Formation of X-ray emitting stationary shocks in magnetized protostellar jets

Marco Miceli, Rosaria Bonito, Gómez De Castro, Orlando, Bonito, Miceli, López-Santiago, Ustamujic

Risultato della ricerca: Article

5 Citazioni (Scopus)

Abstract

Context. X-ray observations of protostellar jets show evidence of strong shocks heating the plasma up to temperatures of a few million degrees. In some cases, the shocked features appear to be stationary. They are interpreted as shock diamonds. Aims. We investigate the physics that guides the formation of X-ray emitting stationary shocks in protostellar jets; the role of the magnetic field in determining the location, stability, and detectability in X-rays of these shocks; and the physical properties of the shocked plasma. Methods. We performed a set of 2.5-dimensional magnetohydrodynamic numerical simulations that modelled supersonic jets ramming into a magnetized medium and explored different configurations of the magnetic field. The model takes into account the most relevant physical effects, namely thermal conduction and radiative losses. We compared the model results with observations, via the emission measure and the X-ray luminosity synthesized from the simulations. Results. Our model explains the formation of X-ray emitting stationary shocks in a natural way. The magnetic field collimates the plasma at the base of the jet and forms a magnetic nozzle there. After an initial transient, the nozzle leads to the formation of a shock diamond at its exit which is stationary over the time covered by the simulations (~40-60 yr; comparable with timescales of the observations). The shock generates a point-like X-ray source located close to the base of the jet with luminosity comparable with that inferred from X-ray observations of protostellar jets. For the range of parameters explored, the evolution of the post-shock plasma is dominated by the radiative cooling, whereas the thermal conduction slightly affects the structure of the shock.
Lingua originaleEnglish
pagine (da-a)A99-
Numero di pagine14
RivistaASTRONOMY & ASTROPHYSICS
Volume596
Stato di pubblicazionePublished - 2016

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shock
x rays
plasma
magnetic field
diamond
magnetic nozzles
simulation
diamonds
luminosity
magnetic fields
shock heating
conduction
magnetohydrodynamics
temperature effect
nozzles
physics
temperature effects
physical property
heating
cooling

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cita questo

Miceli, M., Bonito, R., Gómez De Castro, Orlando, Bonito, Miceli, ... Ustamujic (2016). Formation of X-ray emitting stationary shocks in magnetized protostellar jets. ASTRONOMY & ASTROPHYSICS, 596, A99-.

Formation of X-ray emitting stationary shocks in magnetized protostellar jets. / Miceli, Marco; Bonito, Rosaria; Gómez De Castro; Orlando; Bonito; Miceli; López-Santiago; Ustamujic.

In: ASTRONOMY & ASTROPHYSICS, Vol. 596, 2016, pag. A99-.

Risultato della ricerca: Article

Miceli, M, Bonito, R, Gómez De Castro, Orlando, Bonito, Miceli, López-Santiago & Ustamujic 2016, 'Formation of X-ray emitting stationary shocks in magnetized protostellar jets', ASTRONOMY & ASTROPHYSICS, vol. 596, pagg. A99-.
Miceli, Marco ; Bonito, Rosaria ; Gómez De Castro ; Orlando ; Bonito ; Miceli ; López-Santiago ; Ustamujic. / Formation of X-ray emitting stationary shocks in magnetized protostellar jets. In: ASTRONOMY & ASTROPHYSICS. 2016 ; Vol. 596. pagg. A99-.
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title = "Formation of X-ray emitting stationary shocks in magnetized protostellar jets",
abstract = "Context. X-ray observations of protostellar jets show evidence of strong shocks heating the plasma up to temperatures of a few million degrees. In some cases, the shocked features appear to be stationary. They are interpreted as shock diamonds. Aims. We investigate the physics that guides the formation of X-ray emitting stationary shocks in protostellar jets; the role of the magnetic field in determining the location, stability, and detectability in X-rays of these shocks; and the physical properties of the shocked plasma. Methods. We performed a set of 2.5-dimensional magnetohydrodynamic numerical simulations that modelled supersonic jets ramming into a magnetized medium and explored different configurations of the magnetic field. The model takes into account the most relevant physical effects, namely thermal conduction and radiative losses. We compared the model results with observations, via the emission measure and the X-ray luminosity synthesized from the simulations. Results. Our model explains the formation of X-ray emitting stationary shocks in a natural way. The magnetic field collimates the plasma at the base of the jet and forms a magnetic nozzle there. After an initial transient, the nozzle leads to the formation of a shock diamond at its exit which is stationary over the time covered by the simulations (~40-60 yr; comparable with timescales of the observations). The shock generates a point-like X-ray source located close to the base of the jet with luminosity comparable with that inferred from X-ray observations of protostellar jets. For the range of parameters explored, the evolution of the post-shock plasma is dominated by the radiative cooling, whereas the thermal conduction slightly affects the structure of the shock.",
keywords = "ISM: jets and outflows; ISM: magnetic fields; ISM: structure; Magnetohydrodynamics (MHD); Stars: protostars; X-rays: ISM; Astronomy and Astrophysics; Space and Planetary Science",
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T1 - Formation of X-ray emitting stationary shocks in magnetized protostellar jets

AU - Miceli, Marco

AU - Bonito, Rosaria

AU - Gómez De Castro, null

AU - Orlando, null

AU - Bonito, null

AU - Miceli, null

AU - López-Santiago, null

AU - Ustamujic, null

PY - 2016

Y1 - 2016

N2 - Context. X-ray observations of protostellar jets show evidence of strong shocks heating the plasma up to temperatures of a few million degrees. In some cases, the shocked features appear to be stationary. They are interpreted as shock diamonds. Aims. We investigate the physics that guides the formation of X-ray emitting stationary shocks in protostellar jets; the role of the magnetic field in determining the location, stability, and detectability in X-rays of these shocks; and the physical properties of the shocked plasma. Methods. We performed a set of 2.5-dimensional magnetohydrodynamic numerical simulations that modelled supersonic jets ramming into a magnetized medium and explored different configurations of the magnetic field. The model takes into account the most relevant physical effects, namely thermal conduction and radiative losses. We compared the model results with observations, via the emission measure and the X-ray luminosity synthesized from the simulations. Results. Our model explains the formation of X-ray emitting stationary shocks in a natural way. The magnetic field collimates the plasma at the base of the jet and forms a magnetic nozzle there. After an initial transient, the nozzle leads to the formation of a shock diamond at its exit which is stationary over the time covered by the simulations (~40-60 yr; comparable with timescales of the observations). The shock generates a point-like X-ray source located close to the base of the jet with luminosity comparable with that inferred from X-ray observations of protostellar jets. For the range of parameters explored, the evolution of the post-shock plasma is dominated by the radiative cooling, whereas the thermal conduction slightly affects the structure of the shock.

AB - Context. X-ray observations of protostellar jets show evidence of strong shocks heating the plasma up to temperatures of a few million degrees. In some cases, the shocked features appear to be stationary. They are interpreted as shock diamonds. Aims. We investigate the physics that guides the formation of X-ray emitting stationary shocks in protostellar jets; the role of the magnetic field in determining the location, stability, and detectability in X-rays of these shocks; and the physical properties of the shocked plasma. Methods. We performed a set of 2.5-dimensional magnetohydrodynamic numerical simulations that modelled supersonic jets ramming into a magnetized medium and explored different configurations of the magnetic field. The model takes into account the most relevant physical effects, namely thermal conduction and radiative losses. We compared the model results with observations, via the emission measure and the X-ray luminosity synthesized from the simulations. Results. Our model explains the formation of X-ray emitting stationary shocks in a natural way. The magnetic field collimates the plasma at the base of the jet and forms a magnetic nozzle there. After an initial transient, the nozzle leads to the formation of a shock diamond at its exit which is stationary over the time covered by the simulations (~40-60 yr; comparable with timescales of the observations). The shock generates a point-like X-ray source located close to the base of the jet with luminosity comparable with that inferred from X-ray observations of protostellar jets. For the range of parameters explored, the evolution of the post-shock plasma is dominated by the radiative cooling, whereas the thermal conduction slightly affects the structure of the shock.

KW - ISM: jets and outflows; ISM: magnetic fields; ISM: structure; Magnetohydrodynamics (MHD); Stars: protostars; X-rays: ISM; Astronomy and Astrophysics; Space and Planetary Science

UR - http://hdl.handle.net/10447/224129

UR - http://www.edpsciences.org/journal/index.cfm?edpsname=aa

M3 - Article

VL - 596

SP - A99-

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

ER -