Supernovae and their host galaxies – V. The vertical distribution of supernovae in disc galaxies

Abstract

We present an analysis of the height distributions of the different types of supernovae (SNe) from the plane of their host galaxies. We use a well-defined sample of 102 nearby SNe appeared inside high-inclined (i 85 • ), morphologically non-disturbed S0-Sd host galaxies from the Sloan Digital Sky Survey. For the first time, we show that in all the subsamples of spirals, the vertical distribution of core-collapse (CC) SNe is about twice closer to the plane of host disc than the distribution of SNe Ia. In Sb-Sc hosts, the exponential scale height of CC SNe is consistent with those of the younger stellar population in the Milky Way (MW) thin disc, while the scale height of SNe Ia is consistent with those of the old population in the MW thick disc. We show that the ratio of scale lengths to scale heights of the distribution of CC SNe is consistent with those of the resolved young stars with ages from ∼ 10 Myr up to ∼ 100 Myr in nearby edge-on galaxies and the unresolved stellar population of extragalactic thin discs. The corresponding ratio for SNe Ia is consistent with the same ratios of the two populations of resolved stars with ages from a few 100 Myr up to a few Gyr and from a few Gyr up to ∼ 10 Gyr, as well as with the unresolved population of the thick disc. These results can be explained considering the age-scale height relation of the distribution of stellar population and the mean age difference between Type Ia and CC SNe progenitors.

Core-collapse supernovae ages and metallicities from emission-line diagnostics of nearby stellar populations

“…In addition, considering that the CCSNe host in old and diffused environment, the measured Hα EW can be more contributed by the underneath stellar populations rather than the emission nebulae. Therefore, these estimated ages can be longer than the typical lifetime of HII regions (up to a few 10 Myrs), and this is consistent with the CCSN ages of Hakobyan et al (2017) using completely different approach based on the CCSN spatial distribution in their host galaxies. While in the real galaxies, planetary nebulae and other sources from x-ray binaries (Woods & Gilfanov 2016) can get into these late ages that are not yet in BPASS models.…”

Supernovae and their host galaxies – VI. Normal Type Ia and 91bg-like supernovae in ellipticals

“…In this case, it is difficult to precisely analyse the spatial distribution of SNe, and associate them with a concrete stellar component (bulge or thick/thin discs, old or intermediate/young) in the hosts due to different or unknown projection effects (e.g. Hakobyan et al 2016Hakobyan et al , 2017. In addition, E-S0 and spiral host galaxies have had different evolutionary paths through major/minor galaxy-galaxy interaction (e.g.…”

SN1991bg-like supernovae are associated with old stellar populations

“…SNe Ia are observed to occur in all galaxy types, from passive to star forming, and there is some evidence that they are found in regions of galaxies occupied by older, several Gyr-old stars (e.g. the vertical distribution of SNe Ia is greater than the vertical distribution of Core collapse supernovae (CCSNe) in edge-on spiral galaxies Hakobyan et al 2017). On the other hand, 91bg-like SNe occur predominantly in early-type galaxies (Perets et al 2010).…”