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arXiv · 1406.1350

The extraordinary far-infrared variation of a protostar: Herschel/PACS observations of LRLL54361

Zoltan Balog·James Muzerolle·Kevin Flaherty·Ors H. Detre·Jeroen Bouwmann·Elise Furlan·Rob Gutermuth·Attila Juhasz·John Bally·Markus Nielbock·Ulrich Klaas·Oliver Krause·Thomas Henning
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Abstract

We report Herschel/PACS photometric observations at 70 {\mu}m and 160 {\mu}m of LRLL54361 - a suspected binary protostar that exhibits periodic (P=25.34 days) flux variations at shorter wavelengths (3.6 {\mu}m and 4.5 {\mu}m) thought to be due to pulsed accretion caused by binary motion. The PACS observations show unprecedented flux variation at these far-infrared wavelengths that are well cor- related with the variations at shorter wavelengths. At 70 {\mu}m the object increases its flux by a factor of six while at 160{\mu}m the change is about a factor of two, consistent with the wavelength dependence seen in the far-infrared spectra. The source is marginally resolved at 70 {\mu}m with varying FWHM. Deconvolved images of the sources show elongations exactly matching the outflow cavities traced by the scattered light observations. The spatial variations are anti-correlated with the flux variation indicating that a light echo is responsible for the changes in FWHM. The observed far-infrared flux variability indicates that the disk and en- velope of this source is periodically heated by the accretion pulses of the central source, and suggests that such long wavelength variability in general may provide a reasonable proxy for accretion variations in protostars.

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Zoltan Balog, James Muzerolle, Kevin Flaherty, Ors H. Detre, Jeroen Bouwmann, Elise Furlan, Rob Gutermuth, Attila Juhasz, John Bally, Markus Nielbock, Ulrich Klaas, Oliver Krause, Thomas Henning. 2014-06-05. The extraordinary far-infrared variation of a protostar: Herschel/PACS observations of LRLL54361. https://doi.org/10.1088/2041-8205/789/2/l38

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