The stellar content of low redshift BL Lacertae host galaxies from multicolour imaging

: Hyvonen T, Kotilainen JK, Falomo R, Orndahl E, Pursimo T

Publisher: EDP SCIENCES S A

: 2007

ASTRONOMY & ASTROPHYSICS

: ASTRON ASTROPHYS

: 476

: 2

: 723

: U15

: 15

: 0004-6361

DOI: https://doi.org/10.1051/0004-6361:20078202

Conclusions. The blue colours are likely caused by a young stellar population component, and indicates a link between star formation caused by an interaction/ merging event and the onset of the nuclear activity. This result is corroborated by stellar population modelling, indicating a presence of young/ intermediate age populations in the majority of the sample, in agreement with low redshift quasar hosts. The lack of strong signs of interaction may require a significant time delay between the event with associated star formation episodes and the start of the nuclear activity.