| | |
| | |
Stat |
Members: 3645 Articles: 2'503'724 Articles rated: 2609
23 April 2024 |
|
| | | |
|
Article overview
| |
|
Variability and parsec-scale radio structure of candidate compact symmetric objects | M. Orienti
; D. Dallacasa
; | Date: |
18 Sep 2020 | Abstract: | We report results on multi-epoch Very Large Array (VLA) and pc-scale Very
Long Baseline Array (VLBA) observations of candidate compact symmetric objects
(CSOs) from the faint sample of high frequency peakers. New VLBA observations
could resolve the radio structure in about 42 per cent of the observed sources,
showing double components that may be either mini-lobes or core-jet structures.
Almost all the sources monitored by the VLA show some variability on time scale
of a decade, and only 1 source does not show any significant variation. In 17
sources the flux density changes randomly as it is expected in blazars, and in
4 sources the spectrum becomes flat in the last observing epoch, confirming
that samples selected in the GHz regime are highly contaminated by beamed
objects. In 16 objects, the pc-scale and variability properties are consistent
with a young radio source in adiabatic expansion, with a steady decrease of the
flux density in the optically-thin part of the spectrum, and a flux density
increase in the optically-thick part. For these sources we estimate dynamical
ages between a few tens to a few hundreds years. The corresponding expansion
velocity is generally between 0.1c and 0.7c, similar to values found in CSOs
with different approaches. The fast evolution that we observe in some CSO
candidates suggests that not all the objects would become classical
Fanaroff-Riley radio sources. | Source: | arXiv, 2009.08995 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |