The discovery of a z=0.7092 OH megamaser with the MIGHTEE survey

We present the discovery of the most distant OH megamaser to be observed in the main lines, using data from the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. At a newly measured redshift of $z = 0.7092$, the system has strong emission in both the 1665MHz ($L \approx 2500$ L$_{\odot}$) and 1667 MHz ($L \approx 4.5\times10^4$ L$_{\odot}$) transitions, with both narrow and broad components. We interpret the broad line as a high-velocity-dispersion component of the 1667 MHz transition, with velocity $v \sim 330$km s$^{-1}$ with respect to the systemic velocity. The host galaxy has a stellar mass of $M_{\star} = 2.95 \times 10^{10}$ M$_{\odot}$ and a star-formation rate of SFR = 371 M$_{\odot}$yr$^{-1}$, placing it $\sim 1.5$dex above the main sequence for star-forming galaxies at this redshift, and can be classified as an ultra-luminous infrared galaxy. Alongside the optical imaging data, which exhibits evidence for a tidal tail, this suggests that the OH megamaser arises from a system that is currently undergoing a merger, which is stimulating star formation and providing the necessary conditions for pumping the OH molecule to saturation. The OHM is likely to be lensed, with a magnification factor of $\sim 2.5$, and perhaps more if the maser emitting region is compact and suitably offset relative to the centroid of its host galaxy's optical light. This discovery demonstrates that spectral line mapping with the new generation of radio interferometers may provide important information on the cosmic merger history of galaxies.Comment: 11 pages, accepted for publication in MNRA

The discovery of a z = 0.7092 OH megamaser with the MIGHTEE survey

DATA AVAILABILITY : The MeerKAT visibility data for the MIGHTEE project are available from the SARAO archive under proposal IDs SCI-20180516-KH-01 and SCI-20180516-KH-02. A public release of the reduced image and catalogue products for the first MIGHTEE spectral line data release covering the COSMOS field is imminent (Heywood et al., in preparation).Please read abstract in the article.The Science and Technology Facilities Council (STFC); a United Kingdom Research and Innovation (UKRI) Frontiers Research Grant; the South African Radio Astronomy Observatory which is a facility of the National Research Foundation (NRF), an agency of the Department of Science and Innovation (DSI); the South African Research Chairs Initiative of the DSI/NRF; the National Science Foundation; the Radcliffe Institute for Advanced Study at Harvard University; the Instituto Nazionale Di Astrofisica (INAF); the Inter-University Institute for Data Intensive Astronomy (IDIA), a partnership of the University of Cape Town, the University of Pretoria, and the University of the Western Cape; the South African Department of Science and Innovation’s National Research Foundation.https://academic.oup.com/mnrashj2024PhysicsNon

The discovery of a z = 0.7092 OH megamaser with the MIGHTEE survey

We present the discovery of the most distant OH megamaser (OHM) to be observed in the main lines, using data from the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. At a newly measured redshift of z = 0.7092, the system has strong emission in both the 1665 MHz (L ≈ 2500 L⊙) and 1667 MHz (L ≈ 4.5 × 104 L⊙) transitions, with both narrow and broad components. We interpret the broad line as a high-velocity-dispersion component of the 1667 MHz transition, with velocity v ∼ 330 km s−1 with respect to the systemic velocity. The host galaxy has a stellar mass of M⋆ = 2.95 × 1010 M⊙ and a star formation rate of SFR = 371 M⊙ yr−1, placing it ∼1.5 dex above the main sequence for star-forming galaxies at this redshift, and can be classified as an ultraluminous infrared galaxy. Alongside the optical imaging data, which exhibit evidence for a tidal tail, this suggests that the OHM arises from a system that is currently undergoing a merger, which is stimulating star formation and providing the necessary conditions for pumping the OH molecule to saturation. The OHM is likely to be lensed, with a magnification factor of ∼2.5, and perhaps more if the maser emitting region is compact and suitably offset relative to the centroid of its host galaxy’s optical light. This discovery demonstrates that spectral line mapping with the new generation of radio interferometers may provide important information on the cosmic merger history of galaxies

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

MULP: A Multi-Layer Perceptron Application to Long-Term, Out-of-Sample Time Series Prediction

A forecasting approach based on Multi-Layer Perceptron (MLP) Artificial Neural Networks (named by the authors MULP) is proposed for the NN5 111 time series long-term, out of sample forecasting competition. This approach follows a direct prediction strategy and is completely automatic. It has been chosen after having been compared with other regression methods (as for example Support Vector Machines (SVMs)) and with a recursive approach to prediction. Good results have also been obtained using the ANNs forecaster together with a dimensional reduction of the input features space performed through a Principal Component Analysis (PCA) and a proper information theory based backward selection algorithm. Using this methodology we took the 10th place among the best 50% scorers in the final results table of the NN5 competitio

La cittadinanza in Italia, una mappa

Il volume registra le trasformazioni in corso in Italia nel modello di cittadinanza democratica ereditato dal '900, con riferimento al quinquennio 2105-2019, in vista di una valutazione degli "effetti di cittadinanza" della emergenza Covid-19

Oocyte competence is comparable between progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) and GnRH-antagonist protocols: A matched case-control study in PGT-A cycles

Objective: To outline oocyte competence after progestin primed ovarian stimulation with Norethisterone acetate (NETA-PPOS) compared to conventional GnRH-antagonist protocol. Study design: Retrospective matched case-control study involving advanced-maternal-age women undergoing ICSI with PGT-A. 89 NETA-PPOS were matched with 178 control patients based on maternal age and ovarian reserve biomarkers. Both groups underwent recombinant-FSH OS with GnRH-agonist ovulation trigger and collected ≥1 MII. In the study group, NETA (10 mg/day) was administered orally starting from day2 of the menstrual cycle. Euploid blastocyst rate per cohort of metaphase-II oocytes (EBR per MII) was the primary outcome. All other embryological and clinical outcomes were reported. Gestational age, birthweight and length were also assessed. Results: The EBR per MII was comparable among PPOS and control (13.9 % ± 19.3 % versus 13.3 % ± 17.9 %; the sample size allowed to exclude up to a 10 % difference). Blastocysts morphology and developmental rate were similar. No difference was reported for all clinical outcomes among the 61 and 107 vitrified-warmed euploid single blastocyst transfers respectively conducted. The cumulative live birth delivery rate per concluded cycles was also comparable (24.7 % versus 21.9 %). Neonatal outcomes were analogous. Conclusions: Oocyte competence after NETA-PPOS and standard OS is comparable. This evidence is reassuring and, because of its lower cost and possibly higher patients' compliance, supports PPOS administration whenever the patients are indicated to freeze-all (e.g., fertility preservation, PGT-A, oocyte donation). More data are required about follicle recruitment, oocyte yield, gestational and perinatal outcomes. Randomized-controlled-trials are advisable to confirm our evidence

The discovery of a z = 0.7092 OH megamaser with the MIGHTEE survey

We present the discovery of the most distant OH megamaser to be observed in the main lines, using data from the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. At a newly measured redshift of z = 0.7092, the system has strong emission in both the 1665 MHz (L ≈ 2500 L⊙) and 1667 MHz (L ≈ 4.5 × 104 L⊙) transitions, with both narrow and broad components. We interpret the broad line as a high-velocity-dispersion component of the 1667 MHz transition, with velocity v ∼ 330 km s−1 with respect to the systemic velocity. The host galaxy has a stellar mass of M⋆ = 2.95 × 1010 M⊙ and a star-formation rate of SFR = 371 M⊙ yr−1, placing it ∼1.5 dex above the main sequence for star-forming galaxies at this redshift, and can be classified as an ultra-luminous infrared galaxy. Alongside the optical imaging data, which exhibits evidence for a tidal tail, this suggests that the OH megamaser arises from a system that is currently undergoing a merger, which is stimulating star formation and providing the necessary conditions for pumping the OH molecule to saturation. The OHM is likely to be lensed, with a magnification factor of ∼2.5, and perhaps more if the maser emitting region is compact and suitably offset relative to the centroid of its host galaxy’s optical light. This discovery demonstrates that spectral line mapping with the new generation of radio interferometers may provide important information on the cosmic merger history of galaxies

The discovery of a z = 0.7092 OH megamaser with the MIGHTEE survey

We present the discovery of the most distant OH megamaser to be observed in the main lines, using data from the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. At a newly measured redshift of z = 0.7092, the system has strong emission in both the 1665 MHz (L ≈ 2500 L⊙) and 1667 MHz (L ≈ 4.5 × 104 L⊙) transitions, with both narrow and broad components. We interpret the broad line as a high-velocity-dispersion component of the 1667 MHz transition, with velocity v ∼ 330 km s−1 with respect to the systemic velocity. The host galaxy has a stellar mass of M⋆ = 2.95 × 1010 M⊙ and a star-formation rate of SFR = 371 M⊙ yr−1, placing it ∼1.5 dex above the main sequence for star-forming galaxies at this redshift, and can be classified as an ultra-luminous infrared galaxy. Alongside the optical imaging data, which exhibits evidence for a tidal tail, this suggests that the OH megamaser arises from a system that is currently undergoing a merger, which is stimulating star formation and providing the necessary conditions for pumping the OH molecule to saturation. The OHM is likely to be lensed, with a magnification factor of ∼2.5, and perhaps more if the maser emitting region is compact and suitably offset relative to the centroid of its host galaxy’s optical light. This discovery demonstrates that spectral line mapping with the new generation of radio interferometers may provide important information on the cosmic merger history of galaxies

The discovery of a z = 0.7092 OH megamaser with the MIGHTEE survey

We present the discovery of the most distant OH megamaser (OHM) to be observed in the main lines, using data from the MeerKAT International Giga-Hertz Tiered Extragalactic Exploration (MIGHTEE) survey. At a newly measured redshift of z = 0.7092, the system has strong emission in both the 1665 MHz (L ≈ 2500 L⊙) and 1667 MHz (L ≈ 4.5 × 104 L⊙) transitions, with both narrow and broad components. We interpret the broad line as a high-velocity-dispersion component of the 1667 MHz transition, with velocity v ∼ 330 km/s with respect to the systemic velocity. The host galaxy has a stellar mass of M⋆ = 2.95 × 10^10 M⊙ and a star formation rate of SFR = 371 M⊙/yr, placing it ∼1.5 dex above the main sequence for star-forming galaxies at this redshift, and can be classified as an ultraluminous infrared galaxy. Alongside the optical imaging data, which exhibit evidence for a tidal tail, this suggests that the OHM arises from a system that is currently undergoing a merger, which is stimulating star formation and providing the necessary conditions for pumping the OH molecule to saturation. The OHM is likely to be lensed, with a magnification factor of ∼2.5, and perhaps more if the maser emitting region is compact and suitably offset relative to the centroid of its host galaxy’s optical light. This discovery demonstrates that spectral line mapping with the new generation of radio interferometers may provide important information on the cosmic merger history of galaxies