Compact symmetric objects (CSOs) show radio features such as jets, lobes, and hot spots that are contained within the central 1 kpc region of their host galaxy. Thus, they are thought to be among the progenitors of large-scale radio galaxies. A debate regarding whether the CSOs are compact primarily because they are young or because they are surrounded by a dense medium impacting their expansion is ongoing. Until now, attempts to discriminate between the environmental and genuine youthfulness scenarios have been inconclusive. We present a study of three CSOs selected on the basis of their puzzling X-ray absorbing properties in prior Beppo-SAX and/or Chandra X-ray Observatory data. Our new XMM-Newton observations unambiguously confirm the nature of their X-ray absorbers. Furthermore, for the first time, our X-ray data reveal the existence of a population of CSOs with intrinsic hydrogen column density N_H > 10^{23} cm^{‑2} that is different from the population of X-ray unabsorbed CSOs. The two groups appear to be separated in the linear size versus radio power plane. This finding suggests that a dense medium in X-ray obscured CSOs may be able to confine the radio jets. Alternatively, X-ray obscured CSOs could be seen as radio brighter than their unobscured counterparts either because they reside in a dense environment or because they have larger jet powers. Our results help constrain the origin of the X-ray emission and the location and size of the X-ray obscurer in CSOs, and indicate that the environment may play a key role during the initial expansion of a radio source.

The Impact of the Environment on the Early Stages of Radio Source Evolution.

L. Ostorero;
2019-01-01

Abstract

Compact symmetric objects (CSOs) show radio features such as jets, lobes, and hot spots that are contained within the central 1 kpc region of their host galaxy. Thus, they are thought to be among the progenitors of large-scale radio galaxies. A debate regarding whether the CSOs are compact primarily because they are young or because they are surrounded by a dense medium impacting their expansion is ongoing. Until now, attempts to discriminate between the environmental and genuine youthfulness scenarios have been inconclusive. We present a study of three CSOs selected on the basis of their puzzling X-ray absorbing properties in prior Beppo-SAX and/or Chandra X-ray Observatory data. Our new XMM-Newton observations unambiguously confirm the nature of their X-ray absorbers. Furthermore, for the first time, our X-ray data reveal the existence of a population of CSOs with intrinsic hydrogen column density N_H > 10^{23} cm^{‑2} that is different from the population of X-ray unabsorbed CSOs. The two groups appear to be separated in the linear size versus radio power plane. This finding suggests that a dense medium in X-ray obscured CSOs may be able to confine the radio jets. Alternatively, X-ray obscured CSOs could be seen as radio brighter than their unobscured counterparts either because they reside in a dense environment or because they have larger jet powers. Our results help constrain the origin of the X-ray emission and the location and size of the X-ray obscurer in CSOs, and indicate that the environment may play a key role during the initial expansion of a radio source.
2019
871
1
1
8
https://iopscience.iop.org/article/10.3847/1538-4357/aaee78/meta
https://arxiv.org/abs/1812.02147
galaxies: active, galaxies: evolution, galaxies: jets, X-rays: galaxies
M. Sobolewska; A. Siemiginowska; M. Guainazzi; M. Hardcastle; G. Migliori; L.Ostorero; L. Stawarz
File in questo prodotto:
File Dimensione Formato  
2019sobolewska_environment-of-young-radio-sources.pdf

Accesso aperto

Descrizione: PDF editoriale
Tipo di file: PDF EDITORIALE
Dimensione 1.47 MB
Formato Adobe PDF
1.47 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1695396
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 25
  • ???jsp.display-item.citation.isi??? 22
social impact