A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: Implications for annihilating dark matter

Ioana Ciucă; Daisuke Kawata; Shin'ichiro Ando; Francesca Calore; Justin I. Read; Cecilia Mateu

doi:10.1093/MNRAS/STY1994

A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: Implications for annihilating dark matter

Ioana Ciucă, Daisuke Kawata, Shin'ichiro Ando, Francesca Calore, Justin I. Read, Cecilia Mateu

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

Abstract

We make the first attempt to find dwarf galaxies in eight Fermi-LAT extended, unassociated, source fields using Gaia DR2. After probing previously unexplored heliocentric distances of d < 20 kpc with an extreme-deconvolution (XD) technique, we find no sign of a dwarf galaxy in any of these fields despite Gaia's excellent astrometric accuracy. Our detection limits are estimated by applying the XD method to mock data, obtaining a conservative limit on the stellarmass of M* < 10⁴ M_⊙ for d < 20 kpc. Such a low stellar mass implies either a low-mass subhalo or a massive stripped-down subhalo. We use an analytic model for stripped subhaloes to argue that, given the sizes and fluxes of the Fermi-LAT sources, we can reject the hypothesis that they owe to dark matter annihilation.

Original language	English
Pages (from-to)	2284-2291
Number of pages	8
Journal	Monthly Notices of the Royal Astronomical Society
Volume	480
Issue number	2
DOIs	https://doi.org/10.1093/MNRAS/STY1994
Publication status	Published - Oct 2018
Externally published	Yes

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10.1093/MNRAS/STY1994

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title = "A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: Implications for annihilating dark matter",

abstract = "We make the first attempt to find dwarf galaxies in eight Fermi-LAT extended, unassociated, source fields using Gaia DR2. After probing previously unexplored heliocentric distances of d < 20 kpc with an extreme-deconvolution (XD) technique, we find no sign of a dwarf galaxy in any of these fields despite Gaia's excellent astrometric accuracy. Our detection limits are estimated by applying the XD method to mock data, obtaining a conservative limit on the stellarmass of M* < 104 M⊙ for d < 20 kpc. Such a low stellar mass implies either a low-mass subhalo or a massive stripped-down subhalo. We use an analytic model for stripped subhaloes to argue that, given the sizes and fluxes of the Fermi-LAT sources, we can reject the hypothesis that they owe to dark matter annihilation.",

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author = "Ioana Ciuc{\u a} and Daisuke Kawata and Shin'ichiro Ando and Francesca Calore and Read, {Justin I.} and Cecilia Mateu",

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volume = "480",

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T1 - A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources

T2 - Implications for annihilating dark matter

AU - Ciucă, Ioana

AU - Kawata, Daisuke

AU - Ando, Shin'ichiro

AU - Calore, Francesca

AU - Read, Justin I.

AU - Mateu, Cecilia

PY - 2018/10

Y1 - 2018/10

N2 - We make the first attempt to find dwarf galaxies in eight Fermi-LAT extended, unassociated, source fields using Gaia DR2. After probing previously unexplored heliocentric distances of d < 20 kpc with an extreme-deconvolution (XD) technique, we find no sign of a dwarf galaxy in any of these fields despite Gaia's excellent astrometric accuracy. Our detection limits are estimated by applying the XD method to mock data, obtaining a conservative limit on the stellarmass of M* < 104 M⊙ for d < 20 kpc. Such a low stellar mass implies either a low-mass subhalo or a massive stripped-down subhalo. We use an analytic model for stripped subhaloes to argue that, given the sizes and fluxes of the Fermi-LAT sources, we can reject the hypothesis that they owe to dark matter annihilation.

AB - We make the first attempt to find dwarf galaxies in eight Fermi-LAT extended, unassociated, source fields using Gaia DR2. After probing previously unexplored heliocentric distances of d < 20 kpc with an extreme-deconvolution (XD) technique, we find no sign of a dwarf galaxy in any of these fields despite Gaia's excellent astrometric accuracy. Our detection limits are estimated by applying the XD method to mock data, obtaining a conservative limit on the stellarmass of M* < 104 M⊙ for d < 20 kpc. Such a low stellar mass implies either a low-mass subhalo or a massive stripped-down subhalo. We use an analytic model for stripped subhaloes to argue that, given the sizes and fluxes of the Fermi-LAT sources, we can reject the hypothesis that they owe to dark matter annihilation.

KW - Astrometry -Galaxy: halo

KW - Catalogues

KW - Galaxies: dwarf

KW - Galaxy: structure

KW - Gamma-rays: general

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DO - 10.1093/MNRAS/STY1994

M3 - Article

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EP - 2291

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 2

ER -

A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: Implications for annihilating dark matter

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