Rapid variability of the compact radio sources in Arp220 Evidence for a population of microblazars?

Batejat, Fabien,1979Chalmers tekniska högskola,Chalmers University of Technology (author)

Context. The two nuclei of the starburst galaxy Arp220 contain multiple compact radio sources previously identified as radio supernovae or supernova remnants. Aims. In order to search for an embedded radio AGN, or other possible exotic objects, we have carried out a programme of VLBI monitoring at 6 cm over three epochs each separated by four months. Methods. Combining the new data with existing data at 6 cm and 18 cm (spanning 4 and 12 years respectively) we are able to characterise source flux density variability on a range of timescales. Additionally we analyse the variability of sources in shape and position. Results. We detect rapid (<4 months) variability in three sources (W7, W26, and W29). These sources show possible superluminal motion (>4c) of jet-like features near rapidly varying almost stationary components. These enigmatic sources might be associated with an AGN or a highly beamed microquasar (i.e. microblazar). Other hypotheses include that the apparent variability is intrinsic and is produced by neutron star powered central components within a supernova remnant, by a sequence of several supernovae within super star clusters, or is extrinsic and is produced by Galactic interstellar scintillation of very compact non-varying objects. Conclusions. A microquasar/microblazar origin seems to be the best explanation for the nature of the variable sources in Arp220.

NATURVETENSKAP Fysik Astronomi, astrofysik och kosmologi hsv//swe
NATURAL SCIENCES Physical Sciences Astronomy, Astrophysics and Cosmology hsv//eng
Radio continuum: stars
Galaxies: starburst
Galaxies: individual: Arp220
Galaxies: nuclei
X-rays: binaries

Conway, John,1963Chalmers tekniska högskola,Chalmers University of Technology(Swepub:cth)jconway (author)
Rushton, Anthony,1983European Southern Observatory (ESO),Chalmers tekniska högskola,Chalmers University of Technology(Swepub:cth)rushton (author)
Parra, R.European Southern Observatory Santiago (author)
Diamond, P. J.Commonwealth Scientific and Industrial Research Organisation (CSIRO),University of Manchester (author)
Lonsdale, C. J.National Radio Astronomy Observatory,Massachusetts Institute of Technology (MIT) (author)
Chalmers tekniska högskolaEuropean Southern Observatory (ESO) (creator_code:org_t)

By the author/editor: Batejat, Fabien, ...; Conway, John, 19 ...; Rushton, Anthony ...; Parra, R.; Diamond, P. J.; Lonsdale, C. J.

About the subject

NATURAL SCIENCES: NATURAL SCIENCES; and Physical Science ...; and Astronomy Astrop ...

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.