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Title: DARK MATTER SUB-HALO COUNTS VIA STAR STREAM CROSSINGS

Abstract

Dark matter sub-halos create gaps in the stellar streams orbiting in the halos of galaxies. We evaluate the sub-halo stream crossing integral with the guidance of simulations to find that the linear rate of gap creation, R{sub U}, in a typical cold dark matter (CDM) galactic halo at 100 kpc is R{sub U}{approx_equal}0.0066 M-hat{sub 8}{sup -0.35}kpc{sup -1}Gyr{sup -1}, where M-hat{sub 8}({identical_to} M-hat /10{sup 8} M{sub Sun }) is the minimum mass halo that creates a visible gap. The relation can be recast entirely in terms of observables, as R{sub U}{approx_equal}0.059w{sup -0.85}kpc{sup -1}Gyr{sup -1}, for w in kpc, normalized at 100 kpc. Using published data, the density of gaps is estimated for M31's NW stream and the Milky Way Pal 5 stream, Orphan stream, and Eastern Banded Structure. The estimated rates of gap creation all have errors of 50% or more due to uncertain dynamical ages and the relatively noisy stream density measurements. The gap-rate-width data are in good agreement with the CDM-predicted relation. The high density of gaps in the narrow streams requires a total halo population of 10{sup 5} sub-halos above a minimum mass of 10{sup 5} M{sub Sun }.

Authors:
 [1]
  1. Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada)
Publication Date:
OSTI Identifier:
22016181
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 748; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTERIZED SIMULATION; MASS; MILKY WAY; NONLUMINOUS MATTER; STARS

Citation Formats

Carlberg, R. G., E-mail: carlberg@astro.utoronto.ca. DARK MATTER SUB-HALO COUNTS VIA STAR STREAM CROSSINGS. United States: N. p., 2012. Web. doi:10.1088/0004-637X/748/1/20.
Carlberg, R. G., E-mail: carlberg@astro.utoronto.ca. DARK MATTER SUB-HALO COUNTS VIA STAR STREAM CROSSINGS. United States. https://doi.org/10.1088/0004-637X/748/1/20
Carlberg, R. G., E-mail: carlberg@astro.utoronto.ca. 2012. "DARK MATTER SUB-HALO COUNTS VIA STAR STREAM CROSSINGS". United States. https://doi.org/10.1088/0004-637X/748/1/20.
@article{osti_22016181,
title = {DARK MATTER SUB-HALO COUNTS VIA STAR STREAM CROSSINGS},
author = {Carlberg, R. G., E-mail: carlberg@astro.utoronto.ca},
abstractNote = {Dark matter sub-halos create gaps in the stellar streams orbiting in the halos of galaxies. We evaluate the sub-halo stream crossing integral with the guidance of simulations to find that the linear rate of gap creation, R{sub U}, in a typical cold dark matter (CDM) galactic halo at 100 kpc is R{sub U}{approx_equal}0.0066 M-hat{sub 8}{sup -0.35}kpc{sup -1}Gyr{sup -1}, where M-hat{sub 8}({identical_to} M-hat /10{sup 8} M{sub Sun }) is the minimum mass halo that creates a visible gap. The relation can be recast entirely in terms of observables, as R{sub U}{approx_equal}0.059w{sup -0.85}kpc{sup -1}Gyr{sup -1}, for w in kpc, normalized at 100 kpc. Using published data, the density of gaps is estimated for M31's NW stream and the Milky Way Pal 5 stream, Orphan stream, and Eastern Banded Structure. The estimated rates of gap creation all have errors of 50% or more due to uncertain dynamical ages and the relatively noisy stream density measurements. The gap-rate-width data are in good agreement with the CDM-predicted relation. The high density of gaps in the narrow streams requires a total halo population of 10{sup 5} sub-halos above a minimum mass of 10{sup 5} M{sub Sun }.},
doi = {10.1088/0004-637X/748/1/20},
url = {https://www.osti.gov/biblio/22016181}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 748,
place = {United States},
year = {Tue Mar 20 00:00:00 EDT 2012},
month = {Tue Mar 20 00:00:00 EDT 2012}
}