Results from HOPS: A Multiwavelength Census of Orion Protostars

Abstract

Surveys with the Spitzer and Herschel space observatories are now enabling the discovery and characterization of large samples of protostars in nearby molecular clouds, providing the observational basis for a detailed understanding of star formation in diverse environments. We are pursuing this goal with the Herschel Orion Protostar Survey (HOPS), which targets 328 Spitzer-identified protostars in the Orion molecular clouds, the largest star-forming region in the nearest 500 pc. The sample encompasses all phases of protostellar evolution and a wide range of formation environments, from dense clusters to relative isolation. With a grid of radiative transfer models, we fit the 1-870 micron spectral energy distributions (SEDs) of the protostars to estimate their envelope densities, cavity opening angles, inclinations, and total luminosities. After correcting the bolometric luminosities and temperatures of the sources for foreground extinction and inclination, we find a spread of several orders of magnitude in luminosity at all evolutionary states, a constant median luminosity over the more evolved stages, and a possible deficit of high-inclination, rapidly infalling envelopes among the Spitzer-identified sample. We have detected over 100 new sources in the Herschel images; some of them may fill this deficit. We also report results from modeling the pre- and post-outburst 1-870 micron SEDs of V2775 Ori (HOPS 223), a known FU Orionis outburster in the sample. It is the least luminous FU Ori star with a protostellar envelope.

Accepted to Astronomische Nachrichten (Cool Stars 17 proceedings)

References in corpus (3)

• The Spitzer Space Telescope Survey of the Orion A & B Molecular Clouds - Part I: A Census of Dusty Young Stellar Objects and a Study of their Mid-IR Variability
• Observed luminosity spread in young clusters and Fu Ori stars: a unified picture
• Multiwavelength Observations of V2775 Ori, an Outbursting Protostar in L 1641: Exploring the Edge of the FU Orionis Regime

Cited by in corpus (24)

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• The Formation and Evolution of Wide-Orbit Stellar Multiples In Magnetized Clouds
• Chemical tracers of episodic accretion in low-mass protostars
• Zooming in on Individual Star Formation: Low- and High-mass Stars
• VISION - Vienna survey in Orion. III. Young stellar objects in Orion A
• An HST Survey for 100-1000 AU Companions around Young Stellar Objects in the Orion Molecular Clouds: Evidence for Environmentally Dependent Multiplicity
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): A Hot Corino Survey toward Protostellar Cores in the Orion Cloud
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• CO in Protostars (COPS): $Herschel$-SPIRE Spectroscopy of Embedded Protostars
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• 300: An ACA 870 $\mu$m Continuum Survey of Orion Protostars and their Evolution
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• Herschel PACS observations of 4-10 Myr old Classical T Tauri stars in Orion OB1
• The Column Density Structure of Orion A Depicted by N-PDF
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• Infrared and sub-mm observations of outbursting young stars with Herschel and Spitzer
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