A reevaluation of the 2MASS zero points using CALSPEC spectrophotometry complemented with Gaia Data Release 2 parallaxes
- Author(s)
- J. Maíz Apellániz, M. Pantaleoni González
- Abstract
Context. 2MASS is the reference survey in the near-infrared (NIR) part of the spectrum due to its whole-sky coverage, large dynamic range, and proven calibration uniformity. However, previous studies disagree on the value of the zero points (ZPs) for its three bands JHK at the hundredth of a magnitude level. The disagreement should become more noticeable now that Gaia provides whole-sky optical photometry calibrated below that level. Aims: We want to establish the value of the 2MASS ZPs based on NICMOS/HST spectrophotometry of the CALSPEC standard stars and test it with the help of Gaia DR2 parallaxes. Methods: We have computed the synthetic JHK photometry for a sample of stars using the HST CALSPEC spectroscopic standards and compared it with their 2MASS magnitudes to evaluate the ZPs. We have tested our results by analyzing a sample of FGK dwarfs with excellent 2MASS photometry and accurate Gaia DR2 parallaxes. Results: The Vega ZPs for 2MASS J, H, and K are found to be -0.025 ± 0.005, 0.004 ± 0.005, and -0.015 ± 0.005 mag, respectively. The analysis of the FGK sample indicates that the new ZPs are more accurate than previous ones.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Centro de Astrobiología (CSIC-INTA), Universidad Complutense de Madrid
- Journal
- Astronomy & Astrophysics
- Volume
- 616
- ISSN
- 0004-6361
- Publication date
- 08-2018
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/d9bcee2f-ad19-4fad-8dff-43aae2ca99b2