Two-point Separation Functions for Modeling Wide Binary Systems in Nearby Dwarf Galaxies
Publication Date
2022-04-01Journal Title
The Astrophysical Journal
ISSN
0004-637X
Publisher
American Astronomical Society
Volume
929
Issue
1
Language
en
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Kervick, C., Walker, M. G., Peñarrubia, J., & Koposov, S. E. (2022). Two-point Separation Functions for Modeling Wide Binary Systems in Nearby Dwarf Galaxies. The Astrophysical Journal, 929 (1) https://doi.org/10.3847/1538-4357/ac5b5f
Abstract
<jats:title>Abstract</jats:title>
<jats:p>We use a geometric method to derive (two-dimensional) separation functions among pairs of objects within populations of specified position function <jats:inline-formula>
<jats:tex-math>
<?CDATA ${dN}/d{\boldsymbol{R}}$?>
</jats:tex-math>
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<mml:mi mathvariant="italic">dN</mml:mi>
<mml:mrow>
<mml:mo stretchy="true">/</mml:mo>
</mml:mrow>
<mml:mi>d</mml:mi>
<mml:mi mathvariant="bold-italic">R</mml:mi>
</mml:math>
<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac5b5fieqn1.gif" xlink:type="simple" />
</jats:inline-formula>. We present analytic solutions for separation functions corresponding to a uniform surface density within a circular field, a Plummer sphere (viewed in projection), and the mixture thereof—including contributions from binary objects within both subpopulations. These results enable inferences about binary object populations via direct modeling of object position and pair separation data, without resorting to standard estimators of the two-point correlation function. Analyzing mock data sets designed to mimic known dwarf spheroidal galaxies, we demonstrate the ability to recover input properties including the number of wide binary star systems and, in cases where the number of resolved binary pairs is assumed to be ≳a few hundred, characteristic features (e.g., steepening and/or truncation) of their separation function. Combined with forthcoming observational capabilities, this methodology opens a window onto the formation and/or survival of wide binary populations in dwarf galaxies, and offers a novel probe of inferred dark matter substructure on the smallest galactic scales.</jats:p>
Keywords
310, Galaxies and Cosmology
Sponsorship
National Science Foundation (NSF) (AST-1813881)
National Science Foundation (NSF) (AST-1909584)
National Aeronautics and Space Administration (NASA) (NNG16PJ28C)
Identifiers
apjac5b5f, ac5b5f, aas33466
External DOI: https://doi.org/10.3847/1538-4357/ac5b5f
This record's URL: https://www.repository.cam.ac.uk/handle/1810/336131
Rights
Licence:
http://creativecommons.org/licenses/by/4.0/
Statistics
Total file downloads (since January 2020). For more information on metrics see the
IRUS guide.