|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'500'096
Articles rated: 2609
18 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
A study of purely astrometric selection of extragalactic point sources | | Kasper E. Heintz
; Johan P. U. Fynbo
; Erik Høg
; | | Date: |
10 Mar 2015 | | Abstract: | Selection of extragalactic point sources, e.g. QSOs, is often hampered by
significant selection effects causing existing samples to have rather complex
selection functions. We explore whether a purely astrometric selection of
extragalactic point sources, e.g. QSOs, is feasible with the ongoing Gaia
mission. Such a selection would be interesting as it would be unbiased in terms
of colours of the targets and hence would allow selection also with colours in
the stellar sequence. We have analyzed a total of 18 representative regions of
the sky by using extit{GUMS}, the simulator prepared for ESAs Gaia mission,
both in the range of $12le G le 20$ mag and $12le G le 18$ mag. For each
region we determine the density of apparently stationary stellar sources, i.e.
sources for which Gaia cannot measure a significant proper motion. The density
is contrasted with the density of extragalactic point sources, e.g. QSOs, in
order to establish in which celestial directions a pure astrometric selection
is feasible. When targeting regions at galactic latitude $|b| ge
30^mathrm{o}$ the ratio of QSOs to apparently stationary stars is above 50\%
and when observing towards the poles the fraction of QSOs goes up to about
$sim80$\%. We show that the proper motions from the proposed Gaia successor
mission in about 20 years would dramatically improve these results at all
latitudes. Detection of QSOs solely from zero proper motion, unbiased by any
assumptions on spectra, might lead to the discovery of new types of QSOs or new
classes of extragalactic point sources. | | Source: | arXiv, 1503.2874 | | 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 claudebot
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER