Spectral evolution of young stellar objects

  title={Spectral evolution of young stellar objects},
  author={Fred C. Adams and Charles J. Lada and Frank Hsia-San Shu},
  journal={The Astrophysical Journal},
An evolutionary sequence, from protostars to pre-main sequence stars, for the classification of young stellar objects is derived by comparing the predictions of the theoretical protostar models of Adams and Shu (AS, 1986) with the morphological classification scheme of Lada and Wilking (1984). It is shown that the AS models adequately explain the emergent spectral energy distributions of unidentified objects with negative spectral indices in the mid-IR and near-IR in both Taurus and Ophiuchus… 

IRAC Observations of Taurus Pre-Main-Sequence Stars

We present infrared photometry obtained with the IRAC camera on the Spitzer Space Telescope of a sample of 82 pre-main-sequence stars and brown dwarfs in the Taurus star-forming region. We find a

Classification of a selected sample of weak T Tauri stars

We studied a sample of 27 T Tauri stars (TTs) showing a weak Ha line, selected from the Pico dos Dias Survey, a search for young stellar objects. A model to fit the spectral energy distribution is

The accretion disk paradigm for young stars

  • C. Bertout
  • Physics
    Proceedings of the International Astronomical Union
  • 2007
Abstract Accretion and magnetic fields play major roles in several of the many models put forward to explain the properties of T Tauri stars since their discovery by Alfred Joy in the 1940s. Early

From Pre-Stellar Cores to Protostars: The Initial Conditions of Star Formation

The last decade has witnessed significant advances in our observational understanding of the earliest stages of low-mass star formation. The advent of sensitive receivers on large radio telescopes

Herbig-Haro objects—tracers of the formation of low-mass stars and sub-stellar objects

Abstract Herbig-Haro objects (HHOs) are caused by outflows from young objects. Since the outflow relies on mass accretion from a circumstellar disk, it indicates ongoing growth. Recent results of

Analysis of the dust evolution in the circumstellar disks of T Tauri stars

Aims. We present a compositional analysis of 8-13μm spectra of 32 young stellar objects (YSOs). Our sample consists of 5 intermediate-mass stars and 27 low-mass stars. Although some previous studies

The Physical Natures of Class I and Flat-Spectrum Protostellar Photospheres: A Near-Infrared Spectroscopic Study

We present high-resolution (R ≃ 18,000), high signal-to-noise ratio, 2 μm spectra of 52 IR-selected Class I and flat-spectrum young stellar objects in the Taurus-Auriga, ρ Ophiuchi, Serpens, Perseus,

Mid-infrared Spectra of Class I Protostars in Taurus

We present Spitzer Space Telescope Infrared Spectrograph observations in the 5.3-20 μm range of five young stellar objects in Taurus that have Class I continuum spectral energy distributions (λFλαλn,

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We consider the effect of binarity of young stars on the spectral energy distribution of the IR radiation from circumstellar dust. The formation of a common dust envelope in a binary system with a

On the Evolutionary Status of Class I Stars and Herbig-Haro Energy Sources in Taurus-Auriga

We present high-resolution (R ~ 34,000) optical (6330-8750 Å) spectra obtained with the HIRES spectrograph on the W. M. Keck I telescope of stars in Taurus-Auriga whose circumstellar environment