TY - JOUR
T1 - The Missing Satellite Problem Outside of the Local Group. I. Pilot Observation
AU - Tanaka, Masayuki
AU - Chiba, Masashi
AU - Hayashi, Kohei
AU - Komiyama, Yutaka
AU - Okamoto, Takashi
AU - Cooper, Andrew P.
AU - Okamoto, Sakurako
AU - Spitler, Lee
N1 - Funding Information:
Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS website is http://www.sdss.org/.
Funding Information:
The Digitized Sky Surveys were produced at the Space Telescope Science Institute under U.S. Government grant NAG W-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions. The National Geographic Society—Palomar Observatory Sky Atlas (POSS-I) was made by the California Institute of Technology with grants from the National Geographic Society. The Second Palomar Observatory Sky Survey (POSS-II) was made by the California Institute of Technology with funds from the National Science Foundation, the National Geographic Society, the Sloan Foundation, the Samuel Oschin Foundation, and the Eastman Kodak Corporation. The Oschin Schmidt Telescope is operated by the California Institute of Technology and Palomar Observatory. The UK Schmidt Telescope was operated by the Royal Observatory Edinburgh, with funding from the UK Science and Engineering Research Council (later the UK Particle Physics and Astronomy Research Council), until 1988 June, and thereafter by the Anglo-Australian Observatory. The blue plates of the southern Sky Atlas and its Equatorial Extension (together known as the SERC-J), as well as the Equatorial Red (ER), and the Second Epoch [red] Survey (SES) were all taken with the UK Schmidt.
Funding Information:
The Pan-STARRS1 Surveys (PS1) have been made possible through contributions from the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, Queens University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation under Grant No. AST-1238877, the University of Maryland, and Eotvos Lorand University (ELTE) and the Los Alamos National Laboratory.
Funding Information:
A.P.C. is supported by the Science and Technology Facilities Council ST/L00075X/1 and ST/P000541/1 and thanks Wojteck Hellwing for access to the COCO simulations. This work used the DiRAC Data Centric system at Durham University, operated by the Institute for Computational Cosmology on behalf of the STFC DiRAC HPC Facility (www.dirac.ac.uk). This equipment was funded by BIS National E-infrastructure capital grant ST/K00042X/1, STFC capital grant ST/H008519/1, and STFC DiRAC Operations grant ST/K003267/1 and Durham University. DiRAC is part of the National E-Infrastructure.
Funding Information:
This work is based on data collected at the Subaru Telescope, which is operated by the Subaru Telescope and Astronomy Data Center at National Astronomical Observatory of Japan. This work is supported in part by MEXT Grant-in-Aid for Scientific Research on Innovative Areas (No. 15H05892, 15H05889, 16H01086, 16H01090, and 17H01101). T.O. acknowledges the financial support of MEXT KAKENHI Grant (16H01085). Numerical simulations were carried out with Cray XC30 in CfCA at NAOJ. We thank the anonymous referee for helpful comments that improved the paper.
Funding Information:
The Hyper Suprime-Cam (HSC) collaboration includes the astronomical communities of Japan and Taiwan, and Princeton University. The HSC instrumentation and software was developed by the National Astronomical Observatory of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA), and Princeton University. Funding was contributed by the FIRST program from Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University.
Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved.
PY - 2018/10/1
Y1 - 2018/10/1
N2 - We present results from a pilot observation of nearby (∼20 Mpc) galaxies with masses similar to that of the Milky Way (MW) to address the missing satellite problem. This is the first paper from an ongoing project to address the problem with a statistical sample of galaxies outside of the Local Group (LG) without employing an assumption that the LG is a typical halo in the universe. Thanks to the close distances of our targets, dwarf galaxies around them can be identified as extended, diffuse galaxies. By applying a surface brightness cut together with a careful visual screening to remove artifacts and background contamination, we construct a sample of dwarf galaxies. The luminosity function (LF) of one of the targets is broadly consistent with that of the MW, but the other has a more abundant dwarf population. Numerical simulations by Okamoto seem to overpredict the number of dwarfs on average, while more recent predictions from Copernicus Complexio are in better agreement. In both observations and simulations, there is a large diversity in the LFs, demonstrating the importance of addressing the missing satellite problem with a statistically representative sample. We also characterize the projected spatial distributions of the satellites and do not observe strong evidence for alignments around the central galaxies. Based on this successful pilot observation, we are carrying out further observations to increase the sample of nearby galaxies, which we plan to report in our future paper.
AB - We present results from a pilot observation of nearby (∼20 Mpc) galaxies with masses similar to that of the Milky Way (MW) to address the missing satellite problem. This is the first paper from an ongoing project to address the problem with a statistical sample of galaxies outside of the Local Group (LG) without employing an assumption that the LG is a typical halo in the universe. Thanks to the close distances of our targets, dwarf galaxies around them can be identified as extended, diffuse galaxies. By applying a surface brightness cut together with a careful visual screening to remove artifacts and background contamination, we construct a sample of dwarf galaxies. The luminosity function (LF) of one of the targets is broadly consistent with that of the MW, but the other has a more abundant dwarf population. Numerical simulations by Okamoto seem to overpredict the number of dwarfs on average, while more recent predictions from Copernicus Complexio are in better agreement. In both observations and simulations, there is a large diversity in the LFs, demonstrating the importance of addressing the missing satellite problem with a statistically representative sample. We also characterize the projected spatial distributions of the satellites and do not observe strong evidence for alignments around the central galaxies. Based on this successful pilot observation, we are carrying out further observations to increase the sample of nearby galaxies, which we plan to report in our future paper.
KW - cosmology: observations
KW - galaxies: dwarf
KW - galaxies: luminosity function
KW - mass function
UR - http://www.scopus.com/inward/record.url?scp=85054817856&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85054817856&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aad9fe
DO - 10.3847/1538-4357/aad9fe
M3 - Article
AN - SCOPUS:85054817856
SN - 0004-637X
VL - 865
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 125
ER -