The FMOS-COSMOS survey of star-forming galaxies at z~1.6 using Subaru/FMOS

2014 年度 実施状況報告書

• 研究課題/領域番号: 26400221
• 研究機関: 東京大学
• 研究代表者: SILVERMAN John 東京大学, カブリ数物連携宇宙研究機構, 特任助教 (90573030)
• 研究期間 (年度): 2014-04-01 – 2017-03-31
• キーワード: 光学赤外線天文学

研究実績の概要

Our first science question,“What regulates star formation?”has been the focus of three scientific papers(Zahid et al.2014a,b; Rodighiero et al.2014).Two papers have established the observed relation between the stellar mass of galaxies and their chemical composition of the interstellar medium, indicative of the rate of stellar evolution.

Significant progress has been achieved for the acquisition of data and analysis of observations carried out with the Subaru Telescope.JSPS funds were used to support travel to meet with collaborators at the COSMOS meeting and extended visits to the University of Hawaii(David Sanders;Jan 2014) and ANU(Lisa Kewley).We now have a catalog of galaxy properties with measurements on the emission-line properties and spectroscopic redshifts for over 1000 galaxies, a unique resource for distant galaxies that will be made public imminently with the publication of the survey design paper(Silverman et al.arXiv:1409.0447).Further results have been achieved with the analysis of followup observations of 5 starbursts galaxies in our FMOS survey with ALMA(Silverman et al. in preparation) that demonstrate that starbursts are converting gas to stars at a high efficiency.

We have developed analysis tools to characterize the large-scale environment to address the question“Does the star formation rate depend on environment?”We have a measure of the clustering of galaxies over scales of 100 kpc to 40 Mpc at z~1.6(Kashino et al.in preparation), an unprecedented range for a high-redshift sample.The tools will be applicable for scientific analysis to be completed.

現在までの達成度 (区分)

2: おおむね順調に進展している

理由

The level of attainment met in FY14 is best described by category‘2’. This is due to facts that include the following: (1) three scientific papers have been accepted to leading peer-reviewed journals, (2) additional data acquisition with Subaru Telescope has completed the observations to be taken through the first Subaru Intensive program (S12B-045), (3) completion of high-level data products including spectra and catalogs to be made public, (4) development of analysis tools for measuring the local environment, (5) scientific results have been presented at major international meetings, (6) the award of a second intensive observing program on Subaru Telescope (S15A-134) and additional observations through the University of Hawaii (PI Dave Sanders) and Australian National University (PI Lisa Kewley), and (7) new y-band imaging with Subaru’s Hyper-suprime-cam, acquired through a collaboration with the University of Hawaii led to the improvement in target selection for future FMOS observations in FY15 and beyond.

今後の研究の推進方策

The research plan for FY2015 is the same as proposed for item I“Mapping large-scale structures at z~1.6 and the impact on star formation”.

Item II‘Morphological properties of star-forming galaxies as function of SFR, metallicity and environment’will be pushed to FY2016 since Mohammad Akhlaghi is diverting his time to other work related to his thesis. As a replacement, we plan to address in FY15 the science goal“II. A study on the ionization state of the ISM in galaxies at z~1.6.” We plan to further elucidate the physical reasons that high redshift galaxies are offset in standard emission line diagrams based on the ratios of [NII]/Halpha and [OIII]/Hbeta. We have preliminary results (Kartaltepe et al. submitted) under review. Further understanding of the observational data require comparisons with theoretical models. To aid, we have acquired optical spectroscopy with Keck to detect the [OII] emission line that enables us to break the degeneracy between metallicity and ionisation parameter. Similar observations with the Very Large Telescope are pending. Furthermore, we will use the ratio of the sulfer lines to infer the electron density, hence pressure, of the ISM thus elucidating the state of the ISM at high redshift. Our study will place much focus on the massive (Mstellar >10の11乗 Msun) galaxy population yet to be studied with statistical samples at these redshifts.

研究成果

• [雑誌論文] A multi-wavelength consensus on the main sequence of star-forming galaxies at z ~ 2 (2014)
  • 著者名/発表者名: G. Rodighiero, A. Renzini, E. Daddi, I. Baronchelli, S. Berta, G. Cresci, A. Franceshini, C. Gruppioni, D. Lutz, C. Mancini, P. Santini, G. Zamorani, J. Silverman, D. Kashino, P. Andreani, A. Cimatti, H. Dominguez Sanchez, E. Le Floch, B. Magnelli, P. Popesso, F. Pozzi
  • 雑誌名: Monthly Notices of the Royal Astronomical Society 巻: 443 ページ: 19-30
  • DOI: 10.1093/mnras/stu1110
  • 査読あり / オープンアクセス
• [雑誌論文] The FMOS-COSMOS Survey of Star-forming Galaxies at z ~ 1.6. II. The Mass-Metallicity Relation and the Dependence on Star Formation Rate and Dust Extinction (2014)
  • 著者名/発表者名: H. J. Zahid, D. Kashino, J. D. Silverman, L. J. Kewley, E. Daddi, A. Renzini, G. Rodighiero, T. Nagao, N. Arimoto, D. B. Sanders, J. Kartaltepe, S. J. Lilly, C. Maier, M. J. Geller, P. Capak, C. M. Carollo, J. Chu, G. Hasinger, O. Ilbert, M. Kajisawa, A. M. Koekemoer, K. Kovac, O. Le Fevre, D. Masters, et al.
  • 雑誌名: The Astrophysical Journal 巻: 792 ページ: 75-96
  • DOI: 10.1088/0004-637X/792/1/75
  • 査読あり / オープンアクセス
• [雑誌論文] The universal relation of galactic chemical evolution: the origin of the mass-metallicity relation (2014)
  • 著者名/発表者名: H. J. Zahid, G. I. Dima, R.-P. Kudritzki, L. J. Kewley, M. J. Geller, H. S. Hwang, J. D. Silverman, and D. Kashino
  • 雑誌名: The Astrophysical Journal 巻: 791 ページ: 130-146
  • DOI: 10.1088/0004-637X/791/2/130
  • 査読あり / オープンアクセス
• [学会発表] Surveying the star-forming galaxy population at z ~ 1.6 in COSMOS with Subaru/FMOS (2015)
  • 著者名/発表者名: J. Silverman
  • 学会等名: Astrophysics seminar
  • 発表場所: University of Portsmouth, UK
  • 年月日: 2015-03-20 – 2015-03-20
  • 招待講演
• [学会発表] Molecular gas content of Extreme Outliers from the star-forming main-sequence at z~1.6 (2014)
  • 著者名/発表者名: J. Silverman
  • 学会等名: Revolution in Astronomy with ALMA, 3rd year
  • 発表場所: Tokyo, Japan
  • 年月日: 2014-12-08 – 2014-12-08
• [学会発表] Surveying the star-forming galaxy population at z ~ 1.6 in COSMOS with Subaru/FMOS (2014)
  • 著者名/発表者名: J. Silverman
  • 学会等名: Astrophysics seminar
  • 発表場所: CEA-Saclay, France
  • 年月日: 2014-09-22 – 2014-09-22
  • 招待講演
• [学会発表] Surveying the star-forming galaxy population at z ~ 1.6 in COSMOS with Subaru/FMOS (2014)
  • 著者名/発表者名: J. Silverman
  • 学会等名: Astrophysics seminar
  • 発表場所: Institute d’Astrophysique, Paris, France
  • 年月日: 2014-09-19 – 2014-09-19
  • 招待講演
• [学会発表] Surveying the star-forming galaxy population at z ~ 1.6 in COSMOS with Subaru/FMOS (2014)
  • 著者名/発表者名: J. Silverman
  • 学会等名: Astrophysics seminar
  • 発表場所: Laboratoire d’Astrophysique, Marseille, France
  • 年月日: 2014-09-12 – 2014-09-12
  • 招待講演
• [学会発表] Molecular gas content of Extreme Outliers from the star-forming main-sequence at z~1.6 (2014)
  • 著者名/発表者名: J. Silverman
  • 学会等名: Transformational Science in the ALMA Era
  • 発表場所: Charlottesville, VA, USA
  • 年月日: 2014-08-04 – 2014-08-04
• [学会発表] An update on (high-res) FMOS-COSMOS and an ALMA followup of OFF-MS galaxies (2014)
  • 著者名/発表者名: J. Silverman
  • 学会等名: COSMOS team meeting
  • 発表場所: Zagreb, Croatia
  • 年月日: 2014-05-19 – 2014-05-19