Spectrophotometric calibration of low-resolution spectra

Abstract

Low-resolution spectroscopy is a frequently used technique. Aperture prism spectroscopy in particular is an important tool for large-scale survey observations. The ongoing ESA space mission Gaia is the currently most relevant example. In this work we analyse the fundamental limitations of the calibration of low-resolution spectrophotometric observations and introduce a calibration method that avoids simplifying assumptions on the smearing effects of the line spread functions. To this aim, we developed a functional analytic mathematical formulation of the problem of spectrophotometric calibration. In this formulation, the calibration process can be described as a linear mapping between two suitably constructed Hilbert spaces, independently of the resolution of the spectrophotometric instrument. The presented calibration method can provide a formally unusual but precise calibration of low-resolution spectrophotometry with non-negligible widths of line spread functions. We used the Gaia spectrophotometric instruments to demonstrate that the calibration method of this work can potentially provide a significantly better calibration than methods neglecting the smearing effects of the line spread functions.

arXiv commentFinal version

References in corpus (14)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• A Method of Correcting Near-Infrared Spectra for Telluric Absorption
• Gaia Data Release 2: Photometric content and validation
• Gaia broad band photometry
• A standard stellar library for evolutionary synthesis. III. Metallicity calibration
• Spectrophotometric Libraries, Revised Photonic Passbands and Zero-points for UBVRI, Hipparcos and Tycho Photometry
• An X-shooter composite of bright 1 < z < 2 quasars from UV to infrared
• A reanalysis of the Gaia Data Release 2 photometric sensitivity curves using HST/STIS spectrophotometry
• Revised Gaia Data Release 2 passbands
• Gaia data release 1: Principles of the photometric calibration of the G band
• Multi-dimensional Functional Principal Component Analysis
• Passband reconstruction from photometry

Cited by in corpus (8)

• Gaia Data Release 3: External calibration of BP/RP low-resolution spectroscopic data
• Internal calibration of Gaia BP/RP low-resolution spectra
• The Villafranca catalog of Galactic OB groups: I. Systems with O2-O3.5 stars
• Analysing spectral lines in Gaia low-resolution spectra
• The Alma catalogue of OB stars. III. A cross-match with Gaia DR3 and an extension based on new spectral classifications
• The GALANTE photometric survey of the northern Galactic plane: Project description and pipeline
• An in-depth analysis of the differentially expanding star cluster Stock 18 (Villafranca O-036) using Gaia DR3 and ground-based data
• Photometric Catalogue for Space and Ground Night-Time Remote-Sensing Calibration: RGB Synthetic Photometry from Gaia DR3 Spectrophotometry