Astro-Theology and Cosmology

Walker, Theodore; Wickramasinghe, Chandra

doi:10.1057/9781137535030_1

Cited by 10 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dwarf galaxy Reticulum II (RetII) was discovered in 2015 in first year Dark Energy Survey data [5,6]. Spectroscopic follow-ups [7][8][9] confirmed that the object is an ultra-faint dSph galaxy, satellite of the Milky Way. They found RetII to be strongly DM dominated with a measured velocity dispersion around 3.5 km/s and a mass-tolight ratio within its half-light radius around 500 M /L .…”

Section: Introductionmentioning

confidence: 99%

Dark matter in the Reticulum II dSph: a radio search

Regis

Richter

Colafrancesco

2017

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

We present a deep radio search in the Reticulum II dwarf spheroidal (dSph) galaxy performed with the Australia Telescope Compact Array. Observations were conducted at 16 cm wavelength, with an rms sensitivity of 0.01 mJy/beam, and with the goal of searching for synchrotron emission induced by annihilation or decay of weakly interacting massive particles (WIMPs). Data were complemented with observations on large angular scales taken with the KAT-7 telescope. We find no evidence for a diffuse emission from the dSph and we derive competitive bounds on the WIMP properties. In addition, we detect more than 200 new background radio sources. Among them, we show there are two compelling candidates for being the radio counterpart of the possible γ-ray emission reported by other groups using Fermi-LAT data.

show abstract

Section: Introductionmentioning

confidence: 99%

Dark matter in the Reticulum II dSph: a radio search

Regis

Richter

Colafrancesco

2017

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

show abstract

“…The consideration of SIDM comes from the discrepancies between the numerical N-body simulations using the hypothesis of CCDM and the astrophysical observations on the * chianshu@gmail.com † glin@cc.nctu.edu.tw ‡ chris.py99g@g2.nctu.edu.tw small structure of the universe [12]. The CCDM simulations [13] predict cuspy profiles in the center regions of galaxies, which conflict with flatten cores found in our Milky Way (MW) [14], other nearby dwarfs [15], and low luminous galaxies [16,17]. There are additional puzzles concerning the sizes of subhalos.…”

Section: Pacs Numbersmentioning

confidence: 99%

Thermal transport of the solar captured dark matter and its impact on the indirect dark matter search

Chen

Lin²,

Lin

2016

Physics of the Dark Universe

View full text Add to dashboard Cite

We study the thermal transport occurring in the system of solar captured dark matter (DM) and explore its impact on the DM indirect search signal. We particularly focus on the scenario of self-interacting DM (SIDM). The flows of energies in and out of the system are caused by solar captures via DM-nucleon and DM-DM scatterings, the energy dissipation via DM annihilation, and the heat exchange between DM and solar nuclei. We examine the DM temperature evolution and demonstrate that the DM temperature can be higher than the core temperature of the Sun if the DM-nucleon cross section is sufficiently small such that the energy flow due to DM self-interaction becomes relatively important. We argue that the correct DM temperature should be used for accurately predicting the DM annihilation rate, which is relevant to the DM indirect detection. PACS numbers:Dark matter (DM) composes about 25% of the energy density of in the universe and plays an important role in the structure formation. It was shown that if the galactic halo is constituted by weakly interacting massive particles (WIMPs), there is a high possibility that these WIMPs are captured by the Sun [1-8, 10]. In general there are thermal energy flows between the captured DMs and the nuclei in the Sun. Microscopically, such flows are caused by particle scatterings. For collisionless cold dark matter (CCDM), the scatterings are only between the DM and solar nuclei. Regarding the huge difference in abundance between the two, it is reasonable to take the DM temperature to be identical to the core temperature of the Sun. However, the scenario of SIDM can change the picture dramatically. In such a scenario, the energy transports via DM self-capture and DM-nucleus scattering compete with each other. In particular, if DM-nucleus interaction is much weaker than expected, the thermal exchange between DMs and nuclei would be much less efficient. As a result, the DM temperature can be distinct from the solar core temperature.It is worth mentioning that the DM abundance is not much affected with a suppressed DM-nucleon cross section σ χp provided SIDM is considered [11]. The accumulated DM abundance is determined by the balance among the capture, the evaporation, and the annihilation rates. Earlier works on such processes only consider DM-nucleon interactions. The new effects from DM selfinteraction are investigated recently [8][9][10][11]. The consideration of SIDM comes from the discrepancies between the numerical N-body simulations using the hypothesis of CCDM and the astrophysical observations on the * small structure of the universe [12]. The CCDM simulations [13] predict cuspy profiles in the center regions of galaxies, which conflict with flatten cores found in our Milky Way (MW) [14], other nearby dwarfs [15], and low luminous galaxies [16,17]. There are additional puzzles concerning the sizes of subhalos. The observed MW satellites are hosted by much less massive subhalos compared to sizes of the most massive subhalos arising from simulations. The absence of such mas...

show abstract

“…Besides the DM-nucleon interaction, inconsistencies in the small-scale structure between the observations and the N -body simulations [34][35][36][37][38][39][40][41][42][43][44] imply the existence of self-interacting DM (SIDM) [45][46][47][48][49][50][51]. The constraint given in Ref.…”

Section: Introductionmentioning

confidence: 99%

Reheating neutron stars with the annihilation of self-interacting dark matter

Chen¹,

Lin²

2018

J. High Energ. Phys.

View full text Add to dashboard Cite

Compact stellar objects such as neutron stars (NS) are ideal places for capturing dark matter (DM) particles. We study the effect of self-interacting DM (SIDM) captured by nearby NS that can reheat it to an appreciated surface temperature through absorbing the energy released due to DM annihilation. When DM-nucleon cross section σ χn is small enough, DM self-interaction will take over the capture process and make the number of captured DM particles increased as well as the DM annihilation rate. The corresponding NS surface temperature resulted from DM self-interaction is about hundreds of Kelvin and is potentially detectable by the future infrared telescopes. Such observations could act as the complementary probe on DM properties to the current DM direct searches.

show abstract

Astro-Theology and Cosmology

Cited by 10 publications

References 0 publications

Dark matter in the Reticulum II dSph: a radio search

Dark matter in the Reticulum II dSph: a radio search

Thermal transport of the solar captured dark matter and its impact on the indirect dark matter search

Reheating neutron stars with the annihilation of self-interacting dark matter

Contact Info

Product

Resources

About