English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We conduct a detailed investigation of the properties of the stellar initialmass function (IMF) in two massive early-type lens galaxies with velocitydispersions of sigma ~245 km/s and sigma ~325 km/s, for which both HST imagingand X-Shooter spectra are available. We compare the inferences obtained fromtwo fully independent methods: (i) a combined gravitational lensing and stellardynamics (L&D) analysis of the data sets employing self-consistent axisymmetricmodels, and (ii) a spectroscopic simple stellar population (SSP) analysis ofoptical line-strength indices, assuming single power-law IMFs. The results fromthe two approaches are found to be in agreement within the 1-sigmauncertainties. Both galaxies are consistent with having a Salpeter IMF(power-law slope of x = 2.35), which is strongly favoured over a Chabrier IMF(x = 1.8), with probabilities inferred from the joint analysis of 89% and 99%,respectively. Bottom-heavy IMFs significantly steeper than Salpeter (x >= 3.0)are ruled out with decisive evidence (Bayes factor B > 1000) for both galaxies,as they exceed the total mass derived from the L&D constraints. Our analysisallows, for the first time, the inference of the low-mass cut-off of the IMF(M_low). Combining the joint L&D and SSP analyses of both galaxies, we infer anIMF slope of x = 2.22 +/- 0.14, consistent with Salpeter IMF, and a low-masslimit M_low = 0.13 +/- 0.03 M_sun, just above the hydrogen burning limit.

A low-mass cut-off near the hydrogen burning limit for Salpeter-like initial mass functions in early-type galaxies