### The Gaia-WISE Extragalactic Astrometric Catalog

Status Report From: arXiv.org e-Print archive
Posted: Tuesday, April 10, 2018

Jennie Paine, Jeremy Darling, Alexandra Truebenbach
(Submitted on 5 Apr 2018)

The Gaia mission has detected a large number of active galactic nuclei (AGN) and galaxies, but these objects must be identified among the 1000-fold more numerous stars. Extant astrometric AGN catalogs do not have the uniform sky coverage required to detect and characterize the all-sky low-multipole proper motion signals produced by the barycenter motion, gravitational waves, and cosmological effects. To remedy this, we present an all-sky sample of 567,721 AGN in Gaia Data Release 1, selected using WISE two-color criteria. The catalog has fairly uniform sky coverage beyond the Galactic plane, with a mean density of 12.8 AGN per square degree. The objects have magnitudes ranging from $G=8.8$ down to Gaia's magnitude limit, $G=20.7$. The catalog is approximately 50% complete but suffers from low stellar contamination, roughly 0.2%. We predict that the end-of-mission Gaia proper motions for this catalog will enable detection of the secular aberration drift to high significance (23$\sigma$) and will limit the anisotropy of the Hubble expansion to about 2%.

Comments:    11 pages, 7 figures; Submitted to ApJS
Subjects:    Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Cite as:    arXiv:1804.02064 [astro-ph.GA] (or arXiv:1804.02064v1 [astro-ph.GA] for this version)
Submission history
From: Jennie Paine
[v1] Thu, 5 Apr 2018 21:31:25 GMT (1269kb)
https://arxiv.org/abs/1804.02064

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