TY - JOUR

T1 - The structure of the Milky Way based on unWISE 3.4 μm integrated photometry

AU - Mosenkov, Aleksandr V.

AU - Savchenko, Sergey S.

AU - Smirnov, Anton A.

AU - Camps, Peter

PY - 2021/11/1

Y1 - 2021/11/1

N2 - We present a detailed analysis of the Galaxy structure using an unWISE wide-field image at 3.4μm. We perform a 3D photometric decomposition of the Milky Way taking into account (i) the projection of the Galaxy on the celestial sphere and (ii) that the observer is located within the Galaxy at the solar radius. We consider a large set of photometric models starting with a pure disc model and ending with a complex model that consists of thin and thick discs plus a boxy-peanut-shaped bulge. In our final model, we incorporate many observed features of the Milky Way, such as the disc flaring and warping, several overdensities in the plane, and the dust extinction. The model of the bulge with the corresponding X-shape structure is obtained from N-body simulations of a Milky Way-like galaxy. This allows us to retrieve the parameters of the aforementioned stellar components, estimate their contribution to the total Galaxy luminosity, and constrain the position angle of the bar. The mass of the thick disc in our models is estimated to be 0.4–1.3 of that for the thin disc. The results of our decomposition can be directly compared to those obtained for external galaxies via multicomponent photometric decomposition.

AB - We present a detailed analysis of the Galaxy structure using an unWISE wide-field image at 3.4μm. We perform a 3D photometric decomposition of the Milky Way taking into account (i) the projection of the Galaxy on the celestial sphere and (ii) that the observer is located within the Galaxy at the solar radius. We consider a large set of photometric models starting with a pure disc model and ending with a complex model that consists of thin and thick discs plus a boxy-peanut-shaped bulge. In our final model, we incorporate many observed features of the Milky Way, such as the disc flaring and warping, several overdensities in the plane, and the dust extinction. The model of the bulge with the corresponding X-shape structure is obtained from N-body simulations of a Milky Way-like galaxy. This allows us to retrieve the parameters of the aforementioned stellar components, estimate their contribution to the total Galaxy luminosity, and constrain the position angle of the bar. The mass of the thick disc in our models is estimated to be 0.4–1.3 of that for the thin disc. The results of our decomposition can be directly compared to those obtained for external galaxies via multicomponent photometric decomposition.

KW - Galaxy: bulge

KW - Galaxy: disc

KW - Galaxy: formation

KW - Galaxy: fundamental parameters

KW - Galaxy: structure

KW - THICK DISKS

KW - SURFACE PHOTOMETRY

KW - DARK-MATTER UNIVERSE

KW - ON SPIRAL GALAXIES

KW - INSIDE-OUT FORMATION

KW - INFRARED-EMISSION

KW - RED CLUMP

KW - DIGITAL SKY SURVEY

KW - X-SHAPED STRUCTURES

KW - GALACTIC DISC

UR - https://ui.adsabs.harvard.edu/abs/2021MNRAS.507.5246M/abstract

UR - http://www.scopus.com/inward/record.url?scp=85117210414&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/2e755b00-2c14-3396-b0ae-80979777bc68/

U2 - 10.1093/mnras/stab2445

DO - 10.1093/mnras/stab2445

M3 - Article

VL - 507

SP - 5246

EP - 5263

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -