Gökada Merkezlerindeki Maser Disklerin Denge Eğrilik Profillerinin Belirlenmesi

Year 2022, , 551 - 558, 25.11.2022

Ayşe Ulubay

https://doi.org/10.29233/sdufeffd.1167825

Abstract

Gökada merkezlerindeki süper kütleli kara delikleri çevreleyen maser diskler, merkezlerindeki kara deliğin kütlesinin belirlenmesi ve kütle aktarım süreçlerinin incelenmesi gibi güncel astrofizik problemleri hakkında faydalı bilgiler sunar. Gözlemler, bu disklerin çoğu durumda düzlemsel olmayıp, eğrilik sergilediğine işaret etmektedir. Bu çalışmada, kütleleri ile iç ve dış yarıçapları gözlemlerden belirlenen, NGC 2960, NGC 5765b, NGC 6323, UGC 3789 ve NGC 6264 gökadalarının merkezlerindeki eğri maser disklerin, tüm yarıçapları boyunca tek bir frekansta presesyon hareketi yapacakları denge durumları araştırılmıştır. Yapılan sayısal hesaplamalarda diskler, iç içe geçmiş, dairesel ve birbirlerine eğimli halkalar olarak modellenmiş ve disklerin öz-çekimleri göz önüne alınmıştır. Her bir maser disk için belli bir presesyon frekansına karşılık gelen denge eğrilik profilleri elde edilmiştir. Denge profilinin elde edildiği presesyon frekansı için, NGC 5765b maser diskinin toplam eğriliğin yaklaşık 17°, diğer maser disklerin eğriliklerinin ise 10°’den küçük olduğu bulunmuştur.

Keywords

Gökada merkezleri, Kütle aktarım diskleri, Eğri diskler, Yöntemler: sayısal

Determination of Equilibrium Warp Profiles of Maser Discs in Galactic Nuclei

Abstract

Maser discs surrounding supermassive black holes in galactic nuclei provide useful information on astrophysical problems such as determining the masses of their central black holes and investigating the accretion processes. Observations indicate that these discs are often not planar, and exhibit warping. We investigated the warped equilibria, where the discs precess with a single frequency throughout their radial ranges, for the maser discs in the galaxies NGC 2960, NGC 5765b, NGC 6323, UGC 3789 and NGC 6264, whose masses, and inner and outer radii are given by the observations. In our numerical calculations the discs are modelled as concentric, circular and mutually tilted rings, and the self-gravity of the discs is taken into account. Warped equilibria corresponding to certain precession frequencies for each maser disc are obtained. It is found that for the precession frequency for which the equilibrium is obtained, the total warp in the maser disc of NGC 5765b is about 17° while the warps in the other maser discs are less than 10°.

Keywords

Galactic nuclei, Accretion discs, Warped discs, Methods: numerical

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