Medical laryngoscope has been widely used in medical diagnosis, but traditional laryngoscope still has many deficiencies, especially in the ability of data storage and processing. Therefore, in this ...paper, the Wireless HD Laryngoscope System combines the Hadoop cloud platform. The images and video information collected by laryngoscope can real-time transmission to the remote client through streaming server and be saved in Hadoop cloud platform. In consequence, the client can replay history video at any time and any place.
The particle acceleration of blazar jets is crucial to high-energy astrophysics, yet the acceleration mechanism division in blazar subclasses and the underlying nature of these mechanisms remain ...elusive. In this work, we utilized the synchrotron spectral information (synchrotron peak frequency, \(\log \nu_{\rm sy}\), and corresponding curvature, \(b_{\rm sy}\)) of 2705 blazars from the literature and studied the subject of particle acceleration in blazar jets by analysing the correlation between \(\log \nu_{\rm sy}\) and \(1/b_{\rm sy}\). Our results suggested that the entire sample follows an energy-dependent probability acceleration (EDPA). Specifically, the low inverse Compton peak sources (LCPs) follow the mechanism that fluctuations of fractional gain acceleration (FFGA), while the high inverse Compton peak sources (HCPs) follow an acceleration mechanism of EDPA. Our results indicated that the separation between LCPs and HCPs results from the electron peak Lorentz factor (\(\gamma_{\rm p}\)), and the differentiation should originate from different acceleration mechanisms. Moreover, our study revealed a transition in the acceleration mechanism from FFGA to EDPA around \(\log \nu_{\rm sy} \sim 15\) through a detailed analysis of binned-\(\log \nu_{\rm sy}\). The mechanism of FFGA dominates the particle acceleration in LCP jets because of stronger jets and the EDPA dominates the particle energy gain in the HCPs due to a more efficient acceleration process.
Aiming to delineate the physical framework of blazars, we present an effective method to estimate four important parameters based on the idea proposed by \citet{BK95}, including the upper limit of ...central black hole mass \(M\), the Doppler factor \(\delta\), the distance along the axis to the site of the \(\gamma\)-ray production \(d\) (which then can be transformed into the location of \(\gamma\)-ray-emitting region \(R_{\gamma}\)) and the propagation angle with respect to the axis of the accretion disk \(\Phi\). To do so, we adopt an identical sample with 809 {\it Fermi}-LAT-detected blazars which had been compiled in \citet{Pei20PASA}. These four derived parameters stepping onto the stage may shed new light on our knowledge regarding \(\gamma\)-ray blazars. With regard to the paper of \citet{BK95}, we obtain several new perspectives, mainly in: (1) putting forward an updated demarcation between BL Lacs and FSRQs based on the relation between broad-line region luminosity and disk luminosity both measured in Eddington units, i.e., \(L_{\rm disk}/L_{\rm Edd}=4.68\times10^{-3}\), indicating that there are some differences between BL Lacs and FSRQs on the accretion power in the disk; (2) proposing that there is a so-called `appareling zone', a potential transition field between BL Lacs and FSRQs where the changing-look blazars perhaps reside; (3) the location of \(\gamma\)-ray emission region is principally constrained outside the broad-line region, and for some BL Lacs are also away from the dusty molecular torus, which means the importance of emission components in the jet.
The studies and constraints on the emission region are crucial to the blazar radiation mechanism. Yet the previous works mainly focus on individual sources. In this work, we make use of the largest ...and the latest spectral energy distribution (SED) fitting results in the literature to statistically study the blazar emission region property in the framework of leptonic one-zone. Our results reveal (1) FSRQs show lower electron energy (\(\gamma_{\rm p} \lesssim 1.6 \times 10^{3}\)) than BL Lacs and tend to have a stronger magnetic field (\(B\)) and smaller electron-to-magnetic energy ratio (\(U_{\rm e}/U_{\rm B}\)) than BL Lacs; (2) we find the electro-magnetic equipartition would rather happen in the jets of BL Lacs than happen in the jets of FSRQs; (3) there are 682 blazars with a magnetic field weaker critical value of generating the Kelvin-Helmholtz instability, thus one-third of the blazars in our sample are able to produce this instability; (4) the distance (\(d_{\rm em}\)) between the emission region and the central black hole (BH) is in the scale of \(\sim\)0.1 pc, the location of the emission region may be evenly distributed inside and outside the broad line region (BLR).
A two-component model of radio emission has been used to explain some radio
observational properties of Active Galactic Nuclei (AGNs) and, in particular,
of blazars. In this work, we extend the ...two-component idea to the $\gamma$-ray
emission and assume that the total $\gamma$-ray output of blazars consists of
relativistically beamed and unbeamed components. The basic idea leverages the
correlation between the radio core-dominance parameter and the $\gamma$-ray
beaming factor. To do so, we evaluate this correlation for a large sample of
584 blazars taken from the fourth source catalog of the Fermi Large Area
Telescope (Fermi-LAT) and correlated their $\gamma$-ray core-dominance
parameters with radio core-dominance parameters. The $\gamma$-ray beaming
factor is then used to estimate the beamed and unbeamed components. Our
analysis confirms that the $\gamma$-ray emission in blazars is mainly from the
beamed component.
Blazars are a subclass of active galactic nuclei (AGNs) with extreme
observation properties, which is caused by the beaming effect, expressed by a
Doppler factor, in a relativistic jet. Doppler ...factor is an important parameter
in the blazars paradigm to indicate all of the observation properties, and many
methods were proposed to estimate its value. In this paper, we present a method
following Mattox et al. to calculate the lower limit on gamma-ray Doppler
factor for 809 selected Fermi/LAT-detected gamma-ray blazars by adopting the
available gamma-ray and X-ray data. Our sample included 342 flat-spectrum radio
quasars (FSRQs) and 467 BL Lac objects (BL Lacs), out of which 507 sources are
compiled with available radio core-dominance parameter (R) from our previous
study. Our calculation shows that the average values of the lower limit on
gamma-ray Doppler factor for FSRQs and BL Lacs are 6.87 and 4.31, respectively.
We compare and discuss our results with those from the literature. We found
that the derived lower limit on gamma-ray Doppler factor for some sources are
higher than that from the radio estimation, which could be possibly explained
by the jet bending within those blazars. Our results also suggest that the
gamma-ray and radio regions perhaps share the same relativistic effects. The
gamma-ray Doppler factor has been found to be correlated with both the
gamma-ray luminosity and core-dominance parameter, implying that the jet is
possibly continuous in the gamma-ray bands, and R is perhaps an indicator for a
beaming effect.
A two-component model of radio emission has been used to explain some radio observational properties of Active Galactic Nuclei (AGNs) and, in particular, of blazars. In this work, we extend the ...two-component idea to the \(\gamma\)-ray emission and assume that the total \(\gamma\)-ray output of blazars consists of relativistically beamed and unbeamed components. The basic idea leverages the correlation between the radio core-dominance parameter and the \(\gamma\)-ray beaming factor. To do so, we evaluate this correlation for a large sample of 584 blazars taken from the fourth source catalog of the Fermi Large Area Telescope (Fermi-LAT) and correlated their \(\gamma\)-ray core-dominance parameters with radio core-dominance parameters. The \(\gamma\)-ray beaming factor is then used to estimate the beamed and unbeamed components. Our analysis confirms that the \(\gamma\)-ray emission in blazars is mainly from the beamed component.
Blazars are a subclass of active galactic nuclei (AGNs) with extreme observation properties, which is caused by the beaming effect, expressed by a Doppler factor, in a relativistic jet. Doppler ...factor is an important parameter in the blazars paradigm to indicate all of the observation properties, and many methods were proposed to estimate its value. In this paper, we present a method following Mattox et al. to calculate the lower limit on gamma-ray Doppler factor for 809 selected Fermi/LAT-detected gamma-ray blazars by adopting the available gamma-ray and X-ray data. Our sample included 342 flat-spectrum radio quasars (FSRQs) and 467 BL Lac objects (BL Lacs), out of which 507 sources are compiled with available radio core-dominance parameter (R) from our previous study. Our calculation shows that the average values of the lower limit on gamma-ray Doppler factor for FSRQs and BL Lacs are 6.87 and 4.31, respectively. We compare and discuss our results with those from the literature. We found that the derived lower limit on gamma-ray Doppler factor for some sources are higher than that from the radio estimation, which could be possibly explained by the jet bending within those blazars. Our results also suggest that the gamma-ray and radio regions perhaps share the same relativistic effects. The gamma-ray Doppler factor has been found to be correlated with both the gamma-ray luminosity and core-dominance parameter, implying that the jet is possibly continuous in the gamma-ray bands, and R is perhaps an indicator for a beaming effect.
Active galactic nuclei (AGNs) have been attracting research attention due to
their special observable properties. Specifically, a majority of AGNs are
detected by Fermi-LAT missions, but not by ...Fermi-LAT, which raises the question
of whether any differences exist between the two. To answer this issue, we
compile a sample of 291 superluminal AGNs (189 FDSs and 102 non-FDSs) from
available multi-wavelength radio, optical, and X-ray (or even $\gamma$-ray)
data and Doppler factors and proper motion ($\mu$) (or apparent velocity
($\beta_{\rm{app}}$)); calculated the apparent velocity from their proper
motion, Lorentz factor ($\Gamma$), viewing angle ($\phi$) and co-moving viewing
angle ($\phi_{co}$) for the sources with available Doppler factor ($\delta$);
and performed some statistical analyses for both types. Our study indicated
that1. In terms of average values, FDSs have higher proper motions ($\mu$),
apparent velocities ($\beta_{\rm app}$), Doppler factor ($\delta$), Lorentz
factor ($\Gamma$), and smaller viewing angle ($\phi$). Nevertheless, there is
no clear difference in co-moving viewing angles ($\phi_{\rm co}$).
