Search Publications
Radiation from matter-antimatter annihilation in the quark nugget model of dark matter
Flambaum, V. V.; Samsonov, I. B.
We revisit the properties of positron cloud in quark nugget (QN) model of dark matter (DM). In this model, dark matter particles are represented by compact composite objects composed of a large number of quarks or antiquarks with total baryon number B ∼1024. These particles have a very small number density in our galaxy which makes them…
The Physical Drivers of the Luminosity-weighted Dust Temperatures in High-redshift Galaxies
Casey, Caitlin M.; Zavala, Jorge A.; Chen, Chian-Chou +7 more
The underlying distribution of galaxies' dust spectral energy distributions (SEDs) (i.e., their spectra reradiated by dust from rest-frame ∼3 µm to 3 mm) remains relatively unconstrained owing to a dearth of far-IR/(sub)millimeter data for large samples of galaxies. It has been claimed in the literature that a galaxy's dust temperature—obser…
Spatially offset black holes in the Horizon-AGN simulation and comparison to observations
Ferreira, Pedro G.; Devriendt, Julien; Slyz, Adrianne +2 more
We study the displacements between the centres of galaxies and their supermassive black holes (BHs) in the cosmological hydrodynamical simulation Horizon-AGN, and in a variety of observations from the literature. The BHs in Horizon-AGN feel a subgrid dynamical friction force, sourced by the surrounding gas, which prevents recoiling BHs being eject…
Photometry of Kuiper belt object (486958) Arrokoth from New Horizons LORRI
Buratti, Bonnie J.; Singer, Kelsi N.; Stern, S. Alan +12 more
On January 1st 2019, the New Horizons spacecraft flew by the classical Kuiper belt object (486958) Arrokoth (provisionally designated 2014 MU69), possibly the most primitive object ever explored by a spacecraft. The I/F of Arrokoth is analyzed and fit with a photometric function that is a linear combination of the Lommel-Seeliger (lunar) and Lambe…
Atacama Cosmology Telescope measurements of a large sample of candidates from the Massive and Distant Clusters of WISE Survey. Sunyaev-Zeldovich effect confirmation of MaDCoWS candidates using ACT
Hilton, Matt; Sifón, Cristóbal; Choi, Steve K. +35 more
Context. Galaxy clusters are an important tool for cosmology, and their detection and characterization are key goals for current and future surveys. Using data from the Wide-field Infrared Survey Explorer (WISE), the Massive and Distant Clusters of WISE Survey (MaDCoWS) located 2839 significant galaxy overdensities at redshifts 0.7 ≲ z ≲ 1.5, whic…
Bayesian calibration of the mixing length parameter αML and of the helium-to-metal enrichment ratio ΔY/ΔZ with open clusters: the Hyades test-bed
Valle, G.; Dell'Omodarme, M.; Prada Moroni, P. G. +2 more
We tested the capability of a Bayesian procedure to calibrate both the helium abundance and the mixing length parameter (αML), using precise photometric data for main-sequence (MS) stars in a cluster with negligible reddening and well-determined distance. The method has been applied first to a mock data set generated to mimic Hyades MS …
Volatiles and Refractories in Surface-Bounded Exospheres in the Inner Solar System
Leblanc, François; Nishino, Masaki N.; Vervack, Ronald J. +11 more
Volatiles and refractories represent the two end-members in the volatility range of species in any surface-bounded exosphere. Volatiles include elements that do not interact strongly with the surface, such as neon (detected on the Moon) and helium (detected both on the Moon and at Mercury), but also argon, a noble gas (detected on the Moon) that s…
Linking Soft Excess in Ultraluminous X-Ray Sources with Optically Thick Wind Driven by Supercritical Accretion
Feng, Hua; Qiu, Yanli
Supercritical accretion onto compact objects may drive massive winds that are nearly spherical, optically thick, and Eddington limited. Blackbody emission from the photosphere is the direct observational signature of the wind. Here we investigate whether or not it can explain the soft emission component seen in the energy spectra of ultraluminous …
Three-dimensional Structure and Dust Extinction in the Small Magellanic Cloud
Dolphin, Andrew E.; Yanchulova Merica-Jones, Petia; Williams, Benjamin F. +6 more
We examine the three-dimensional structure and dust extinction properties in a ∼200 pc × 100 pc region in the southwest bar of the Small Magellanic Cloud (SMC). We model a deep Hubble Space Telescope optical color-magnitude diagram (CMD) of red clump and red giant branch stars in order to infer the dust extinction and galactic structure. We model …
Martian cloud climatology and life cycle extracted from Mars Express OMEGA spectral images
Bibring, Jean-Pierre; Langevin, Yves; Gondet, Brigitte +7 more
A Martian water-ice cloud climatology has been extracted from OMEGA data covering 7 Martian years (MY 26-32) on the dayside. We derived two products, the Reversed Ice Cloud Index (ICIR) and the Percentage of Cloudy Pixels (PCP), indicating the mean cloud thickness and nebulosity over a regular grid (1° longitude × 1° latitude × 1° Ls × 1 h Local T…