Two‐dimensional Photometric Decomposition of the TeV BL Lacertae Objects Markarian 421, Markarian 501, and 1ES 2344+514

Abstract

We have obtained high-resolution R-band images of three BL Lacertae objects, Mrk 421, Mrk 501, and 1ES 2344]514, that have been detected at high-energy (TeV) c-rays. Because of their TeV emission, these three objects have been targets of intensive optical monitoring during the last few years. We have studied the morphology of host galaxies by Ðtting ellipses and two-dimensional galaxy]core models to the observed surface brightness distribution. We Ðnd the host galaxies to be large (e ective radii 7È40 kpc) and bright to [24.6) elliptical galaxies, whose surface brightness distribution can be described (M R \ [23.2 by a single power law I(r) P r~b with b \ 0.10È0.36 to an accuracy of D0.2 mag. The isophotes of the host galaxies are found to be ellipses with no apparent " " boxyness ÏÏ or " " diskyness.ÏÏ The host galaxies of Mrk 501 and 1ES 2344]514 also exhibit a position angle twist that increases linearly with distance from the nucleus. Using the two-dimensional photometric decomposition we have constructed tables of host galaxy magni-tude as a function of measuring aperture diameter and seeing. These tables can be used to " " clean ÏÏ photo-metric data of the host galaxy contribution.