Looking deep into the Rosette Nebula's heart : the (sub)stellar content of the massive young cluster NGC 2244
Date
14/08/2019Author
Grant ID
ST/R00824/1
Keywords
Metadata
Show full item recordAltmetrics Handle Statistics
Altmetrics DOI Statistics
Abstract
As part of the ongoing effort to characterize the low-mass (sub)stellar population in a sample of massive young clusters, we have targeted the ~2 Myr old cluster NGC 2244. The distance to NGC 2244 from Gaia DR2 parallaxes is 1.59 kpc, with errors of 1% (statistical) and 11% (systematic). We used the Flamingos-2 near-infrared camera at the Gemini-South telescope for deep multi-band imaging of the central portion of the cluster (~2.4 pc2). We determined membership in a statistical manner, through a comparison of the cluster's color–magnitude diagram to that of a control field. Masses and extinctions of the candidate members are then calculated with the help of evolutionary models, leading to the first initial mass function (IMF) of the cluster extending into the substellar regime, with the 90% completeness limit around 0.02 M ⊙. The IMF is well represented by a broken power law (dN/dM ∝ M −α ) with a break at ~0.4 M ⊙. The slope on the high-mass side (0.4–7 M ⊙) is α = 2.12 ± 0.08, close to the standard Salpeter slope. In the low-mass range (0.02–0.4 M ⊙), we find a slope α = 1.03 ± 0.02, which is at the high end of the typical values obtained in nearby star-forming regions (α = 0.5–1.0), but still in agreement within the uncertainties. Our results reveal no clear evidence for variations in the formation efficiency of brown dwarfs (BDs) and very low-mass stars due to the presence of OB stars, or for a change in stellar densities. Our finding rules out photoevaporation and fragmentation of infalling filaments as substantial pathways for BD formation.
Citation
Muzic , K , Scholz , A , Pena Ramirez , K , Jayawardhana , R , Schodel , R , Geers , V C , Cieza , L A & Bayos , A 2019 , ' Looking deep into the Rosette Nebula's heart : the (sub)stellar content of the massive young cluster NGC 2244 ' , Astrophysical Journal , vol. 881 , no. 1 , 79 . https://doi.org/10.3847/1538-4357/ab2da4
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
Rights
Copyright © 2019 The American Astronomical Society. All rights reserved. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.3847/1538-4357/ab2da4
Description
A.S.'s work is supported by the STFC grant No. ST/R000824/1.Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.