26,344 research outputs found
Kinematic properties of the dual AGN system J0038+4128 based on long-slit spectroscopy
The study of kiloparsec-scale dual active galactic nuclei (AGN) will provide
important clues to understand the co-evolution between the host galaxies and
their central supermassive black holes undergoing a merging process. We present
long-slit spectroscopy of the J00384128, a kiloparsec-scale dual AGN
candidate discovered by Huang et al. recently, using the Yunnan Faint Object
Spectrograph and Camera (YFOSC) mounted on Li-Jiang 2.4-m telescope at Yunnan
observatories. From the long-slit spectra, we find that the average relative
line-of-sight (LOS) velocity between the two nuclei (J00384128N and
J00384128S) is about 150 km s. The LOS velocities of the emission
lines from the gas ionized by the nuclei activities and of the absorption lines
from stars governed by the host galaxies for different regions of the
J00384128 exhibit the same trend. The same velocities trend indicates that
the gaseous disks are co-rotating with the stellar disks in this ongoing merge
system. We also find several knots/giant HII regions scattered around the two
nuclei with strong star formation revealed by the observed line ratios from the
spectra. Those regions are also detected clearly in HST -band and HST
-band images.Comment: 12 pages, 5 figures, 3 tables, Research in Astronomy and Astrophysics
accepte
Black hole solution and strong gravitational lensing in Eddington-inspired Born-Infeld gravity
A new theory of gravity called Eddington-inspired Born-Infeld (EiBI) gravity
was recently proposed by Ba\~{n}ados and Ferreira. This theory leads to some
exciting new features, such as free of cosmological singularities. In this
paper, we first obtain a charged EiBI black hole solution with a nonvanishing
cosmological constant when the electromagnetic field is included in. Then based
on it, we study the strong gravitational lensing by the asymptotic flat charged
EiBI black hole. The strong deflection limit coefficients and observables are
shown to closely depend on the additional coupling parameter in the
EiBI gravity. It is found that, compared with the corresponding charged black
hole in general relativity, the positive coupling parameter will
shrink the black hole horizon and photon sphere. Moreover, the coupling
parameter will decrease the angular position and relative magnitudes of the
relativistic images, while increase the angular separation, which may shine new
light on testing such gravity theory in near future by the astronomical
instruments.Comment: 14 pages, 7 figures, 1 table. Two issues on the deflection angle and
photon sphere were corrected and clarifie
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