Core-collapse supernova progenitor constraints using the spatial distributions of massive stars in local galaxies

¹ Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, 21500 Piikkiö, Finland
e-mail: tjakan@utu.fi
² Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, 21500 Piikkiö, Finland
³ Institute of Astronomy (IoA), University of Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
⁴ Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN, UK
⁵ Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool, L3 5RF, UK
⁶ The Department of Physics and Astronomy, The University of Sheffield, Hicks Building, Hounsfield Road, Sheffield, S3 7RH, UK

Received: 12 April 2016
Accepted: 20 August 2016

Abstract

We studied the spatial correlations between the Hα emission and different types of massive stars in two local galaxies, the Large Magellanic Cloud (LMC) and Messier 33. We compared these to correlations derived for core-collapse supernovae (CCSNe) in the literature to connect CCSNe of different types with the initial masses of their progenitors and to test the validity of progenitor mass estimates which use the pixel statistics method. We obtained samples of evolved massive stars in both galaxies from catalogues with good spatial coverage and/or completeness, and combined them with coordinates of main-sequence stars in the LMC from the SIMBAD database. We calculated the spatial correlation of stars of different classes and spectral types with Hα emission. We also investigated the effects of distance, noise and positional errors on the pixel statistics method. A higher correlation with Hα emission is found to correspond to a shorter stellar lifespan, and we conclude that the method can be used as an indicator of the ages, and therefore initial masses, of SN progenitors. We find that the spatial distributions of type II-P SNe and red supergiants of appropriate initial mass (≳9 M_⊙) are consistent with each other. We also find the distributions of type Ic SNe and WN stars with initial masses ≳20 M_⊙ consistent, while supergiants with initial masses around 15 M_⊙ are a better match for type IIb and II-L SNe. The type Ib distribution corresponds to the same stellar types as type II-P, which suggests an origin in interacting binaries. On the other hand, we find that luminous blue variable stars show a much stronger correlation with Hα emission than do type IIn SNe.