Service interruption on Monday 11 July from 12:30 to 13:00: all the sites of the CCSD (HAL, EpiSciences, SciencesConf, AureHAL) will be inaccessible (network hardware connection).
Skip to Main content Skip to Navigation
Journal articles

The Nature of Class I Sources: Periodic Variables in Orion

Abstract : We present a quantitative, empirically based argument that at least some Class I sources are low-mass, pre-main-sequence stars surrounded by spatially extended envelopes of dusty gas. The source luminosity arises principally from stellar gravitational contraction, as in optically visible pre-main-sequence stars that lack such envelopes. We base our argument on the fact that some Class I sources in Orion and other star-forming regions have been observed by Spitzer to be periodic variables in the mid-infrared, and with periods consistent with T Tauri rotation rates. Using a radiative transfer code, we construct a variety of dust envelopes surrounding rotating, spotted stars, to see whether an envelope that produces a Class I spectral energy distribution at least broadly matches the observed modulations in luminosity. Acceptable envelopes can be either spherical or flattened and may or may not have polar cavities. The key requirement is that they have a modest equatorial optical depth at the Spitzer waveband of 3.6 μm, typically τ 3.6 ≈ 0.6. The total envelope mass, based on this limited study, is at most about 0.1 M , less than a typical stellar mass. Future studies should focus on the dynamics of the envelope, to determine whether material is actually falling onto the circumstellar disk.
Document type :
Journal articles
Complete list of metadata

https://hal-insu.archives-ouvertes.fr/insu-03702948
Contributor : Nathalie POTHIER Connect in order to contact the contributor
Submitted on : Thursday, June 23, 2022 - 2:58:17 PM
Last modification on : Saturday, June 25, 2022 - 3:06:19 AM

Links full text

Identifiers

Collections

Citation

Elizabeth A. Ellithorpe, Gaspard Duchene, Steven W. Stahler. The Nature of Class I Sources: Periodic Variables in Orion. The Astrophysical Journal, 2019, 885, ⟨10.3847/1538-4357/ab4651⟩. ⟨insu-03702948⟩

Share

Metrics

Record views

0