WISE photometry of EXor sources and candidates

TL;DR

This paper provides the first comprehensive mid-infrared survey of EXor sources using WISE data, revealing differences in disk properties and variability, and aims to build a database for understanding their luminosity fluctuations.

Contribution

It offers the first uniform mid-IR photometric survey of EXor objects, highlighting differences between classical and new sources and analyzing their variability.

Findings

Two-color diagrams show segregation between classical and new sources.

Spectral energy distributions suggest the presence of inner disk holes.

Mid-IR variability studies are initiated, providing insights into luminosity fluctuations.

Abstract

We present a collection of WISE photometry of EXor sources and candidates (more recently identified). This represents the first complete survey of such objects in the mid-IR (3.4 - 22 um) that was carried out with the same instrumentation. Two-color diagrams constructed with WISE data evidence a clear segregation between classical and newly identified sources, being these latter characterized by colder (and less evolved) circumstellar disks. By combining 2MASS and WISE data, we obtain spectral energy distributions (SED's) that are compatible with the existence of an inner hole in the circumstellar disk. A compilation of all EXor observations given in the literature at wavelengths very similar to those of WISE is also provided. This allows us to study their mid-IR variability, which has been poorly investigated so far and without any coordination with shorter wavelengths surveys. The presented it WISE photometry and the compilation of the literature data are intended as a first step toward the construction of a significant database in this spectral regime. Preliminary indications on the mechanisms responsible for the luminosity fluctuations are provided.