B3 Non-refereed article in a conference publication
The stellar content of low redshift BL Lac host galaxies from multicolour imaging
Authors: Hyvönen T, Kotilainen JK, Falomo R, Pursimo T
Conference name: The Nuclear Region, Host Galaxy and Environment of Active Galaxies
Publication year: 2008
Journal: Revista mexicana de astronomía y astrofísica : serie de conferencias
Journal name in source: NUCLEAR REGION, HOST GALAXY AND ENVIRONMENT OF ACTIVE GALAXIES
Journal acronym: REV MEX AST ASTR
Series title: Revista Mexicana de Astronomia y Astrofisica Serie de Conferencias
Volume: 32
First page : 161
Last page: 163
Number of pages: 2
ISBN: 978-970-32-5297-8
ISSN: 1405-2059
Web address : https://www.astroscu.unam.mx/rmaa/RMxAC..32/PDF/RMxAC..32_thyvonen.pdf
Abstract
We present UBV-band imaging of 18 low redshift (z <= 0.3) BL Lac objects. These data are used to investigate the blue-red-near-infrared colours and colour gradients of the host galaxies. The distributions of the integrated blue/near-infrared colour and colour gradient of the BL Lac hosts are much wider than those for inactive ellipticals, and most BL Lac objects have bluer hosts and/or steeper colour gradients than those in inactive ellipticals. 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 supported by stellar population modelling, indicating a presence of young/intermediate age populations in the majority of the sample.
We present UBV-band imaging of 18 low redshift (z <= 0.3) BL Lac objects. These data are used to investigate the blue-red-near-infrared colours and colour gradients of the host galaxies. The distributions of the integrated blue/near-infrared colour and colour gradient of the BL Lac hosts are much wider than those for inactive ellipticals, and most BL Lac objects have bluer hosts and/or steeper colour gradients than those in inactive ellipticals. 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 supported by stellar population modelling, indicating a presence of young/intermediate age populations in the majority of the sample.
Keywords:
BL Lacertae objects : general, galaxies : active, galaxies : interactions, galaxies : nuclei, galaxies : photometry
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