• article-nadcTAP Call for Proposals Semester 2021B
    Proposals awarded 2020B/2021A time but not scheduled are encouraged to apply again.
    for writing proposals Four TAP workshops have been held at PKU/KIAA (1st), NAOC (2nd,3rd), XMU (4th ...
    ) and SYSU(5th).
    It isnotsufficient to simply say, "We require 2300s exposure time to reach S/N=10 for g=24 mag" ...
    ; if g=24 and S/N=10 are not also justified.
  • article-nadc南山26米望远镜氨分子观测研究进展
    氨分子(NH3)是宇宙中探测到的第一种多原子星际分子，其谱线包含了很多频率接近的精细跃迁，便于计算分子云的温度、密度等物理参数。
    较之于一氧化碳分子（CO），氨分子示踪的气体密度高一个量级（n~10⁴ cm⁻³)，在低温时不易冻结耗散，特别适于观测研究分子云中的冷致密气体成分。
    新疆天文台恒星形成与演化团组科研人员使用南山26米射电望远镜对天鹰座巨分子云的小质量恒星形成区（Serpens South）和大质量恒星形成区（W40）进行NH₃(1,1)和(2,2)谱线成图观测研究， ...
    图1.利用南山26米射电望远镜对天鹰座恒星区域的NH₃观测，左图：NH₃(1,1)线 积分强度图；右图：NH₃(2,2)线积分强度图。
  • article-nadcLAMOST-Kepler/K2时域中分辨率光谱巡天首个成果发布
    结果表明，当光谱S/N=20时，恒星有效温度、表面重力加速度、金属丰度和视向速度的内部误差分别为80 K、0.08 dex、0.05 dex和1km/s。
    -N., De Cat, P., et al. 2020, ApJS, 251, 16 Fu, J.
    -N., De Cat, P., Zong, W., et al. 2020, RAA, 20, 167 Liu, N., Fu, J.
    -N., De Cat, P., et al. 2018, ApJS, 238, 30 De Cat, P., Fu, J.-N., Ren, A.
    -B., et al. 2015, ApJS, 220, 19 新闻来源：http://www.nao.cas.cn/xwzx/kydt/202011/t20201118_5754470.html ...
  • metadataLAMOST DR5 v1 A, F, G and K type stars catalog
    The LAMOST DR5 V1 A, F, G and K type star catalog lists 5,348,664 spectra information obtained by LAMOST ...
    during October 24th 2011 and June 16th 2017, including 85,845 A type stars, 1,694,167 F type stars, ...
    2,739,446 G type stars and 829,206 K type stars.
    These targets are selected with the criterions of S/N in g band greater than 6 in dark nights, and S/ ...
    N in g band greater than 15 in bright nights.
  • article-nadc天文学家构建深度学习模型估计LAMOST中分辨光谱的恒星参数和元素丰度
    对于信噪比大于 10 的LAMOST 中分辨率光谱，其有效温度和表面重力误差水平为119 K和0.17 dex，13 种化学元素[C/H]、 [N/H]、[O/H]、[Mg/H]、[Al/H]、[Si/ ...
    H]、[S/H]、[Ca/H]、[Ti/H]、[Cr/H]、[Fe/H]和[Ni/H]的误差水平为0.06-0.12 dex，[Cu/H]的精度为0.19 dex。
  • article-nadc穿越时空的发现 ——公众超新星搜寻项目2021年首个发现
    它现在被编号为M31N 2012-01b，然而更有趣的是，天文学家发现它与M31N 1923-12c来自相同的前身天体，也就是说，这是一个少见的再发新星！
    图1：M31N 1923-12c（左）与M31N 2012-01b（右）（图像来源A. W. Shafter等人） 不知不觉我们来到了2021年7月3日。
    经查验，发现该候选体位置非常接近M31N 1923-12c和M31N 2012-01b，疑为M31N 1923-12c有记录的第三次爆发。
    1923-12c（亦被称为M31N 2012-01b，见ATel #3914，https://www.astronomerstelegram.org/? ...
    该光谱也显示出He I发射线的初步证据。这与2012年爆发的He/N型分类一致（ATel #3914）。
  • article-nadc研究人员基于LAMOST数据揭示富钡恒星的起源
    图 2 LAMOST矮星和亚巨星的C、N元素丰度随金属丰度的分布，等值线表示的是Ba元素丰度正常的恒星，带颜色的点表示富Ba恒星，颜色表示温度。
    本项研究的对象主要是温度为5000-6700K、质量范围约为0.9-1.4倍太阳质量的FGK型矮星和亚巨星。
    在此基础上，研究人员进一步细致分析了它们的C、N、Mg、Al、Si等元素的丰度分布模式；并将LAMOST数据与Gaia数据结合，获取和分析了这些恒星在六维相空间的运动学性质。
    其中大约1/3的恒星可能经历了双星演化过程中的物质交换，它们不仅钡元素丰度高，C和N元素也显著增丰，这符合恒星演化过程中AGB阶段内部核合成产生的元素丰度模式，并与过去人们对钡增丰巨星的形成机制的认识是一致的 ...
    另有2/3的恒星没有显示出明显的C和N元素增丰，而是呈现出Mg，Ti，Ni等元素丰度的异常。其中，Mg元素丰度比普通恒星更低，这与高温、中等质量钡元素增丰的恒星情况相似。
  • article-nadc鹿林天文台1米望远镜时间申请
    除光谱仪跟TRIPOL不再说明之外，U42的相机可以使用的滤镜主要有 U、V、B、V、R、I、O3、S2、Ha，彗星滤镜如CN、C2、NH2、Rc等 , 以及SDSS 的g' r' i' z'； 3 ...
  • article-nadc国家天文科学数据中心公众超新星搜寻项目发现M31N 1984-07a有记录的第4次爆发
    Hornoch等人在ATel#15760中报告他们捕捉到该候选体的增亮阶段，并将其编号为M31N 2022-11b，此外，他们也透露正在尝试确认这是M31N 1984-07a的再次爆发。
    Valladon（圣迭戈州立大学），K. Hornoch，H. Kucakova（捷克科学院天文研究所） 2022年11月27日；世界时20:19 可信度认证：Allen W.
    为了确认M31N 2022-11b与再发新星M31N 1984-07a的联系，我们将圣迭戈州立大学拉古纳山天文台（MLO）40英寸反射望远镜拍摄的M31N 2022-11b图像(拍摄于世界时2022年11 ...
    因此，我们得出结论，M31N 2022-11b是已知再发新星M31N 1984-07a被报告的第四次爆发。 4次爆发并没有使该新星显示出明确的平均重现时间。
    自从发现M31N 1984-07a的这次最新爆发以来，我们一直在跟踪M31N 2022-11b的亮度演变，以表征其光变曲线；特别是，要确定它达到最大亮度后变暗的速度（即它的t2时间）。
  • article-nadc基于天马望远镜的星际化学分子谱线探测研究取得新进展
    该样本包含了银河系内的几十个红外暗云，观测波段是天马望远镜的K波段（18-26.5 GHz），主要探测的目标谱线是三条具有很强化学表征性的分子探针——氨分子（NH3）、硫化双碳（ ...
    CCS）和氰基乙炔（HC3N）。
    注1：氨分子（NH3）被认为是星际介质的灵敏温度计。
  • metadataBasic Information and Derived Properties of the Final AGN Sample
    Re_arcsec (arcsec): Half-light radius of the AGN host galaxy from image decomposition in the i band after ...
    Re_kpc (kpc): Half-light radius of the AGN host galaxy from image decomposition in the i band after correcting ...
    Re_kpc_e: Uncertainty of Re_kpc. n_i: Sersic index from image decomposition in the i band after correcting ...
    for systematic effects. n_i_e: Uncertainty of n_i. color (mag): Rest-frame SDSS g-r color from SED fitting ...
    Morph: Morphological classification based on n_i.
  • metadataBasic Information and Derived Properties of the Final AGN Sample
    Re_arcsec (arcsec): Half-light radius of the AGN host galaxy from image decomposition in the i band after ...
    Re_kpc (kpc): Half-light radius of the AGN host galaxy from image decomposition in the i band after correcting ...
    n_i: Sersic index from image decomposition in the i band after correcting for systematic effects.
    n_i_e: Uncertainty of n_i. color (mag): Rest-frame SDSS g-r color from SED fitting.
    Morph: Morphological classification based on n_i.
  • metadataBasic Information and Derived Properties of the Final AGN Sample
    Re_arcsec (arcsec): Half-light radius of the AGN host galaxy from image decomposition in the i band after ...
    Re_kpc (kpc): Half-light radius of the AGN host galaxy from image decomposition in the i band after correcting ...
    n_i: Sersic index from image decomposition in the i band after correcting for systematic effects.
    n_i_e: Uncertainty of n_i. color (mag): Rest-frame SDSS g-r color from SED fitting.
    Morph: Morphological classification based on n_i.
  • metadataBasic Information and Derived Properties of the Final AGN Sample
    Re_arcsec (arcsec): Half-light radius of the AGN host galaxy from image decomposition in the i band after ...
    Re_kpc (kpc): Half-light radius of the AGN host galaxy from image decomposition in the i band after correcting ...
    n_i: Sersic index from image decomposition in the i band after correcting for systematic effects.
    n_i_e: Uncertainty of n_i. color (mag): Rest-frame SDSS g-r color from SED fitting.
    Morph: Morphological classification based on n_i.
  • metadata LAMOST Data Release 7 V1.2
    The LAMOST seventh Data Release V1.2 contains low resolution spectra obtained from October 24th 2011 ...
    to June 18th 2019, and medium resolution spectra obtained from September 2017 to June 2019.
    There are total 10,599,979 low resolution spectra, among them 8,819,957 with S/N> 10.
    million non-time domain medium resolution spectral data, among them 670 thousands of spectra with S/N> ...
    10; and 2.87 million time domain medium resolution spectra, among them 1.60 million spectra with S/N> ...
  • metadataA Model RRNet for Spectral Information Exploitation and LAMOST Medium-resolution Spectrum Parameter Estimation
    For spectra with S/N >= 10, the precision of estimations Teff and log g are 88 K and 0.13 dex respectively ...
    , elements C, Mg, Al, Si, Ca, Fe, Ni are 0.05 dex to 0.08 dex, and N, O, S, K, Ti, Cr, Mn are 0.09 dex ...
  • metadataA Model RRNet for Spectral Information Exploitation and LAMOST Medium-resolution Spectrum Parameter Estimation
    For spectra with S/N >= 10, the precision of estimations Teff and log g are 88 K and 0.13 dex respectively ...
    , elements C, Mg, Al, Si, Ca, Fe, Ni are 0.05 dex to 0.08 dex, and N, O, S, K, Ti, Cr, Mn are 0.09 dex ...
  • metadataLAMOST DR8 MRS CSN Stellar Parameters and Chemical Abundances Catalog
    Abundances Catalog provides a catalog of stellar parameters and chemical elements (C, Na, Mg, Si, Ca, Ti ...
    incorporates the physical model and data-driven approaches to improve the shortcomings of the low S/N ...
    coordinate information (right ascension (RA), declination (Dec)), signal-to-noise of the spectra (S/N ...
  • metadataLAMOST DR8 MRS CSN Stellar Parameters and Chemical Abundances Catalog
    Abundances Catalog provides a catalog of stellar parameters and chemical elements (C, Na, Mg, Si, Ca, Ti ...
    incorporates the physical model and data-driven approaches to improve the shortcomings of the low S/N ...
    coordinate information (right ascension (RA), declination (Dec)), signal-to-noise of the spectra (S/N ...
  • metadataLAMOST DR8 MRS CSN Stellar Parameters and Chemical Abundances Catalog
    Abundances Catalog provides a catalog of stellar parameters and chemical elements (C, Na, Mg, Si, Ca, Ti ...
    incorporates the physical model and data-driven approaches to improve the shortcomings of the low S/N ...
    coordinate information (right ascension (RA), declination (Dec)), signal-to-noise of the spectra (S/N ...
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