搜索结果: 1-15 共查到“天文学 the SDSS”相关记录43条 . 查询时间(0.137 秒)
近日，国家天文台白宇副研究员、刘继峰研究员基于LAMOST和SDSS数据库，利用机器学习的方法，开发天体分类器和恒星温度回归器，并把天体分类器应用到最新发布的Gaia DR2星表，揭示了Gaia DR2中天体类型组成。这是国际上使用最大样本开发的天体分类器和恒星温度回归器，该项研究成果已经被《天文学杂志》（AJ）接收，应用于Gaia DR2的最新结果已经发表在《天文和天体物理学研究》（2018，R...
近日，国家天文台天体丰度与星系演化研究团组博士后依明阿吉与赵刚研究员合作，首次利用我国LAMOST释放的第四次巡天数据与美国SDSS释放的第八次巡天数据中天琴座RR变星，测量出银河系旋转速度与银河系质量，该项研究结果已在国际核心期刊《天体物理学报》（The Astrophysical Journal）上发表。
近年来，随着大规模巡天项目（测光和光谱）的开展，进而可以测量银河系的质量分布，更加细...
利用LAMOST和SDSS数据证认人马矮星系星流新分支（图）
LAMOST SDSS数据 人马矮星系 星流分支
2017/3/10
近日，山东大学威海校区石维彬副教授等人通过分析LAMOST K巨星数据与SDSS RGB数据确认了一个已知分支，并在人马矮星系Leading星流上证认了一个新分支。这个新分支有助于限制人马矮星系星流的子结构和银河系势能。此成果已发表在国际知名天文期刊“Astronomy & Astrophysics”（A&A,2017, 597, A54）上。
Ongoing assembly of massive galaxies by major merging in large groups and clusters from the SDSS
general surveys
2014/12/23
We investigate the incidence of major mergers creating massive (Mstar > 1011 M⊙) galaxies in present-day (z≤ 0.12) groups and clusters. Using a volume-limited sample of 845 groups with dark matter hal...
经过三年多的准备工作，中国科学院上海天文台作为正式成员单位参与的国际大规模巡天“斯隆数字化巡天第四阶段项目”（以下简称SDSS-IV）于7月1日正式启动，开始为期六年的巡天观测和科学研究任务。
利用云南天文台丽江2.4m望远镜对一个新发现的射电噪窄线赛弗特1(RL-NLS1)活动星系核SDSSJ125438.25+114105.8进行了光学波段的短时标监测,观测结果表明,SDSSJ125438.25+114105.8存在光学微光变,典型的光变幅度为0.05～0.1 mag,光变时标仅为h的量级。这个天体是到目前为止极少数几个探测到光学微光变的RL-NLSl之一,推断出它的光学光度至少有一...
Spatially-Resolved Spectroscopy of SDSS J0952+2552: a Confirmed Dual AGN
Spectroscopy SDSS J0952+2552: Confirmed Dual AGN
2011/10/9
Most massive galaxies contain supermassive black holes (SMBHs) in their cores. When galaxies merge, gas is driven to nuclear regions and can accrete onto the central black hole. Thus one expects to se...
Structure Function and Variability Mechanism of Quasars from SDSS Stripe 82
Structure Function Variability Mechanism Quasars
2011/10/13
Theoretical predictions for the ensemble quasar structure function are tested using multi-epoch observations of Stripe 82 collected by the Sloan Digital Sky Survey. We reanalyze the entire available v...
The luminosities of the brightest cluster galaxies and brightest satellites in SDSS groups
galaxies: luminosity function
2011/10/11
We show that the distribution of luminosities of Brightest Cluster Galaxies, in two SDSS-based group catalogs, suggests that BCG luminosities are just the statistical extremes of the group galaxy lumi...
Investigation of the errors in SDSS proper-motion measurements using samples of quasars
Investigation of the errors in SDSS proper-motion measurements using samples of quasars
2011/10/17
We investigate in detail the probability distribution function (pdf) of the proper-motion measurement errors in the SDSS+USNO-B proper-motion catalog of \citet{mun04} using clean quasar samples. The p...
Photometric SN Ia Candidates from the Three-Year SDSS-II SN Survey Data
Photometric Candidates Three-Year SDSS-II SN Survey Data
2011/10/21
We analyze the three-year SDSS-II Superernova (SN) Survey data and identify a sample of 1070 photometric SN Ia candidates based on their multi-band light curve data. This sample consists of SN candida...
Cosmological implications from the full shape of the large-scale power spectrum of the SDSS DR7 luminous red galaxies
large-scale structure of Universe – cosmology: theory – cosmology: observations – cosmological parameters
2011/10/12
We obtain cosmological constraints from a measurement of the spherically averaged power spectrum (PS) of the distribution of about 90000 luminous red galaxies (LRGs) across 7646 deg2 in the Northern G...
Theoretical Spectra of the Am CVn Binary System SDSS J0926+3624 : Effects of Irradiation onto the Donor Stars
Theoretical Spectra Binary System Effects Irradiation Donor Stars
2011/9/29
Taking into account a range of parameters determined from the evolutionary models and available observational data, the detailed non-LTE spectra for the primary star and the irradiated donor star in t...
Transformations between WISE, 2MASS, SDSS and BVRI photometric systems: I. Transformation equations for dwarfs
cosmology – gravitational lensing – fl exion – dark matter halo
2011/9/29
We present colour transformations for the conversion of the W1 and W2 magnitudes of WISE photometric system to the Johnson-Cousins' BVRI, SDSS (gri), and 2MASS (JHK_s) photometric systems, for dwarfs....
SDSS J133401.39+331534.3: A New Subarcsecond Gravitationally Lensed Quasar
Subarcsecond Gravitationally Lensed Quasar
2011/9/29
The quasar SDSS J133401.39+331534.3 at z = 2.426 is found to be a two-image gravitationally lensed quasar with the image separation of 0.833. The object is first identified as a lensed quasar candidat...