Abstract
Progress in understanding the embedded stars in LkHα 225 has been hampered by their variability, making it hard to compare data taken at different times, and by the limited resolution of the available data, which cannot probe the small scales between the two stars. In an attempt to overcome these difficulties, we present new near-infrared data on this object taken using the adaptive optics with a laser for astronomy adaptive optics system with the MPE 3D integral field spectrometer and the near-infrared camera Omega-Cass. The stars themselves have K-band spectra which are dominated by warm dust emission, analogous to classes I-II for low-mass young stellar objects (YSOs), suggesting that the stars are in a phase where they are still accreting matter. On the other hand, the ridge of continuum emission between them is rather bluer, suggestive of extinct and/or scattered stellar light rather than direct dust emission. The compactness of the CO emission seen toward each star argues for accretion disks (which can also account for much of the K-band veiling) rather than a neutral wind. In contrast to other YSOs with CO emission, LkHα 225 has no detectable Brγ emission. In addition, there is no H2 detected on the northern star, although we do confirm that the strongest H2 emission is on the southern star, where we find it is excited primarily by thermal mechanisms. A second knot of H2 is observed to its northeast, with a velocity shift of -75 km s-1 and a higher fraction of nonthermal emission. This is discussed with reference to the H2O maser, the molecular outflow, and [S II] emission observed between the stars.
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