Outflow Activity in the Brown Dwarf Mass Regime

• Applicant: Emma Whelan, Ph.D.
• Subject Area: Astrophysics and Astronomy
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 252106471

• Final Report Year: 2016

Final Report Abstract

How brown dwarfs form is an important open question in star formation. It is known that that brown dwarfs in their earliest stages accrete and drive outflows like solar mass stars yet how their outflows compare to stellar flows is not well known. The goal of this project was to increase the number of known BD outflows through optical and sub-millimeter studies and to use X-Shooter to study the accretion and ejection properties of known and new outflows. Through the work carried out in the project eight new BD outflows have been added to the list of known outflows. Two of these outflows are from like proto-BD candidates, something which was not anticipated prior to the commencement of this work. The pilot study of the outflow efficiency of ISO-217 with X-Shooter demonstrated how better data and analytical techniques provide more accurate estimates of the outflow efficiency. In the case of ISO-217 the outflow efficiency was found to lie within the limits predicted by magneto-centrifugal jet launching models. Work is on-going and in particular it is planned that the outflow and accretion properties of the new BD outflows detected as part of this project will be investigated using the techniques applied to ISO-217.

Publications

• (2014), “Accretion-ejection connection in the young brown dwarf candidate ISO-ChaI 217”, In: Astronomy & Astrophysics, 570A, 59W
  Whelan, E. T.; Alcalá, J. M.; Bacciotti, F.; Nisini, B.; Bonito, R.; Antoniucci, S.; Stelzer, B.; Biazzo, K.; D’Elia, V.; Ray, T. P.
  
• (2014), “ESO-Hα 574 and Par-Lup 3-4 jets: Exploring the spectral, kinematical, and physical properties”, In: Astronomy & Astrophysics, 565A, 80W
  Whelan, E. T.; Bonito, R.; Antoniucci, S.; Alcalá, J. M.; Giannini, T.; Nisini, B.; Bacciotti, F.; Podio, L.; Stelzer, B.; Comern, F.
  
• (2015), ”HH 1158: The Lowest Luminosity Externally Irradiated Herbig- Haro Jet”, In: Astrophysical Journal Letters, 815L, 31R
  Riaz, B., Whelan, E. T.
  
• (2015), ”Very low-luminosity Class I/flat outflow sources in σ Orionis”, In: Monthly Notices of the Royal Astronomical Society, 446, 2550R
  Riaz, B., Thompson, M., Whelan, E. T., Lodieu, N.