An all-sky proper-motion map of the Sagittarius stream using Gaia DR2

Autor: Cecilia Mateu, Friedrich Anders, Julio A. Carballo-Bello, Carme Jordi, P. Ramos, Amina Helmi, Teresa Antoja
Přispěvatelé: Astronomy, European Commission, Ministerio de Economía y Competitividad (España), Universidad de Barcelona, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España)
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Galaxy: haloGalaxy: kinematics and dynamics
Proper motion
Milky Way
media_common.quotation_subject
Population
FOS: Physical sciences
Astrophysics
Sagittarius Stream
Astrophysics::Cosmology and Extragalactic Astrophysics
MASS
01 natural sciences
VIEW
0103 physical sciences
education
010303 astronomy & astrophysics
Red clump
Astrophysics::Galaxy Astrophysics
SATELLITE
media_common
Physics
education.field_of_study
010308 nuclear & particles physics
Astronomy and Astrophysics
Astrometry
galaxies: dwarf
Astrophysics - Astrophysics of Galaxies
CATALOG
haloGalaxy: kinematics and dynamics [Galaxy]
CLOUD
Galaxy: halo
dwarf [Galaxies]
Stars
DWARF GALAXY
formation [Galaxy]
Space and Planetary Science
Sky
Galaxy: formation
Astrophysics of Galaxies (astro-ph.GA)
DISCOVERY
astrometry
MILKY-WAY
Galaxy: kinematics and dynamics
GALACTIC HALO
STARS
Zdroj: Astronomy & astrophysics, 635:3. EDP Sciences
Astronomy & Astrophysics
Digital.CSIC. Repositorio Institucional del CSIC
instname
ISSN: 1432-0746
0004-6361
DOI: 10.1051/0004-6361/201937145
Popis: [Aims]: We aim to measure the proper motion along the Sagittarius stream, which is the missing piece in determining its full 6D phase space coordinates. [Methods]: We conduct a blind search of over-densities in proper motion from the Gaia second data release in a broad region around the Sagittarius stream by applying wavelet transform techniques. [Results]: We find that for most of the sky patches, the highest intensity peaks delineate the path of the Sagittarius stream. The 1500 peaks identified depict a continuous sequence spanning almost 2π in the sky, only obscured when the stream crosses the Galactic disk. Altogether, around 100 000 stars potentially belong to the stream as indicated by a coarse inspection of the color-magnitude diagrams. From these stars, we determine the proper motion along the Sagittarius stream, making it the proper-motion sequence with the largest span and continuity ever measured for a stream. A first comparison with existing N-body models of the stream reveals some discrepancies, especially near the pericenter of the trailing arm and an underestimation of the total proper motion for the leading arm. [Conclusions]: Our study provides a starting point for determining the variation of the population of stars along the stream, the distance to the stream from the red clump stars, and the solar motion. It also permits much more accurate measurement of the Milky Way potential.
This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos. esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 745617 and No. 800502. This work was supported by the MINECO (Spanish Ministry of Economy) through grant ESP2016-80079-C2-1-R and RTI2018-095076-B-C21 (MINECO/FEDER, UE), and MDM-2014-0369 of ICCUB (Unidad de Excelencia “María de Maeztu”). This project has received support from the DGAPA/UNAM PAPIIT program grant IG100319. AH acknowledges financial support from a VICI grant from the Netherlands Organisation for Scientific Research, NWO. JAC-B acknowledges financial support to CAS-CONICYT 17003.
Databáze: OpenAIRE
Externí odkaz: