The University of Southampton
University of Southampton Institutional Repository

The structure of the outer galactic disc as revealed by IPHAS early A stars

Sale, S. E., Drew, J. E., Knigge, C., Zijlstra, A. A., Irwin, M. J., Morris, R. A. H., Phillipps, S., Drake, J. J., Greimel, R., Unruh, Y. C., Groot, P. J., Mampaso, A. and Walton, N. A. (2010) The structure of the outer galactic disc as revealed by IPHAS early A stars Monthly Notices of the Royal Astronomical Society, 402, (2), pp. 713-723. (doi:10.1111/j.1365-2966.2009.15746.x).

Record type: Article


This study is an investigation of the stellar density profile of the Galactic disc in the anticentre direction. We select over 40?000 early A stars from INT/WFC Photometric H? Survey of the Northern Galactic Plane (IPHAS) photometry in the Galactic longitude range 160° < l < 200° close to the equatorial plane (?1° < b < +1°) .

We then compare their observed reddening-corrected apparent magnitude distribution with simulated photometry obtained from parametrized models in order to set constraints on the anticentre stellar density profile. By selecting A stars, we are appraising the properties of a population only ?100 Myr old.

We find that the stellar density profile of young stars is well fit to an exponential with length-scale of (3020 ± 120statistical± 180systematic) pc , which is comparable to that obtained in earlier studies, out to a Galactocentric radius of RT= (13.0 ± 0.5statistical± 0.6systematic) kpc . At larger radii, the rate of decline appears to increase with the scalelength dropping to (1200 ± 300statistical± 70systematic) pc.

This result amounts to a refinement of the conclusions reached in previous studies that the stellar density profile is abruptly truncated. The IPHAS A star data are not compatible with models that propose a sudden change in metallicity at RG= 10 kpc .

Full text not available from this repository.

More information

Published date: February 2010
Keywords: surveys, galaxy, abundances, disc, stellar content, structure


Local EPrints ID: 144155
ISSN: 0035-8711
PURE UUID: 61ad7d0a-2e4b-4587-9341-06417ee03405

Catalogue record

Date deposited: 16 Apr 2010 15:43
Last modified: 18 Jul 2017 23:08

Export record



Author: S. E. Sale
Author: J. E. Drew
Author: C. Knigge
Author: A. A. Zijlstra
Author: M. J. Irwin
Author: R. A. H. Morris
Author: S. Phillipps
Author: J. J. Drake
Author: R. Greimel
Author: Y. C. Unruh
Author: P. J. Groot
Author: A. Mampaso
Author: N. A. Walton

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.