Our paper reviews the planned space-based gamma-ray telescope GAMMA-400 and evaluates in details its opportunities in the field of dark matter (DM) indirect searches. We estimated GAMMA-400 mean sensitivity to the diphoton DM annihilation cross section in the Galactic center for DM particle masses in the range of 1-500 GeV. We obtained the sensitivity gain at least by 1.2-1.5 times (depending on DM particle mass) with respect to the expected constraints from 12 years of observations by Fermi-LAT for the case of Einasto DM density profile. The joint analysis of the data from both telescopes may yield the gain up to 1.8-2.3 times. Thus the sensitivity reaches the level of annihilation cross section $\langle σv \rangle_{γγ}(m_χ=100~\mbox{GeV})\approx 10^{-28}$ cm$^3$/s. This will allow us to test the hypothesized narrow lines predicted by specific DM models, particularly the recently proposed pseudo-Goldstone boson DM model. We also considered the decaying DM - in this case the joint analysis may yield the sensitivity gain up to 1.1-2.0 times reaching the level of DM lifetime $τ_{γν}(m_χ=100~\mbox{GeV}) \approx 2\cdot 10^{29}$ s. We estimated the GAMMA-400 sensitivity to axion-like particle (ALP) parameters by a potential observation of the supernova explosion in the Local Group. This is very sensitive probe of ALPs reaching the level of ALP-photon coupling constant $g_{aγ} \sim 10^{-13}~\mbox{GeV}^{-1}$ for ALP masses $m_a \lesssim 1$ neV. We also calculated the sensitivity to ALPs by constraining the modulations in the spectra of the Galactic gamma-ray pulsars due to possible ALP-photon conversion. GAMMA-400 is expected to be more sensitive than the CAST helioscope for ALP masses $m_a \approx (1-10)$ neV reaching $g_{aγ}^{min} \approx 2\cdot 10^{-11}~\mbox{GeV}^{-1}$. Other potentially interesting targets and candidates are briefly considered too.
The Gamma-Ray and AntiMatter Survey (GRAMS) project is a proposed next-generation balloon/satellite mission targeting both MeV gamma-ray observations and antimatter-based dark matter searches. A cost-effective, large-scale Liquid Argon Time Projection Chamber (LArTPC) detector technology will allow GRAMS to have a significantly improved sensitivity to MeV gamma rays while extensively probing dark matter parameter space via antimatter measurements.
High-energetic gamma rays from astrophysical targets constitute a unique probe for annihilation or decay of heavy particle dark matter (DM). After several decades, diverse null detections have resulted in strong constraints for DM particle masses up to the TeV scale. While the gamma-ray signature is expected to be universal from various targets, uncertainties of astrophysical origin strongly affect and weaken the limits. At the same time, spurious signals may originate from non-DM related processes. The many gamma-ray targets in the extragalactic sky being searched for DM play a crucial role t…
If dark matter is composed of weakly interacting particles with mass in the GeV-TeV range, their annihilation or decay may produce gamma rays that could be detected by gamma-ray telescopes. Observations of dwarf spheroidal satellite galaxies of the Milky Way (dSphs) benefit from the relatively accurate predictions of dSph dark matter content to produce robust constraints to the dark matter properties. The sensitivity of these observations for the search for dark matter signals can be optimized thanks to the use of advanced statistical techniques able to exploit the spectral and morphological p…
The Large Array Telescope for Tracking Energetic Sources (LATTES), is a novel concept for an array of hybrid EAS array detectors, composed of a Resistive Plate Counter array coupled to a Water Cherenkov Detector, planned to cover gamma rays from less than 100 GeV up to 100 TeVs. This experiment, to be installed at high altitude in South America, could cover the existing gap in sensitivity between satellite and ground arrays. The low energy threshold, large duty cycle and wide field of view of LATTES makes it a powerful tool to detect transient phenomena and perform long term observations of va…
For decades, searches for electroweak-scale dark matter (DM) have been performed without a definitive detection. This lack of success may hint that DM searches have focused on the wrong mass range. A proposed candidate beyond the canonical parameter space is ultra-heavy DM (UHDM). In this work, we consider indirect UHDM annihilation searches for masses between 30 TeV and 30 PeV, extending well beyond the unitarity limit at $\sim$100 TeV, and discuss the basic requirements for DM models in this regime. We explore the feasibility of detecting the annihilation signature, and the expected reach fo…
The DArk Matter Particle Explorer (DAMPE) is a space high-energy cosmic-ray detector covering a wide energy band with a high energy resolution. One of the key scientific goals of DAMPE is to carry out indirect detection of dark matter by searching for high-energy gamma-ray line structure. To promote the sensitivity of gamma-ray line search with DAMPE, it is crucial to improve the acceptance and energy resolution of gamma-ray photons. In this paper, we quantitatively prove that the photon sample with the largest ratio of acceptance to energy resolution is optimal for line search. We therefore d…
Gamma-ray bursts (GRBs) are among the most powerful events observed in our universe and have long been considered as possible sources of ultra-high-energy cosmic rays, which makes them promising neutrino source candidates. Previous IceCube searches for neutrino correlations with GRBs focused on the prompt (main emission) phase of the GRB and found no significant correlation between neutrino events and the observed GRBs. This motivates us to extend our search beyond the prompt phase. We perform analyses looking for evidence of neutrino emission up to 14 days before and after the prompt phase of…
We propose a new method to search for axion-like particles (ALPs) based on the gamma-rays produced concomitant with high-energy astrophysical neutrinos. The existence of high-energy neutrinos implies production of gamma-rays in the same sources. Photons can convert into ALPs in the sources' magnetic fields, and will travel as ALPs through extragalactic space. Back-conversion in the Milky Way's magnetic field leads to a diffuse anisotropic high-energy photon flux that existing and upcoming gamma-ray detectors, like HAWC, CTA, and LHAASO can detect. This method probes unexplored ALP parameter sp…
Cold dark matter subhalos are expected to populate galaxies in numbers. If dark matter self-annihilates, these objects turn into prime targets for indirect searches, in particular with gamma-ray telescopes. Incidentally, the Fermi-LAT catalog already contains many unidentified sources that might be associated with subhalos. In this paper, we determine the probability for subhalos to be identified as gamma-ray pointlike sources from their predicted distribution properties. We use a semi-analytical model for the Galactic subhalo population, which, in contrast to cosmological simulations, can be …
It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the typical parameter search space spans wide ranges in four dimensions. It is even more demanding when the pulsar is in a binary system, where the orbital motion introduces several additional unknown parameters. Building on earlier work by Pletsch & Clark (arXiv:1408.6962), we present optimal methods for such searches. These can also incorporate external constraints …
During a core-collapse supernova (SN), axion-like particles (ALPs) could be produced through the Primakoff process and subsequently convert into gamma rays in the magnetic field of the Milky Way. Using a sample of well studied extragalactic SNe at optical wavelengths, we estimate the time of the core collapse and search for a coincident gamma-ray burst with the Fermi Large Area Telescope (LAT). Under the assumption that at least one SN was contained within the LAT field of view, we exclude photon-ALP couplings within a factor of $\sim$5 of previous limits from SN1987A. With the increasing numb…
The impact of gamma-ray propagation effects on indirect dark matter searches
Universidad Autónoma de Madrid（马德里自治大学）；Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)（能源、环境和技术中心）；Instituto de Física Teórica, IFT UAM-CSIC（理论物理研究所）；Institut d’Astrophysique de Paris, Sorbonne Université（巴黎天体物理学研究所，索邦大学）；Laboratoire de Physique Nucléaire et des Hautes Énergies, Sorbonne Université（核物理与高能实验室，索邦大学）
An important open question today is the understanding of the relevance that dark matter (DM) halo substructure may have for DM searches. In the standard cosmological framework, subhalos are predicted to be largely abundant inside larger halos, i.e., galaxies like ours, and are thought to form first and later merge to form larger structures. Dwarf satellite galaxies -- the most massive exponents of halo substructure in our own galaxy -- are already known to be excellent targets and, indeed, they are constantly scrutinized by current gamma-ray experiments in their search for DM annihilation sign…
Searches for inspiral gravitational waves associated with short gamma-ray bursts in LIGO's fifth and Virgo's first science run
两个致密物体的合并，比如两颗中子星或一颗中子星和一个黑洞，很可能是短伽马射线暴的起源。这些事件也是有希望的引力波来源，目前正在激发国际引力波探测器网络的相关搜索。在这里，我们描述了一个搜索的引力波从螺旋阶段的两个合并紧凑的对象，在巧合的短伽玛射线暴发生在LIGO的第五次科学运行和处女座的第一次科学运行。这次搜索包括22个GRB，这些GRB的数据来自LIGO/Virgo网络中的多个探测器。没有发现统计上显著的引力波候选者，参数检验表明在我们的伽玛暴样本中没有多余的弱引力波信号。90%~ C. L.在中子星-黑洞祖先模型假设下，我们的样本中伽玛暴的中位排斥距离为6.7 Mpc。
The pulsar glitches are generally assumed to be an apparent manifestation of the superfluid interior of the neutron stars. Most of them were discovered and extensively studied by continuous monitoring in the radio wavelengths. The Fermi-LAT space telescope has made a revolution uncovering a large population of gamma-ray pulsars. In this paper we suggest to employ these observations for the searches of new glitches. We develop the method capable of detecting step-like frequency change associated with glitches in a sparse gamma-ray data. It is based on the calculations of the weighted H-test sta…
Stringent Constraints On The Dark Matter Annihilation Cross Section From Subhalo Searches With The Fermi Gamma-Ray Space Telescope
银河系的暗物质晕被预测包含了非常大量的较小的次晕。由于暗物质湮灭发生在这样的物体内，最接近的大质量暗晕可能表现为点状或空间扩展的伽马射线源，在其他波长处没有可观测到的对应物。在本文中，我们使用宝瓶座模拟的结果来预测附近的subhalos的分布，并将其与费米伽马射线太空望远镜观测到的不明伽马射线源的特征进行比较。关注最亮的高纬度源，我们利用这种比较来推导出暗物质湮灭截面的极限。对于轻于~200 GeV的暗物质粒子，所得到的极限是迄今为止最强的，比矮星系或银河系中心的观测结果更为严格。我们还推导出独立的限制的基础上缺乏身份不明的伽马射线源与可辨别的空间扩展，但这些限制是一个因素的2-10弱于那些基于点状subhalos。最后，我们注意到10个最亮的高纬度源中有4个呈现出类似的光谱形状，这与30-60 GeV的暗物质粒子湮灭为b夸克相一致，湮灭截面的数量级为sigma v ~（5-10）x 10^-27 cm ^3/s，或8-10 GeV的暗物质粒子湮灭为τ，σ v ~（2.0-2.5）x 10^-27 cm ^3/s。
We investigate a scenario where dark matter (DM) particles can be captured and accumulate in the Sun, and subsequently annihilate into a pair of long-lived mediators. These mediators can decay further out in the Sun or outside of the Sun. Compared to the standard scenario where DM particles annihilate directly into Standard Model particles close to the solar core, here we also obtain fluxes of gamma rays and charged cosmic rays. We simulate this scenario using a full three-dimensional model of the Sun, and include interactions and neutrino oscillations. In particular, we perform a model-indepe…
In this thesis, we examined the possibilities offered by multi-messenger astronomy in the context of indirect dark matter detection. We have applied a multi-wavelength strategy by studying different signals across the electromagnetic spectrum (gamma-rays, X-rays, radio waves) produced at different scales of the Universe (galactic, extragalactic, cosmic web filaments). In Part I, we obtained the first-ever prediction of the cross-correlation signal between the extragalactic gamma-ray flux and the 21cm line emitted by hydrogen atoms in dark matter halos. We showed that the neutral hydrogen distr…
