Systematic study of the stellar initial mass function and its variation

• Project/Area Number: 15K17600
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: The University of Tokyo
• Principal Investigator: MORE Surhud 東京大学, カブリ数物連携宇宙研究機構, 特任助教 (00646044)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: Stellar IMF constraints / HSC weak lensing / Weak lensing / Initial mass function / Assembly bias / Edges of galaxy clusters

Outline of Final Research Achievements

The purpose of this project was to develop methods to put constraints on the　initial mass function of stars using weak gravitational lensing and　stacking of　stellar spectra. High signal-to-noise ratio stacked spectra of SDSS-BOSS　galaxies as a function of different BOSS galaxy properties have been　obtained　and the theoretical analysis of these stacked spectra is ongoing. We were　able　to infer limits on the stellar mass of BOSS galaxies using the weak　gravitational lensing signal from the CFHTLS survey which could distinguish　between theoretical estimates based on different initial mass functions.　Measurement of the stellar masses of BOSS galaxies will require the　measurement of the weak lensing signal in crowded regions in the Hyper　Suprime-Cam (HSC) survey. We have developed and implemented a blendedness　parameter to identify blended objects. As part of this project, we have also　developed a weak lensing pipeline for the analysis of Hyper Suprime-Cam data.

Research Products

• [Int'l Joint Research] Carnegie Melon University/Princeton University/Jet Propulsion Laboratory Caltech(米国)
• [Int'l Joint Research] Max Planck Institute for astrophysics(Germany)
• [Int'l Joint Research] NASA/Kavli Insitute for Cosmological Physics/Princeton University(米国)
• [Int'l Joint Research] University of Geneva/ETH Zurich(Switzerland)
• [Int'l Joint Research] Institut dAstrophysique de Paris(France)
• [Int'l Joint Research] University of Durham(英国)
• [Int'l Joint Research] Max Planck Institut fur Astrophysik(Germany)
• [Journal Article] Testing gravity on large scales by combining weak lensing with galaxy clustering using CFHTLenS and BOSS CMASS (2017)
  • Author(s): Alam, S., Miyatake, H., More, S., Ho, S. and Mandelbaum, R.
  • Journal Title: MNRAS Volume: 465 Issue: 4 Pages: 4853-4865
  • DOI: 10.1093/mnras/stw3056
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] A new quadruple gravitational lens from the Hyper Suprime-Cam Survey: the puzzle of HSC J115252+004733 (2017)
  • Author(s): More, A., More, S. (8th author in 19 authors) et. al
  • Journal Title: MNRAS Volume: 465 Issue: 2 Pages: 2411-2419
  • DOI: 10.1093/mnras/stw2924
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Interpreting the Strongly Lensed Supernova iPTF16geu: Time Delay Predictions, Microlensing, and Lensing Rates (2017)
  • Author(s): More, A., Suyu, S.H., Ogur, M., More, S. and Lee, C.-H.
  • Journal Title: Astrophysical Journal Letters Volume: 835 Issue: 2 Pages: L25-L25
  • DOI: 10.3847/2041-8213/835/2/l25
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Detection of the Splashback Radius and Halo Assembly Bias of Massive Galaxy Clusters (2016)
  • Author(s): S. More, H. Miyatake, M. Takada et al. (13 co-authors)
  • Journal Title: The Astrophysical Journal Volume: 825 Issue: 1 Pages: 39-39
  • DOI: 10.3847/0004-637x/825/1/39
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] The Subaru FMOS galaxy redshift survey (FastSound). IV. New constraint on gravity theory from redshift space distortions at z~1.4 (2016)
  • Author(s): T. Okumura, et al. (including R. Takahashi, the 21th in 25 co-authors)
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 68 Issue: 3 Pages: 38-38
  • DOI: 10.1093/pasj/psw029
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Strong bimodality in the host halo mass of central galaxies from galaxy-galaxy lensing (2016)
  • Author(s): Mandelbaum, R., Wang, W., Zu, Y., White, S., Henriques, B. and More, S.
  • Journal Title: MNRAS Volume: 457 Issue: 3 Pages: 3200-3218
  • DOI: 10.1093/mnras/stw188
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] EVOLUTION OF STELLAR-TO-HALO MASS RATIO AT z=0-7 IDENTIFIED BY CLUSTERING ANALYSIS WITH THE HUBBLE LEGACY IMAGING AND EARLY SUBARU/HYPER SUPRIME-CAM SURVEY DATA (2016)
  • Author(s): Harikane, Ouchi et al.
  • Journal Title: The Astrophysical Journal Volume: 821 Issue: 2 Pages: 123-145
  • DOI: 10.3847/0004-637x/821/2/123
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Evidence of Halo Assembly Bias in Massive Clusters (2016)
  • Author(s): H. Miyatake, S. More, M. Takada et al.
  • Journal Title: Phys. Rev. Letters Volume: 116 Issue: 4 Pages: 041301-041301
  • DOI: 10.1103/physrevlett.116.041301
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] The Splashback Radius as a Physical Halo Boundary and the Growth of Halo Mass (2015)
  • Author(s): More, S., Diemer, B., Kravtsov, A.
  • Journal Title: The Astrophysical Journal Volume: 810:36 Issue: 1 Pages: 36-36
  • DOI: 10.1088/0004-637x/810/1/36
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] Systematics in photometric redshifts: tests > using weak lensing (2017)
  • Author(s): Surhud More
  • Organizer: HSC Weak lensing internal workshop
  • Place of Presentation: Princeton University, Princeton (USA)
  • Int'l Joint Research
• [Presentation] Detection of the Splashback radius and assembly bias of clusters (2016)
  • Author(s): Surhud More
  • Organizer: The Galaxy-Halo connection
  • Place of Presentation: Snowbird Ski & Summer Resort, Salt Lake City, USA
  • Year and Date: 2016-03-16
  • Int'l Joint Research / Invited
• [Presentation] Assembly bias and Splashback radius of Galaxy clusters (2016)
  • Author(s): Surhud More
  • Organizer: From theory to Lensing: Century of Gravitational lensing applications
  • Place of Presentation: Leiden University, Leiden (Netherlands)
  • Int'l Joint Research
• [Presentation] Structure and large scale distribution of dark matter halos: Overview and new horizons (2015)
  • Author(s): Surhud More
  • Organizer: Dark side of the Universe
  • Place of Presentation: Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan
  • Year and Date: 2015-12-15
  • Int'l Joint Research / Invited