Journal article
The contribution of N-rich stars to the Galactic stellar halo using APOGEE red giants
Monthly notices of the Royal Astronomical Society, Vol.500(4), pp.5462-5478
02/01/2021
DOI: 10.1093/mnras/staa3598
Abstract
The contribution of dissolved globular clusters (GCs) to the stellar content of the Galactic halo is a key constraint on models for GC formation and destruction, and the mass assembly history of the Milky Way. Earlier results from APOGEE pointed to a large contribution of destroyed GCs to the stellar content of the inner halo, by as much as 25 per cent, which is an order of magnitude larger than previous estimates for more distant regions of the halo. We set out to measure the ratio between nitrogen-rich (N-rich) and normal halo field stars, as a function of distance, by performing density modelling of halo field populations in APOGEE DR16. Our results show that at 1.5 kpc from the Galactic Centre, N-rich stars contribute a much higher 16.81(-7.0)(+10.0) per cent fraction to the total stellar halo mass budget than the 2.7(-0.8)(-1.0) per cent ratio contributed at 10 kpc. Under the assumption that N-rich stars are former GC members that now reside in the stellar halo field, and assuming the ratio between first and second population GC stars being 1:2, we estimate a total contribution from disrupted GC stars of the order of 27.5(-11.5)(+15.4) per cent at r = 1.5 kpc and 4.2(-1:3)(+1.5) per cent at r = 10 kpc. Furthermore, since our methodology requires fitting a density model to the stellar halo, we integrate such density within a spherical shell from 1.5 to 15 kpc in radius, and find a total stellar mass arising from dissolved and/or evaporated GCs of M-GC(total) = 9.6-2.6(+4.0) x 10(7) M-circle dot.
Details
- Title: Subtitle
- The contribution of N-rich stars to the Galactic stellar halo using APOGEE red giants
- Creators
- Danny Horta - Liverpool John Moores UniversityJ. Ted Mackereth - University of TorontoRicardo P. Schiavon - Liverpool John Moores UniversitySten Hasselquist - University of UtahJo Bovy - Canadian Institute for Theoretical AstrophysicsCarlos Allende Prieto - Instituto de Astrofísica de CanariasTimothy C. Beers - University of Notre DameKatia Cunha - University of ArizonaD. A. Garcia-Hernandez - Inst Astrofis Canarias, E-38200 Tenerife, SpainShobhit S. Kisku - Liverpool John Moores UniversityRichard R. Lane - Pontificia Universidad Católica de ChileSteven R. Majewski - University of VirginiaAndrew C. Mason - Liverpool John Moores UniversityDavid M. Nataf - Johns Hopkins UniversityAlexandre Roman-Lopes - University of La SerenaMathias Schultheis - Observatoire de la Côte d’Azur
- Resource Type
- Journal article
- Publication Details
- Monthly notices of the Royal Astronomical Society, Vol.500(4), pp.5462-5478
- DOI
- 10.1093/mnras/staa3598
- ISSN
- 0035-8711
- eISSN
- 1365-2966
- Publisher
- Oxford Univ Press
- Number of pages
- 17
- Grant note
- University of Notre Dame New York University Universidad Nacional Autonoma de Mexico Harvard-Smithsonian Center for Astrophysics; Smithsonian Institution Lawrence Berkeley National Laboratory; United States Department of Energy (DOE) State Research Agency (AEI) of the Spanish Ministry of Science, Innovation and Universities (MCIU); Spanish Government Ohio State University PHY 14-30152 / US National Science Foundation; National Science Foundation (NSF) National Astronomical Observatories of China Chilean Participation Group
- Language
- English
- Date published
- 02/01/2021
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701732002771
Metrics
9 Record Views