Milky Way Tomography with K and M Dwarf Stars: the Vertical Structure of
the Galactic Disk
D. Ferguson, S. Gardner, and B. Yanny. (2017)cite arxiv:1706.01900Comment: 42 pages, 17 figures, accepted for publication in ApJ.
Abstract
We use the number density distributions of K and M dwarf stars with vertical
height from the Galactic disk, determined using observations from the Sloan
Digital Sky Survey (SDSS), to probe the structure of the Milky Way disk across
the survey's footprint. Using photometric parallax as a distance estimator we
analyze a sample of several million disk stars in matching footprints above and
below the Galactic plane, and we determine the location and extent of vertical
asymmetries in the number counts in a variety of thin and thick disk subsamples
in regions of some 200 square degrees within 2 kpc in vertical distance from
the Galactic disk. These disk asymmetries present wave-like features as
previously observed on other scales and distances from the Sun. We additionally
explore the scale height of the disk and the implied offset of the Sun from the
Galactic plane at different locations, noting that the scale height of the disk
can differ significantly when measured using stars only above or only below the
plane. Moreover, we compare the shape of the number density distribution in the
north for different latitude ranges with a fixed range in longitude and find
the shape to be sensitive to the selected latitude window. We explain why this
may be indicative of a change in stellar populations in the compared latitude
regions, possibly allowing access to the systematic metallicity difference
between thin and thick disk populations through photometry.
Description
Milky Way Tomography with K and M Dwarf Stars: the Vertical Structure of
the Galactic Disk
%0 Generic
%1 ferguson2017milky
%A Ferguson, Deborah
%A Gardner, Susan
%A Yanny, Brian
%D 2017
%K mdwarf
%T Milky Way Tomography with K and M Dwarf Stars: the Vertical Structure of
the Galactic Disk
%U http://arxiv.org/abs/1706.01900
%X We use the number density distributions of K and M dwarf stars with vertical
height from the Galactic disk, determined using observations from the Sloan
Digital Sky Survey (SDSS), to probe the structure of the Milky Way disk across
the survey's footprint. Using photometric parallax as a distance estimator we
analyze a sample of several million disk stars in matching footprints above and
below the Galactic plane, and we determine the location and extent of vertical
asymmetries in the number counts in a variety of thin and thick disk subsamples
in regions of some 200 square degrees within 2 kpc in vertical distance from
the Galactic disk. These disk asymmetries present wave-like features as
previously observed on other scales and distances from the Sun. We additionally
explore the scale height of the disk and the implied offset of the Sun from the
Galactic plane at different locations, noting that the scale height of the disk
can differ significantly when measured using stars only above or only below the
plane. Moreover, we compare the shape of the number density distribution in the
north for different latitude ranges with a fixed range in longitude and find
the shape to be sensitive to the selected latitude window. We explain why this
may be indicative of a change in stellar populations in the compared latitude
regions, possibly allowing access to the systematic metallicity difference
between thin and thick disk populations through photometry.
@misc{ferguson2017milky,
abstract = {We use the number density distributions of K and M dwarf stars with vertical
height from the Galactic disk, determined using observations from the Sloan
Digital Sky Survey (SDSS), to probe the structure of the Milky Way disk across
the survey's footprint. Using photometric parallax as a distance estimator we
analyze a sample of several million disk stars in matching footprints above and
below the Galactic plane, and we determine the location and extent of vertical
asymmetries in the number counts in a variety of thin and thick disk subsamples
in regions of some 200 square degrees within 2 kpc in vertical distance from
the Galactic disk. These disk asymmetries present wave-like features as
previously observed on other scales and distances from the Sun. We additionally
explore the scale height of the disk and the implied offset of the Sun from the
Galactic plane at different locations, noting that the scale height of the disk
can differ significantly when measured using stars only above or only below the
plane. Moreover, we compare the shape of the number density distribution in the
north for different latitude ranges with a fixed range in longitude and find
the shape to be sensitive to the selected latitude window. We explain why this
may be indicative of a change in stellar populations in the compared latitude
regions, possibly allowing access to the systematic metallicity difference
between thin and thick disk populations through photometry.},
added-at = {2017-06-09T05:11:15.000+0200},
author = {Ferguson, Deborah and Gardner, Susan and Yanny, Brian},
biburl = {https://www.bibsonomy.org/bibtex/23dd8eea727512de03261de1b932ddcf3/superjenwinters},
description = {Milky Way Tomography with K and M Dwarf Stars: the Vertical Structure of
the Galactic Disk},
interhash = {26a02afb1a8393319fe38846e9a971ab},
intrahash = {3dd8eea727512de03261de1b932ddcf3},
keywords = {mdwarf},
note = {cite arxiv:1706.01900Comment: 42 pages, 17 figures, accepted for publication in ApJ},
timestamp = {2017-06-09T05:11:15.000+0200},
title = {Milky Way Tomography with K and M Dwarf Stars: the Vertical Structure of
the Galactic Disk},
url = {http://arxiv.org/abs/1706.01900},
year = 2017
}