178 research outputs found
Multiwavelength observations of nova SMCN 2016-10a — one of the brightest novae ever observed
We report on multiwavelength observations of nova SMCN 2016-10a. The present observational set is one of the most comprehensive for any nova in the Small Magellanic Cloud, including: low, medium, and high resolution optical spectroscopy and spectropolarimetry from SALT, FLOYDS, and SOAR; long-term OGLE V- and I- bands photometry dating back to six years before eruption; SMARTS optical and near-IR photometry from ∼ 11 days until over 280 days post-eruption; Swift satellite X-ray and ultraviolet observations from ∼ 6 days until 319 days post-eruption. The progenitor system contains a bright disk and a main sequence or a sub-giant secondary. The nova is very fast with t2 ≃ 4.0 ± 1.0 d and t3 ≃ 7.8 ± 2.0 d in the V-band. If the nova is in the SMC, at a distance of ∼ 61 ± 10 kpc, we derive MV, max ≃ −10.5 ± 0.5, making it the brightest nova ever discovered in the SMC and one of the brightest on record. At day 5 post-eruption the spectral lines show a He/N spectroscopic class and a FWHM of ∼ 3500 km s−1 indicating moderately high ejection velocities. The nova entered the nebular phase ∼ 20 days post-eruption, predicting the imminent super-soft source turn-on in the X-rays, which started ∼ 28 days post-eruption. The super-soft source properties indicate a white dwarf mass between 1.2 M⊙ and 1.3 M⊙ in good agreement with the optical conclusions
Mixed g-monotone property and quadruple fixed point theorems in partially ordered metric spaces
Effect of Intensified Training Camp on Psychometric Status, Mood State, and Hematological Markers in Youth Soccer Players
During training camps, training load is purposefully intensified. Intensified training loads (TL) are associated with psychological variations, increased fatigue, insufficient recovery, decreased muscular performance, and biological changes in adult athletes, but whether these changes occur during training camps in youth athletes has not been established. The aim of this study was to assess changes in psychometric status, vertical jump performance (i.e., height), and hematological markers before and after an intensive training camp in youth soccer players. In this case, 15male youth soccer players (mean ± SD: age: 14.8 ± 0.4 years; height: 172.0 ± 6.9 cm, body mass: 60.8 ± 7.9 kg; training experience: 5.2 ± 0.7 years) completed a 2-week training program consisting of 1 week of moderate TL (MT) and 1 week of intensive training camp (TC). Rate of perceived exertion (RPE), TL, monotony, strain, and psychometric status (total quality of recovery (TQR) and well-being indices (sleep, stress, fatigue, and muscle soreness) were monitored before each first daily training session across two weeks. The profile of mood states (POMS), countermovement jump (CMJ) height, and blood markers (complete blood count, urea, and creatinine) were assessed before and after TC. TL (d = 5.39, large), monotony (d = 3.03, large), strain (d = 4.38, large), and well-being index (d = 7.5, large) scores increased and TQR (d = 4.6, large) decreased during TC. The TC increased tension, fatigue, and total mood disturbance and decreased vigor (all p <0.01). CMJ performance p < 0.01, d = 0.52, moderate), creatinine (p < 0.01, d = 1.29, large), and leukocyte concentration (p < 0.01, d = 1.4, large) and granulocyte concentration (p < 0.01, d = 1.93, large) increased after TC. Percentage of lymphocytes (p < 0.05, d = 1.17, large) and monocytes (p < 0.01, d = 1.05, large) decreased while the percentage of granulocytes (p < 0.05, d = 0.86, large) increased significantly. Well-being, quality of recovery, mood, granulocyte concentration, and creatinine were all altered during the week-long intensified training camp. These results may provide coaches with valuable information about psychometric status and physiological fatigue and recovery of youth soccer players to better prescribe and adjust training loads during intensive training periods
Detection of 7Be II in the Small Magellanic Cloud
We analyse high-resolution spectra of two classical novae that exploded in the Small Magellanic Cloud (SMC). 7 Be II resonance transitions are detected in both ASASSN-19qv and ASASSN-20ni novae. This is the first detection outside the Galaxy and confirms that thermo-nuclear runaway reactions, leading to the 7 Be formation, are ef fecti ve also in the low-metallicity regime, characteristic of the SMC. Derived yields are of N( 7 Be = 7 Li)/N(H) = (5.3 ±0.2) ×10 −6 which are a factor 4 lower than the typical values of the Galaxy. Inspection of two historical novae in the Large Magellanic Cloud observed with IUE in 1991 and 1992 showed also the possible presence of 7 Be and similar yields. For an ejecta of M H , ej = 10 −5 M ⊙, the amount of 7 Li produced is of M 7 Li = (3 . 7 ±0 . 6) ×10 −10 M ⊙per nova event. Detailed chemical evolutionary model for the SMC shows that no vae could hav e made an amount of lithium in the SMC corresponding to a fractional abundance of A(Li) ≈2.6. Therefore, it is argued that a comparison with the abundance of Li in the SMC, as measured by its interstellar medium, could ef fecti vely constrain the amount of the initial abundance of primordial Li, which is currently contro v ersial
7Be detection in the 2021 outburst of RS Oph
The recurrent nova RS Oph underwent a new outburst on August 8, 2021,
reaching a visible brightness of V = 4.8 mag. Observations of the 2021 outburst
made with the high resolution UVES spectrograph at the Kueyen-UT2 telescope of
ESO-VLT in Paranal enabled detection of the possible presence of 7Be freshly
made in the thermonuclear runaway reactions. The 7Be yields can be estimated in
N(Be)/N(H) = 5.7 x 10^(-6), which are close to the lowest yields measured in
classical novae so far. 7Be is short-lived and decays only into 7Li. By means
of a spectrum taken during the nebular phase we estimated an ejected mass of
about 1.1 x 10^(-5) Msun, providing an amount of about 4.4x 10^(-10) Msun of
7Li created in the 2021 event. Recurrent novae of the kind of RS Oph may
synthesize slightly lower amount of 7Li per event as classical novae, but occur
10^3 times more frequently. The recurrent novae fraction is in the range of
10-30% and they could have contributed to the making of 7Li we observe today.
The detection of 7Be in RS Oph provides further support to the recent
suggestion that novae are the most effective source of 7Li in the Galaxy.Comment: Accepted 2022 September 17. Received 2022 September 16; in original
form 2022 April 20. 12 pages, 13 figure
7Be in the outburst of the ONe nova V6595 Sgr
We report on the search for the 7Be ii isotope in the outbursts of the classical nova V6595 Sgr by means of high-resolution Ultraviolet and Visual Echelle Spectrograph (UVES) observations taken at the European Southern Observatory's Very Large Telescope in 2021 April, about two weeks after its discovery and under difficult circumstances due to the pandemic. Narrow absorption components with velocities at -2620 and-2820 km s-1, superposed on broader and shallow absorption, are observed in the outburst spectra for the 7Be ii λλ313.0583, 313.1228 nm doublet resonance lines, as well as in several other elements such as Ca ii, Fe i, Mg i, Na i, H i and Li i. Using the Ca ii K line as a reference element, we infer N(7Be)/N(H) ≈ 7.4 × 10-6, or ≈ 9.8 × 10-6 when the 7Be decay is taken into account. The 7Be abundance is about half of the value most frequently measured in novae. The possible presence of overionization in the layers where 7Be ii is detected is also discussed. Observations taken at the Telescopio Nazionale Galileo in La Palma 91 days after discovery showed prominent emission lines of oxygen and neon, which allow us to classify the nova as ONe type. Therefore, although 7Be is expected to be higher in CO novae, it is found at comparable levels in both nova types
Some new fixed point theorems for the Meir-Keeler contractions on partial Hausdorff metric spaces
Detection of 7Be ii in the Small Magellanic Cloud
We analyse high-resolution spectra of two classical novae that exploded in the Small Magellanic Cloud (SMC). 7 Be II resonance transitions are detected in both ASASSN-19qv and ASASSN-20ni novae. This is the first detection outside the Galaxy and confirms that thermo-nuclear runaway reactions, leading to the 7 Be formation, are ef fecti ve also in the low-metallicity regime, characteristic of the SMC. Derived yields are of N( 7 Be = 7 Li)/N(H) = (5.3 ±0.2) ×10 −6 which are a factor 4 lower than the typical values of the Galaxy. Inspection of two historical novae in the Large Magellanic Cloud observed with IUE in 1991 and 1992 showed also the possible presence of 7 Be and similar yields. For an ejecta of M H , ej = 10 −5 M ⊙, the amount of 7 Li produced is of M 7 Li = (3 . 7 ±0 . 6) ×10 −10 M ⊙per nova event. Detailed chemical evolutionary model for the SMC shows that no vae could hav e made an amount of lithium in the SMC corresponding to a fractional abundance of A(Li) ≈2.6. Therefore, it is argued that a comparison with the abundance of Li in the SMC, as measured by its interstellar medium, could ef fecti vely constrain the amount of the initial abundance of primordial Li, which is currently contro v ersial.LI was supported by grants from VILLUM FONDEN (project number 16599 and 25501). AA is supported by a Villum Experiment Grant (project number 36225). This work was partially supported by the European Union (ChETEC-INFRA, project no. 101008324 and ChETEC, CA16117). EA acknowledges NSF award AST-1751874, NASA award 11-Fermi 80NSSC18K1746, NASA award 16-Swift 80NSSC21K0173, and a Cottrell fellowship of the Research Corporation. M.H. acknowledges support from grant PID2019-108709GB-I00 from MICINN (Spain)
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