大质量年轻星体的^(13)CO(1→0)谱线发射

利用紫金山天文台青海站的 13.7m毫米波望远镜对 133个大质量年轻星体或其候选体进行了 13CO( 1→ 0 ) ( J=1→ 0 )的谱线观测 .在 115个源中观测到了 13CO( 1→ 0 )的发射 ,其中 94个天体是第一次探测到 13CO( 1→ 0 )谱线 .根据多样性的 13CO( 1→ 0 )谱线轮廓 ,分析了大质量年轻星成协分子云核的运动和结构 .用 L TE方法导出了每个被测源的 13CO( 1→ 0 )光学厚度和 H2 分子柱密度 .计算了 8个与大质量年轻星候选体成协分子云核的 mvir/mcl。

A Novel Pyrazoline-based Starburst Amorphous Molecular Material

A pyrazoline-containing starburst molecule, 4,4’,4"-tris[(1,3-diphenyl-4,5-dihydro-1H- pyrazol)-5-yl]-triphenylamine (Tris-5-DPP), was synthesized in a facile way, which can form amorphous thin films with glass transition temperature as high as 136 °C.

银道面致密HⅡ区的成协分子云

利用紫金山天文台青海站的 1 3.7m毫米波望远镜 ,对银道面的一个包含 1 9个致密HⅡ区的大质量星形成区进行了13 CO(J =1_ 0 )的谱线成图观测 .以较高的分辨率给出了该区域完整的大尺度 ( 2 8′× 45′) 13 CO发射的结构 .结合其远红外发射和尘埃色温度的空间分布图 ,发现在新形成的大质量星和成协分子云间可能存在多种形式的动力学联系 .对该区域新的致密冷核和分子发射空洞的形成及其与大质量星形成和演化的关系进行了探讨 ,导出了所有HⅡ区激发星的光度及成协分子云的主要物理参数 .结果表明 ,新形成大质量星的光度与成协分子云的参数———13 CO柱密度。

W51A的谱线与连续谱研究——CO,NH_3谱线与3mm连续谱

以研究星系旋臂上大质量星形成区为目的 ,对W5 1IRS1为中心的 5′×4′(约等于 1 1pc× 9pc)天区的 3.4mm的连续谱和CO(J =1 0 )线作观测 ,并对NH3(1 ,1 ) ,(2 ,2 ) ,(3,3)和 (4,4)四反演线作同时观测 .氨分子的谱形分析和辐射转移统计平衡计算结果表明 ,在波长 3.4mm连续谱的W5 1IRS1 ,IRS2以及 (e1 /e2 )源中心方向的NH3反演线谱有来自HⅡ区前的氨分子的相对发射线红移的吸收特征 ;由东部边缘区向中心 ,有密度 3～ 1 0倍的递增趋势 ,进一步显示了光学不可见的分子云核的塌缩现象 .在以IRS1为中心 40″为半径的圆内的各个射电、近 (远 )红外、UCHⅡ源所形成的外场辐射对区内分子 (例如NH3)的激发产生不可忽略的影响 .CO(J =1 0 )的谱形在此圆区内由东到西发生由不对称的双峰 (约等于 6 0 ,6 8km·s-1)转化为三峰 ,即与致密电离氢区G49.4 0 .3成协的约等于 5 3km·s-1分量亦在谱线上呈现 .可见 40″圆区内有明显的大质量星形成的各种活动迹象 .

Synthesis and photovoltaic properties of a star-shaped molecule based on a triphenylamine core and branched terthiophene end groups

A new star-shaped donor-acceptor molecule has been synthesized for application as the donor material in solution-processed bulk-heterojunction organic solar cells (OSCs). The molecule consists of a triphenylamine (TPA) unit as the core and a donor unit with three arms containing benzo[1,2,5]thiadiazole (BT) acceptor units and 5,5''-dihexyl-2,2′:3′,2″-terthiophene (tTh) end groups. The molecule, denoted S(TPA-BT-tTh), exhibits a broad absorption band in the wavelength range 300-650 nm and high hole mobility of 1.1×10 -4 cm2 V -1 s 1 . An OSC device based on S(TPA-BT-tTh) as donor and [6,6]-phenyl C71 -butyric acid methyl ester (PC 70 BM) as the acceptor (1:3, w/w) exhibited a power conversion efficiency of 2.28% with a short circuit current density of 6.39 mA/cm2 under illumination of AM.1.5, 100 mW/cm2 .

On the nature of X-ray “unobscured” Seyfert 2 galaxies

We present a systematic study to reveal the effect of host galaxy contamination to the identification of X-ray "unobscured" Seyfert 2 galaxies.We compiled a sample of 14 X-ray "unobscured" Seyfert 2 galaxies and 29 X-ray obscured Seyfert 2s,with infrared [Ne II] and [O IV] emission line flux measurements.In this work we classify Seyfert 2s as "unobscured" or obscured in X-ray simply based on X-ray spectral fitting.We find that our X-ay "unobscured" Seyfert 2s have statistically higher [Ne II]/[O IV] line ratios,compared with obscured ones.Since the [Ne II]/[O IV] line ratio reflects the relative strength of star formation activity comparing with the SMBH accretion,the observed differences in [Ne II]/[O IV] line ratios clearly indicate relatively stronger X-ray contamination from star formation in the host galaxies in X-ray "unobscured" Seyfert 2s.Therefore we could attribute the X-ray "unobscured" appearance to host galaxy contamination for most(if not all) of our X-ray "unobscured" Seyfert 2s.Further analysis indicates that "unobscured" Seyfert 2s have intrinsically lower AGN luminosity but similar star formation rates,compared with obscured ones.This is also consistent with previous studies showing most X-ray "unobscured" Seyfert 2s are at lower luminosities,and relatively stronger contaminations from the host galaxies are thus expected.Finally we develop a screening criterion to distinguish potential pure Seyfert 2s from X-ray "unobscured" appearances which could be caused by strong host galaxy contamination.

The global star formation law of galaxies revisited in the radio continuum

We study the global star formation law, the relation between the gas and star formation rate （SFR） in a sample of 130 local galaxies with infrared （IR） luminosities spanning over three orders of magnitude （109-1012 Lo）, which includes 91 normal spiral galaxies and 39 （ultra）luminous IR galaxies [（U）LIRGs]. We derive their total （atomic and molecular） gas and dense molecular gas masses using newly available HI, CO and HCN data from the literature. The SFR of galaxies is determined from total IR （8-1000 μm） and 1.4 GHz radio continuum （RC） luminosities. The galaxy disk sizes are defined by the de-convolved elliptical Gaussian FWHM of the RC maps. We derive the galaxy disk-averaged SFRs and various gas surface densities, and investigate their relationships. We find that the galaxy disk-averaged surface density of dense molecular gas mass has the tightest correlation with that of SFR （scatter -0.26 dex）, and is linear in log-log space （power-law slope of N=1.03±0.02） across the full galaxy sample. The correlation between the total gas and SFR surface densities for the full sample has a somewhat larger scatter （-0.48 dex）, and is best fit by a power-law with slope 1.45±0.02. However, the slope changes from -1 when only normal spirals are considered, to -1.5 when more and more （U）LIRGs are included in the fitting. When different CO-to-H2 conversion factors are used to infer molecular gas masses for normal galaxies and （U）LIRGs, the bi-modal relations claimed recently in CO observations of high-redshift galaxies appear to also exist in local populations of star-forming galaxies.

Five E+A (post-starburst) galaxies as Brightest Cluster Galaxies

Brightest Cluster Galaxies （BCGs） are mostly elliptical galaxies and very rarely have prominent star formations. We found that five out of 8,812 BCGs are E＋A （i.e., post-starburst） galaxies, having an Hd absorption line with an equivalent width 〉2.5 A and no distinct emission lines in [O II] and Ha-. The E＋A features we identified from the BCGs for the first time are not as significant as those in general galaxies, indicating that historically the star formations were not very violent.

Molecular lines and continuum from W51A (I) --CO and NH_3 spectra and 3 mm continuum

As for the 5′ × 4′(～llpc × 9pc) region centered at W51 lRSl the observations of the 3.4 mm continuum, CO (J = 1-0) line and simultaneous NH3(1,1), (2,2), (3,3), (4,4) inverse lines were made for studying the massive star formation region located in the main spiral arms of the Galaxy. In the directions of W51 IRS1, IRS2 and el/e2 in 3.4 mm continuum, analyses of the line profiles show that the absorption lines of ammonia, which arise from the gas in front of the HII region, are red-shifted with respect to the emission lines, which arise from the surrounding cloud. Furthermore, a radiation transfer and statistical equilibrium calculation of ammonia molecules show that the densities increase by 3–10 times from the eastern border to the center. These points hint that the collapse is happening in the molecular cloud core obscured in optical wavelengths. The effects of the radiation fields from radio, infrared and UCHII sources is non-negligible on the excitation of various molecules (e.g. NH3) within the circle of radius 40″ centered at IRS1. The profiles of the COJ = 1–0 line in the circle change from double peaks ( ～ 60, ～ 68 km. s-1) to triple peaks, i.e. the component ～53 km·s?1, which associates with UCHII, also appears in the spectra. There are indications that the circle of radius 40″ centered at IRSI is a region of massive star forming activity

^(13)CO mapping study for massive molecular cloud cores

Using the newly installed SIS receiving system on the 13.7 m telescope at Qinghai Station of PMO, United Radio Astronomy of CAS, CO isotope 13 CO J=1-0 and C18 O J=1-0 lines were observed for thr ee sources S241, S39 and ON3. Results show that the three sources have massive cor es, of which the size is ～2-5 pc, masses are ～103-104 M⊙. The wid t hs of lines are also larger than those in low mass cores. And high velocity char acteristics were observed for all the sources. The V LSR distribution p resents rotation of the core in ON3. And all the three cores contain deeply embe dded forming massive stars. The young stellar objects in S241 and ON3 seem to be moving away from their birth sites.

Implications of the cosmic infrared background excess for the cosmic star formation

By phenomenologically describing the high-redshift star formation history, i.e., ,ρ.（z） oc [（1 ＋z）/4.5]-% and semi-analytically calculating the fractions of high-redshift Pop I/II and Pop II! stars, we investigate the contributions from both high-redshfit Pop I/II and Pop II/stars to the observed near-infrared （3 μm 〈// 〈 5 μm） excess in the cosmic infrared background emission. In order to account for the observational level of the near-infrared excess, the power-law index or of the assumed star formation history is constrained to within the range of 0 ≤a≤1. Such a constraint is obtained under the condition that the viral temperature of dark matter halos belongs to the range of 500 K ≤ Tvir≤ 104 K.

Expression and role of PAK6 after spinal cord injury in adult rat

Objective： To observe p21-activated kinase 6 （PAK6） expression and its possible role after spinal cord injury （SCI） in adult rat.Methods： Sprague-Dawley rats were subjected to spinal cord injury. To explore the pathological and physiological significance of PAK6, the expression patterns and distribution of PAK6 were observed by Western blot, immunohistochemistry and immunofluorescence.Results： Western blot analysis showed PAK6 protein level was significantly up-regulated on day 2 and day 4,then reduced and had no up-regulation till day 14. Immunohistochemistry analysis showed that the expression of PAK6 was significantly increased on day 4 compared with the control group. Besides, double immunofluorescence staining showed PAK6 was primarily expressed in the neurons and astrocytes in the control group. While after injury, the expression of PAK6 was increased significantly in the astrocytes and neurons, and the astrocytes were largely proliferated. We also examined the expression of proliferating cell nuclear antigen （PCNA） and found its change was correlated with the expression of PAK6. Importantly, double immunofluorescence staining revealed that cell proliferation evaluated by PCNA appeared in many PAK6-expressing cells on day 4 after injury.Conclusion： The up-regulation of PAK6 in the injured spinal cord may be associated with glial proliferation.