Search Publications
The mass of our Milky Way
Ishigaki, Miho N.; Cautun, Marius; Wang, WenTing +2 more
We perform an extensive review of the numerous studies and methods used to determine the total mass of the Milky Way. We group the various studies into seven broad classes according to their modeling approaches. The classes include: i) estimating Galactic escape velocity using high velocity objects; ii) measuring the rotation curve through termina…
More than softer-when-brighter: The X-ray powerlaw spectral variability in NGC 4051
Cai, Zheng; Kang, Jia-Lai; Cai, Zhen-Yi +3 more
The powerlaw X-ray spectra of active galactic nuclei at moderate to high accretion rates normally appear softer when they brighten, for which the underlying mechanisms are yet unclear. Utilizing XMM-Newton observations and excluding photons < 2 keV to avoid contamination from the soft excess, in this work we scrutinize the powerlaw spectral var…