • The Astrophysical Journal, Vol. 881, Issue 1
  • DOI: 10.3847/1538-4357/ab2c02

emcee : The MCMC Hammer
journal, March 2013

  • Foreman-Mackey, Daniel; Hogg, David W.; Lang, Dustin
  • Publications of the Astronomical Society of the Pacific, Vol. 125, Issue 925
  • DOI: 10.1086/670067

Stellar lifetimes and abundance ratios in chemical evolution
journal, May 1979

  • Tinsley, B. M.
  • The Astrophysical Journal, Vol. 229
  • DOI: 10.1086/157039

Nucleosynthesis and Evolution of Massive Metal-Free Stars
journal, November 2010


Triangulum II. Not Especially Dense After All
journal, March 2017

  • Kirby, Evan N.; Cohen, Judith G.; Simon, Joshua D.
  • The Astrophysical Journal, Vol. 838, Issue 2
  • DOI: 10.3847/1538-4357/aa6570

Neutron-capture element deficiency of the Hercules dwarf spheroidal galaxy
journal, May 2013


Metal Abundances, Radial Velocities, and Other Physical Characteristics for the rr Lyrae Stars in the Kepler Field
journal, August 2013


Evidence of enrichment by individual SN from elemental abundance ratios in the very metal-poor dSph galaxy Boötes I
journal, October 2009


Analysis and calibration of Ca ii triplet spectroscopy of red giant branch stars from VLT/FLAMES observations: Calibration of Ca ii triplet spectroscopy
journal, December 2007


Gaia Proper Motions and Orbits of the Ultra-faint Milky Way Satellites
journal, August 2018


The Oxygen Abundance of HE 1327-2326
journal, January 2006

  • Frebel, Anna; Christlieb, Norbert; Norris, John E.
  • The Astrophysical Journal, Vol. 638, Issue 1
  • DOI: 10.1086/500592

Ships Passing in the Night: Spectroscopic Analysis of Two Ultra-faint Satellites in the Constellation Carina
journal, April 2018


Star-Formation Histories, Abundances, and Kinematics of Dwarf Galaxies in the Local Group
journal, September 2009


The Highly Unusual Chemical Composition of the Hercules Dwarf Spheroidal Galaxy
journal, November 2008

  • Koch, Andreas; McWilliam, Andrew; Grebel, Eva K.
  • The Astrophysical Journal, Vol. 688, Issue 1
  • DOI: 10.1086/595001

Ultra-metal-poor Stars: Spectroscopic Determination of Stellar Atmospheric Parameters Using Iron Non-LTE Line Abundances
journal, October 2017

  • Ezzeddine, Rana; Frebel, Anna; Plez, Bertrand
  • The Astrophysical Journal, Vol. 847, Issue 2
  • DOI: 10.3847/1538-4357/aa8875

DETAILED CHEMICAL ABUNDANCES IN THE r -PROCESS-RICH ULTRA-FAINT DWARF GALAXY RETICULUM 2
journal, February 2016


Detection of a Population of Carbon-enhanced Metal-poor Stars in the Sculptor Dwarf Spheroidal Galaxy
journal, April 2018

  • Chiti, Anirudh; Simon, Joshua D.; Frebel, Anna
  • The Astrophysical Journal, Vol. 856, Issue 2
  • DOI: 10.3847/1538-4357/aab663

A New Type of Extremely Metal-poor Star
journal, March 2007

  • Cohen, Judith G.; McWilliam, Andrew; Christlieb, Norbert
  • The Astrophysical Journal, Vol. 659, Issue 2
  • DOI: 10.1086/518031

Multiple Stellar Populations in Globular Clusters
journal, September 2018


The first Population II stars formed in externally enriched mini-haloes
journal, July 2015

  • Smith, Britton D.; Wise, John H.; O'Shea, Brian W.
  • Monthly Notices of the Royal Astronomical Society, Vol. 452, Issue 3
  • DOI: 10.1093/mnras/stv1509

Astropy: A community Python package for astronomy
journal, September 2013


The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization era
journal, November 2014


The Bizarre Chemical Inventory of ngc 2419, an Extreme Outer halo Globular Cluster
journal, November 2012


THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. I. HUBBLE SPACE TELESCOPE /WFC3 DATA AND ORBIT IMPLICATIONS
journal, February 2013

  • Kallivayalil, Nitya; van der Marel, Roeland P.; Besla, Gurtina
  • The Astrophysical Journal, Vol. 764, Issue 2
  • DOI: 10.1088/0004-637X/764/2/161

Observational constraints on the origin of the elements: I. 3D NLTE formation of Mn lines in late-type stars
journal, October 2019


Observational Constraints on First-Star Nucleosynthesis. i. Evidence for Multiple Progenitors of Cemp-No Stars
journal, December 2016

  • Yoon, Jinmi; Beers, Timothy C.; Placco, Vinicius M.
  • The Astrophysical Journal, Vol. 833, Issue 1
  • DOI: 10.3847/0004-637X/833/1/20

The Chemical Evolution of the ursa Minor Dwarf Spheroidal Galaxy
journal, July 2010


R-process enrichment from a single event in an ancient dwarf galaxy
journal, March 2016

  • Ji, Alexander P.; Frebel, Anna; Chiti, Anirudh
  • Nature, Vol. 531, Issue 7596
  • DOI: 10.1038/nature17425

OBSERVATIONAL CONSTRAINTS ON FIRST-STAR NUCLEOSYNTHESIS. II. SPECTROSCOPY OF AN ULTRA METAL-POOR CEMP-no STAR
journal, December 2016

  • Placco, Vinicius M.; Frebel, Anna; Beers, Timothy C.
  • The Astrophysical Journal, Vol. 833, Issue 1
  • DOI: 10.3847/0004-637X/833/1/21

Reionization and the Abundance of Galactic Satellites
journal, August 2000

  • Bullock, James S.; Kravtsov, Andrey V.; Weinberg, David H.
  • The Astrophysical Journal, Vol. 539, Issue 2
  • DOI: 10.1086/309279

Neutron-Capture Elements in the Early Galaxy
journal, September 2008


Segue 1: an Unevolved Fossil Galaxy from the Early Universe
journal, April 2014


The Gaia mission
journal, November 2016


THE MOST METAL-POOR STARS. IV. THE TWO POPULATIONS WITH [Fe/H] ≲ –3.0
journal, December 2012


CHEMISTRY OF THE MOST METAL-POOR STARS IN THE BULGE AND THE z ≳ 10 UNIVERSE
journal, August 2015


THE s -PROCESS IN ASYMPTOTIC GIANT BRANCH STARS OF LOW METALLICITY AND THE COMPOSITION OF CARBON-ENHANCED METAL-POOR STARS
journal, February 2012

  • Lugaro, Maria; Karakas, Amanda I.; Stancliffe, Richard J.
  • The Astrophysical Journal, Vol. 747, Issue 1
  • DOI: 10.1088/0004-637X/747/1/2

THE MOST METAL-POOR STARS. II. CHEMICAL ABUNDANCES OF 190 METAL-POOR STARS INCLUDING 10 NEW STARS WITH [Fe/H] ⩽ –3.5, ,
journal, December 2012


High-Resolution Spectroscopy of Extremely Metal-Poor Stars in the Least Evolved Galaxies: leo iv
journal, May 2010


A stochastically sampled IMF alters the stellar content of simulated dwarf galaxies
journal, November 2019

  • Applebaum, Elaad; Brooks, Alyson M.; Quinn, Thomas R.
  • Monthly Notices of the Royal Astronomical Society, Vol. 492, Issue 1
  • DOI: 10.1093/mnras/stz3331

Influence of departures from LTE on calcium, titanium, and iron abundance determinations in cool giants of different metallicities
journal, September 2016


Chemical Diversity in the Ultra-Faint Dwarf Galaxy Tucana ii
journal, November 2016


Carbon-Enhanced Metal-Poor star Frequencies in the Galaxy: Corrections for the Effect of Evolutionary Status on Carbon Abundances
journal, November 2014

  • Placco, Vinicius M.; Frebel, Anna; Beers, Timothy C.
  • The Astrophysical Journal, Vol. 797, Issue 1
  • DOI: 10.1088/0004-637X/797/1/21

Proper Motions of Milky Way Ultra-faint Satellites with Gaia DR2 × DES DR1
journal, April 2019


The Aquarius Project: the subhaloes of galactic haloes
journal, December 2008


Chemical Abundances of Metal-Poor rr Lyrae Stars in the Magellanic Clouds
journal, August 2012


An r -process Enhanced Star in the Dwarf Galaxy Tucana III
journal, March 2017

  • Hansen, T. T.; Simon, J. D.; Marshall, J. L.
  • The Astrophysical Journal, Vol. 838, Issue 1
  • DOI: 10.3847/1538-4357/aa634a

Extremely Metal‐poor Stars. VII. The Most Metal‐poor Dwarf, CS 22876−032
journal, September 2000

  • Norris, John E.; Beers, Timothy C.; Ryan, Sean G.
  • The Astrophysical Journal, Vol. 540, Issue 1
  • DOI: 10.1086/309320

Kinematics and Chemistry of Recently Discovered Reticulum 2 and Horologium 1 Dwarf Galaxies
journal, September 2015

  • Koposov, Sergey E.; Casey, Andrew R.; Belokurov, Vasily
  • The Astrophysical Journal, Vol. 811, Issue 1
  • DOI: 10.1088/0004-637X/811/1/62

Non-LTE analysis of the formation of KI lines in the spectra of A-K stars
journal, June 2000

  • Ivanova, D. V.; Shimanskii, V. V.
  • Astronomy Reports, Vol. 44, Issue 6
  • DOI: 10.1134/1.163861

Uncovering Extremely Metal-Poor Stars in the Milky Way's Ultrafaint Dwarf Spheroidal Satellite Galaxies
journal, September 2008

  • Kirby, Evan N.; Simon, Joshua D.; Geha, Marla
  • The Astrophysical Journal, Vol. 685, Issue 1
  • DOI: 10.1086/592432

Carbon-enhanced metal-poor stars in dwarf galaxies
journal, October 2015

  • Salvadori, Stefania; Skúladóttir, Ása; Tolstoy, Eline
  • Monthly Notices of the Royal Astronomical Society, Vol. 454, Issue 2
  • DOI: 10.1093/mnras/stv1969

A CEMP-no star in the ultra-faint dwarf galaxy Pisces II
journal, September 2018


Na-O anticorrelation and HB: IX. Kinematics of the program clusters A link between systemic rotation and HB morphology?
journal, January 2012