Skip navigation
  • INAF logo
  • Home
  • Communities
    & Collections
  • Research outputs
  • Researchers
  • Organization units
  • Projects
  • Explore by
    • Research outputs
    • Researchers
    • Organization units
    • Projects
  • Login:
    • My DSpace
    • Receive email
      updates
    • Edit Account details
  • Italian
  • English

  1. OA@INAF
  2. PRODOTTI RICERCA INAF
  3. 1 CONTRIBUTI IN RIVISTE (Journal articles)
  4. 1.01 Articoli in rivista
Please use this identifier to cite or link to this item: http://hdl.handle.net/20.500.12386/29173
Title: A DECam view of the diffuse dwarf galaxy Crater II: the colour-magnitude diagram
Authors: Walker, A. R.
Martínez-Vázquez, C. E.
Monelli, M.
Vivas, A. K.
Bono, G.
Gallart, C.
CASSISI, Santi 
ANDREUZZI, Gloria 
Bernard, E. J.
DALL'ORA, Massimo 
FIORENTINO, Giuliana 
Nidever, D. L.
Olsen, K.
PIETRINFERNI, Adriano 
Stetson, P. B.
Issue Date: 2019
Journal: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 
Number: 490
Issue: 3
First Page: 4121
Abstract: We present a deep Blanco/DECam colour-magnitude diagram (CMD) for the large but very diffuse Milky Way satellite dwarf galaxy Crater II. The CMD shows only old stars with a clearly bifurcated subgiant branch (SGB) that feeds a narrow red giant branch. The horizontal branch (HB) shows many RR Lyrae and red HB stars. Comparing the CMD with [Fe/H] = -2.0 and [α/Fe] = + 0.3 alpha-enhanced BaSTI isochrones indicates a mean age of 12.5 Gyr for the main event and a mean age of 10.5 Gyr for the brighter SGB. With such multiple star formation events Crater II shows similarity to more massive dwarfs that have intermediate age populations, however for Crater II there was early quenching of the star formation and no intermediate age or younger stars are present. The spatial distribution of Crater II stars overall is elliptical in the plane of the sky, the detailed distribution shows a lack of strong central concentration, and some inhomogeneities. The 10.5 Gyr subgiant and upper main-sequence stars show a slightly higher central concentration when compared to the 12.5 Gyr population. Matching to Gaia DR2 we find the proper motion of Crater II: μ<SUB>α</SUB>cos δ = -0.14 ± 0.07, μ<SUB>δ</SUB> = -0.10 ± 0.04 mas yr<SUP>-1</SUP>, approximately perpendicular to the semimajor axis of Crater II. Our results provide constraints on the star formation and chemical enrichment history of Crater II, but cannot definitively determine whether or not substantial mass has been lost over its lifetime.
URI: http://hdl.handle.net/20.500.12386/29173
URL: https://academic.oup.com/mnras/article/490/3/4121/5585412
ISSN: 0035-8711
DOI: 10.1093/mnras/stz2826
Bibcode ADS: 2019MNRAS.490.4121W
Fulltext: open
Appears in Collections:1.01 Articoli in rivista

Files in This Item:
File Description SizeFormat 
stz2826.pdfPdf editoriale4.13 MBAdobe PDFView/Open
Show full item record

Page view(s)

4
checked on Jan 16, 2021

Download(s)

2
checked on Jan 16, 2021

Google ScholarTM

Check

Altmetric


Items in DSpace are published in Open Access, unless otherwise indicated.


Explore by
  • Communities
    & Collections
  • Research outputs
  • Researchers
  • Organization units
  • Projects

Informazioni e guide per autori

https://openaccess-info.inaf.it: tutte le informazioni sull'accesso aperto in INAF

Come si inserisce un prodotto: le guide a OA@INAF

La Policy INAF sull'accesso aperto

Documenti e modelli scaricabili

Feedback
Built with DSpace-CRIS - Extension maintained and optimized by Logo 4SCIENCE