2013/12/10 by K. R. W. Tristram, Konrad R. W. Tristram, Tristram, Konrad R. W. · 1 citation
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #astro-ph.GA #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.1312.3607
15 pages, 17 figures and 3 tables (original version from Oct. 2009)
arxiv created 2013/12/10 · openalex publication_date 2013/12/10 · arxiv updated 2013/12/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In principle, the MID-infrared Interferometric instrument (MIDI) at the Very Large Telescope Array (VLTI) should always measure the same calibrated total flux spectrum for a specific source, independent of the instrument settings and the baseline geometry. In the data on the Circinus galaxy, however, there is (a) a general offset of the flux values for 2009 and (b) a slow drift of the total fluxes at short wavelengths during two nights (2008-04-17 and 2009-04-14). The latter seems to depend on the hour angle of the observation. In this document, a more detailed analysis of these two effects is carried out and summarised. The goal is to find an explanation for these variations in the photometry.