Modelling the Milky Way – I. Method and first results fitting the thick disc and halo with DES-Y3 data-Reference-Cited by-同舟云学术

Modelling the Milky Way – I. Method and first results fitting the thick disc and halo with DES-Y3 data

Published:2020-07-09 Issue:2 Volume:497 Page:1547-1562
ISSN:0035-8711
Container-title:Monthly Notices of the Royal Astronomical Society
language:en
Short-container-title:

Author:

Pieres A¹²^ORCID,Girardi L¹³^ORCID,Balbinot E⁴^ORCID,Santiago B¹⁵,da Costa L N¹²,Carnero Rosell A¹⁶^ORCID,Pace A B⁷^ORCID,Bechtol K⁸,Groenewegen M A T⁹,Drlica-Wagner A¹⁰¹¹,Li T S¹⁰¹¹^ORCID,Maia M A G¹²,Ogando R L C¹²^ORCID,dal Ponte M¹⁵,Diehl H T¹⁰,Amara A¹²,Avila S¹³^ORCID,Bertin E¹⁴¹⁵,Brooks D¹⁶,Burke D L¹⁷¹⁸,Carrasco Kind M¹⁹²⁰^ORCID,Carretero J²¹,De Vicente J⁶^ORCID,Desai S²²,Eifler T F²³²⁴^ORCID,Flaugher B¹⁰,Fosalba P²⁵²⁶,Frieman J¹⁰¹¹,García-Bellido J¹³,Gaztanaga E²⁵²⁶^ORCID,Gerdes D W²⁷²⁸,Gruen D¹⁷¹⁸²⁹^ORCID,Gruendl R A¹⁹²⁰,Gschwend J¹²,Gutierrez G¹⁰,Hollowood D L³⁰,Honscheid K³¹³²,James D J³³,Kuehn K³⁴,Kuropatkin N¹⁰,Marshall J L⁷,Miquel R²¹³⁵,Plazas A A³⁶^ORCID,Sanchez E⁶,Serrano S²⁵²⁶,Sevilla-Noarbe I⁶,Sheldon E³⁷,Smith M³⁸^ORCID,Soares-Santos M³⁹^ORCID,Sobreira F¹⁴⁰,Suchyta E⁴¹^ORCID,Swanson M E C²⁰,Tarle G²⁸,Thomas D⁴²^ORCID,Vikram V⁴³,Walker A R⁴⁴

Affiliation:

1. Laboratório Interinstitucional de e-Astronomia - LIneA, Rua Gal. José Cristino 77, Rio de Janeiro, RJ - 20921-400, Brazil

2. Observatório Nacional, Rua Gal. José Cristino 77, Rio de Janeiro, RJ - 20921-400, Brazil

3. Osservatorio Astronomico di Padova, INAF, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy

4. Kapteyn Astronomical Institute, University of Groningen, Landleven 12, NL-9747 AD Groningen, the Netherlands

5. Instituto de Física, UFRGS, Caixa Postal 15051, Porto Alegre, RS - 91501-970, Brazil

6. Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), E-28040 Madrid, Spain

7. George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, and Department of Physics and Astronomy, Texas A&M University, College Station, TX 77843, USA

8. LSST 933 North Cherry Avenue, Tucson, AZ 85721, USA

9. Koninklijke Sterrenwacht van België, Ringlaan 3, B-1180 Brussels, Belgium

10. Fermi National Accelerator Laboratory, PO Box 500, Batavia, IL 60510, USA

11. Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637, USA

12. Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 16, CH-8093 Zurich, Switzerland

13. Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid, E-28049 Madrid, Spain

14. CNRS, UMR 7095, Institut d’Astrophysique de Paris, F-75014 Paris, France

15. Sorbonne Universités, UPMC Univ Paris 06, UMR 7095, Institut d’Astrophysique de Paris, F-75014 Paris, France

16. Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, UK

17. Kavli Institute for Particle Astrophysics & Cosmology, PO Box 2450, Stanford University, Stanford, CA 94305, USA

18. SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA

19. Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801, USA

20. National Centre for Supercomputing Applications, 1205 West Clark St., Urbana, IL 61801, USA

21. Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, E-08193 Bellaterra (Barcelona), Spain

22. Department of Physics, IIT Hyderabad, Kandi, Telangana 502285, India

23. Department of Astronomy/Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA

24. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109, USA

25. Institut d’Estudis Espacials de Catalunya (IEEC), E-08034 Barcelona, Spain

26. Institute of Space Sciences (ICE, CSIC), Campus UAB, Carrer de Can Magrans, s/n, E-08193 Barcelona, Spain

27. Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA

28. Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA

29. Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305, USA

30. Santa Cruz Institute for Particle Physics, Santa Cruz, CA 95064, USA

31. Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210, USA

32. Department of Physics, The Ohio State University, Columbus, OH 43210, USA

33. Harvard-Smithsonian Centre for Astrophysics, Cambridge, MA 02138, USA

34. Australian Astronomical Optics, Macquarie University, North Ryde, NSW 2113, Australia

35. Institució Catalana de Recerca i Estudis Avançats, E-08010 Barcelona, Spain

36. Department of Astrophysical Sciences, Princeton University, Peyton Hall, Princeton, NJ 08544, USA

37. Brookhaven National Laboratory, Bldg 510, Upton, NY 11973, USA

38. School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK

39. Physics Department, Brandeis University, 415 South Street, Waltham, MA 02453, USA

40. Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, 13083-859 Campinas, SP, Brazil

41. Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

42. Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK

43. Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA

44. Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena, Chile

Abstract

ABSTRACT We present a technique to fit the stellar components of the Galaxy by comparing Hess Diagrams (HDs) generated from trilegal models to real data. We apply this technique, which we call mwfitting, to photometric data from the first 3 yr of the Dark Energy Survey (DES). After removing regions containing known resolved stellar systems such as globular clusters, dwarf galaxies, nearby galaxies, the Large Magellanic Cloud, and the Sagittarius Stream, our main sample spans a total area of ∼2300 deg2. We further explore a smaller subset (∼1300 deg2) that excludes all regions with known stellar streams and stellar overdensities. Validation tests on synthetic data possessing similar properties to the DES data show that the method is able to recover input parameters with a precision better than 3 per cent. We fit the DES data with an exponential thick disc model and an oblate double power-law halo model. We find that the best-fitting thick disc model has radial and vertical scale heights of 2.67 ± 0.09 kpc and 925 ± 40 pc, respectively. The stellar halo is fit with a broken power-law density profile with an oblateness of 0.75 ± 0.01, an inner index of 1.82 ± 0.08, an outer index of 4.14 ± 0.05, and a break at 18.52 ± 0.27 kpc from the Galactic centre. Several previously discovered stellar overdensities are recovered in the residual stellar density map, showing the reliability of mwfitting in determining the Galactic components. Simulations made with the best-fitting parameters are a promising way to predict Milky Way star counts for surveys such as the LSST and Euclid.

Funder

U.S. Department of Energy

National Science Foundation

Science and Technology Facilities Council

Higher Education Funding Council for England

Centre for Cosmology and AstroParticle Physics

Financiadora de Estudos e Projetos

Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Ministério da Ciência, Tecnologia e Inovação

Deutsche Forschungsgemeinschaft

Argonne National Laboratory