Cores in warm dark matter haloes: A Catch 22 problem

Andrea Maccio, Sinziana Paduroiu, Donnino Anderhalden, Aurel Schneider, Ben Moore

Research output: Contribution to journalArticle

Abstract

The free streaming of warm dark matter particles dampens the fluctuation spectrum, flattens the mass function of haloes and sets a fine-grained phase density limit for dark matter structures. The phase-space density limit is expected to imprint a constant-density core at the halo centre in contrast to what happens for cold dark matter. We explore these effects using high-resolution simulations of structure formation in different warm dark matter scenarios. We find that the size of the core we obtain in simulated haloes is in good agreement with theoretical expectations based on Liouville's theorem. However, our simulations show that in order to create a significant core (kpc) in a dwarf galaxy (M∼ 10 10M ), a thermal candidate with mass as low as 0.1keV is required. This would fully prevent the formation of the dwarf galaxy in the first place. For candidates satisfying large-scale structure constraints (m ν larger than ≈1-2keV), the expected size of the core is of the order of 10 (20) pc for a dark matter halo with a mass of 10 10 (10 8) M . We conclude that 'standard' warm dark matter is not a viable solution for explaining the presence of cored density profiles in low-mass galaxies.

Original languageEnglish (US)
Pages (from-to)1105-1112
Number of pages8
JournalMonthly Notices of the Royal Astronomical Society
Volume424
Issue number2
DOIs
StatePublished - Aug 1 2012

Fingerprint

halos
dark matter
dwarf galaxies
Liouville theorem
space density
simulation
galaxies
high resolution
profiles

Keywords

  • Dark matter
  • Galaxies: haloes

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Cores in warm dark matter haloes : A Catch 22 problem. / Maccio, Andrea; Paduroiu, Sinziana; Anderhalden, Donnino; Schneider, Aurel; Moore, Ben.

In: Monthly Notices of the Royal Astronomical Society, Vol. 424, No. 2, 01.08.2012, p. 1105-1112.

Research output: Contribution to journalArticle

Maccio, Andrea ; Paduroiu, Sinziana ; Anderhalden, Donnino ; Schneider, Aurel ; Moore, Ben. / Cores in warm dark matter haloes : A Catch 22 problem. In: Monthly Notices of the Royal Astronomical Society. 2012 ; Vol. 424, No. 2. pp. 1105-1112.
@article{044f829b87d04eb4927002d47d95af8b,
title = "Cores in warm dark matter haloes: A Catch 22 problem",
abstract = "The free streaming of warm dark matter particles dampens the fluctuation spectrum, flattens the mass function of haloes and sets a fine-grained phase density limit for dark matter structures. The phase-space density limit is expected to imprint a constant-density core at the halo centre in contrast to what happens for cold dark matter. We explore these effects using high-resolution simulations of structure formation in different warm dark matter scenarios. We find that the size of the core we obtain in simulated haloes is in good agreement with theoretical expectations based on Liouville's theorem. However, our simulations show that in order to create a significant core (kpc) in a dwarf galaxy (M∼ 10 10M ⊙), a thermal candidate with mass as low as 0.1keV is required. This would fully prevent the formation of the dwarf galaxy in the first place. For candidates satisfying large-scale structure constraints (m ν larger than ≈1-2keV), the expected size of the core is of the order of 10 (20) pc for a dark matter halo with a mass of 10 10 (10 8) M ⊙. We conclude that 'standard' warm dark matter is not a viable solution for explaining the presence of cored density profiles in low-mass galaxies.",
keywords = "Dark matter, Galaxies: haloes",
author = "Andrea Maccio and Sinziana Paduroiu and Donnino Anderhalden and Aurel Schneider and Ben Moore",
year = "2012",
month = "8",
day = "1",
doi = "10.1111/j.1365-2966.2012.21284.x",
language = "English (US)",
volume = "424",
pages = "1105--1112",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "2",

}

TY - JOUR

T1 - Cores in warm dark matter haloes

T2 - A Catch 22 problem

AU - Maccio, Andrea

AU - Paduroiu, Sinziana

AU - Anderhalden, Donnino

AU - Schneider, Aurel

AU - Moore, Ben

PY - 2012/8/1

Y1 - 2012/8/1

N2 - The free streaming of warm dark matter particles dampens the fluctuation spectrum, flattens the mass function of haloes and sets a fine-grained phase density limit for dark matter structures. The phase-space density limit is expected to imprint a constant-density core at the halo centre in contrast to what happens for cold dark matter. We explore these effects using high-resolution simulations of structure formation in different warm dark matter scenarios. We find that the size of the core we obtain in simulated haloes is in good agreement with theoretical expectations based on Liouville's theorem. However, our simulations show that in order to create a significant core (kpc) in a dwarf galaxy (M∼ 10 10M ⊙), a thermal candidate with mass as low as 0.1keV is required. This would fully prevent the formation of the dwarf galaxy in the first place. For candidates satisfying large-scale structure constraints (m ν larger than ≈1-2keV), the expected size of the core is of the order of 10 (20) pc for a dark matter halo with a mass of 10 10 (10 8) M ⊙. We conclude that 'standard' warm dark matter is not a viable solution for explaining the presence of cored density profiles in low-mass galaxies.

AB - The free streaming of warm dark matter particles dampens the fluctuation spectrum, flattens the mass function of haloes and sets a fine-grained phase density limit for dark matter structures. The phase-space density limit is expected to imprint a constant-density core at the halo centre in contrast to what happens for cold dark matter. We explore these effects using high-resolution simulations of structure formation in different warm dark matter scenarios. We find that the size of the core we obtain in simulated haloes is in good agreement with theoretical expectations based on Liouville's theorem. However, our simulations show that in order to create a significant core (kpc) in a dwarf galaxy (M∼ 10 10M ⊙), a thermal candidate with mass as low as 0.1keV is required. This would fully prevent the formation of the dwarf galaxy in the first place. For candidates satisfying large-scale structure constraints (m ν larger than ≈1-2keV), the expected size of the core is of the order of 10 (20) pc for a dark matter halo with a mass of 10 10 (10 8) M ⊙. We conclude that 'standard' warm dark matter is not a viable solution for explaining the presence of cored density profiles in low-mass galaxies.

KW - Dark matter

KW - Galaxies: haloes

UR - http://www.scopus.com/inward/record.url?scp=84863865861&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84863865861&partnerID=8YFLogxK

U2 - 10.1111/j.1365-2966.2012.21284.x

DO - 10.1111/j.1365-2966.2012.21284.x

M3 - Article

VL - 424

SP - 1105

EP - 1112

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 2

ER -