Phase analysis of sunspot group numbers on both solar hemispheres

Cross-correlation analysis and wavelet transform methods are proposed to investigate the phase relationship between the monthly sunspot group numbers in the solar northern and southern hemispheres. It is found that （1） the monthly sunspot group numbers in the northern hemisphere begin two months earlier than those in the southern one, which should lead to phase asynchrony between them but with a slight effect; （2） the Schwabe cycle length for the monthly sunspot group numbers in the two hemispheres obviously differs from each other, and the mean Schwabe cycle length of the monthly sunspot group numbers in the northern hemisphere is slightly larger than that in the southern one; （3） the monthly sunspot group numbers in the northern hemisphere precede those in the southern hemisphere during the years of about 1874- 1927, after which, the southern hemisphere leads the northern hemisphere in the years 1928-1964, and then the northern hemisphere leads in time till the present.

Long-term hemispheric variation of the flare index

The long-term hemispheric variation of the flare index is investigated. It is found that, （1） the phase difference of the flare index between the northern and southern hemispheres is about 6-7 months, which is near the time delay between flare activity and sunspot activity; （2） both the dominant and phase-leading hemisphere of the flare index is the northern hemisphere in the considered time interval, implying that the hemispheric asynchrony of solar activity has a close connection with the N-S asymmetry of solar activity.

Discovery of six high-redshift quasars with the Lijiang 2.4 m telescope and the Multiple Mirror Telescope

Quasars with redshifts greater than 4 are rare, and can be used to probe the structure and evolution of the early universe. Here we report the discovery of six new quasars with i-band magnitudes brighter than 19.5 and redshifts between 2.4 and 4.6 from spectroscopy with the Yunnan Faint Object Spectrograph and Camera (YFOSC) at the Lijiang 2.4 m telescope in February, 2012. These quasars are in the list of z > 3.6 quasar candidates selected by using our proposed J K/i Y criterion and the photometric redshift estimations from the SDSS optical and UKIDSS near-IR photometric data. Nine candidates were observed by YFOSC, and five among six new quasars were identified as z > 3.6 quasars. One of the other three objects was identified as a star and the other two were unidentified due to the lower signal-to-noise ratio of their spectra. This is the first time that z > 4 quasars have been discovered using a telescope in China. Thanks to the Chinese Telescope Access Program (TAP), the redshift of 4.6 for one of these quasars was confirmed by the Multiple Mirror Telescope (MMT) Red Channel spectroscopy. The continuum and emission line properties of these six quasars, as well as their central black hole masses and Eddington ratios, were obtained.

Magneto-induced Line Broadening of Magneto-sensitive Lines in Solar Magnetized Atmospheres

We analyze the spectral line broadening of those magneto-sensitive lines in solar magnetized atmospheres. The broadening at the line wings is due to the increase of the effective width of energy levels involved in Zeeman splitting,and the broadening at the line core also originated in Zeeman splitting under the condition that the Zeeman components are mixed. Therefore, the magneto-induced or Zeeman broadening take effects on the whole line. The observed Stokes parameter data in a sunspot and outside it acquired by Solar Stokes Spectrum Telescope （S^3T） are analyzed for the demonstration of this mechanism, and the Zeeman broadening rates are calculated for Fe16302.5 under some assumptions.Our result shows that the broadening is increased as the magnetic field strength becomes stronger, but the rate of increase at the line core is decreased as the field strength increases, while the rate at the wing does not show such an obvious regularity. The broadening is more effective in the line core than in the wings.

Chirality of Eruptive Neutral Line Indicated by Bipolar Double Dimmings

As a key on-disk proxy of coronal mass ejection （CME）, bipolar double dimmings （BDDs） during eruption of filament or coronal sigmoid are explained to mark footpoints of a flux rope. One thus expects the configuration of BDDs to be linked with chirality of associated filament or sigmoid. In the paper, we investigate four events in association with BDDs and halo or partial halo CMEs. In each hemisphere, two neutral lines （NLs） underlying eruptive filament or sigmoid are presented, in which one obeys and another disobeys the well-known hemispheric chirality rule. Between two possible configurations of BDDs for an eruptive NL, we find that only one, depending on the chirality of the NL, can occur. By considering axial orientation of BDDs as from the positive dimming to the negative one, and by defining ＂dextral/sinistral BDDS＂ as the axial orientation having rightward/leftward component parallel to the NL to an observer at its positive-polarity side, eruptive dextral/sinistral NLs have no-exception correlation with dextral/sinistral BDDs. It is also found that dextral/sinistral BDDs can invariably undergo clockwise/counterclockwise rotation. These observations suggest that configurations and rotations of BDDs also have chirality patterns that are consistent with that of the associated filaments, sigmoids, and their environments.

Twist in a polar blowout jet

It is well known that some coronal jets exhibit helical structures and un- twisting. We attempt to inspect the origin of twist in a blowout jet. By means of multiwavelength and multi-angle observations from Solar Dynamics Observatory （SDO） and Solar Terrestrial Relations Observatory-Ahead （STEREO-A）, we firstly report a polar untwisting jet that is a blowout jet which leads to a jet-like coronal mass ejection. From the viewpoint of SDO, the jet shows clear untwisting behavior and two jet-spires. However, from the viewpoint of STEREO-A the jet actually comes from the whiplike prominence eruption and is followed by a white-light jet. Our observations indicate that twist in blowout jets may result from the erupting mini-prominences/mini- filaments in the jet base.

Radiatively Inefficient Accretion Flows with Outflow

We construct a family of self-similar solutions to describe radiatively inefficient accretion flows with outflow. We show that outflow has important effects on the dynamical structure of accretion flows. In particular, we prove that outflow can be an effective mechanism of removing the released gravitational energy of accreted gas.