The Faint End of the Centaurus A Satellite Luminosity Function
The Faint End of the Centaurus A Satellite Luminosity Function
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DOI：
10.3847/1538-4357/aafbe7
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发表时间：
2018-09
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通讯作者：
D. Crnojevi'c;D. Sand;P. Bennet;S. Pasetto;K. Spekkens;N. Caldwell;P. Guhathakurta;B. McLeod;A. Seth;J. Simon;J. Strader;E. T. U. O. Tampa;Tâmpa;Fl;USA.;D. PhysicsAstronomy;Texas Tech University;Lubbock;Tx;D. O. Astronomy;S. Observatory;U. Arizona;Tucson;Az;Observatories of the Carnegie Institution for Science-Observatories-of-the-Carnegie-Institution-for-102557742;Pasadena;Ca;Department of Materials Science;Royal Military College of Canada;Kingston;Ontario;Canada;H. C. F. Astrophysics;Cambridge;Ma;D. O. AstronomyAstrophysics;University of California at Santa Cruz;D. Physics;Astronomy;U. Utah;Salt lake City;Ut;M. University;E. Lansing.;Mi;U. Pacific;Stockton
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作者：
D. Crnojevi'c;D. Sand;P. Bennet;S. Pasetto;K. Spekkens;N. Caldwell;P. Guhathakurta;B. McLeod;A. Seth;J. Simon;J. Strader;E. T. U. O. Tampa;Tâmpa;Fl;USA.;D. PhysicsAstronomy;Texas Tech University;Lubbock;Tx;D. O. Astronomy;S. Observatory;U. Arizona;Tucson;Az;Observatories of the Carnegie Institution for Science-Observatories-of-the-Carnegie-Institution-for-102557742;Pasadena;Ca;Department of Materials Science;Royal Military College of Canada;Kingston;Ontario;Canada;H. C. F. Astrophysics;Cambridge;Ma;D. O. AstronomyAstrophysics;University of California at Santa Cruz;D. Physics;Astronomy;U. Utah;Salt lake City;Ut;M. University;E. Lansing.;Mi;U. Pacific;Stockton
半人马座和雕塑器的全景成像勘测(双鱼座)正在构建一张广域地图，显示这两个邻近的突出星系扩展的光晕中已分解的恒星种群。我们提供了新的麦哲伦/巨型摄像头成像的半人马座A(CEN A)周围的∼3 Dec2区域，它填补了我们在其南部的大部分覆盖范围，留下了一张几乎完整的晕图，投影半径为∼150kpc，使我们能够识别两个新的已解析矮星系。此外，我们还获得了深度哈勃太空望远镜对Cen A周围发现的13个候选矮小星系中的11个的光学成像，这是由Crnojević等人提出的。2016a：7颗被确认为Cen A的卫星，4颗被发现为背景星系。我们为我们的HST/ACS成像确认的七个候选者推导出准确的距离、结构参数、光度和光度金属活性。我们进一步研究了与Dw3相关的∼60kpc长(投影中)流上的恒星群，它的初始亮度可能为mV∼−15，并显示出沿其长度的金属丰度梯度的证据。利用双鱼座调查发现的11颗矮星以及之前已知的13颗更亮的CEN A卫星的样本，我们给出了CEN A星团的修正后的星系光度函数，其极限星等为MV∼−8，其斜率为−1.14±0.17，与在本地星系团和其他邻近星系群中看到的结果相当。
The Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) is constructing a wide-field map of the resolved stellar populations in the extended halos of these two nearby, prominent galaxies. We present new Magellan/Megacam imaging of a ∼3 deg2 area around Centaurus A (Cen A), which filled in much of our coverage to its south, leaving a nearly complete halo map out to a projected radius of ∼150 kpc and allowing us to identify two new resolved dwarf galaxies. We have additionally obtained deep Hubble Space Telescope (HST) optical imaging of 11 out of the 13 candidate dwarf galaxies identified around Cen A and presented in Crnojević et al. 2016a: seven are confirmed to be satellites of Cen A, while four are found to be background galaxies. We derive accurate distances, structural parameters, luminosities, and photometric metallicities for the seven candidates confirmed by our HST/ACS imaging. We further study the stellar population along the ∼60 kpc long (in projection) stream associated with Dw3, which likely had an initial brightness of MV ∼ −15 and shows evidence for a metallicity gradient along its length. Using the total sample of 11 dwarf satellites discovered by the PISCeS survey, as well as 13 brighter previously known satellites of Cen A, we present a revised galaxy luminosity function for the Cen A group down to a limiting magnitude of MV ∼ −8, which has a slope of −1.14 ± 0.17, comparable to that seen in the Local Group and in other nearby groups of galaxies.