Jet Power of Jetted Active Galactic Nuclei: Implication for Evolution and Unification

We construct samples of jetted active galactic nuclei (AGNs) with low-frequency radio data from the recent released TGSS AD1 catalog at 150 MHz. With these samples, we compare the properties of jet power for blazars, radio-loud narrow-line Seyfert 1 galaxies (RL-NLS1s), young radio sources (YRSs) and radio galaxies. The jet-disk connection, and the unification of jetted AGNs are explored. On the Eddington ratio --- Eddington-scaled jet power plane, jetted AGNs can be generally divided into two populations. Low power radio galaxies, low excitation FR IIs (LEG/FR IIs), and most YRSs show larger jet power than accretion power, while FSRQs, RL-NLS1s, and high excitation FR IIs (HEG/FR IIs) are on the contrary. LEG/FR IIs share similar jet power properties with HEG/FR IIs, while their accretion properties are different with the latter. These facts suggest an evolutional sequence from HEG/FR IIs, LEG/FR IIs to FR Is, where the accretion and jet activities get dimmed gradually. LEG/FR IIs are the transitional objects that accretion processes have switched off, while jets are still active. After correcting the contribution from radio core of blazars, the unification between blazars and radio galaxies is confirmed with the jet power distributions. The unification involved RL-NLS1s is more complicated than the simple scenarios of black hole growth or orientation effect. In addition, our results manifest that low synchrotron peaked BL Lacs (LBLs) contain two distinct groups on the distribution of jet power, with one group similar with FSRQs and the other similar with intermediate synchrotron peaked BL Lacs. The LBLs with higher jet powers might be the aligned counterparts of LEG/FR IIs.Comment: 16 pages, 11 figures, 1 table, accepted by Ap

The Radio/Gamma Connection of Blazars from High to Low Radio Frequencies

We construct a large sample of gamma-ray blazars with low-frequency radio data using the recent released TGSS AD1 catalog at 150 MHz. The radio/gamma connections of blazars are compared from 143 GHz to 150 MHz. The radio flux density at all radio frequencies shows strong correlation with gamma-ray flux for blazars, as well as for the two subclasses, FSRQs and BL Lacs. But the correlations get worse from high to low radio frequencies, which indicates that the low-frequency radio emission is the mixture of extended and core components for blazars. In addition, we find that the correlation between 150 MHz radio flux density and gamma-ray flux is more significant for BL Lacs than that for FSRQs. The slope for the luminosity correlation between radio and gamma-ray also get flatter than unity at 150 MHz. These results indicate that the core dominance at 150 MHz for BL Lacs is larger than that for FSRQs. We also compare the radio luminosity from direct TGSS observation and the extended radiation at 150 MHz for blazars. The results show that the ratio between core and extended component at 150 MHz is about 1:1 on average.Comment: 10 pages, 6 figures, 2 tables, accepted by Ap

What determines the observational differences of blazars?

We examine the scenario that the Doppler factor determines the observational differences of blazars in this paper. Significantly negative correlations are found between the observational synchrotron peak frequency and the Doppler factor. After correcting the Doppler boosting, the intrinsic peak frequency further has a tightly linear relation with the Doppler factor. It is more interesting that this relation is consistent with the scenario that the black hole mass governs both the bulk Lorentz factor and the synchrotron peak frequency. In addition, the distinction of the kinetic jet powers between BL Lacs and FSRQs disappears after the boosting factor $\delta^2$ is considered. The negative correlation between the peak frequency and the observational isotropic luminosity, known as the blazar sequence, also disappears after the Doppler boosting is corrected. We also find that the correlation between the Compton dominance and the Doppler factor exists for all types of blazars. Therefore, this correlation is unsuitable to examine the external Compton emission dominance.Comment: 15 pages, 6 figures, 1 tabl

Revisit the fraction of radio-loud narrow line Seyfert 1 galaxies with LoTSS DR1

Radio-Loud narrow-line Seyfert 1 galaxies (NLS1s), especially the extremely radio-loud ones, are widely accepted as the jetted versions of NLS1s. We explore the radio-loud fraction for NLS1s with recently released LoTSS DR1 at 150 MHz. The radio detection rate is about 28\% for LoTSS DR1. The radio detected NLS1s have lower redshift than the non-detected ones. Moreover, the 150 MHz radio luminosity of NLS1s detected by LoTSS are about two orders of magnitude weaker than that of the previous samples. By defining the radio loudness with the ratio between 150 MHz radio flux and SDSS \textit{r} band flux, the radio-loud fraction is about 1\% with the critical radio loudness equalling to 100. Radio loudness shows no dependence on central black hole mass, while weak correlations are found between radio loudness and disk luminosity, as well as Eddington ratio.Comment: 12 pages, 6 figures, accepted by Universe for the Special Issue "Seyfert Galaxies Astrophysics

Discovery of γ\gamma-ray emission from the radio-intermediate quasar III Zw 2: violent jet activity with intraday γ\gamma-ray variability

III Zw 2 is the prototype of radio-intermediate quasars. Although there is the evidence of possessing strong jet, significant $\gamma$-ray emission has not been reported before. In this work, we carry out a detailed analysis of the latest {\it Fermi}-LAT {\it Pass} 8 data. No significant $\gamma$-ray signal has been detected in the time-averaged 7-year {\it Fermi}-LAT data of III Zw 2, we however have identified two distinct $\gamma$-ray flares with isotropic luminosities of $\sim 10^{45}$ erg $\rm s^{-1}$. Multiwavelength data analysis (including also the optical photometric observations from Yunnan Observatories) are presented and the main finding is the simultaneous optical and $\gamma$-ray flares of III Zw 2 appearing in Nov. 2009. Violent $\gamma$-ray variability with doubling timescale of 2.5 hours was detected in another $\gamma$-ray flare in May 2010, for which the 3-hour $\gamma$-ray peak flux is $\sim 250$ times of the average flux in 7 years. Rather similar behaviors are observed in blazars and the blazar model can reasonably reproduce the spectral energy distribution of III Zw 2 in a wide energy range, strongly suggesting that its central engine resembles that of blazars. In view of its core which shares radio similarities with young radio sources together with the weak extended radio lobe emission, we suggest that III Zw 2 harbors a recurrent activity core and serves as a valuable target for investigating the fuelling and triggering of the activity in radio loud AGNs.Comment: ApJS in press, welcome any comment

Bouncing behavior and dissipative characterization of a chain-filled granular damper

We have experimentally investigated the bouncing behavior and damping performance of a container partially filled with granular chains, namely a chain-filled damper. The motion of the chain-filled damper, recorded by a particle tracing technology, demonstrates that the granular chains can efficiently absorb the collisional energy of the damper. We extract both the restitution coefficient of the first collision and the total flight time to characterize the dissipation ability of the damper. Two containers and three types of granular chains, different in size, stiffness and restitution coefficient, are used to examine the experimental results. We find that the restitution coefficient of the first collision of a single-chain-filled damper can linearly tend to vanish with increasing the chain length and obtain a minimum filling mass required to cease the container at the first collision (no rebound). When the strong impact occurs, the collisional absorption efficiency of a chain-filled damper is superior to a monodisperse-particle-filled damper. Furthermore, the longer the chains are, the better the dissipative effect is

A quantum algorithm for greatest common divisor problem

We present a quantum algorithm solving the greatest common divisor (GCD) problem. This quantum algorithm possesses similar computational complexity with classical algorithms, such as the well-known Euclidean algorithm for GCD. This algorithm is an application of the quantum algorithms for the hidden subgroup problems, the same as Shor factoring algorithm. Explicit quantum circuits realized by quantum gates for this quantum algorithm are provided. We also give a computer simulation of this quantum algorithm and present the expected outcomes for the corresponding quantum circuit

The Connection between Radio and Gamma Ray Emission in Fermi/LAT Blazars

We collect the 2LAC and MOJAVE quasi-simultaneous data to investigate the radio-gamma connection of blazars. The cross sample contains 166 sources. The statistic analysis based on this sample confirms positive correlations between these two bands, but the correlations become weaker as the gamma-ray energy increases. The statistic results between various parameters show negative correlations of gamma-ray photon spectral index with gamma-ray loudness for both FSRQs and BL Lacertae objects, positive correlations of gamma-ray variability index with the gamma-ray loudness for FSRQs, a negative correlation of the gamma-ray variability index with the gamma-ray photon spectral index for FSRQs, and negative correlations of gamma-ray photon spectral index with gamma-ray luminosity for FSRQs. These results suggest that the gamma-ray variability may be due to changes inside the gamma-ray emission region like the injected power, rather than changes in the photon density of the external radiation fields, and the variability amplitude tends to be larger as the gamma-rays are closer to the high energy peak of spectral energy distribution. No correlation of variability index found for BL Lacertae objects implies that variability behavior may differ below and above the peak energy.Comment: 10 pages, 10 figures, Accepted by RA

Reddening of the BLR and NLR in AGN From a Systematic Analysis of Balmer Decrement

We selected an active galactic nuclei (AGN) sample ($0 < z \le 0.35$) from Sloan Digital Sky Survey Data Release 7, and measured the broad- (${\rm H\alpha^{b}/H\beta^{b}}$) and narrow-line Balmer decrements (${\rm H\alpha^{n}/H\beta^{n}}$) of 554 selected AGNs. We found that the distributions of Balmer decrements can be fitted by a Gaussian function and give the best estimates of ${\rm H\alpha^{b}/H\beta^{b}} = 3.16$ with a standard deviation 0.07 dex, and ${\rm H\alpha^{n}/H\beta^{n}} = 4.37$ with a standard deviation 0.10 dex. We inspected the distributions of ${\rm H\alpha^{b}/H\beta^{b}}$ and ${\rm H\alpha^{n}/H\beta^{n}}$ in the Baldwin$-$Phillips$-$Terlevich (BPT) diagram and found that only narrow-line Balmer decrements depend on the physical conditions of the narrow-line region (NLR). We tested the relationship between ${\rm H\alpha^{b}/H\beta^{b}}$ and ${\rm H\alpha^{n}/H\beta^{n}}$, and found that ${\rm H\alpha^{b}/H\beta^{b}}$ does not correlate with ${\rm H\alpha^{n}/H\beta^{n}}$. We investigated the relationship between Balmer decrements and Seyfert sub-type, and found that only broad-line Balmer decrements correlate with Seyfert sub-type, We also examined the dependency of Balmer decrements on AGN properties, and found that Balmer decrements have no correlation with optical luminosity, but show some dependence on accretion rate. These results indicate that the NLR is subject to more reddening by dust than the broad-line region (BLR).Comment: 10 pages, 9 figures, 1 table, accepted for publication in MNRA

Optical Spectroscopy of Four Young Radio Sources

We report the optical spectroscopy of four young radio sources which are observed with the Lijiang 2.4m telescope. The Eddington ratios of these sources are similar with those of narrow-line Seyfert 1 galaxies (NLS1s). Their Fe {\sc ii} emission is strong while [O {\sc iii}] strength is weak. These results confirm the NLS1 features of young radio sources, except that the width of broad H$\beta$ of young radio sources is larger than that of NLS1s. We thus suggest that the young radio sources are the high black hole mass counterparts of steep-spectrum radio-loud NLS1s. In addition, the broad H$\beta$ component of \astrobj{4C 12.50} is the blue wing of the narrow component, but not from the broad line region.Comment: 11 pages, 5 Figures, 2 Tables, accepted by New Astronom