Search Publications
Hubble constant from the cluster-lensed quasar system SDSS J 1004 +4112 : Investigation of the lens model dependence
Oguri, Masamune; Liu, Yuting; Cao, Shuo
As a fundamental parameter for modern cosmology, the Hubble constant H0 is experiencing a serious crisis. In this paper, we explore an independent approach to measure H0 based on the time-delay cosmography with strong gravitational lensing of a quasar by a galaxy cluster. Specifically we focus on the strong lensing system SDS…
Electron density revealing the boundaries of Mercury's magnetosphere via serendipitous measurements by SORBET during BepiColombo first and second Mercury swing-bys
Pantellini, F.; Issautier, K.; Kasaba, Y. +3 more
Aims: We aim to establish the boundaries of Mercury's magnetosphere through a comparison of the drops and rises of the electron density revealed by PWI/SORBET, during BepiColombo's first and second swing-bys of Mercury carried out on 1 October 2021 and 23 June 2022, with global 3D magnetohydrodynamic simulations.
Methods: SORBET was swit…
Weighing the Local Interstellar Medium Using Gamma Rays and Dust
Widmark, Axel; Korsmeier, Michael; Linden, Tim
Cold gas forms a significant mass fraction of the Milky Way disk, but is its most uncertain baryonic component. The density and distribution of cold gas is of critical importance for Milky Way dynamics, as well as models of stellar and galactic evolution. Previous studies have used correlations between gas and dust to obtain high-resolution measur…
Observation of the radiation environment and solar energetic particle events in Mars orbit in May 2018- June 2022
Gopalswamy, Nat; Semkova, Jordanka; Koleva, Rositza +19 more
The dosimeter Liulin-MO for measuring the radiation environment onboard the ExoMars Trace Gas Orbiter (TGO) is a module of the Fine Resolution Epithermal Neutron Detector (FREND). Here we present results from measurements of the charged particle fluxes, dose rates and estimation of dose equivalent rates at ExoMars TGO Mars science orbit, provided …
Constraining dark matter interactions mediated by a light scalar with white dwarfs
Ramirez-Quezada, Maura E.
Observations of white dwarfs in dark matter-rich environments can provide strong limits on the strength of dark matter interactions. Here we apply the recently improved formalism of the dark matter capture rate in white dwarfs to a general model in which dark matter interacts with the white dwarf ion components via a light scalar mediator. We comp…
Metallicity-PAH Relation of MIR-selected Star-forming Galaxies in AKARI North Ecliptic Pole-wide Survey
Hashimoto, Tetsuya; Jeong, Woong-Seob; Hwang, Ho Seong +9 more
We investigate the variation in the mid-infrared spectral energy distributions of 373 low-redshift (z < 0.4) star-forming galaxies, which reflects a variety of polycyclic aromatic hydrocarbon (PAH) emission features. The relative strength of PAH emission is parameterized as q PAH, which is defined as the mass fraction of PAH particle…
Unveiling the gravitationally unstable disc of a massive star-forming galaxy using NOEMA and MUSE
Cannon, John M.; Hayes, Matthew; Östlin, Göran +7 more
Using new high-resolution data of CO (2-1), H$\alpha$ and H$\beta$ obtained with the Northern Extended Millimeter Array (NOEMA) and the Multi-Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope, we have performed a Toomre Q disc stability analysis and studied star formation, gas depletion times and other environmental parameters on sub-…
Classification of Chandra X-Ray Sources in Cygnus OB2
Naylor, Tim; Drake, Jeremy J.; Wright, Nicholas J. +11 more
We have devised a predominantly Naive Bayes-based method to classify X-ray sources detected by Chandra in the Cygnus OB2 association into members, foreground objects, and background objects. We employ a variety of X-ray, optical, and infrared characteristics to construct likelihoods using training sets defined by well-measured sources. Combination…
The age, kinematics, and metallicity of nearby Sun-like stars and the history of the Milky Way disc
Gondoin, P.
Contact. Investigating how the Milky Way formed and has evolved is an important topic in astrophysics that requires the determination of precise ages for large samples of stars over long periods.
Aims: The present study addresses the formation history of nearby Sun-like stars using the emission reversal in the cores of their Ca II H&K Fra…
The Direct-method Oxygen Abundance of Typical Dwarf Galaxies at Cosmic High Noon
Richard, Johan; Siana, Brian; Freeman, William R. +5 more
We present a Keck/MOSFIRE rest-optical composite spectrum of 16 typical gravitationally lensed star-forming dwarf galaxies at 1.7 ≲ z ≲ 2.6 (z mean = 2.30), all chosen independent of emission-line strength. These galaxies have a median stellar mass of $\mathrm{log}{({M}_{* }/{M}_{\odot })}_{\mathrm{med}}={8.29}_{-0.43}^{+0.51}$ and a me…