A High Resolution Spectroscopic Survey of FUor and EXor Candidates
Abstract
As part of an ongoing effort to monitor and classify the small group of known young eruptive variables, we present High Resolution Near-Infrared ( 2-5 micron) spectra of 4 FUor, EXor and FUor-like sources which show emission and absorption features not necessarily indicative of their presumed classification. This work makes clear that the natures of these objects are not well described by singular classic FUor or EXor accretion models and begins to define a continuum of source types. Specifically, ZCMa, an FUor-like system, as well as PV Cep, an EXor system, show CO absorption at 5 microns but exhibit CO emission at 2 microns, while Brackett gamma is also in emission for both. XZ Tau, a purported EXor, shows Brackett gamma is in emission while the CO at both 2 and 5 microns is in absorption. L1551 IRS 5 shows absorption for CO at 2 microns, but shows emission at 5 microns. Weak Brackett gamma absorption is detected for this source. Hence, we discuss the implications of using the overtone bandheads of CO as a circumstellar diagnostic.
- Publication:
-
American Astronomical Society Meeting Abstracts #217
- Pub Date:
- January 2011
- Bibcode:
- 2011AAS...21743421L