A theoretical investigation of the He-PH ( 3 − ) complex is presented. We perform ab initio calculations of the interaction potential energy surface and discuss its error bounds with relevance to cold collisions, and we carry out accurate calculations of bound energy levels of the complex including the molecular fine structure and magnetic-field effect. We find the potential has two shallow minima and supports ten and 13 bound levels in complex with 3 He and 4 He, respectively. Based on the potential the quantum scattering calculations are then implemented for elastic and inelastic cross sections of the magnetically trappable low-field-seeking state of PH ( 3 − ) in collision with 3 He atom. The cold-collision properties and the influence of the external magnetic field as well as the effect of the uncertainty of interaction potential on the collisionally induced Zeeman relaxation are explored and discussed in detail. The ratio of elastic to inelastic cross sections is large over a wide range of collision energy, magnetic field, and scaling factor of the potential, so that helium buffer-gas loading and evaporative cooling of PH is a good prospect.

A comprehensive study of multifrequency correlations can shed light on the nature of variation for blazars. In this work, we collect the long-term radio, optical and γ-ray light curves of PKS 1502+106. After performing the localized cross-correlation function analysis, we find that correlations between radio and γ-ray or V band are beyond the 3σ significance level. The lag of the γ-ray relative to 15 GHz is −60 +5 −10 days, translating to a distance 3.18 +0.50 −0.27 parsec (pc) between them. Within uncertainties, the locations of the γ-ray and optical emitting regions are roughly the same, and are away from the jet base within 1.2 pc. The derived magnetic field in optical and γ-ray emitting regions is about 0.36 G. The logarithm of γ-ray flux is significantly linearly correlated with that of V band fluxes, which can be explained by the synchrotron self-Compton (SSC) process, the external Compton (EC) processes, or the combination of them. We find a significant linear correlation in the plot of log (polarization degree) versus log νF ν at V band, and use the empirical relation Π ∼ sin n θ ′ (θ ′ is the observing angle in the comoving frame blob) to explain it. The behaviors of color index (generally redder when brighter at the active state) and γ-ray spectral index (softer when brighter) could be well explained by the twisted jet model. These findings suggest that the curvature effect (mainly due to the change of the viewing angle) is dominant in the variation phenomena of fluxes, spectral indices, and polarization degrees for PKS 1502+106.

The first ab initio potential energy surface of the Kr-OCS complex is developed using the coupled-cluster singles and doubles with noniterative inclusion of connected triples [CCSD(T)]. The mixed basis sets, aug-cc-pVTZ for the O, C, and S atom, and aug-cc-pVQZ-PP for the Kr atom, with an additional (3s3p2d1f) set of midbond functions are used. A potential model is represented by an analytical function whose parameters are fitted numerically to the single point energies computed at 228 configurations. The potential has a T-shaped global minimum and a local linear minimum. The global minimum occurs at R = 7.146 a(0), θ = 105.0° with energy of -270.73 cm(-1). Bound state energies up to J = 9 are calculated for three isotopomers (82)Kr-OCS, (84)Kr-OCS, and (86)Kr-OCS. Analysis of the vibrational wavefunctions and energies suggests the complex can exist in two isomeric forms: T-shaped and quasi-linear. The calculated transition frequencies and spectroscopic constants of the three isotopomers are in good agreement with the experimental values.

We collect long term γ-ray, optical and radio 15 GHz light curves of quasar object PMN J2345-1555. The correlation analyses between them are performed via the local cross-correlation function (LCCF). We found that all the optical V , R band and the infrared J band are correlated with the radio 15 GHz at beyond 3σ significance level, and the lag times are −221.81 +6.26 −6.72 , −201.38 +6.42 −6.02 and −192.27 +8.26 −7.37 days, respectively. The γ-ray is strongly correlated with optical, but weakly correlated with the radio. We present that time lags between different frequencies can be used as an alternative parameter to derive the core-shift measurement. For this target, the magnetic field and particle density at 1 parsec in jet are derived to be 0.61 Gauss and 1533/γ min cm −3 , respectively. The black hole mass and the 15 GHz core position in jet are estimated to be 10 8.44 M ⊙ and 30 parsec, respectively. The lag times enable us to derive that the optical and the γ-ray emitting regions coincide, which are located at 4.26 +0.83 −0.79 pc away from 15 GHz core position in jet and beyond the broad line region (BLR). We found that a 3σ correlation between the color index and the radio light curve, which indicates that opacity may play an important role in the variation. The δV − δR behaviors are complex, while the R − J shows a bluer when brighter trend. As hinted from radio images, we proposed a positional dependent spectral index model to explain the color index behaviors, which is complementary for the shock in jet model. The curvature effects and contribution from accretion disk may also affect variables of blazars in many aspects.

The γ-ray narrow-line Seyfert 1 (NLS1) galaxies can be considered to be the third class of γ-ray active galactic nuclei possessing relativistic jets. In this paper, we present multi-band high-resolution Very Long Baseline Array (VLBA) images of the γ-ray NLS1, SDSS J211852.96-073227.5 (J2118-0732, z = 0.26). We find a core-jet radio morphology and significant flux density variations in the radio core. The high brightness temperature estimated from VLBA images and core variability demonstrate that it exhibits substantial relativistic beaming effects. By considering radio emission in several bands, we find that the source has an inverted spectrum above 1 GHz but a steep spectrum at low frequencies ranging from 74 MHz–1 GHz; these may arise from the present activity and the old diffuse/extended emission, respectively. The core-jet morphology, significant flux density variations, and beaming effect make J2118-0732 resemble a blazar. Considering the low mass of its central black hole and the ongoing merger environment, J2118-0732 may represent a low-mass, low-power counterpart of blazars, and may finally evolve into a blazar.