MESIN PANAS FOTO-CARNOT LUBANG HITAM NON-STASIONER

Di dalam makalah ini disajikan suatu analisis teoritik dari desain mesin panas foto-Carnot dengan sumber energi berupa lubang hitam non-stasioner. Diharapkan dari kajian ini dapat diketahui potensi penggunaan lubang hitam sebagai sumber “bahan bakar” dari suatu mesin panas. Desain mesin panas berbasis lubang hitam dikembangkan karena melalui mekanika kuantum lubang hitam dapat mengemisikan partikel dan memiliki temperatur layaknya dalam proses radiasi benda hitam. Perhitungan temperatur lubang hitam non-stasioner yang meradiasikan foton dilakukan berdasarkan gambaran tunneling dengan menggunakan metode Hamilton-Jacobi. Sebagai hasilnya, lubang hitam non-stasioner memiliki temperatur yang juga bergantung terhadap laju perubahan massa. Desain mesin panas yang dikaji dalam makalah ini terdiri dari dua buah lubang hitam non-stasioner berbeda massa sehingga memiliki perbedaan tekanan radiasi yang dapat menggerakkan piston. Secara umum, efisiensi dari mesin foto-Carnot bergantung pada massa lubang hitam, laju perubahan massa, serta suatu fungsi penyeimbang dalam metrik Vaidya.Kata kunci: mesin foto-Carnot, termodinamika lubang hitam, non-stasioner. Non-Stationary Black Hole Photo-Carnot Heat Engine Abstract This paper presents a theoretical analysis of a photo-Carnot heat engine design with an energy source from a non-stationary black hole. This study may provide a clue about the potential use of black hole as a “fuel” of a heat engine. Heat engine design was developed because according to quantum mechanics a black hole may emit particles and it has temperature like in the black-body radiation. The calculation of non-stationary black hole temperature which radiate photons is based on the tunneling picture by using the Hamilton-Jacobi method. As a result, the temperature of non-stationary black hole also depends on the mass flow rate. The model of heat engine that studied in this work contains two non-stationary black holes with different masses that have different radiation pressure to move the piston. In general, the efficiency of photo-Carnot engine depend on the mass of the black hole, the mass flow rate, and the balance function in the Vaidya metric. Keywords: photo-Carnot engine, black hole thermodynamics, non-stationary.

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Coronal accretion: the power of X-ray emission in AGN

Proceedings of the International Astronomical Union ◽

10.1017/s1743921315007462 ◽

2014 ◽

Vol 10 (S312) ◽

pp. 52-55

Author(s):

B.-F. Liu ◽

R. E. Taam ◽

E. Qiao ◽

W. Yuan

Keyword(s):

Black Hole ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Gas Flow ◽

Thin Disk ◽

X Ray ◽

Hot Gas ◽

Hot Corona ◽

Gravitational Capture

AbstractThe optical/UV and X-ray emissions in luminous AGN are commonly believed to be produced in an accretion disk and an embedded hot corona respectively. We explore the possibility that a geometrically thick coronal gas flow, which is supplied by gravitational capture of interstellar medium or stellar wind, condenses partially to a geometrically thin cold disk and accretes via a thin disk and a corona onto the supermassive black hole. We found that for mass supply rates less than about 0.01 (expressed in Eddington units), condensation does not occur and the accretion flow takes the form of a corona/ADAF. For higher mass supply rates, corona gas condenses to the disk. As a consequence, the coronal mass flow rate decreases and the cool mass flow rate increases towards the black hole. Here the thin disk is characterized by the condensation rate of hot gas as it flows towards the black hole. With increase of mass supply rate, condensation becomes more efficient, while the mass flow rate of the coronal gas attains values of order 0.02 in the innermost regions of the disk, which can help to elucidate the production of strong X-ray with respect to the optical and ultraviolet radiation in high luminosity AGN.

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