p716
886-2-2789-6779
mwu [at] gate.sinica.edu.tw
p716
886-2-2789-6779
mwu [at] gate.sinica.edu.tw
Sam, Svetlana CY. / 886-2-2789-8386
(1) | 國內學術研究獎項 | 2019-10 | 108年國家理論科學研究中心物理組年輕理論學者獎 |
(1) | 西元年:2020 研究人員(中):吳孟儒、Projjwal Banerjee, Zhen Yuan 研究人員(英):MENG-RU, WU, Projjwal Banerjee, Zhen Yuan 研究成果名稱(中):雙中子星合併為銀河系主要的快中子過程元素來源 研究成果名稱(英):Neutron Star Mergers as the Main Source of R-process in Milky Way 簡要記述(中):雙中子星合併為目前最可能產生快中子補獲過程形成重元素的天文環境. 然而在太陽系附近觀測到的恆星表面豐度演化於近年來被用來指出可能需要有其他來源或者是需要非標準的雙中子星合併延遲分佈函數(delay-time distribution function). 在此工作內我們首次考慮雙中子星系統誕生時所獲得的系統速度(kick velocity)與銀河系的演化對豐度演化的影響. 我們發現若同時考慮這兩種效應, 可以解決前述需要有其他來源或者是需要非標準的雙中子星合併延遲分佈函數的問題. 簡要記述(英):Binary neutron star mergers (BNSMs) are currently the most promising source of r-process thanks to the detection of GW170817. However, the decreasing trend of [Eu/Fe] versus [Fe/H] of disk stars for [Fe/H] >~ -1 in the solar neighborhood is inconsistent with the flat trend expected from BNSMs with a standard delay time distribution (DTD) proportional to t^-1. This has led to the suggestion that either additional sources or modification to the DTD of BNSMs is required to match the observations. In this work, we show that when key inputs from simulations of the inside-out disk evolution are combined with natal kicks, BNSMs can naturally reproduce the observed decreasing trend of [Eu/Fe] with [Fe/H] in the solar neighborhood without the need for modification to the DTD or additional r-process sources.
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(2) | 西元年:2019 研究人員(中):吳孟儒、Jennifer Barnes, Gabriel Martinez-Pinedo, Brian D. Metzger 研究人員(英):MENG-RU, WU, Jennifer Barnes, Gabriel Martinez-Pinedo, Brian D. Metzger 研究成果名稱(中):千倍新星晚期觀測將能提供自然界中最重元素的合成證據 研究成果名稱(英):Late-time kilonova observations can shed light on the synthesis of nature's heaviest nuclei 簡要記述(中):中央研究院物理研究所助研究員吳孟儒與合作者在一項理論研究中指出,透過對於雙中子星合併產生的電磁輻射 – 千倍新星 – 在合併後數個月的精精準量測,科學家將有機會能夠找到自然界中最重的元素如何形成的證據。 此研究成果發表於2019年2月的《物理評論快報》期刊。 簡要記述(英):In a theoretical research work led by Dr. Meng-Ru Wu in the Institute of Physics, he and his collaborators show that a precise measurement of light emitted from the merger of two neutron stars – the kilonova – at months after the merger, can provide the elusive definitive proof of how the nature's heaviest nuclei are made in our universe. The work has been published in Physical Review Letters in February, 2019.
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(3) | 西元年:2018 研究人員(中):吳孟儒、Tobias Fischer, Niels-Uwe F. Bastian, Petr Baklanov, Elena Sorokina, Sergei Blinnikov, Stefan Typel, Thomas Klaehn, David Blaschke 研究人員(英):MENG-RU, WU, Tobias Fischer, Niels-Uwe F. Bastian, Petr Baklanov, Elena Sorokina, Sergei Blinnikov, Stefan Typel, Thomas Klaehn, David Blaschke 研究成果名稱(中):強子夸克相變引發之超新星爆炸 研究成果名稱(英):Supernova explosion triggered by quark-hadron phase transition 簡要記述(中):在一項與多國多位研究人員共同進行的理論研究中指出, 在超越原子核內部物質密度狀態下, 可能發生的強子態轉換至夸克態的一階相變, 可以解釋天文上觀測到, 尚未解決的兩個問題 - 極大質量恆星的超新星爆炸及極重中子星的生成(詳見英文記述). 簡要記述(英):In a research work done together with physicists and astrophysicists from Germany, Poland, Russia, we show that a possible first-order transition from the hadronic state to the quark state at super-nuclear saturation density can help explain two astronomical puzzles:(1) How do very massive stars die as supernovae? (2) How were heavy neutron stars born in nature? In the typical theory of core-collapse supernova, the explosion is triggered by the so-called “neutrino-driven” mechanism, within which the neutrinos are responsible for transferring the energy from the central remnant to the stalled shock in order to explode the entire star. However, over the past decades, researchers found that for very massive stars that weight about 50 solar mass, such an energy transfer mechanism is not powerful enough to deliver a successful explosion. Nevertheless, supernova explosions associated with these massive stars were in fact seen by telescope observations, which still puzzles astrophysicists. In this novel work, it was found that, deeply inside the proto-neutron star formed during the gravitational core-collapse, if a first-order phase transition from the hadronic phase to the quark phase occurs at a density that is about 2 times larger than the nuclear saturation density, a second collapse can happen within the proto-neutron star and generates a powerful shock that is strong enough to explode the whole star as heavy as 50 solar mass initially. Moreover, the remnant left behind from such an explosion will be a “neutron star” with a quark core that weights about 2 times of the solar mass. This naturally provides a formation mechanism for the observed heaviest neutron star in the Universe. Such strong explosions can also yield very bright transients on the sky, with the brightness ranging between the normal supernovae and the super-luminous supernovae, thereby offering a potential connection between massive stars and super-luminous supernovae. In addition, this work predicts that if such an explosion happens in our Milky Way galaxy, the existing and future multi-kiloton neutrino detectors will be able to record a unique “milli-second” neutrino burst to confirm this scenario.
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