Context: The redshift of
Aims: We intend to provide a lower limit for the distance of the object.
Methods: We used a χ2 procedure to constrain the apparent magnitude of the host galaxy in archived HST images. Supposing that the host galaxy is typical of BL Lac objects (MR -22.8), a lower limit to the distance can be obtained from the limit on the apparent magnitude of the host galaxy.
Results: Using the 3σ limit on the host galaxy magnitude, the redshift is found to be ≥0.25.
Conclusions: The redshift of
Astronomy and Astrophysics
- Pub Date:
- October 2007
- galaxies: active;
- BL Lacertae objects: individual: PG 1553+11;
- gamma rays: observations;
- Accepted for publication in A&