| Abstract | dc.description.abstract | Aims. IRAS 19410+2336 is a young massive star forming region with an intense outflow activity. Outflows are frequently studied in
the near-infrared (NIR) since the H2 emission in this wavelength range often traces the shocked molecular gas. However, the mechanisms
behind the H2 emission detected in IRAS 19410+2336 have not been clarified yet. We present here spatially resolved NIR
spectroscopy which allows us to verify whether the H2 emission originates from thermal emission in shock fronts or from fluorescence
excitation by non-ionizing UV photons. Moreover, NIR spectroscopy also offers the possibility of studying the characteristics
of the putative driving source(s) of the H2 emission by the detection of photospheric and circumstellar spectral features, and of the
environmental conditions (e.g. extinction).
Methods. We obtained long-slit, intermediate-resolution, NIR spectra of IRAS 19410+2336 using LIRIS, the NIR imager/
spectrographer mounted on the 4.2m William Herschel Telescope. As a complement, we also obtained J, H and Ks images
with the Las Campanas 2.5m Du Pont Telescope, and archival mid-infrared (MIR) Spitzer images at 3.6, 4.5, 5.8 and 8.0 μm.
Results. We confirm the shocked nature of the H2 emission, with an excitation temperature of about 2000 K, based on the analysis
of relevant H2 line ratios, ortho-to-para ratios and excitation diagrams. We have also identified objects with very different properties
and evolutionary stages in IRAS 19410+2336. The most massive source at millimeter wavelengths, mm1, with a mass of a few tens
of solar masses, has a bright NIR (and MIR) counterpart. This suggests that emission – probably coming through a cavity created by
one of the outflows present in the region, or from the outflow cavity itself – is leaking at these wavelengths. The second most massive
millimeter source, mm2, is only detected at λ >∼ 6 μm, suggesting that it could be a high-mass protostar still in its main accretion
phase. The NIR spectra of some neighboring sources show CO first-overtone bandhead emission which is associated with neutral
material located in the inner regions of the circumstellar environment of YSOs. | en_US |
