A study of the association of<i>Fermi</i>sources with massive young galactic objects

Munar-Adrover, P.; Paredes, J. M.; Romero, Gustavo E.

doi:10.1051/0004-6361/201116580

Cited by 15 publications

(15 citation statements)

References 35 publications

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“…The following sections in this paper are devoted to this purpose by assessing the observational evidence and theoretical expectations in the Mon R2 case. The present work complements other efforts to identify massive YSOs as potential counterparts of some galactic Fermi sources (Munar-Adrover et al 2011). …”

Section: Introductionsupporting

confidence: 58%

The star forming region Monoceros R2 as a gamma-ray source

Martı́

Luque-Escamilla

Muñoz‐Arjonilla

et al. 2013

A&A

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Context. After the release of the gamma-ray source catalog produced by the Fermi satellite during its first two years of operation, a significant fraction of sources still remain unassociated at lower energies. In addition to well-known high-energy emitters (pulsars, blazars, supernova remnants, etc.), theoretical expectations predict new classes of gamma-ray sources. In particular, gamma-ray emission could be associated with some of the early phases of stellar evolution, but this interesting possibility is still poorly understood. Aims. The aim of this paper is to assess the possibility of the Fermi gamma-ray source 2FGL J0607.5−0618c being associated with the massive star forming region Monoceros R2. Methods. A multi-wavelength analysis of the Monoceros R2 region is carried out using archival data at radio, infrared, X-ray, and gamma-ray wavelengths. The resulting observational properties are used to estimate the physical parameters needed to test the different physical scenarios. Results. We confirm the 2FGL J0607.5−0618c detection with improved confidence over the Fermi two-year catalog. We find that a combined effect of the multiple young stellar objects in Monoceros R2 is a viable picture for the nature of the source.

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Section: Introductionsupporting

confidence: 58%

The star forming region Monoceros R2 as a gamma-ray source

Martı́

Luque-Escamilla

Muñoz‐Arjonilla

et al. 2013

A&A

Self Cite

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“…Araudo et al 2007;Bosch-Ramon et al 2010;Munar-Adrover et al 2011). The organisation of the paper is the following.…”

Section: Introductionmentioning

confidence: 99%

Protostars: Forges of cosmic rays?

Padovani

Marcowith

Hennebelle

et al. 2016

A&A

128

156

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Context. Galactic cosmic rays are particles presumably accelerated in supernova remnant shocks that propagate in the interstellar medium up to the densest parts of molecular clouds, losing energy and their ionisation efficiency because of the presence of magnetic fields and collisions with molecular hydrogen. Recent observations hint at high levels of ionisation and at the presence of synchrotron emission in protostellar systems, which leads to an apparent contradiction. Aims. We want to explain the origin of these cosmic rays accelerated within young protostars as suggested by observations. Methods. Our modelling consists of a set of conditions that has to be satisfied in order to have an efficient cosmic-ray acceleration through diffusive shock acceleration. We analyse three main acceleration sites (shocks in accretion flows, along the jets, and on protostellar surfaces), then we follow the propagation of these particles through the protostellar system up to the hot spot region. Results. We find that jet shocks can be strong accelerators of cosmic-ray protons, which can be boosted up to relativistic energies. Other promising acceleration sites are protostellar surfaces, where shocks caused by impacting material during the collapse phase are strong enough to accelerate cosmic-ray protons. In contrast, accretion flow shocks are too weak to efficiently accelerate cosmic rays. Though cosmic-ray electrons are weakly accelerated, they can gain a strong boost to relativistic energies through re-acceleration in successive shocks. Conclusions. We suggest a mechanism able to accelerate both cosmic-ray protons and electrons through the diffusive shock acceleration mechanism, which can be used to explain the high ionisation rate and the synchrotron emission observed towards protostellar sources. The existence of an internal source of energetic particles can have a strong and unforeseen impact on the ionisation of the protostellar disc, on the star and planet formation processes, and on the formation of pre-biotic molecules.

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“…Several approaches to attack this problem on both statistical grounds (e.g., Munar-Adrover et al 2011;Ackermann et al 2012b;D'Abrusco et al 2013) and observational grounds (e.g., Mirabal & Halpern 2009;Shaw et al 2012Shaw et al , 2013 were applied in recent years.…”

Section: Introductionmentioning

confidence: 99%

BL Lacertae identifications in a ROSAT-selected sample ofFermiunidentified objects

Masetti

Sbarufatti

Parisi

et al. 2013

A&A

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The optical spectroscopic followup of 27 sources belonging to a sample of 30 high-energy objects selected by positionally cross correlating the first Fermi/LAT Catalog and the ROSAT All-Sky Survey Bright Source Catalog is presented here. It has been found or confirmed that 25 of them are BL Lacertae objects (BL Lacs), while the remaining two are Galactic cataclysmic variables (CVs). This strongly suggests that the sources in the first group are responsible for the GeV emission detected with Fermi, while the two CVs most likely represent spurious associations. We thus find an 80% a posteriori probability that the sources selected by matching GeV and X-ray catalogs belong to the BL Lac class. We also show suggestions that the BL Lacs selected with this approach are probably high-synchrotron-peaked sources and in turn good candidates for the detection of ultra-high-energy (TeV) photons from them.

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A study of the association ofFermisources with massive young galactic objects

Cited by 15 publications

References 35 publications

The star forming region Monoceros R2 as a gamma-ray source

The star forming region Monoceros R2 as a gamma-ray source

Protostars: Forges of cosmic rays?

BL Lacertae identifications in a ROSAT-selected sample ofFermiunidentified objects

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