The IPHAS-POSS-I proper motion survey of the Galactic Plane

TL;DR

This survey uses IPHAS and POSS-I data to measure proper motions in the Galactic plane, identifying white dwarfs, subdwarfs, and Hα emission objects with motions below 150 mas/yr.

Contribution

It provides a large proper motion catalogue in the northern Galactic plane, including new identifications of white dwarfs and emission-line objects using combined survey data.

Findings

Catalog of 103,058 objects with proper motions below 150 mas/yr.

Identification of white dwarfs, subdwarfs, and Hα emission objects.

Discovery of several known and new white dwarfs with significant proper motions.

Abstract

We present a proper motion survey of the Galactic plane, using IPHAS data and POSS-I Schmidt plate data as a first epoch, that probes down to proper motions below 50 milliarcseconds per year. The IPHAS survey covers the northern plane ($|b| < 5^{\circ}$) with CCD photometry in the $r$, $i$ and H${\alpha}$ passbands. We examine roughly 1400 sq. deg. of the IPHAS survey area and draw up a catalogue containing 103058 objects with significant proper motions below 150 millarcseconds per year in the magnitude range 13.5$< r' <$19. Our survey sample contains large samples of white dwarfs and subdwarfs which can be identified using a reduced proper motion diagram. We also found several objects with IPHAS colours suggesting H${\alpha}$ emission and significant proper motions. One is the known cataclysmic variable GD552; two are known DB white dwarfs and five others are found to be non-DA (DB and DC) white dwarfs, which were included in the H$\alpha$ emission line catalogue due to their lack of absorption in the H$\alpha$ narrow-band.