اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدDetecting Low-Mass Supermassive Black Holes
286
0
0.0
(
0
)
تأليف
Himel Ghosh
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We demonstrate the feasibility of uncovering supermassive black holes in late-type, quiescent spiral galaxies by detecting signs of very low-level nuclear activity. We use a combination of x-ray selection and multi-wavelength follow-up. Here, we apply this technique to NGC 3184 and NGC 5457, both of type Scd, and show that strong arguments can be made that both host AGNs.
قيم البحث
اقرأ أيضاً
The nature of dark matter is still an open problem. The simplest assumption is that gravity is the only force coupled certainly to dark matter and thus the micro black holes could be a viable candidate. We investigated the possibility of direct detec
tion of micro black holes with masses around and upward the Planck scale (10$^{-5}$ g), ensuring classical gravitational treatment of these objects in the next generation of huge LAr detectors. We show that the signals (ionization and scintillation) produced in LAr enable the discrimination between micro black holes or other particles. It is expected that the trajectories of these micro black holes will appear as crossing the whole active medium, in any direction, producing uniform ionization and scintillation on all the path.
The spin modulated gravitational wave signals, which we shall call smirches, emitted by stellar mass black holes tumbling and inspiralling into massive black holes have extremely complicated shapes. Tracking these signals with the aid of pattern matc
hing techniques, such as Wiener filtering, is likely to be computationally an impossible exercise. In this article we propose using a mixture of optimal and non-optimal methods to create a search hierarchy to ease the computational burden. Furthermore, by employing the method of principal components (also known as singular value decomposition) we explicitly demonstrate that the effective dimensionality of the search parameter space of smirches is likely to be just three or four, much smaller than what has hitherto been thought to be about nine or ten. This result, based on a limited study of the parameter space, should be confirmed by a more exhaustive study over the parameter space as well as Monte-Carlo simulations to test the predictions made in this paper.
Supermassive black holes have generally been recognized as the most destructive force in nature. But in recent years, they have undergone a dramatic shift in paradigm. These objects may have been critical to the formation of structure in the early un
iverse, spawning bursts of star formation and nucleating proto-galactic condensations. Possibly half of all the radiation produced after the Big Bang may be attributed to them, whose number is now known to exceed 300 million. The most accessible among them is situated at the Center of Our Galaxy. In the following pages, we will examine the evidence that has brought us to this point, and we will understand why many expect to actually image the event horizon of the Galaxys central black hole within this decade.
The origin of spin of low-mass supermassive black hole (SMBH) is still a puzzle at present. We here report a study on the host galaxies of a sample of radio-selected nearby ($z<0.05$) Seyfert 2 galaxies with a BH mass of $10^{6-7} M_odot$. By modelin
g the SDSS $r$-band images of these galaxies through a 2-dimensional bulge+disk decomposition, we identify a new dependence of SMBHs radio power on host bulge surface brightness profile, in which more powerful radio emission comes from a SMBH associated with a more disk-like bulge. This result means low-mass and high-mass SMBHs are spun up by two entirely different modes that correspond to two different evolutionary paths. A low-mass SMBH is spun up by a gas accretion with significant disk-like rotational dynamics of the host galaxy in the secular evolution, while a high-mass one by a BH-BH merger in the merger evolution.
The ngVLA will facilitate deep surveys capable of detecting the faint and compact signatures of accreting supermassive black holes (SMBHs) with masses below one million solar-masses hosted by low-mass ($< 10^9$ solar-masses) galaxies. This will provi
de important new insights on both the origins of supermassive black holes and the possible impact of active galactic nucleus-driven feedback in a currently unexplored mass regime.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
