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1. Chemical abundances in the outskirts of nearby galaxy groups measured with joint Suzaku and Chandra observations

   https://doi.org/10.1093/mnras/stac2416  

   Sarkar, Arnab; Su, Yuanyuan; Truong, Nhut; Randall, Scott; Mernier, François; Gastaldello, Fabio; Biffi, Veronica; Kraft, Ralph (August 2022, Monthly Notices of the Royal Astronomical Society)

   ABSTRACT We report results from deep Suzaku and mostly snapshot Chandra observations of four nearby galaxy groups: MKW4, Antlia, RXJ1159+5531, and ESO3060170. Their peak temperatures vary over 2–3 keV, making them the smallest systems with gas properties constrained to their viral radii. The average Fe abundance in the outskirts (R > 0.25R200) of their intragroup medium is $$Z_{\rm Fe}=0.309\pm 0.018\, Z_\odot$$ with χ2 = 14 for 12 degrees of freedom, which is remarkably uniform and strikingly similar to that of massive galaxy clusters, and is fully consistent with the numerical predictions from the IllustrisTNG cosmological simulation. Our results support an early-enrichment scenario among galactic systems over an order of magnitude in mass, even before their formation. When integrated out to R200, we start to see a tension between the measured Fe content in intracluster medium and what is expected from supernovae yields. We further constrain their O, Mg, Si, S, and Ni abundances. The abundance ratios of those elements relative to Fe are consistent with the predictions (if available) from IllustrisTNG. Their Type Ia supernovae fraction varies between 14 per cent and 21 per cent. A pure core-collapsed supernovae enrichment at group outskirts can be ruled out. Their cumulative iron-mass-to-light ratios within R200 are half that of the Perseus cluster, which may imply that galaxy groups do not retain all of their enriched gas due to their shallower gravitational potential wells, or that groups and clusters may have different star formation histories. 

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2. Joint Inversion of Surface Wave Dispersions and Receiver Functions with P Velocity Constraints: Application to Southeastern Tibet: Joint Inversion and Application to Tibet

   https://doi.org/10.1002/2017JB014135  

   Li, Jiangtao; Song, Xiaodong; Zhu, Lupei; Deng, Yangfan (September 2017, Journal of Geophysical Research: Solid Earth)

   null (Ed.)
3. Euclid-Roman joint microlensing survey: Early mass measurement, free floating planets, and exomoons

   https://doi.org/10.1051/0004-6361/202140351  

   Bachelet, E.; Specht, D.; Penny, M.; Hundertmark, M.; Awiphan, S.; Beaulieu, J.-P.; Dominik, M.; Kerins, E.; Maoz, D.; Meade, E.; et al (August 2022, Astronomy & Astrophysics)

   As the Kepler mission has done for hot exoplanets, the ESA Euclid and NASA Roman missions have the potential to create a breakthrough in our understanding of the demographics of cool exoplanets, including unbound, or free-floating, planets (FFPs). Roman will dedicate part of its core survey program to the detection of cool exoplanets via microlensing, while Euclid may undertake a microlensing program as an ancillary science goal. In this study, we demonstrate the complementarity of the two missions and propose two joint surveys to better constrain the mass and distance of microlensing events. We first demonstrate that an early brief Euclid survey (~7 h) of the Roman microlensing fields will allow the measurement of at least 30% of the events’ relative proper motions µ rel and 42% of the lens magnitudes. This survey would place strong constraints on the mass and distance on thousands of microlensing events observed by Roman just after the first year of observation. Then, we study the potential of simultaneous observations by Roman and Euclid to enable the measurement of the microlensing parallax for the shortest microlensing events and, ultimately, obtain a direct measurement of the masses, distances, and transverse motions of FFPs. Using detailed simulations of the joint detection yield we show that within one year Roman-Euclid observations will be at least an order of magnitude more sensitive than current ground-based measurements. The recent tentative detection of an excess of short-duration events by the OGLE survey is consistent with a scenario of up to ten Earth-mass FFPs per Galactic star. For such a scenario a joint Roman-Euclid campaign should detect around 130 FFP events within a year, including 110 with measured parallax that strongly constrain the FFP mass, and around 30 FFP events with direct mass and distance measurements. The ability of the joint survey to completely break the microlens mass-distance-velocity degeneracy for a significant subset of events provides a unique opportunity to verify unambiguously the FFP hypothesis or else place abundance limits for FFPs between Earth and Jupiter masses that are up to two orders of magnitude stronger than provided by ground-based surveys. Finally, we study the capabilities of the joint survey to enhance the detection and characterization of exomoons, and find that it could lead to the detection of the first exomoon. 

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4. Semi-Parametric Joint Modeling of Survival and Longitudinal Data: The R Package JSM

   https://doi.org/10.18637/jss.v093.i02  

   Xu, Cong; Hadjipantelis, Pantelis Z.; Wang, Jane-Ling (January 2020, Journal of Statistical Software)
5. Upper Crustal Vp / Vs Ratios at the Endeavour Segment, Juan de Fuca Ridge, From Joint Inversion of P and S Traveltimes: Implications for Hydrothermal Circulation

   https://doi.org/10.1029/2018GC007921  

   Kim, Eunyoung; Toomey, Douglas R.; Hooft, Emilie E. E.; Wilcock, William S. D.; Weekly, Robert T.; Lee, Sang‐Mook; Kim, Young Hee (January 2019, Geochemistry, Geophysics, Geosystems)

   Abstract The Endeavour segment of the Juan de Fuca Ridge is one of the most active and long‐lived hydrothermal areas of the mid‐ocean ridge system. However, the permeability structure that gives rise to long‐term venting at well‐established fields, such as the High Rise, Main Endeavour, and Mothra fields, is not fully understood. Here we jointly invertPgandSgtraveltimes from a seismic refraction experiment conducted at the Endeavour segment usingP‐to‐Scoupling constraints. We then calculate porosity and crack density as a function of crack aspect ratio by applying the differential effective medium theory to the seismic velocities. At 1.4‐km depth, averageVp~5 km off axis increases by ~0.4 km/s compared to the ridge axis. The averageVp/Vshas a minimum of ~1.75 on the ridge axis and increases to a maximum of ~1.84 off axis. The inferred porosity and crack density distributions show that the proportion of thick versus thin cracks decreases from the ridge axis to the flanks, since theoretical models indicate thatVp/Vsincreases going from thick to thin cracks (aspect ratio decreasing from 0.1 to 0.01). The dominant presence of thick cracks on the axis may provide long‐term conduits for upflow in high‐temperature hydrothermal circulation potentially forming the vent fields. The increased proportion of thin cracks on the flanks, coupled with the increased seismic velocity, indicates a decrease in permeability caused by progressive clogging of thick cracks due to mineral precipitation likely in the downflow zone of hydrothermal circulation. 

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