Gamma-ray emission from massive young stellar objects

Context.Massive stars form in dense and massive molecular cores. The exact formation mechanism is unclear, but it is possible that some massive stars are formed by processes similar to those that produce the low-mass stars, with accretion/ejection phenomena occurring at some point of the evolution o...

Descripción completa

Detalles Bibliográficos
Autores principales: Araudo, Anabella Teresa, Romero, Gustavo Esteban, Bosch Ramon, V., Paredes, J. M.
Formato: Articulo
Lenguaje:Inglés
Publicado: 2007
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83146
Aporte de:
id I19-R120-10915-83146
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Gamma rays: theory
Stars: formation
Stars: individual: IRAS 16547-4247
spellingShingle Ciencias Astronómicas
Gamma rays: theory
Stars: formation
Stars: individual: IRAS 16547-4247
Araudo, Anabella Teresa
Romero, Gustavo Esteban
Bosch Ramon, V.
Paredes, J. M.
Gamma-ray emission from massive young stellar objects
topic_facet Ciencias Astronómicas
Gamma rays: theory
Stars: formation
Stars: individual: IRAS 16547-4247
description Context.Massive stars form in dense and massive molecular cores. The exact formation mechanism is unclear, but it is possible that some massive stars are formed by processes similar to those that produce the low-mass stars, with accretion/ejection phenomena occurring at some point of the evolution of the protostar. This picture seems to be supported by the detection of a collimated stellar wind emanating from the massive protostar IRAS 16547-4247. A triple radio source is associated with the protostar: a compact core and two radio lobes. The emission of the southern lobe is clearly non-thermal. Such emission is interpreted as synchrotron radiation produced by relativistic electrons locally accelerated at the termination point of a thermal jet. Since the ambient medium is determined by the properties of the molecular cloud in which the whole system is embedded, we can expect high densities of particles and infrared photons. Because of the confirmed presence of relativistic electrons, inverse Compton and relativistic Bremsstrahlung interactions are unavoidable. Aims.We aim to make quantitative predictions of the spectral energy distribution of the non-thermal spots generated by massive young stellar objects, with emphasis on the particular case of IRAS 16547-4247.Methods.We study the high-energy emission generated by the relativistic electrons which produce the non-thermal radio source in IRAS 16547-4247. We also study the result of proton acceleration at the terminal shock of the thermal jet and make estimates of the secondary gamma rays and electron-positron pairs produced by pion decay.Results.We present spectral energy distributions for the southern lobe of IRAS 16547-4247, for a variety of conditions. We show that high-energy emission might be detectable from this object in the gamma-ray domain. The source may also be detectable in X-rays through long exposures with current X-ray instruments.Conclusions.Gamma- ray telescopes such as GLAST, and even ground-based Cherenkov arrays of new generation can be used to study non-thermal processes occurring during the formation of massive stars.
format Articulo
Articulo
author Araudo, Anabella Teresa
Romero, Gustavo Esteban
Bosch Ramon, V.
Paredes, J. M.
author_facet Araudo, Anabella Teresa
Romero, Gustavo Esteban
Bosch Ramon, V.
Paredes, J. M.
author_sort Araudo, Anabella Teresa
title Gamma-ray emission from massive young stellar objects
title_short Gamma-ray emission from massive young stellar objects
title_full Gamma-ray emission from massive young stellar objects
title_fullStr Gamma-ray emission from massive young stellar objects
title_full_unstemmed Gamma-ray emission from massive young stellar objects
title_sort gamma-ray emission from massive young stellar objects
publishDate 2007
url http://sedici.unlp.edu.ar/handle/10915/83146
work_keys_str_mv AT araudoanabellateresa gammarayemissionfrommassiveyoungstellarobjects
AT romerogustavoesteban gammarayemissionfrommassiveyoungstellarobjects
AT boschramonv gammarayemissionfrommassiveyoungstellarobjects
AT paredesjm gammarayemissionfrommassiveyoungstellarobjects
bdutipo_str Repositorios
_version_ 1764820488334344194