|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'506'133
Articles rated: 2609
27 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
Mid-Infrared Variability from the Spitzer Deep, Wide-Field Survey | | Szymon Kozlowski
; Christopher S. Kochanek
; Daniel Stern
; Matthew L. N. Ashby
; Roberto J. Assef
; J. J. Bock
; C. Borys
; K. Brand
; M. Brodwin
; M. J. I. Brown
; R. Cool
; A. Cooray
; S. Croft
; Arjun Dey
; P. R. Eisenhardt
; A. Gonzalez
; V. Gorjian
; R. Griffith
; N. Grogin
; R. Ivison
; J. Jacob
; B. T. Jannuzi
; A. Mainzer
; L. Moustakas
; H. Rottgering
; N. Seymour
; H. A. Smith
; S. A. Stanford
; J. R. Stauffer
; I. S. Sullivan
; W. van Breugel
; S. P. Willner
; E. L. Wright
; | | Date: |
18 Feb 2010 | | Abstract: | We use the multi-epoch, mid-infrared Spitzer Deep, Wide-Field Survey to
investigate the variability of 474,179 objects in 8.1 deg^2 of the NDWFS Bootes
field. We perform a Difference Image Analysis of the four available epochs
between 2004 and 2008, focusing on the deeper 3.6 and 4.5 micron bands. We find
that 1.1% of the studied sample meet our standard selection criteria for being
classed as a variable source. We require that the 3.6 and 4.5 micron
light-curves are strongly correlated (r>0.8) and that their joint variance
exceeds that for all sources with the same magnitude by 2 sigma. We then
examine the mid-IR colors of the variable sources and match them with X-ray
sources from the XBootes survey, radio catalogs, 24 micron-selected AGN
candidates, and spectroscopically identified AGNs from the AGN and Galaxy
Evolution Survey (AGES). Based on their mid-IR colors, most of the variable
sources are AGNs (76%), with smaller contributions from stars (11%), galaxies
(6%), and unclassified objects. Most of the stellar, galaxy and unclassified
sources are false positives. For our standard selection criteria, 11-12% of the
mid-IR counterparts to X-ray sources, 24 micron-selected AGN candidates and
spectroscopically identified AGNs show variability. Mid-IR AGN variability can
be well described by a single power-law structure function with a power-law
index of 0.5 at both 3.6 and 4.5 microns, and an amplitude of 0.1 mag on
rest-frame time scales of 2 years. The variability amplitude is higher for
shorter rest-frame wavelengths and lower luminosities. (Abridged) | | Source: | arXiv, 1002.3365 | | 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:
| |
REGISTER