The host galaxies of BL Lac objects in the near { infraredJ
نویسندگان
چکیده
We present near{infrared imaging of 11 BL Lac objects. The host galaxy is resolved in 7 low redshift (z0.24) BL Lacs, while the 4 unresolved BL Lacs have either high (z0.5) or unknown redshift. The host galaxies of low redshift BL Lacs are luminous (average M(H) = { 25.80.5), i.e. slightly brighter than L* galaxies, and of similar luminosity to or slightly fainter than brightest cluster galaxies. The optical/near{ infrared colour and colour gradient of the BL Lac hosts (R{H = 2.20.5; (R{H)//(log r) = {0.090.04) are consistent with those of normal el-lipticals, indicating that the nuclear activity has only a marginal eeect on the properties of the hosts. The BL Lac hosts appear slightly less luminous than those of higher redshift at spectrum radio quasars.
منابع مشابه
The stellar content of low redshift BL Lac host galaxies from multicolour imaging
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