检索结果-南通市图书馆

Observation of HⅠaround three Satellite galaxies of M31 with FAST:AndromedaⅡ,NGC 205,and NGC 185

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第8期24卷 52-59页

作者： Ziming Liu Jie Wang Yingjie Jing Chen Xu Tiantian Liang Qingze Chen Zerui Liu Zhipeng Hou Yougang Wang National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China

With the exceptional sensitivity of the Five-hundred-meter Aperture Spherical radio Telescope,we conducted observations of the neutral hydrogen(HⅠ)in the circumgalactic medium of Andromeda’s(M31)satellite galaxies,specifically AndromedaⅡ,NGC 205,and NGC ***,three drift scans were executed for these satellites,with a detection limit of 4×10^(18)cm^(-2)(approximately 1.88×10^(3)M_Θof HⅠmass),followed by a more in-depth scan of a specific *** discovered a C-shaped HⅠarc structure sharing a position and line-of-sight velocity similar to a stellar ring structure around AndromedaⅡ,hinting at a potential connection with AndromedaⅡ.In the context of NGC 205,we identified two mass concentrations in the northeast direction,which could be indicative of tidal streams resulting from the interaction between this galaxy and *** new lumps discovered could be very helpful in solving the missing interstellar medium problem for NGC *** regarding NGC 185are consistent with previous studies,and we did not detect any additional HⅠmaterial around this *** observational results enhance our understanding of the evolution of these satellite galaxies and provide insight into their historical interactions with the galaxy M31.

关键词： ISM structure-(Galaxy)local interstellar matter-galaxies interactions-galaxies ISM-(galaxies)Local Group-radio lines ISM-radio lines galaxies

Chemical Evolution of Blue Compact galaxies

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2006年第6期6卷 641-648页

作者： Fci Shi Xu Kong Fu-Zhcn Chcng Center for Astrophysics University of Science and Technology of China Hefei 230026 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

Based on a sample of 72 Blue Compact galaxies （BCGs） observed with the 2.16 m telescope of the National Astronomical Observatories, Chinese Academy of Sciences （NAOC） and about 4000 strong emission line galaxies from the Sloan Digital Sky Survey, we analyzed their chemical evolution history using the revised chemical evolution model of Larsen et al. Our sample covers a much larger metallicity range （7.2 〈 12 ＋ log（O/H）〈 9.0）. We found that, in order to reproduce the observed abundance pattern and gas fraction over the whole metallicity range, a relatively continuous star formation history is needed for high metallicity galaxies, while assuming a series of instantaneous bursts with long quiescent periods （some Gyrs） for low metallicity galaxies. Model calculations also show that only the closed-box model is capable of reproducing the observational data over the whole metallicity range. Models that consider the ordinary winds and/or inflow can only fit the observations in the low metallicity range, and a model with enriched wind cannot fit the data in the whole metallicity range. This implies that the current adopted simple wind and inflow models are not applicable to massive galaxies, where the underlying physics of galactic winds or inflow could be more complicated.

关键词： galaxies abundance - galaxies evolution -galaxies starburst- stars formarion

Velocity Dispersion σ_(aper)Aperture Corrections as a Function of Galaxy Properties from Integral-field Stellar Kinematics of 10,000 MaNGA galaxies

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2023年第8期23卷 53-64页

作者： Kai Zhu Ran Li Xiaoyue Cao Shengdong Lu Michele Cappellari Shude Mao National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Department of Astronomy Tsinghua UniversityBeijing 100084China Sub-department of Astrophysics Department of PhysicsUniversity of OxfordDenys Wilkinson BuildingKeble RoadOxfordOX13RHUK

The second moment of the stellar velocity within the effective radius,denoted by σ^(2)_(e),is a crucial quantity in galaxy studies,as it provides insight into galaxy properties and their mass ***,large spectroscopic surveys typically do not measure σ_(e) directly,instead providing σ_(aper),the second moment of the stellar velocity within a fixed fiber *** this paper,we derive an empirical aperture correction formula,given byσ_(aper)/σ_(e)=(R_(aper)/R_(e))^(α),using spatially resolved stellar kinematics extracted from approximately 10,000 Sloan Digital Sky Survey-Mapping Nearby galaxies at Apache Point Observatory integral field unit *** analysis reveals a strong dependence ofαon the r-band absolute magnitude M_(r),g-i color,and Sérsic index nSer,whereαvalues are lower for brighter,redder galaxies with higher Sérsic *** results demonstrate that the aperture correction derived from previous literature on early-type galaxies cannot be applied to predict the aperture corrections for galaxies with intermediate Sérsic *** provide a lookup table ofαvalues for different galaxy types,with parameters in the ranges of-18>M_(r)>-24,0.4

关键词： galaxies evolution-galaxies formation-galaxies kinematics and dynamics-galaxies structure

A new estimation of manganese distribution for local dwarf spheroidal galaxies

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2016年第9期16卷 137-144页

作者： Men-Quan Liu Zhong-Xiang Wang School of Physics and Space Science China West Normal University Shanghai Astronomical Observatory Chinese Academy of Sciences

The distribution of abundance for iron-peak elements in dwarf spheroidal galaxies （dSphs） is important for galaxy evolution and supernova （SN） nucleosynthesis. Nowadays, manganese （Mn） is one of the most observed iron-peak elements in local dSphs. Studies of its distributions allow us to derive and understand the evolution history of these dSphs. We improve a phenomenological model by a two-curve model including a new initial condition, that includes detailed calculations of SN explosion rates and yields. We compare the results with the observed Mn distribution data for three dSphs： Fornax, Sculpture and Sextans. We find that the model can describe the observed Fe and Mn distributions well simultaneously for the three dSphs. The results also indicate that the initial conditions should be determined by the low metallicity sam- ples in the beginning time of the galaxies and the previous assumption of metellicity-dependant Mn yield of SNIa is not needed when a wide mass range of core-collapse SNe is included. Our method is applicable to the chemical evolution of other iron-peak elements in dSphs and can be modified to provide more detailed processes for the evolution of dSphs.

关键词： galaxies dwarf-- galaxies individual (Fornax, Sculptor, Sextans) -- galaxies evolution --supernovae general

A search for double-peaked narrow emission line galaxies and AGNs in the LAMOST DR1

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2014年第10期14卷 1234-1250页

作者： Zhi-Xin Shi A-Li Luo Georges Comte Xiao-Yan Chen Peng Wei Yong-Heng Zhao Fu-Chao Wu Yan-Xia Zhang Shi-Yin Shen Ming Yang Hong Wu Xue-Bing Wu Hao-Tong Zhang Ya-Juan Lei Jian-Nan Zhang Ting-Gui Wang Ge Jin Yong Zhang Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of Sciences University of Chinese Academy of Sciences Aix-Marseille Universite&CNRS Institut PytheasLAM(Laboratoire d'Astrophysique de Marseille)UMR7326F-13388 Marseille Shanghai Astronomical Observatory Chinese Academy of Sciences Department of Astronomy Peking University University of Science and Technology of China Nanjing Institute of Astronomical Optics & Technology National Astronomical ObservatoriesChinese Academy of Sciences

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope （LAMOST） has released more than two million spectra, which provide the opportunity to search for double-peaked narrow emission line （NEL） galaxies and active galactic nuclei （AGNs）. The double-peaked narrow-line profiles can be well modeled by two velocity components, respectively blueshifted and redshifted with respect to the sys- temic recession velocity. This paper presents 20 double-peaked NEL galaxies and AGNs found from LAMOST DR1 using a search method based on a multi-Gaussian fit of the narrow emission lines. Among them, ten have already been published by other authors, either listed as genuine double-peaked NEL objects or as asymmetric NEL objects, and the remaining ten are original discoveries. We discuss some pos- sible origins for the double-peaked narrow-line features, such as interaction between jet and narrow line regions, interaction with companion galaxies, and black hole bina- ries. Spatially resolved optical imaging and/or follow-up observations in other spectral bands are needed to further discuss the physical mechanisms at work.

关键词： galaxies emission lines -- quasars emission lines -- methods dataanalysis

Gaseous versus Stellar Velocity Dispersion in Emission-Line galaxies

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2008年第1期8卷 25-38页

作者： Xiao-Yan Chen Cai-Na Hao Jing Wang Tianjin Astrophysics Center Tianjin Normal University Tianjin 300384 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Graduate School of Chinese Academy of Sciences Beijing 100049 Institute of Astronomy Madingley Road Cambridge CB3 0HA UK

We compare the ionized gas velocity dispersion σgas with the stellar velocity dispersion σ＊ in star-forming galaxies, composite galaxies, Low Ionization Nuclear Emissionline Regions （LINERs） and Seyfert 2s, compiled from a cross-identification of Sloan Digital Sky Survey Fourth Data Release （SDSS DR4） and Point Source Catalogue Redshift Survey （PSCz）. We measure σgas from the FWHMs of emission lines （Hα, [NⅡ]λλ6548, 6583 and [SⅡ]λλ6716, 6731）. A significant correlation between the gas and stellar velocity dispersion exists, despite substantial scatter. The mean value of the gas to stellar velocity dispersion ratio is close to unity. This suggests that gas velocity dispersion can substitute for the stellar velocity dispersion as a tracer of the gravitational potential well for all the four types of galaxies, but the involved uncertainties are different from type to type. We also studied -↑σgas, as a function of the redshift and the axial ratio to test the effects of aperture and galaxy inclination, and found that both effects are weak. Finally we checked the trend of -↑σgas/σ＊ with the infrared luminosity and found no significant correlation.

关键词： galaxies active - galaxies interactions - galaxies star-forming - galaxies Seyfert

Three New Spiral galaxies with Active Nuclei Producing Double Radio Lobes

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2023年第3期23卷 46-53页

作者： X.Y.Gao Z.S.Yuan J.L.Han Z.L.Wen S.S.Shan National Astronomical Observatories Chinese Academy of SciencesBejing 10011China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy University of Chinese Academy of SciencesBeijing 100049China

Double radio lobes are generally believed to be produced by active nuclei of elliptical ***,several double-lobed radio sources have been solidly found to be associated with spiral *** cross-matching~9×105 spiral galaxies selected from the Sloan Digital Sky Survey DR8 data with the full 1.4 GHz radio source catalogs of NRAO VLA Sky Survey and Faint Images of the Radio Sky at Twenty-centimeters,we identify three new spiral galaxies:J0326-0623,J1110+0321 and J1134+3046 that produce double radio lobes,and five doublelobed spirals previously *** combining the newly discovered and all the other known cases in literature,we confirm the relation that more massive spiral galaxies could produce more powerful radio *** find that most of these spiral galaxies are located in a galaxy group or a poor cluster,in which the environment is denser than in the field,and about half of them are the central brightest galaxies in their parent *** therefore suggest that the environment is one of the key factors for a spiral to produce double radio lobes.

关键词： galaxies galaxy massive

Star-Forming galaxies at z～2 in the Hubble Ultra Deep Field

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2008年第1期8卷 1-11页

作者： Xu Kong Wei Zhang Min Wang Center for Astrophysics University of Science and Technology of China Hefei 230026 Joint Institute for Galaxy and Cosmology （JOINGC） of SHAO and USTC National Astronomical Observatories Chinese Academy of Sciences Beijing 100012

Using a simple color selection based on B-, z- and K-band photometry, BzK =（z - K）AB - （B - Z）AB 〉 -0.2, we picked out 52 star-forming galaxies at 1.4 ≤z ≤ 2.5 （sBzKs） from a K-band selected sample （Kvega 〈 22.0） in an area of - 5.5 arcmin^2 of the Hubble Ultra Deep Field （UDF）. We develop a new photometric redshift method, and the error in our photometric redshifts is less than 0.02（1 ＋ z）. From the photometric redshift distribution, we find the BzK color criterion can be used to select star-forming galaxies at 1.4≤ z ≤ 2.5 with Kvega 〈 22.0. Down to Kvega 〈 22.0, the number counts of sBzKs increase linearly with the K magnitude; the sBzKs are strongly clustered, and most of them have irregular morphologies on the ACS images. They have a median reddening of E（B - V） - 0.28, an average star formation rate of - 36 M⊙ yr^-1 and a typical stellar mass of - 10^10 M⊙. The UV criterion for the galaxies at z - 2 can select most of the faint sBzKs in the UDF, but it does not work well for bright, massive, highly-reddened, actively star-forming galaxies.

关键词： galaxies evolution -galaxies high-redshift - galaxies photometry - cosmology observations

The local and global properties of different types of supernova host galaxies

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2020年第11期20卷 169-181页

作者： Li Zhou Yan-Chun Liang Jun-Qiang Ge Yi-Nan Zhu Xu Shao Hong Wu Wei-Bin Shi Li-Cai Deng Department of Astronomy School of Physics and AstronomySun Yat-sen UniversityZhuhai 519082China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and PhysicsShandong University at WeihaiWeihai 264209China

By using Data Analysis Pipeline(DAP)products of Mapping Nearby galaxies at Apache Point Observatory(MaNGA),which are publicly available from the SDSS Data Release 15,we analyze the local properties at the SN explosion sites and global properties of different types of SN host galaxies to explore the explosion environments of different types of *** our sample,there are 67 SN host galaxies in the field of view of MaNGA,including 32 Type Ia,29 core collapse SNe(CCSNe),1 superluminous SN(SLSN),1 Type I and 4 unclassified type of SNe,with which we can apply the K-S test for analysis and derive statistically robust *** to the limited sample size,we could not remove the mass dependence in this work,which is likely the true driver of the trends for the properties presented in this *** global star formation rate(SFR)and EW(H)for SN Ia hosts are slightly lower than those for CCSN hosts on *** Ia host galaxies are0.3 dex more massive than CCSN hosts,which implies that the number ratio of CCSNe to Type Ia SNe will decrease with increasing stellar mass of host *** stellar population age of SN Ia host galaxies is older than that of CCSN hosts on *** is no significant difference between different types of SN hosts for some properties,including local SFR density(SFR),and local and global gas-phase oxygen *** most galaxies in our sample,the global gas-phase oxygen abundance estimated from the integrated spectra of SN hosts can represent the local gas-phase oxygen abundance at the SN explosion sites with small bias.

关键词： galaxies abundances galaxies general galaxies stellar content supernovae general